JP2007537965A - Silicon structure - Google Patents

Abstract

  The present invention relates to a new method for producing macroporous silicon and a new macroporous silicon product. The present invention relates to a new method for combining porous silicon with a hydrophilic compound. The method for producing macroporous silicon of the present invention involves consolidating a silicon particle product that can then be anodized. The resulting macroporous silicon product comprises macropores substantially surrounded by regions of microporous silicon and / or mesoporous silicon. The method of loading the hydrophilic compound includes the step of compacting the silicon particle product and the hydrophilic compound.

Description

  The present invention relates to new silicon structures and methods for producing silicon structures. The silicon structure of the present invention can include one or more hydrophilic materials.

  The present invention also relates to a new method for producing macroporous silicon and a new macroporous silicon product. A method for producing macroporous silicon involves compacting a silicon particle product and then anodizing the consolidated product. The resulting macroporous silicon product can include macropores substantially surrounded by microporous silicon and / or mesoporous silicon.

  Porous silicon has various properties that allow porous silicon to be used for various medical uses. For example, porous silicon is a biocompatible and resorbable material, as described in International Patent Application Publication WO 9706101; Porous silicon is damaged as described in International Patent Application Publication WO 0195952. Can be used as a scaffold for bone repair or replacement; porous silicon can be used in dermatological compositions, as described in International Patent Application Publication No. WO0215863; Can be used to deliver beneficial substances such as drugs, as described in International Patent Application Publication No. WO9953898; and porous silicon can be used in various ways as described in International Patent Application Publication No. WO03015636. Can be used in any diagnostic device. The biological properties of porous silicon often depend on the porosity and pore size. Porous silicon having a porosity as low as 2% and porous silicon having a porosity of more than 90% have been formed, and porous silicon can be classified by this pore size; Contains pores with a diameter of less than 20 mm, mesoporous silicon contains pores with a diameter in the range of 20 mm to 500 mm, and macroporous silicon contains pores with a diameter greater than 500 mm To do.

  Two main methods by which porous silicon can be produced are anodization and stain etching. Anodization typically involves immersing a solid sample of silicon (eg, a bulk crystalline silicon wafer) in a hydrofluoric acid solution. Electrical contact is made with a sample of silicon and a potential difference is applied between the silicon and a second electrode that is also placed in the solution. HF etches silicon to create pores, which results in the formation of porous silicon. Preferably, the sample is a semiconductor throughout this volume to allow a uniform potential difference to be established.

  Stain etching involves immersing a silicon sample in a hydrofluoric acid solution containing a strong oxidizing agent. No electrical contact is made with silicon and no electrical potential is applied. Hydrogen fluoride etches the silicon surface, creating pores.

  This technique is generally used to etch relatively small silicon particles because it is difficult to attach an electrode to each small particle.

  Anodization and stain etching typically result in the formation of silicon-hydrogen bonds at the surface of the porous silicon, making the surface of the porous silicon hydrophobic. Porous silicon may be used to deliver drugs to animal or human patients, and due to this hydrophobic nature, loading of hydrophilic drugs into porous silicon can be a problem.

  One of the major drawbacks of anodization is its relatively low throughput, which results in high costs. The use of electrochemical cells reduces the rate at which silicon can be processed and thus increases costs. Furthermore, the silicon used for anodization is preferably a semiconductor throughout this volume, which typically means that relatively expensive silicon wafers are used.

  Stain etching allows the use of particulate silicon, which can be obtained at a lower cost than silicon wafers, and does not involve the use of time-consuming electrochemical processes.

  However, it is easier to control the pore size and / or porosity of the porous silicon produced by anodization than by the stain etching technique.

  The following documents provide background information relevant to this application. US Pat. No. 5,164,138 describes a process for producing an article having particles comprising silicon-based material; in this case, the particles are bonded together by reaction with a liquid drug. U.S. Pat. No. 4,357,443 describes a process for producing silicon-containing articles comprising the step of coating particles with boron oxide. U.S. Pat. No. 4,040,848 describes a process for producing a sintered body of polycrystalline silicon comprising the step of forming a particle mixture of silicon powder and boron. U.S. Pat. No. 4,865,245 describes a method of joining together two semiconductor devices, each having a number of metal contacts. US Pat. No. 6,126,894 describes a method for producing high density sintered articles from iron-silicon alloys. U.S. Pat. No. 4,818,482 describes a process for manufacturing a workpiece that includes water atomizing a metal alloy. U.S. Pat. No. 5,711,866 describes a process for compacting a powder comprising removing oxides from the surface of a metal-coated composite. U.S. Patent No. 6,057,469 describes a process for preparing silicon powder that includes grinding metallurgical grade silicon. U.S. Pat. No. 4,040,848 describes a process for producing a polycrystalline sintered body. International Patent Application Publication WO 01/95952 describes a fixator comprising porous silicon, which can be used for repair of damaged bone. International Patent Application Publication No. WO 03/101504 describes a method for preparing a scaffold from a block comprising porous silicon. U.S. Pat. No. 4,767,585 describes a process for producing molded products from granular silicon. U.S. Pat. No. 4,759,887 describes a process for producing shaped products from silicon granules. JP8109012 describes compression molding at high temperatures. "Compression molding of silicon oxide powder" by RG Stephen & FL Riley (Journal of European Ceramic Society, 9 (1992), 301-307) describes the production of silicon dioxide coated silicon particles resulting in agglomeration. "Manufacture of polycrystalline silicon sheets for photovoltaic applications by compressing and sintering silicon powder" by Derbouz Draoua et al. Describes the production of wafers from silicon powder by compression molding and heating at temperatures close to the melting point of silicon. To do. “Semiconductor Wafer Bonding: Science and Technology” (Wiley, New York, ISBN 041774813, 1999) describes bonding two planar single crystal wafer surfaces.

  It is an object of the present invention to at least partially solve at least some of the above problems. It is a further object of the present invention to provide a process that allows low cost and rapid production of porous silicon with well-defined porosity and pore size.

  It is a still further object of the present invention to provide a method for combining a hydrophilic compound with porous silicon. It is a still further object of the present invention to provide a new method of drug loading by consolidating silicon particle products and hydrophilic drugs.

According to one aspect, the present invention provides a method for producing a silicon structure comprising the following steps:
(A) obtaining a silicon particle product comprising a number of free silicon particles; and (b) compacting at least a portion of the silicon particle product to form a number of bonded silicon particles (in this case, Each bonded silicon particle is bonded to at least one other bonded silicon particle).

  The method can include a further step performed between step (a) and step (b) that combines at least a portion of the silicon particle product with the beneficial agent. The beneficial substance can be a hydrophilic compound.

  At least one of the bonds formed between at least two of the bonded silicon particles may be a covalent Si—Si bond. At least a part of the bonded silicon particles can be bonded by Si—Si covalent bonding. Step (b) can be performed in such a way that a covalent bond of Si—Si is formed between at least two of the silicon particles. Step (b) can be performed such that sufficient pressure is applied to at least a portion of the silicon particle product from which a large number of bonded silicon particles are formed.

  Step (a) and step (b) can be performed in such a manner that a silicon monolithic body comprising at least some of the bonded silicon particles is formed.

Step (a) and step (b) can be performed in such a manner that the silicon monolith includes at least 10 bonded silicon particles. Step (a) and step (b) can be performed in such a manner that the silicon monolith includes at least 100 bonded silicon particles. Step (a) and step (b) can be performed in such a manner that the silicon monolith includes at least 1,000 bonded silicon particles. Steps (a) and (b) can be performed in such a manner that the silicon monolith includes from 10 to 10 ²⁶ bonded silicon particles. Steps (a) and (b) can be performed in such a manner that the silicon monolith includes from 10 ⁴ to 10 ¹⁶ bonded silicon particles.

  The monolith may be porous, in which case pores are formed by the gaps between the bonded silicon particles. This porosity can result in a relatively large surface area.

  Step (a) and step (b) can be carried out in such a way that a silicon monolith with a breaking strength between 30 MPa and 7,000 MPa is formed.

  Step (a) and step (b) can be performed in such a way that a silicon monolith with a breaking strength between 70 MPa and 7,000 MPa is formed.

  Step (a) and step (b) can be performed in such a way that a silicon monolith with a breaking strength between 40 MPa and 250 MPa is formed.

  Step (a) and step (b) can be carried out in such a way that a silicon monolith with a breaking strength between 50 MPa and 150 MPa is formed.

Step (a) and step (b) can be performed in such a way that a silicon monolith having an electrical resistivity between 10 KΩcm and 10 ⁻⁵ Ωcm is formed when measured at this longest distance. . Step (a) and step (b) can be performed in such a way that a silicon monolith having a resistivity between 10 KΩcm and 200 KΩcm is formed when measured at this longest distance. Step (a) and step (b) can be performed in such a way that a silicon monolith having a resistivity of between 10 KΩcm and 60 KΩcm is formed when measured at this longest distance.

  Formation of a silicon-silicon covalent bond between bonded silicon particles can result in a monolith having a relatively high mechanical strength and low electrical resistivity.

  In general, the electrical resistivity of the bond formed between two bonded silicon particles is greater than the electrical resistivity of the silicon from which either of those particles is formed. Thus, the monolithic body appears to have a significantly higher electrical resistivity than the silicon from which the respective particles are formed. The greater the number of bonds, the greater the resistivity when calculated from the resistance of the monolith during this longest distance.

  Step (a) and step (b) are such that each bonded silicon particle from which the monolithic body is formed is integrated with each other bonded silicon particle from which the silicon monolith is formed. Can be done in style.

  The method of the present invention can include a further step (r) of reducing a portion of the silicon particle product. Step (r) can be performed before step (b). Step (r) can include substantially removing silicon oxide from at least a portion of the surface of the free silicon particles. Step (r) can include a step of treating at least a portion of the free silicon particles with a reducing agent. Step (r) can include treating at least a portion of the free silicon particles with a reducing agent selected from one or more of NaOH, KOH, and HF. In the step (r), at least a part of the free silicon particles is treated with a hydrofluoric acid solution selected from one or more of an HF aqueous solution, an ethanolic HF solution, a methanolic HF solution, and an ethanoic acid HF solution. Can be included. Step (r) can include treating at least a portion of the free silicon particles with HF vapor. Step (r) can be performed in such a manner that Si—H bonds are formed on the surface of at least some of the free silicon particles. Step (r) can be carried out in such a way that Si—H bonds are formed on the surface of most of the free silicon particles.

  Treatment of free silicon particles with hydrofluoric acid results in the formation of free silicon particles having a surface that is at least partially hydrogen-terminated, and any oxygen atoms that have bound to the surface of the free silicon particles are at least Convenient because it is partly excluded.

  The presence of oxygen atoms on the surface of the free silicon particles has been found to make it more difficult to compact the silicon particle product. That is, the presence of oxygen bonded to the silicon surface makes it more difficult to form a Si—Si covalent bond between the bonded silicon particles. The presence of oxygen reduces the stability of the monolith in a solution of HF, which makes it more likely to fragment. Surface oxides can also increase the electrical resistivity of the monolith.

  The presence of hydrogen atoms at the surface of the free silicon particles is also advantageous as it helps to prevent oxygen recombination to the silicon surface prior to consolidation.

  Consolidation of a silicon particle product containing surface Si-H bonds may result in silane formation. The method of the present invention can include a further step (h) of detecting silane gas derived from the formation of bonded silicon particles. Silane formation provides evidence of Si-H bond breakage and Si-Si bond formation.

  Step (b) can include a step (p) of applying pressure to at least a portion of the free silicon particles.

  Step (b) may include (ci) placing at least a portion of the free silicon particles in a container and (di) reducing the volume of the container.

  Step (ci) and step (di) can be performed in such a way that pressure is applied to at least a portion of the free silicon particles contained in the container.

  Step (b) can include placing at least a portion of the free silicon particles in a container and applying a uniaxial or isostatic pressure to the free silicon particles contained in the container. .

  Step (b) can include placing at least a portion of the free silicon particles in a container and applying isotropic pressure to the free silicon particles contained in the container.

  Uniaxial pressure can be between 5,000 MPa and 50 MPa.

  The uniaxial pressure can be between 1,000 MPa and 100 MPa.

  The uniaxial pressure can be between 1,000 MPa and 200 MPa.

  The uniaxial pressure can be between 750 MPa and 200 MPa.

  The uniaxial pressure can be between 50 MPa and 10 MPa.

  The isotropic pressure can be between 5,000 MPa and 50 MPa.

  The isotropic pressure can be between 1,000 MPa and 100 MPa.

  The isotropic pressure can be between 1,000 MPa and 200 MPa.

  The isotropic pressure can be between 750 MPa and 200 MPa.

  The isotropic pressure can be between 50 MPa and 10 MPa.

  Step (b) can include (cii) placing at least a portion of the free silicon particles into a volume surrounded by at least a portion of the template, and (dii) reducing the enclosed volume.

  Step (cii) and step (dii) can be performed in such a way that pressure is applied to at least a portion of the free silicon particles contained in the mold.

  The silicon particle product can include semiconductor silicon. The particulate silicon product can include one or more of polycrystalline silicon, amorphous silicon, bulk crystalline silicon, and metallurgical grade silicon. The silicon particle product can include silicon particles prepared by chemical vapor deposition. The silicon particle product can include silicon particles having hydrogen ends, where each particle having hydrogen ends includes semiconducting silicon and surface Si-H bonds. The silicon particle product can include silicon particles having an oxygen terminus, where each particle having an oxygen terminus includes semiconductor silicon and surface Si-O bonds.

  For the purposes of this specification, metallurgical standard silicon is silicon that has been prepared by reducing silica with carbon in an arc furnace at a temperature between 1500 ° C. and 2500 ° C., between 95% and 99.9. % Purity.

  At least a portion of the free silicon particles can include semiconductor silicon. At least a portion of the free silicon particles can include one or more of polycrystalline silicon, amorphous silicon, bulk crystalline silicon, and metallurgical standard silicon. Free silicon particles can include silicon particles prepared by chemical vapor deposition.

  The silicon particle product can include porous silicon. At least a portion of the free silicon particles can include porous silicon. Each of the free silicon particles can include porous silicon.

  Consolidation of the silicon particle product can result in a porous monolith, where pores are formed from the spaces between the bonded silicon particles. However, the free silicon particles may themselves be porous prior to consolidation. For example, the free silicon particles may be made porous by stain etching.

  The silicon particle product can include one or more of the following elements: Y, P, Sb, In, Fe, As, La, Ca, Pd, Sr, I, Co, Ir, B, Ge, Cu, Pb. Sn and Au. At least a portion of the free silicon particles can include one or more of the following elements: Y, P, Sb, In, Fe, As, La, Ca, Pd, Sr, I, Co, Ir, B, Ge, Cu, Pb, Sn and Au.

  Preferably, the silicon particle product can contain one or more of the following elements: Y, B, P and Sn. Preferably, at least some of the free silicon particles can contain one or more of the following elements: Y, B, P and Sn.

  The method of the present invention can include a further step (e) of making at least a portion of the silicon monolith porous. The method of the present invention can include a further step (e) of porousizing at least a portion of the silicon monolith by anodizing the silicon monolith in a solution of hydrofluoric acid. The method of the present invention can include a further step (e) of making at least a portion of the silicon monolith by porosity anodizing the silicon monolith in a solution of hydrofluoric acid containing a surfactant. . The surfactant can include one or more of ethanol, methanol, acetic acid, a cationic surfactant, an anionic surfactant.

  The addition of the surfactant to the HF acid solution can improve the wettability of the silicon integrated molded body by the HF solution.

  Step (e) can include the step of allowing a solution of HF to enter into the pores of the monolith, where the pores are bonded silicon from which the monolith is formed. Formed by the space between the particles.

  In order for the porosity of the integrally formed body by anodization to be effective, the integrally formed body must have a sufficiently large electric conductivity, and when it is immersed in a solution of HF, it has a sufficient structure. Must have stability. The monolith can be formed from a large number of free silicon particles, and thus the required stability and conductivity is achieved by forming a correspondingly large number of bonds between the silicon particles. Can only be done. The strength of the bond formed and the degree of contact between the bonded silicon particles also affects the success of the anodization process.

  The use of a surfactant can help the penetration of the hydrofluoric acid solution into the pores located between the bonded silicon particles.

  The method of the present invention can include a further step (e) of porously forming at least a portion of the silicon monolith by subjecting the silicon monolith to a stain etch in a solution of hydrofluoric acid.

  Prior to step (e), a step of attaching at least one electrode to the silicon monolith can be performed.

  The monolith may include a number of macropores, where each pore is formed at least in part by a gap between bonded silicon particles. The average size of the macropores contained in the integrally formed body can have a size between 500 Å and 200 microns.

  The monolith may include a number of pores, where each pore is at least partially formed by a gap between bonded silicon particles. The monolithic body can include a number of nanoparticles, and the average size of the pores contained in the monolithic body can have a size between 50 サ イ ズ and 1 micron.

  Step (e) can include the step of allowing a solution of hydrofluoric acid to pass through at least one of the pores of the monolith. Step (e) can include the step of allowing a solution of hydrofluoric acid to pass through substantially all of the pores of the monolith. Step (e) can include the step of allowing a solution of hydrofluoric acid to pass through some of the pores of the monolith.

  Step (e) can be performed in such a way that at least one of the bonded silicon particles is porous throughout this volume. Step (e) can be performed in such a way that at least one of the bonded silicon particles is porous throughout this volume. Step (e) can be performed in such a manner that substantially each of the bonded silicon particles is made porous through substantially the entire volume.

  Production of macroporous silicon monoliths in this manner allows anodization of relatively inexpensive silicon particle products (eg, metallurgical grade silicon). The silicon particle product is compacted to form a unitary body with sufficient mechanical strength and size to allow attachment of the electrode and thus to allow anodization. Silicon macropores have a large surface area, so that the yield of porous silicon is large relative to the amount of silicon used.

  Step (e) can be performed in such a way that microporous silicon and / or mesoporous silicon is formed from the silicon monolith.

  The monolithic body is a porous silicon particle in which pores are formed from the spaces between the bonded silicon particles and / or the particle product is free before step (e) is performed. It may already be porous as a result of including.

  The method of the present invention can include a further step (g) performed after step (e), which fragments the silicon monolith. Step (g) may include a step of mechanically crushing the integrally formed body. The step (g) can include a step of fragmenting the integrally formed body with ultrasonic waves. Step (g) can be carried out in such a way that a large number of partially surface porous silicon particles are produced, wherein the surface of each partially surface porous particle is a porous region and non-porous. Including sex areas.

  The method comprising steps (e) and (g) allows the formation of small anodized porous silicon particles that cannot be produced by other prior art methods.

  Each bonded silicon particle is bonded to at least one other bonded silicon particle, which bond can be formed by applying pressure to two or more free silicon particles.

  The silicon monolith can include first silicon-bonded particles and second silicon-bonded particles. The first and second bonded silicon particles can be integrated with each other without being in direct contact with each other. That is, the first and second bonded silicon particles can be connected by intermediate bonded silicon particles.

  Step (b) can include a step (h) of heating the silicon particle product. Step (b) can include heating the silicon particle product to a temperature between 50 ° C and 500 ° C. Step (b) can include maintaining the silicon particle product at a substantially constant temperature.

  Step (b) can be carried out at a temperature between −5 ° C. and + 5 ° C. for a time of 1 second to 1 hour. Step (b) may comprise maintaining the silicon particle product at a temperature between −20 ° C. and + 20 ° C. for a time of 0.1 seconds to 1 hour. Step (b) can be carried out at a temperature between −50 ° C. and + 50 ° C. for 1 minute to 10 hours.

  The step (h) of heating the silicon particle product can be performed before the step (p) of applying pressure to at least a part of the free silicon particles.

  Step (b) can include bass compression of at least a portion of the silicon particle product.

Step (a) and step (b) can be performed in such a manner that the silicon monolith has a surface area of 10 cm ² or more per gram of silicon. Step (a) and step (b) can be performed in such a manner that the silicon monolith has a surface area of 100 cm ² or more per gram of silicon. Step (a) and step (b) can be performed in such a manner that the silicon monolith has a surface area of 1,000 cm ² or more per gram of silicon.

  The surface area of the silicon monolithic body formed by the bass compression technique may be larger than the surface area of the silicon monolithic body formed by the hot compression technique. This is because hot compression can result in rearrangement of surface silicon atoms that cause cavities and defects to be removed.

  The method of the present invention can further comprise the step (i) of introducing a gas into the region where at least a portion of the free silicon particles are located, wherein the gas is one of nitrogen, helium, argon and hydrogen. The above can be included.

  The method of the present invention can include the step (v) of removing the gas from the region where at least some of the free silicon particles are located. The method of the present invention can include removing the gas from the region where at least some of the free silicon particles are located in such a manner that the pressure is reduced to less than 1 mm Hg.

Step (b) can be performed in an inert atmosphere or in an atmosphere containing H ₂ gas. The inert atmosphere can include a noble gas (eg, argon).

  Step (b) and / or step (h) can be performed after and / or during step (i) and / or step (v).

  The method of the present invention can include a step performed between step (a) and step (b), combining the silicon particle product with a beneficial substance, where step (a) and step (b) ) Is performed in such a way that the beneficial substance is located in the pores between the bonded silicon particles.

  At least in part, the release of the beneficial substance can be controlled by trapping the beneficial substance in the consolidated product formed by steps (a) and (b). Thus, the method of the present invention is particularly beneficial in the manufacture of pharmaceutical products containing hydrophilic drugs that may require controlled release in a physiological environment. Producing bonded silicon particles from free porous silicon particles may be advantageous as it helps to trap beneficial substances in the pores formed by the bonded silicon particles.

  Beneficial substances can include hydrophilic compounds. The beneficial agent can include a number of beneficial agent molecules, where each beneficial agent molecule has more than 100 atoms. Beneficial substances can include hydrophilic compounds. The beneficial agent can include a number of beneficial agent molecules, where each beneficial agent molecule has more than 1000 atoms. Beneficial substances can include hydrophilic compounds. The beneficial substance can include a number of beneficial substance molecules, wherein each of the beneficial substance molecules has from 100 to 5,000 atoms.

  The step of combining the beneficial agent with the silicon particle product comprises at least a portion of the silicon particle product, the beneficial agent vapor, the beneficial agent gas, the liquid beneficial agent, the solid beneficial agent, and the beneficial agent. Contacting with one or more solutions of various substances.

  The method of the present invention may comprise a further step of fragmenting the consolidated product formed by steps (a) and (b).

  For purposes herein, a “beneficial agent” is something that is beneficial overall when administered to a human or animal subject: a beneficial agent is a toxin, ie, an unwanted cell. / Can be toxic to interfere with undesirable physiological processes. For example, even though this purpose is to kill cancer cells, anti-cancer substances are considered “beneficial”.

The silicon particle product can have an average particle size between 1 × 10 ⁻⁴ microns and 1 × 10 ⁻² microns. The silicon particle product can have an average particle size between 1 × 10 ⁻³ microns and 1 × 10 ⁻² microns. The silicon particle product can have an average particle size between ² × 10 ⁻³ microns and 1 × 10 ⁻² microns.

  The silicon particle product can have an average particle size between 0.01 microns and 5 mm. The silicon particle product can have an average particle size between 1 and 500 microns. The silicon particle product can have an average particle size between 1 micron and 1 mm. The silicon particle product can have an average particle size between 1 nm and 150 microns.

At least 1/10 of the free silicon particles from which the silicon particle product is formed can each have a maximum size between 1 × 10 ⁻⁴ microns and 1 × 10 ⁻² microns. At least 1/10 of the free silicon particles from which the silicon particle product is formed can each have a maximum size between 1 micron and 500 microns.

According to a further aspect, the present invention provides a method for producing a silicon structure comprising silicon and a beneficial substance, comprising the following steps:
(A) combining a silicon particle product comprising a number of silicon particles with a beneficial substance; and
(B) Consolidating at least a portion of the silicon particle product and at least a portion of the beneficial material to form a silicon structure comprising silicon and the beneficial material.

  The silicon structure can include a unitary body including at least a portion of the beneficial material and at least a portion of the silicon particle product.

  The method of the present invention can include a further step of fragmenting the monolithic body from which the silicon structure is at least partially formed.

  The silicon particle product can include one or more of porous silicon, polycrystalline silicon, bulk crystalline silicon, amorphous silicon, and metallurgical grade silicon. The silicon particle product may include stain etched porous silicon and / or anodized porous silicon. The silicon particle product can include silicon prepared by chemical vapor deposition.

  The porous silicon can include one or more of microporous silicon, macroporous silicon and mesoporous silicon.

  Beneficial substances can include hydrophilic compounds. Beneficial materials can include other drugs that are difficult to introduce into the pores of porous silicon by prior art methods. Beneficial substances can include hydrophilic compounds. The beneficial agent can include a number of beneficial agent molecules, where each beneficial agent molecule has more than 100 atoms. Beneficial substances can include hydrophilic compounds. The beneficial agent can include a number of beneficial agent molecules, where each beneficial agent molecule has more than 1000 atoms. Beneficial substances can include hydrophilic compounds. The beneficial substance can include a number of beneficial substance molecules, wherein each of the beneficial substance molecules has from 100 to 5,000 atoms.

  Step (a) comprises contacting at least a portion of the silicon particle product with one or more of a beneficial substance vapor, a beneficial substance gas, a liquid beneficial substance, a beneficial substance solution. Can do.

  Step (b) can include (ci) placing at least a portion of the silicon particles and at least a portion of the beneficial material into the container, and (di) reducing the volume of the container.

  Steps (ci) and (di) can be performed in such a way that pressure is applied to at least some of the free silicon particles and at least some of the beneficial material contained in the container.

  Step (b) includes placing the silicon particle product and the beneficial substance in a container and applying uniaxial pressure to at least a portion of the beneficial substance and at least a portion of the silicon particle product in the container. Can be included.

  Uniaxial pressure can be between 5,000 MPa and 50 MPa.

  The uniaxial pressure can be between 1,000 MPa and 100 MPa.

  The uniaxial pressure can be between 1,000 MPa and 200 MPa.

  The uniaxial pressure can be between 750 MPa and 200 MPa.

  The uniaxial pressure can be between 500 MPa and 10 MPa.

  Step (b) includes (cii) placing at least a portion of the silicon particles and at least a portion of the beneficial material into a volume surrounded by at least a portion of the template, and (dii) reducing the enclosed volume. Can be included.

  Steps (cii) and (dii) can be performed in such a way that pressure is applied to at least some of the silicon particles contained in the template and at least some of the beneficial substances contained in the template.

  The silicon structure can form at least a portion of a medical device.

  Step (b) may comprise maintaining the silicon particle product and the beneficial substance at a temperature between -5 ° C and + 5 ° C for a time of 1 second to 1 hour. Step (b) may comprise maintaining the silicon particle product and the beneficial substance at a temperature between −20 ° C. and + 20 ° C. for a time of 0.1 seconds to 10 hours. Step (b) may comprise maintaining the silicon particle product and the beneficial substance at a temperature between -50 ° C. and + 50 ° C. for 1 minute to 1 hour.

  According to a further aspect, the present invention provides a method for manufacturing a silicon structure comprising the step of sandwiching a beneficial substance between at least two silicon layers to form the structure.

  Beneficial substances can include hydrophilic compounds. The beneficial agent can include a number of beneficial agent molecules, where each beneficial agent molecule has more than 100 atoms. Beneficial materials can include hydrophilized compounds. The beneficial agent can include a number of beneficial agent molecules, where each beneficial agent molecule has more than 1000 atoms. Beneficial substances can include hydrophilic compounds. The beneficial substance can include a number of beneficial substance molecules, wherein each of the beneficial substance molecules has from 100 to 5,000 atoms.

  The silicon particle product can include one or more of porous silicon, polycrystalline silicon, bulk crystalline silicon, amorphous silicon, and metallurgical grade silicon. The silicon particle product may include stain etched porous silicon and / or anodized porous silicon. The silicon particle product can include silicon prepared by chemical vapor deposition.

  At least one of the silicon layers may include a porous silicon film. At least one of the silicon layers may include a porous silicon film having a maximum size between 0.5 mm and 20 mm. At least one of the silicon layers can be substantially planar. At least one of the silicon layers can be substantially spherical. The beneficial material can constitute one or more layers.

  The porous silicon can include one or more of microporous silicon, macroporous silicon and mesoporous silicon.

  The method of the present invention can further include the step of applying a sealant material to at least a portion of the surface of the silicon structure. The method of the present invention allows the release of beneficial substances different from those caused by erosion of porous silicon or from diffusion through the pores of porous silicon, wherein the silicon structure is placed in a physiological electrolyte. A further step of applying the sealant material to at least a portion of the silicon structure in a manner such that it is substantially impeded.

  The step of sandwiching the beneficial substance can include mechanically contacting the beneficial substance with at least a portion of the at least two silicon layers. The step of sandwiching the beneficial substance can include applying pressure to both or each of the layers in a manner such that the beneficial substance contacts at least a portion of both or each of the layers.

  Various forms can be achieved by alternately stacking layers of silicon and layers of beneficial material and optionally applying sealant to both ends of the sandwich structure. This allows greater control over beneficial substance loading and release, and is particularly beneficial with respect to hydrophilic substance loading. Release of beneficial substances can occur as a result of diffusion through macropores formed by contact between silicon layers when the structure is immersed in a physiological environment. Alternatively, beneficial substance release may occur as a result of diffusion through the silicon layer or as a result of erosion of the silicon layer.

  The method of the present invention can include an additional step of fragmenting the sandwich structure.

  According to a further aspect, the present invention provides a product obtainable by a process as defined in any of the above aspects.

  According to a further aspect, the present invention provides a silicon monolithic body comprising a silicon skeleton.

  The silicon monolith may further include macroporous silicon having an average pore size between 500 and 200 microns, and microporous silicon and / or mesoporous silicon.

  The silicon monolith may further comprise macroporous silicon having an average pore size between 500 and 10 microns, and microporous silicon and / or mesoporous silicon.

  The silicon monolith may further comprise macroporous silicon having an average pore size between 1 micron and 100 microns, and microporous silicon and / or mesoporous silicon.

  The silicon monolith can have a maximum size between 1 mm and 5 cm. The silicon monolith can have a maximum size between 1 cm and 50 cm.

  At least 0.1% of the surface silicon atoms of the integrally molded body may be bonded to hydrogen atoms. At least 1% of the surface silicon atoms of the integrally formed body may be bonded to hydrogen atoms. At least 10% of the surface silicon atoms of the integrally molded body may be bonded to hydrogen atoms.

Silicon integrally molded body may have a surface area of between silicon per gram 10 cm ² of 200 cm ^2. Silicon integrally molded body may have a surface area of between silicon per gram 50 cm ² of 500 cm ^2. Silicon integrally molded body may have a surface area of between silicon per gram 10 cm ² of 10,000 cm ^2.

  At least 1/10 of the bonded silicon particles from which the silicon monolith is formed can each have a maximum size between 0.01 microns and 500 microns.

  At least 1/10 of the bonded silicon particles from which the silicon monolith is formed can each have a maximum size between 1 nm and 10 microns.

  The silicon monolith can include bonded silicon particles having an average particle size between 0.01 microns and 5 mm. The silicon monolith can include bonded silicon particles having an average particle size between 1 and 500 microns. The silicon monolith may include bonded silicon particles having an average particle size between 1 micron and 1 mm. The silicon monolith can include bonded silicon particles having an average particle size between 1 nm and 150 microns.

  The silicon monolith can include bonded silicon nanoparticles having a maximum size in the range of 1 nm to 50 nm, and the silicon monolith is also a microscopic space formed by the space between the bonded nanoparticles. The pores and / or mesopores can be included and can be resorbable in a physiological environment.

The silicon monolith may further comprise microporous silicon having an average pore size between 1 × 10 ⁻⁴ microns and 1 × 10 ⁻² microns, where the micropores are formed by the spaces between the silicon particles. The

The silicon monolith may further comprise microporous silicon having an average pore size between 1 × 10 ⁻³ microns and 1 × 10 ⁻² microns.

The silicon monolith may further comprise microporous silicon having an average pore size between ² × 10 ⁻³ microns and 1 × 10 ⁻² microns.

  For purposes of this specification, interconnected macropores communicate with at least one other macropore by one or more mesopores and / or one or more micropores. Macropores.

  The monolithic body can include at least one interconnected macropore, and the integral body can include at least 10 interconnected macropores. The monolithic body can include at least 100 interconnected macropores, and the monolithic body can include at least 1,000 interconnected macropores.

  The monolith may include at least one interconnected macropore per 10 adjacent macropores. The monolith may include at least one interconnected macropore per 100 adjacent macropores. The monolith may include at least one interconnected macropore per 1,000 adjacent macropores.

  At least one of the macropores may be defined by at least a portion of the macropore surface and / or the mesoporous silicon surface. At least a portion of the macropores may be defined by at least a portion of the macroporous silicon surface and / or the mesoporous silicon surface. Each of the macropores can be defined by at least a portion of the macroporous silicon surface and / or the mesoporous silicon surface.

  In some cases, at least part of the macropores is formed in at least part of the silicon skeleton, and the silicon skeleton or part of the silicon skeleton from which the macropores are formed is formed of microporous silicon and / or mesoporous silicon. At least a portion can be included.

The silicon monolith can have an electrical resistivity between 10 KΩcm and 10 ⁻⁵ Ωcm when measured at this longest distance. The silicon monolith can have an electrical resistivity between 10 KΩcm and 250 KΩcm when measured at this longest distance. The silicon monolith can have an electrical resistivity between 10 KΩcm and 100 KΩcm when measured at this longest distance.

  The silicon integral molded body can have a breaking strength of 30 MPa to 1,000 MPa.

  The silicon integral molded body can have a breaking strength of 70 MPa to 7,000 MPa.

  The silicon integral molded body can have a breaking strength of 40 MPa to 250 MPa.

  The silicon integral molded body can have a breaking strength of 50 MPa to 150 MPa.

The silicon monolith may include one or more of the following elements: Y, P, Sb, In, Fe, As, La, Ca, Pd, Sr, I, Co, Ir, B, Ge, Cu, Pb Sn and Au. The silicon monolith may include one or more of the following isotopes: ⁹⁰ Y, ³² P, ¹²⁴ Sb, ¹¹⁴ In, ⁵⁹ Fe, ⁷⁶ As, ¹⁴⁰ La, ⁴⁷ Ca, ¹⁰³ Pd, ⁸⁹ Sr, ¹³¹ I ¹²⁵ I, ⁶⁰ Co, ¹⁹² Ir, ¹² B, ¹⁰ B, ⁷¹ Ge, ⁶⁴ Cu, ²⁰³ Pb and ¹⁹⁸ Au.

  The silicon monolith can form at least a portion of a cancer treatment device that includes radionuclides and / or cytotoxic agents used in the treatment of cancer.

The silicon monolith can form at least part of a cancer treatment device comprising a radionuclide selected from one or more of the following radionuclides used in cancer treatment: ⁹⁰ Y, ³² P, ¹²⁴ Sb, ¹¹⁴ In, ⁵⁹ Fe, ⁷⁶ As, ¹⁴⁰ La, ⁴⁷ Ca, ¹⁰³ Pd, ⁸⁹ Sr, ¹³¹ I, ¹²⁵ I, ⁶⁰ Co, ¹⁹² Ir, ¹² B, ¹⁰ B, ⁷¹ Ge, ⁶⁴ Cu, ²⁰³ Pb and ¹⁹⁸ Au.

  The silicon monolith can form at least part of a cancer treatment drug delivery device comprising a cytotoxic agent selected from one or more of the following: an alkylating agent (eg, chlorambutyl), a cytotoxic antibody ( For example, doxorubicin and the like, antimetabolites such as fluorouracil, vinca alkaloids such as vinblastine, hormone regulators such as GNRH, and platinum compounds such as cisplatin.

  The silicon monolith can form at least a portion of a drug delivery device that includes a beneficial substance. The silicon monolith can form at least a portion of a drug delivery device that includes a hydrophilic beneficial substance.

The silicon monolith is used in one or more of the following cancer procedures: ⁹⁰ Y, ³² P, ¹²⁴ Sb, ¹¹⁴ In, ⁵⁹ Fe, ⁷⁶ As, ¹⁴⁰ La, ⁴⁷ Ca, ¹⁰³ Pd, ⁸⁹ Can form at least part of a cancer treatment device having one or more of Sr, ¹³¹ I, ¹²⁵ I, ⁶⁰ Co, ¹⁹² Ir, ¹² B, ⁷¹ Ge, ⁶⁴ Cu, ²⁰³ Pb and ¹⁹⁸ Au radionuclides : Prostate cancer, liver cancer, pancreatic cancer, breast cancer, lung cancer, brain cancer and testicular cancer.

  The monolithic body can form at least a portion of an orthopedic scaffold used in bone repair or replacement. The monolithic body can form at least a portion of a tissue engineering scaffold used in soft tissue repair or replacement.

  The silicon monolith can include semiconductor silicon. At least a portion of the free silicon particles can include one or more of polycrystalline silicon, amorphous silicon, bulk crystalline silicon, and metallurgical standard silicon.

  The silicon skeleton can include a number of bonded silicon particles, where each bonded silicon particle is bonded to at least one of the other bonded silicon particles.

  At least a portion of the bonded silicon particles can include one or more of macroporous silicon, mesoporous silicon, and microporous silicon.

  The silicon monolith can form at least a portion of a drug delivery implant that includes a beneficial agent and a binder material, wherein the binder material includes at least a portion of the beneficial agent in the silicon skeleton. It has a predetermined structure and composition so as to be bonded to at least a part.

  The silicon monolith can form at least a portion of a drug delivery implant that includes a beneficial material and a fragmented material, where the fragmented material, when immersed in a physiological electrolyte, and the electrolyte It has a predetermined structure and composition to react and release gas.

  According to a further aspect, the present invention provides a composite monolithic body comprising a composite framework comprising silicon and a beneficial material.

  The silicon particle product can include one or more of porous silicon, polycrystalline silicon, bulk crystalline silicon, amorphous silicon, and metallurgical grade silicon. The silicon particle product may include stain etched porous silicon and / or anodized porous silicon.

  The silicon particle product can include one or more of microporous silicon, macroporous silicon and mesoporous silicon.

  Beneficial substances can include hydrophilic compounds.

  The composite monolithic body can include a number of macropores. The average size of the macropores contained in the one-piece molded body can have a size between 50 and 200 microns.

  The composite monolith can form part of a pharmaceutical product for delivering a beneficial substance to an animal or human subject. The monolithic body can form part of an implant for delivering a beneficial substance to an animal or human subject.

  The composite monolith can form at least a portion of a pharmaceutical product that includes a beneficial material and a binder material, wherein the binder material includes at least a portion of the beneficial material in silicon. It has a predetermined structure and composition so as to be bonded to at least a part.

  The composite monolith can form at least a portion of a pharmaceutical product that includes a beneficial substance and a fragmented substance, where the fragmented substance is electrolyte when immersed in a physiological electrolyte. It has a predetermined structure and composition.

  According to a further aspect, the present invention provides a multi-layered silicon structure comprising two or more silicon layers and one or more layers of beneficial materials, wherein the beneficial materials are of the silicon layer. Or between at least two of the silicon layers.

  The multilayer structure can include alternating layers of beneficial materials and layers of silicon.

  Beneficial substances can include hydrophilic compounds.

  The silicon on which both or each of the silicon layers are formed can include one or more of porous silicon, polycrystalline silicon, amorphous silicon and bulk crystalline silicon.

  At least one of the silicon layers may include a porous silicon film. Such a silicon film or at least one of such silicon films may have a maximum size between 0.5 mm and 20 mm. At least one of the silicon layers can be substantially planar. At least one of the silicon layers can be substantially spherical. The beneficial material can constitute more than one layer.

  The porous silicon can include one or more of microporous silicon, macroporous silicon and mesoporous silicon.

  The silicon structure can include a sealant material in contact with at least a portion of the at least two silicon layers. Silicon structures have a beneficial substance release that differs from the erosion of porous silicon or from diffusion through the pores of porous silicon, where the pharmaceutical product is placed in a physiological electrolyte. A sealant material that is in contact with at least a portion of the at least two silicon layers in a manner that is substantially disturbed when

  According to a further aspect, the present invention provides a partially surface porous silicon particle product comprising a number of partially surface porous silicon particles, wherein each partially surface porous silicon product. The surface of the silicon particle includes a porous region and a non-porous region.

  At least one of the partially superficially porous silicon particles can have at least two separate non-porous regions. At least some of the partially porous silicon particles can each have two or more spaced non-porous regions.

  At least one of the partially surface porous silicon particles can have a first non-porous region and a second non-porous region, wherein the first non-porous region and the second non-porous region are The porous regions are spatially separated from each other by the porous region.

The partially superficially porous silicon particle product can comprise at least 100 partially superficially porous silicon particles. The partially surface porous silicon particle product can comprise between 100 and 10 ²⁶ partially surface porous silicon particles. Partially surface porous silicon particles product may contain partially surface porous silicon particles of between 100 10 ^6. Partially surface porous silicon particles product may contain partially surface porous silicon particles between 100 10 ^3.

  Substantially each partially superficially porous silicon particle can have a size between 0.5 microns and 200 microns.

  10% to 90% of the total of partially surface porous silicon particles can have a size between 1 micron and 150 microns.

At least one of the partially surface porous silicon particles can include one or more of the following elements: Y, P, Sb, In, Fe, As, La, Ca, Pd, Sr, I, Co, Ir, B, Ge, Cu, Pb, Sn and Au. At least one of the partially surface porous silicon particles can include one or more of the following isotopes: ⁹⁰ Y, ³² P, ¹²⁴ Sb, ¹¹⁴ In, ⁵⁹ Fe, ⁷⁶ As, ¹⁴⁰ La, ⁴⁷ Ca. ¹⁰³ Pd, ⁸⁹ Sr, ¹³¹ I, ¹²⁵ I, ⁶⁰ Co, ¹⁹² Ir, ¹² B, ¹⁰ B, ⁷¹ Ge, ⁶⁴ Cu, ²⁰³ Pb and ¹⁹⁸ Au.

At least one of the partially surface porous silicon particle products can include one or more of the following elements: Y, P, Sb, In, Fe, As, La, Ca, Pd, Sr, I, Co, Ir, B, Ge, Cu, Pb, Sn and Au. At least one of the partially surface porous silicon particle product can include one or more of the following isotopes: ⁹⁰ Y, ³² P, ¹²⁴ Sb, ¹¹⁴ In, ⁵⁹ Fe, ⁷⁶ As, ¹⁴⁰ La, ⁴⁷ Ca, ¹⁰³ Pd, ⁸⁹ Sr, ¹³¹ I, ¹²⁵ I, ⁶⁰ Co, ¹⁹² Ir, ¹² B, ¹⁰ B, ⁷¹ Ge, ⁶⁴ Cu, ²⁰³ Pb and ¹⁹⁸ Au.

  At least one of the partially surface porous silicon particles can be bonded to one or more of the other partially surface porous silicon particles from which the particle product is formed.

  At least one of the partially surface porous silicon particles can be covalently bound to one or more of the other partially surface porous silicon particles from which the particle product is formed.

  According to a further aspect, the present invention provides a silicon structure as defined in any of the above aspects for use as a medicament.

  According to a further aspect, the present invention provides a monolithic body as defined in any of the above aspects for use as a medicament.

  According to a further aspect, the present invention provides a fragmented silicon monolith as defined in any of the above aspects for use as a medicament.

  According to a further aspect, the present invention provides metallurgical standard silicon for use as a medicament. Such metallurgical standard silicon can include calcium and / or iron. Metallurgical standard silicon can include calcium, where the molar concentration of calcium is greater than the molar concentration of any other impurities contained in the silicon. Metallurgical standard silicon can include iron, where the molar concentration of iron is greater than the molar concentration of any other impurities contained in the silicon. The metallurgical standard silicon can include a toxic component selected from one or more of arsenic, cadmium, lead and mercury. The toxic component preferably has a concentration of less than 10 ppm. Metallurgical standard silicon can include aluminum, in which case the aluminum can be present at a concentration of less than 1,000 ppm.

The invention will now be described by way of example only and with reference to the following drawings in which:
FIG. 1 shows the time course of the neutral red release measured from day to day from a silicon structure according to the invention.
FIG. 2 shows the effect of neutral red preload on the release rate from a silicon structure according to the invention.
FIG. 3 shows the time course of the cumulative concentration of gamma interferon measured daily from the silicon structure according to the invention.
FIG. 4 shows the time course of the cumulative concentration of placental alkaline phosphate measured daily from the silicon structure according to the invention.
FIG. 5a shows an SEM image of a porous silicon film after being immersed in Trizma buffer for several days.
FIG. 5b shows an SEM image of the porous silicon film after being immersed in Trizma buffer for several days.
6a is a photograph of a first bass compression device used to produce a silicon monolith according to the present invention.
6b shows several photographs of the components from which the first bass compression device of FIG. 6a is formed.
FIG. 7a shows a SEM micrograph of a portion of a silicon monolith according to the invention.
7b shows a SEM micrograph at high magnification of a portion of the same silicon monolith shown in FIG. 7a.
FIG. 8 is a photograph of the components of a second bass compression device used to produce a silicon monolith according to the present invention, the second bass compression device comprising a 5 mm mold 81.
FIG. 9 shows a silicon monolith produced using the second bass compression device whose components are shown in FIG.
FIG. 10 shows a porous surface of a portion of an anodized silicon monolith according to the present invention.
FIG. 11 shows the porous surface shown in FIG. 10 at a high magnification.

  The following description is divided into two sections. The first section provides an explanation of the combination of silicon and beneficial materials, especially by consolidation of silicon particle products. Section 2 includes disclosure of silicon consolidation and anodization of the resulting silicon monolith.

(I) Silicon structure containing beneficial material Approximately 5 mg of neutral red (which is a hydrophilic dye) is mixed with 60 mg of silicon particle product and the mixture is clamped stainless steel having two mating halves. Compaction was achieved by loading on a steel press. Pressure was applied to the mixture by a press for 20 seconds. This consolidation method is shown as Method A. Three different mixtures were prepared using a particle product comprising stain-etched porous silicon, anodized porous silicon, and polycrystalline silicon. These three consolidated samples were then immersed in Trizma buffer and dye release was determined by measuring the change in absorbance at 573 nm. The results shown in FIG. 1 show that the use of anodized porous silicon gives the slowest elution rate (which is labeled AN), and the use of stain-etched porous silicon is an intermediate release. , Which is labeled SE, and the use of polycrystalline silicon gives a relatively fast release (which is labeled poly-Si). These results are particularly relevant to drug delivery as they show that the drug release rate can be controlled by changing the form of silicon used.

  Figures 2 (a) and 2 (b) show the cumulative release of neutral red from anodized and stain-etched porous silicon, respectively.

  The result labeled 2ai is for a mixture of stain-etched porous silicon and neutral red consolidated by Method A. The result labeled 2 aii is for stain-etched porous silicon pre-loaded with neutral red by rotary evaporation or lyophilization prior to compression by Method A. These results indicate that the preload results in a better and sustainable release over a 7 day dissolution period compared to a sample that was not preloaded. Similar results are shown in FIG. The results labeled 2bi are for a mixture of anodized porous silicon and neutral red that has been consolidated by Method A and the results labeled 2bii are prior to consolidation of Method A. About anodized porous silicon preloaded with neutral red.

  Similar experiments were performed by replacing neutral red with placental alkaline phosphate (PLAP) and gamma interferon (γ-IFN). FIG. 3 shows the cumulative release of γ-IFN using anodized porous silicon preloaded by lyophilization. Samples were collected at the end of the 4 day study, ground, and release was measured again on ground samples. An additional 3% of the remaining γ-IFN was released after grinding.

  FIG. 4 shows PLAP release from a sample prepared using Method A from anodized porous silicon (plot 4a) and stain-etched porous silicon (plot 4b). Cumulative release was measured by the pNP method. Throughout 3 days, about 20% release of PLAP was observed.

  Similar experiments were also performed using neutral red compressed between two porous silicon membranes. The sealant was applied to both ends of the sample so that the release of neutral red was primarily through the pores of the porous silicon or as a result of erosion of the porous silicon. FIG. 5 (a) and FIG. 5 (b) show SEM images of the porous silicon film after being immersed in a Trizma buffer solution for several days. The results show that the pore size of the membrane has increased as a result of dissolution. Thereby, it is considered that the diffusion rate of the dye through the film is increased.

(II) Silicon structure and anodized silicon structure A silicon particle product having an average particle size between 1 micron and 50 microns is treated with 40 wt% (w / w) aqueous hydrofluoric acid solution, The surface oxide present was removed from the silicon product and a surface with hydrogen termination was created. The silicon particle product can include metallurgical standard silicon particles that are heavily doped in p + or n + type.

  Hydrofluoric acid was removed from the silicon particle product by washing with deionized water and then rapidly dried in air on filter paper for 15 minutes. The particles were then quickly loaded onto a stainless steel bass compression device 1 (shown in FIG. 6a). The drying and loading steps were performed as quickly as possible to minimize reaction with oxygen or prevent reaction with oxygen and to retain the hydrogen-terminated particle surface. .

  Subsequently, an estimated uniaxial pressure between 1,000 psi and 5,000 psi can be applied by the bass compression device 1 and the temperature of the silicon particle product can be maintained at 20 ° C. The resulting silicon monolith can have the form of a cylindrical consolidated macroporous silicon block having a diameter of 5 mm and a length of 46 mm.

  A small opening was formed in the bass compression device to allow the gas generated during the compression process to escape. FIG. 6b shows the components of the bass compression device made of stainless steel (generally indicated by 2).

  FIG. 7a shows an SEM micrograph of a portion of the silicon monolith 3 according to the present invention. The silicon body is in the form of a cylindrical integral body. The image of FIG. 7a shows a fractured surface 4 where the cylinder has been broken to more clearly show the macroporous nature of the integrally formed body. FIG. 7 b shows a SEM micrograph at higher magnification of the macroporous fracture surface 4.

The electrode can be attached to a silicon monolith, and then with a surfactant (eg, ethanol, etc.) and a current density between 1 mAcm ⁻² and 10 Acm ⁻² (which is measured with respect to the outer surface of the block body) It can be immersed in a 10 to 40% (w / w) aqueous hydrofluoric acid solution and the current can flow for 1 to 200 minutes.

  Hydrofluoric acid can go into the macropore network of the silicon block, and anodization causes the formation of a porous layer on the inner surface of the macropore and on the outside of the silicon block Brought to the surface.

  When the anodization is complete, the block can be washed by repeated soaking in deionized water or methanol and then air dried.

  Finally, if a silicon particle product is required, the block can be mechanically crushed to obtain a large number of partially surface porous silicon particles. Each partially superficially porous particle has a non-porous surface area that bound silicon particles to adjacent silicon particles when still located in a monolithic body. Corresponds to the region.

The monolithic silicon object according to the present invention can be used as a scaffold to provide protection against damaged or diseased tissue or as a scaffold to assist in the regrowth of damaged or diseased tissue. A monolith with the appropriate size and shape is placed in an area that causes tissue regrowth. Have a size between 62,500Myuemu ² from 10,000 ^2, macropores formed in the integrally molded body, tissue to allow to pass through the silicon scaffold. The scaffold can also include mesoporous silicon, where the mesoporous silicon can be designed to erode once tissue growth is complete. This process is described in International Patent Application Publication No. WO0195952, which is incorporated herein by reference in its entirety.

  Next, five examples describing consolidation of various silicon particle products under various conditions are presented. Examples 4 and 5 describe the treatment of a silicon particle product with an aqueous solution of HF prior to consolidation. Both the details of this HF pretreatment and the details of the consolidation process are shown in separate sections following the five examples.

  The experiment was conducted on a first silicon particle product containing silicon kerf having a particle size between 6 and 30 microns, obtained by sawing a polycrystalline silicon ingot. The particle product containing this kerf was uniaxially treated under a vacuum at a pressure of less than 1000 MPa at 293 K in a hardened stainless steel mold 81 having a diameter of 5 mm (this is shown in FIG. 8) using a hydraulic press. Compressed in the direction.

  Consolidation of the particle product resulted in the formation of a silicon monolith in the form of pellets. However, when this process was repeated at an increased pressure of 1000 MPa, it was impossible to form a single molded body from the particle product. This indicates that excessive pressure can be applied to the particle product, but this can result in the failure of the monolith or damage to the monolith when removed from the mold.

  A second silicon particle product containing metallurgical grade silicon with a particle size ranging from 32 microns to 125 microns, which is surface oxidized, is uniaxially compressed at 250 MPa in a 5 mm mold 81, Were formed in the form of pellets. Immediately after removal from the mold 81, the integrally molded body was immersed in a solution containing an equal volume of ethanol and 40% (w / w) HF aqueous solution. After 5 seconds in the solution, the monolithic body collapsed.

  This experiment has shown that bond formation between silicon particles is possible even in the presence of natural surface silicon oxide. However, the bond shows a relatively poor resistance to HF. Of course, the presence of surface oxides is inconvenient for anodization.

  A silicon particle product containing silicon particles, containing surface Si-H bonds, and having a size in the range of 0.005 microns to 0.5 microns was uniaxially compressed in a 5 mm mold 81 at a pressure of 500 MPa. . The resulting silicon monolith was in the form of pellets, which were immersed in a solution containing an equal volume of ethanol and 40% (w / w) HF aqueous solution. The silicon compact was stable in this solution for 30 minutes.

  This means that the presence of surface Si-H bonds in the particle product allows the formation of a greater number of silicon-silicon bonds between the silicon particles when compressed, and the bonds are against HF. It shows more resistance. This property should facilitate anodization and consolidation of the integrally formed body.

  A silicon particle product containing metallurgical standard silicon, particle size between 32 microns and 125 microns, and surface natural silicon oxide treated in aqueous HF solution for 10 minutes and washed in deionized water for 10 minutes And then air dried on filter paper for 10 minutes. 100 mg of the obtained dry powder was transferred to a 5 mm mold 81 and compressed in a uniaxial direction at 1000 MPa under vacuum. A small amount of silane gas was detected when the compression molded pellets were removed from the mold 81. The density of the resulting silicon monolith was in the form of pellets 73% of solid non-porous metallurgical standard silicon. The electrical resistance of the silicon integral molding was 80,000 ohms, combined with the electrical resistance of the electrical contacts. After exposure to air for 16 days, the silicon monolith was immersed in a solution containing an equal volume of ethanol and 40% (w / w) aqueous HF. The monolith was stable in this solution for 20 minutes.

  This result is in contrast to the result of Example 2 and shows the effectiveness of HF pretreatment for replacing the silicon oxide on the surface with Si—H bonds. Application of uniaxial pressure results in consolidation of the silicon particle product, where the Si-H bond is broken and replaced by the Si-Si covalent bond between adjacent silicon particles. Silane release is a by-product of monolith formation resulting from hydrolysis of the silicon-hydrogen surface.

  A silicon particle product containing metallurgical standard silicon, particle size between 32 microns and 125 microns, and including natural surface silicon oxide is treated in aqueous HF solution for 10 minutes and washed in deionized water for 10 minutes. Then, it was air-dried on a filter paper for 10 minutes, and then the dried particle product was quickly transferred to a 5 mm mold 81. A uniaxial pressure of 750 MPa was applied to consolidate the silicon particle product, thereby forming a silicon monolith in the form of pellets having a mass of 100 mg. The porosity of the integrally molded body was about 30%.

  The platinum base was placed in electrical contact with the lower surface of the silicon monolith using a silver paste. Approximately 1 ml droplets of electrolyte containing equal volumes of ethanol and 40% (w / w) aqueous HF were pipetted onto the top surface of the silicon pellets. A thin platinum wire was then dropped into the electrolyte droplet and a potential difference of 12-15 volts was applied, thereby producing a 30 mA current for 20 seconds. As a result of the combined action of evaporation from electrical heating and penetration into the pores of the pellet, the HF droplets gradually decreased in volume. The SEM images shown in FIG. 10 and FIG. 11 on the surface of the anodized pellet revealed that the bonded silicon particles were made porous and mesopores were formed.

Consolidation Procedure FIG. 8 shows a photograph of the components of a second bass compression device used to produce a silicon monolith according to the present invention, where the second bass compression device has a diameter of It includes a 5 mm mold 81 and one movable plunger 82, both of which are formed from hardened stainless steel. The mold 81 is designed so that it can be evacuated. Typically, 100 mg of silicon particle product was loaded into a 5 mm mold 81. The mold is then placed between the platens of a 10 ton laboratory press (not shown) with a digital pressure display with 0.1 ton accuracy. A vacuum line (not shown in the figure) was connected to the mold and the mold was evacuated to a pressure of about 10 ⁻⁴ Torr. Next, an axial pressure between 50 MPa and 1000 MPa was applied to the silicon particle product for 5 minutes. Next, the vacuum line was removed, and the axial pressure was removed from the resulting silicon integral molded body 91 shown in FIG. Before removing the silicon monolith from the mold. The silane sensor was placed on top of the integral molded body when the integral molded body was removed.

HF Pretreatment The silicon particle product was placed in a beaker containing 100 ml of 40% (w / w) and 10 ml of ethanol for 10 minutes and the mixture was occasionally stirred. The presence of ethanol was required to allow wetting of the silicon particles. Next, as much solution as possible was removed by decantation, leaving the particle product in a beaker. The beaker was then filled with 100 ml of deionized water and ethanol and the mixture was then poured into a drying vessel attached to a Buckner pump. Excess solution was removed through a PTFE membrane as a result of the pressure differential. The remaining silicon particle product was rinsed with fresh water or ethanol and an HF detector was used to ensure that no substantial HF remained. Next, the Buckner pump was removed, and the PTFE membrane on which the particle product remained was taken out. The membrane was then placed on the filter paper so that the particle product was in contact with the filter paper and peeled off, leaving a silicon powder. Filter paper was used to remove much of the liquid, after which the powder was dried in air for 10 minutes. The time taken from the initial decantation of the HF solution to the start of the air drying procedure was typically 10 minutes. As a result, the total time for the procedure from start to finish is 30 minutes (10 minutes treatment with ethanolic HF, 10 minutes washing with water, and 10 minutes air drying).

Figure 3 shows the time course of the neutral red release measured from the silicon structure according to the invention, measured daily. Figure 2 shows the effect of neutral red preload on the release rate from a silicon structure according to the present invention. Figure 3 shows the time course of the cumulative concentration of gamma interferon measured daily from a silicon structure according to the invention. Figure 2 shows the time course of the cumulative concentration of placental alkaline phosphate measured from day to day from a silicon structure according to the present invention. 2 shows an SEM image of a porous silicon membrane after being immersed in Trizma buffer for several days. 2 shows an SEM image of a porous silicon membrane after being immersed in Trizma buffer for several days. 2 is a photograph of a first bass compression device used to produce a silicon monolith according to the present invention. Fig. 6b shows several photographs of the components from which the first bass compression device of Fig. 6a is formed. The SEM micrograph of a part of silicon integrated molding by this invention is shown. FIG. 8 shows a SEM micrograph at high magnification of a portion of the same silicon monolith shown in FIG. 7a. 2 is a photograph of the components of a second bass compression device used to produce a silicon monolith according to the present invention, the second bass compression device comprising a 5 mm mold 81; FIG. 9 shows a silicon monolith produced using the second bass compression device whose components are shown in FIG. 2 shows a porous surface of a portion of an anodized silicon monolith according to the present invention. The porous surface shown in FIG. 10 is taken and shown at high magnification.

Claims (21)

A method for producing a silicon monolith, comprising:
(A) obtaining a silicon particle product comprising a number of free silicon particles; and (b) applying pressure to at least a portion of the silicon particle product to form a silicon monolith.
(E) The method comprising the further step of porosity forming at least part of the silicon from which the silicon monolith is formed.   Step (e) anodizes the monolithic body in a hydrofluoric acid solution selected from one or more of an aqueous solution of HF, an ethanolic solution of HF, a methanolic solution of HF, and an ethanoic acid solution of HF. The method according to claim 1, comprising the step of:   The method of claim 1, wherein step (e) comprises the step of stain etching at least some of the free silicon particles with hydrofluoric acid prior to step (b).   The method according to claim 1, characterized in that steps (a) and (b) are performed in such a way that two or more silicon monoliths are formed.   The method according to claim 1, characterized in that step (b) comprises the step of bass compression of the silicon particle product.   The process according to claim 1, characterized in that step (b) is carried out at a temperature between -20 ° C and + 50 ° C.   2. The method according to claim 1, characterized in that it comprises a further step performed after step (b) or during step (b), testing for the presence of silane gas.   The method of claim 1, further comprising a step performed between steps (a) and (b), wherein at least some of the free silicon particles are combined with a beneficial substance.   The method according to claim 1, wherein the beneficial substance is a hydrophilic beneficial substance.   The method of claim 1, wherein the particle product comprises at least 1000 free silicon particles.   2. A method according to claim 1, characterized in that the monolith comprises at least 1000 bonded silicon particles.   The method according to claim 1, characterized in that it comprises the further step of treating the silicon particle product with a reducing agent before step (b) to form surface Si-H bonds.   The method according to claim 12, characterized in that the reducing agent comprises HF.   The method of claim 1, wherein step (b) is performed such that at least one of the silicon particles is covalently bonded to one or more of the other silicon particles.   A silicon integrated molded body obtainable by the method according to any one of claims 1 to 14.   (A) combining a silicon particle product comprising a number of porous silicon particles with a hydrophilic beneficial substance; and (b) consolidating at least a portion of the silicon particle product and at least a portion of the hydrophilic material. Forming a composite monolith including at least a portion of a silicon particle product and at least a portion of a hydrophilic material.   The method according to claim 16, characterized in that it comprises the further step of fragmenting the composite monolith.   Silicon monolith comprising over 1000 covalently bonded silicon particles, each covalently bonded silicon particle being covalently bonded to at least one of the other covalently bonded silicon particles Molded body.   19. The silicon monolithic molded body according to claim 18, wherein at least a part of the surface of the monolithic molded body contains silicon hydride.   Production of partially surface porous silicon particles comprising a number of partially surface porous silicon particles, each partially surface porous particle surface comprising a porous region and a non-porous region object.   Comprising at least one bonded silicon particle, wherein the bonded silicon particle or each bonded silicon particle is covalently bonded to one or more of the other silicon particles from which the particle product is formed. The silicon particle product according to claim 20.

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