JP2005255967A - Surface-reactive crenellated macromolecular microparticle and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide surface-reactive crenellated macromolecular microparticles higher in performance than conventional macromolecular microparticles, having such a shape as to have numerous projections on the surface in order to enlarge its specific surface area while keeping its size intact for the purpose of creating macromolecular microparticles usable in such wide-range fields as drug transport and sustained-releasing carriers, morbid state-catching carriers, gene-transferring carriers and carriers for diagnostic use, and to provide a method for producing the surface-reactive crenated macromolecular microparticles in a single step. <P>SOLUTION: The surface-reactive crenellated macromolecular microparticles are characterized by each having at least one kind of chemically reactive functional group, electrically chargeable functional group or functional group having physically interactive tendency such as hydrogen bond and also having numerous projections on the surface. The method for producing the surface-reactive crenellated macromolecular microparticles in a single step comprises carrying out a copolymerization between a plurality of monomers significantly differing in polymerization rate and solubility to a polymerization solvent and autoorganizing the resultant copolymer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a functional group capable of reacting with other molecules on the surface or electrostatic interaction with other molecules, hydrogen bonding, dipole interaction, charge transfer interaction, hydrophobic interaction, van der Waals interaction, specific Polymeric fine particles having one or more types of functional groups capable of exhibiting physical interaction such as physical affinity (affinity), etc., which are of a flattened-like shape having a large number of protrusions on the surface, a drug transport sustained release carrier, a disease state The present invention relates to fine polymer particles that can be used in a wide range of fields such as capture carriers, carriers for gene introduction, and carriers for diagnostic agents. The present invention also relates to a method for easily producing the polymer fine particles in one step.

  The polymer fine particle is a particle having a diameter of several tens of nanometers to several micrometers, and has a remarkably large surface area relative to its volume. Therefore, it has the characteristic of sorbing other substances with high efficiency and can be used for various purposes. For example, polymer fine particles on which a dye is sorbed have been used for paints for a long time. In addition, polymer fine particles with strong electrolyte functional groups on the surface are used for ion exchange resins, and polymer fine particles with functional groups with other chemical properties on the surface are used for chromatography utilizing their characteristics. ing.

  In particular, polymer fine particles characterized by high hydrophilicity on the surface are excellent in colloidal dispersion stability in water, sorb other water-soluble substances, and can be easily settled and recovered by subsequent centrifugation. Therefore, it can be used as a drug transport sustained release carrier, a disease state capture carrier, a gene introduction carrier, and a diagnostic agent carrier.

  On the other hand, in order to diversify drug species with recent significant development of new drugs, diversify pathogens and diversify antibody types with the development of medicine, sustained release of drug transport with higher performance than conventional polymer fine particles Carriers, disease state capture carriers, carriers for gene introduction, and carriers for diagnostic agents are required. Higher-performance drug transport sustained release carriers, disease state capture carriers, gene transfer carriers, and diagnostic drug carriers have higher substance sorption capacity and sufficiently high colloidal dispersion stability during substance sorption. On the other hand, at the time of recovery, the sediment can be recovered quickly under milder conditions.

  In order to increase the material sorption capacity, it is effective to increase the specific surface area relative to the volume. As such a method, it is effective to reduce the size of the polymer fine particles. On the other hand, if the volume is reduced, the polymer fine particles become lighter. For this reason, the colloidal dispersion stability of the polymer fine particles is also increased. This requires more severe settling conditions during settling recovery. For example, when centrifugation is used, a longer centrifugation process is required at a higher rotational speed. This makes the sorbed material more susceptible to transformation. In other words, the method of changing the size of the polymer microparticles cannot simultaneously improve both the substance sorption capacity and the sediment recovery ability, and it is possible to achieve a higher performance drug transport sustained release carrier, pathological condition capture carrier, and gene transfer This method is not suitable for the development of carriers and diagnostic agents.

  It is effective to make the shape non-spherical as a method of increasing the specific surface area relative to the volume without changing the size of the polymer fine particles. However, the non-spherical shape may give the fine particles direction dependency of substance sorption. This may limit the amount of sorption because the substance does not sorb evenly, and may give difficulty in water dispersibility and sedimentation of the fine particles after sorption, making handling difficult.

  On the other hand, a non-spherical confetti-type fine particle having a large number of protrusions on the surface has a symmetry close to a spherical symmetry, and thus can be expected to have a shape having the smallest dependence on the direction of substance sorption. Therefore, making the polymer fine particles into the confetti type is effective for the development of a higher-performance drug delivery sustained release carrier, a pathological condition capture carrier, a gene introduction carrier, and a diagnostic agent carrier.

As an example of a method of making the shape of the polymer fine particles into a confetti type, first, spherical polymer fine particles are prepared, and another monomer is impregnated therein, and free radical polymerization is performed in the polymer fine particles. It is known that polymer fine particles having various shapes including a confetti type can be synthesized by using a method called a seed polymerization method. (For example, refer nonpatent literature 1.)
Masayoshi Okubo Polymer Volume 50 September Issue 696 p. 2003

  However, this method requires a two-step manufacturing process and is complicated, and also has a problem that the fine particles are likely to be broken and the shape is difficult to maintain. There is also a problem that it is difficult to impart various functional groups to the surface. Furthermore, when the polymer fine particles used as seeds are small, the preparation is difficult, and there is no report on the preparation of gold flat sugar type fine particles of 200 nanometers or less.

As another method of making the shape of the polymer fine particles into a confetti type, first create two types of large and small spherical polymer particles separately, and accumulate the smaller spherical particles on the surface of the larger polymer particles. It is known that a polymer fine particle composite having irregularities on its surface can be produced by a method called aggregation. (For example, see Patent Document 1 and Non-Patent Document 2.)
Patent Publication 10-338710 Keiji Fujimoto, Polymer 50, September, 701, 2003

  However, this method requires two steps or more of manufacturing processes and is troublesome, and also has a problem that the fine particle composite is easily split. Furthermore, the smaller the larger polymer fine particles, the more difficult it is to produce, and there is no report on the production of gold flat sugar-type fine particles of 200 nanometers or less.

One-step method for creating fine polymer particles with functional groups on the surface is a monomer that is a raw material for very hydrophobic polymers such as styrene, and a hydrophilic oligomer with a molecular weight of several thousand such as polyethylene glycol monomethacrylate. There is known a method of free-radical dispersion copolymerization of a monomer called a macromonomer having a polymerizable functional group in a polar solvent. It is also known that when polymer fine particles are produced by this method, if a macromonomer having a functional group is used, the polymer fine particles are accumulated on the surface thereof. (For example, see Non-Patent Document 3.) Further, the polymer fine particles prepared by this method are characterized by high dispersion stability and a single size, and a drug transport sustained release carrier (for example, Patent Document 2 and It can be used as a virus capture carrier (see, for example, Patent Document 4) and an AIDS vaccine material (see, for example, Patent Document 5).
Mitsuru Akashi, Polymer Processing, 37, 120 pages Patent Publication 9-87204 Patent Publication No. 8-268916 Patent Publication 10-045601 Patent Publication 2001-335510

A macromonomer is a polymer having a function as a polymerizable monomer. Macromonomers are assembled from the synthesis of the main chain polymer and the introduction of polymerizable functional groups. For example, anionic living polymerization (termination method, initiation method), cationic polymerization (ring-opening cationic living polymerization, vinyl cationic polymerization, cationic polymerization using iniferter, etc.), a method using chain transfer reaction in radical polymerization, or There is a method of introducing a polymerizable functional group into a functional group such as a terminal of the main chain polymer using chloromethylstyrene, glycidyl methacrylate, methacryloyl isocyanate, methacrolein, methacrylic acid chloride or the like (for example, Non-Patent Document 4). reference.)
Asami Yanagi, Polymer Processing, 33: 439

The present inventors improved the macromonomer method to carry out ternary free radical dispersion copolymerization of styrene, acrylonitrile, and polyethylene glycol monomethacrylate to synthesize polymer fine particles having a confetti-shaped shape having an ether group on the surface. I reported earlier. However, there are only ethylene oxide groups and methoxy groups on the surface of these fine particles, and these functional groups do not show chemical reaction or strong physical interaction with drugs, pathogens, and antibodies. It cannot be used in the fields of capture carriers, gene introduction carriers, and diagnostic agents. (For example, refer nonpatent literature 5.)
Chen Mingqing, Kaneko Tatsuo et al., Chemistry Letters December 1306, 2001

There is also a method of modifying the functional group on the surface of the confetti type microparticles to a functional group that easily shows chemical reaction or physical interaction with drugs, pathogens, and antibodies by using radiation or the like. Since the process of two steps or more is required, the manufacturing method is complicated. In addition, since the types of functional groups that can be introduced are limited, it is difficult to chemically react or physically interact with various drugs, pathogens, and antibodies. It is not suitable for the development of carriers for gene introduction and carriers for diagnostic agents. Further, although the polymer fine particles obtained by ternary free radical dispersion copolymerization of styrene, acrylonitrile and terminal thioethoxymethyl-4-styrenated polymethacrylic acid are surface-reactive, they do not have a confetti-shaped shape. It is not suitable for improving the performance of transport sustained release carriers, disease state capturing carriers, gene introduction carriers, diagnostic agent carriers, and the like. (For example, refer nonpatent literature 6.)
Proceedings of the Society of Polymer Science, Japan, Vol. 52, 499, 2003

  The object of the present invention is to create a drug delivery sustained release carrier, pathologic capture carrier, gene introduction carrier, diagnostic agent carrier and the like that have higher performance than conventional polymer fine particles, and has a high substance sorption ability, and An object of the present invention is to provide polymer fine particles that have sufficiently high colloidal dispersion stability at the time of substance sorption, and that can be quickly recovered by sedimentation under milder conditions at the time of recovery, and to provide a one-step preparation method thereof.

  In order to solve the above problems, the present invention has at least one chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and a large number of protrusions on the surface. Provided is a fine polymer particle characterized by having a confetti-like shape. By adopting this shape, the specific surface area with respect to the volume of the fine particles is increased, so that the material sorption property and the sediment recovery property are improved, while the weight is not changed, so that the colloidal dispersibility is maintained.

  According to this configuration, the surface functional confetti type polymer fine particles chemically react or interact with drugs, pathologies, and antibodies with higher efficiency than spheres, and have a higher sediment recovery than spheres. It can be used as a sustained transport carrier, a disease state capturing carrier, a gene introduction carrier, a diagnostic agent carrier, and the like.

  In order to solve the above problems, the present invention has at least one chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and has a large number of protrusions on the surface. Provided is a polymer fine particle characterized in that it has a confetti-like shape, and the protrusions are regularly arranged.

  According to this configuration, since the uneven arrangement of the sorption site on the surface of the fine particles is reduced by the regular arrangement of the protrusions, the substance sorption occurs evenly. Therefore, a higher-performance drug transport sustained release carrier, pathological condition capture carrier, gene It can be used as a carrier for introduction, a carrier for diagnostic agents, and the like.

  In order to solve the above-mentioned problems, the present invention provides a polymer fine particle characterized in that a spherical portion excluding protrusions has a diameter of 300 nanometers or less, and has a shape of a confetti-like shape having a large number of protrusions on the surface. To do.

  According to this configuration, the gold flat sugar-type polymer fine particles having a diameter of 200 nanometers or less have the largest specific surface area relative to the volume, and the highest performance drug transport sustained release carrier, pathological condition capture carrier, gene introduction carrier, diagnostic drug carrier, etc. Can be used as

  In order to solve the above problems, the present invention has at least one chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and has a large number of protrusions on the surface. Copolymerize multiple monomers with significantly different polymerization rates and solubility in polymerization solvent to produce polymer fine particles characterized by a confetti-like shape in one step, and at the same time self-assemble the polymer A method characterized by the above is provided.

  In order to solve the above problems, the present invention has at least one chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and has a large number of protrusions on the surface. To produce a large number of polymer fine particles characterized by a confetti-like shape in a uniform shape, starting with a plurality of monomers with greatly different solubility and polymerization rate in a polymerization solvent in one step A method is provided.

  In order to solve the above problems, the present invention has at least one chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and has a large number of protrusions on the surface. Highly soluble in polymerization solvent and high polymerization rate to produce polymer fine particles characterized by a confetti-like shape, characterized in that the protrusions are regularly arranged, in one step Provided is a method characterized by starting from a plurality of different monomers.

  According to this configuration, since manufacturing can be performed in one stage, a very simple method can be provided, energy saving is high, and it is advantageous for mass production.

  In order to solve the above problems, the present invention has at least one chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and has a large number of protrusions on the surface. In order to produce polymer fine particles characterized by the shape of a confetti like in one step, various reaction conditions can be used when copolymerizing a plurality of monomers with greatly different solubility and polymerization rate in the polymerization solvent as starting materials. The present invention provides a method for controlling the shape and size of polymer fine particles, which is characterized by being changed.

  According to this configuration, since the surface area of the fine particles can be controlled in various ways, the material sorption property and sedimentation recovery property can be widely controlled.

  In order to solve the above-mentioned problems, the present invention has a large number of protrusions on the surface, characterized in that styrene, acrylonitrile, terminal-polymerizable polyethylene glycol, and one or more other functional macromonomers are copolymerized by free radical dispersion. Provided is a method for producing a large number of polymer particles having a confetti-like shape in a single step in a uniform shape and controlling the shape and size of the polymer particles.

  According to the present invention, since it is a confetti type, it has a specific surface area that is twice or more that of spherical particles of the same size. It is possible to provide surface functional polymer fine particles that can be used as a carrier, a disease state capturing carrier, a gene introduction carrier, a diagnostic agent carrier, and the like.

  The surface functional confetti type polymer fine particle of the present invention has a size in the range of several micrometers to several tens of nanometers, and has a physical interaction such as a chemically reactive functional group, a charged functional group or a hydrogen bond on the surface. It is a fine particle having a shape resembling that of confetti having at least one kind of functional group having a property, a constituent main component being a polymer, and a large number of protrusions on the surface.

  An example of a method for producing surface-functional confetti type polymer fine particles will be described. Polyethylene glycol as a macromonomer with styrene (1.3 mmol) (represented by general formula 1 shown below), acrylonitrile (2.6 mmol) (represented by general formula 2 shown below) in a glass reaction tube Monomethacrylate (0.0189 mmol) (represented by general formula 3 shown below) and terminal thioethoxymethyl-4-styrenated polymethacrylic acid (0.0081 mmol) as functional macromonomer (general formula 4 shown below) And a radical initiator are dissolved in a polymerization solvent, stirred until the mixed solution becomes transparent, and the reaction solution is frozen with liquid nitrogen and degassed under vacuum to remove dissolved oxygen and react. Free radical polymerization was performed by heating the tube after sealing under vacuum. It was confirmed visually that the turbidity of the reaction solution increased with time. The white turbidity of the reaction solution indicates that the dispersion polymerization occurred smoothly. Dialysis was performed to remove unreacted monomer after the reaction. Various measurements were performed using the aqueous dispersion of the product thus obtained and the powder obtained by freeze-drying the product as samples. The polymer fine particles showed high water dispersion stability that maintained a colloidal state without settling for more than a week after dispersion in water. Here, in producing the surface functional confetti type polymer fine particles, the polyethylene glycol monomethacrylate is not particularly limited as long as it is a terminal polymerizable polyethylene glycol. The terminal thioethoxymethyl-4-styrenated polymethacrylic acid is not limited to this, and may be any terminal polymerizable reactive macromonomer. Further, as long as these four monomers are used, the number of moles and the mole ratio are not limited to those shown here.

FIG. 1 is the total reflection (ATR) Fourier transform infrared spectroscopy spectrum (FTIR) of the product powder. The FTIR using spectrum one manufactured by Perkin Elmer, was obtained by measuring the range of from 4000 cm ^-1 to 600 cm ^-1 at a resolution ^{4 cm -1.} Clear sharp peaks were observed at 2238, 1727, 1700, 1602, 1453, 1108, and 701 cm ⁻¹ . These peaks are respectively nitrile group of acrylonitrile unit, carboxylic acid of polymethacrylic acid macromonomer unit, ester group of polyethylene glycol macromonomer unit, aromatic ring of styrene unit, main chain of copolymer and alkyl of polyethylene glycol macromonomer unit. Group, ether group of polyethylene glycol macromonomer unit, aromatic ring of styrene unit, it can be seen that all four monomers charged in the reaction are incorporated into the product, the product is styrene, acrylonitrile , A quaternary copolymer of polyethylene glycol monomethacrylate and polymethacrylic acid macromonomer (represented by general formula 5 shown below).

FIG. 2 shows the results of measurement of a deuterated dimethyl sulfoxide (DMSO) solution of a quaternary copolymer by 400 MHz proton nuclear magnetic resonance spectrum ( ¹ H NMR, JEOL FX400). The chemical shift values of all the peaks are the values when the chemical shift value of the peak of TMS (referring to tetramethylsilane) is 0.00 ppm. Clear peaks are seen at 6.5-7.5, 3.5, and 1.2-2.9 ppm, respectively, aromatic hydrogen, ethylene glycol hydrogen of polyethylene glycol, main chain skeleton hydrogen and polymethacrylic acid side It is attributed to hydrogen of the chain skeleton. This result supports the formation of the quaternary copolymer. In addition, a simple calculation was performed from each integral ratio to determine the composition in the copolymer of styrene and acrylonitrile. At this time, since the charged composition of the macromonomer was 1% or less, it was difficult to calculate the composition in the copolymer by the ¹ H NMR method, so it was assumed that the charged composition was preserved as it was. As a result, the copolymer composition of styrene and acrylonitrile was estimated to be 56 mol% to 42 mol%. As a result, the styrene composition is larger than the charged composition, and the acrylonitrile composition is smaller than the charged composition. Therefore, it is estimated that the reactivity of styrene is high.

  FIG. 3 shows a photograph of the quaternary copolymer taken with a transmission electron microscope (TEM, Hitachi-H-700H) at an acceleration voltage of 150 kV and a magnification of 100,000. The sample was cast from a water-dispersed state on a copper mesh with a collodion film for TEM measurement, dried overnight under reduced pressure, and then subjected to carbon sputtering treatment. It can be seen that the black shaded portion is a quaternary copolymer and has the shape of a confetti type fine particle. The diameter when the protrusion was regarded as a hemisphere was about 50 nm, and the diameter of the central sphere excluding the protrusion was about 280 nm. The distance between protrusions was about 80 nm, and the average number of protrusions per fine particle was about 30. The particle size measured by a laser diffraction scattering method particle size distribution analyzer manufactured by Beckman Coulter in a water-dispersed state is 280 ± 38 nm, which is in good agreement with the TEM results. It is considered that polymer fine particles having the same shape as those in FIG.

FIG. 4 shows a low-angle incident reflection type infrared spectroscopic spectrum (RAS, JASCO FT / IR-610) on the surface of the gold flat sugar type polymer fine particles. In this method, an infrared spectroscopic spectrum only near the surface of the sample can be measured. Compared to FIG. 1, the peaks near 1727 cm ⁻¹ are relatively stronger than the peaks near 1602 and 701 cm ⁻¹ attributed to the aromatic ring of the styrene unit, and the carboxylic acid of the macromonomer unit is present on the surface of the fine particles. It turned out to be accumulating. As a result, it was proved that the gold flat sugar type polymer fine particles had surface functionality.

  Here, regarding the functional group on the surface, the chemically reactive functional group includes a carboxyl group, a thiocarboxyl group, an active carboxylic acid, an amino group, an amine derivative, an aldehyde group, a ketone group, a hydroxyl group, a thiol group, a hydrazine group, an isocyanic group. Functional groups such as nate group, thioisocyanate group, epoxy group, thioepoxy group, halogen group, double bond, triple bond, etc. can be selected, and as the charged functional group, carboxyl group, thiocarboxyl group, amino group , Amine derivatives, imino groups, phenol groups, phosphoric acid groups, sulfonic acid groups, boronic acid groups, etc., and as functional groups having physical interaction, carboxyl groups, thiocarboxyl groups, carboxylic acid derivatives Amide group, thioamide group, thioether group, disulfide group, hydrazine group, urea group, thio Element group, urethane group, thiourethane group, azomethine group, amide group, imide group, isoimide group, thioimide group, phthalazinone group, oxazole group, isoxazole group, thiazole group, imidazole group, triazole group, triazine group, imidazolone group, Imidazopyrrolone group, hydantoin group, pyrazole group, pyrrole group, oxazinone group, quinazolone group, quinazolinedione group, quinoxaline group, purine group, pyrimidine group, pyridine group, pyrazine group, piperidine group, piperazine group, 3 or more carbon atoms Aliphatic chain, cyclic aliphatic chain, aromatic ring and the like can be selected. However, with respect to aliphatic chains having 3 or more carbon atoms, the aliphatic chains existing as the main chain of the vinyl polymer are excluded. Further, the surface-functional confetti type polymer fine particles have one or more functional groups selected from all the functional groups shown here, and have an ester group, an ether group, a nitrile group, and 2 carbon atoms. Polymer fine particles having only a weakly interacting functional group on the surface, such as less than one fatty chain, are excluded.

  FIG. 5 shows a wide-angle X-ray diffraction pattern of the surface-functional confetti type polymer fine particles. As a result of measuring the whole fine particles by the transmission method, a very diffuse diffraction peak appeared at a diffraction angle 2θ of around 22 degrees. This indicates that the sample is amorphous. On the other hand, as a result of measurement by the thin film reflection measurement method, a sharp diffraction peak was observed at around 17.5 degrees in addition to a diffuse diffraction peak at 2θ of around 22 degrees. This peak coincides with the polyacrylonitrile crystal peak. This result shows that the acrylonitrile unit is crystallized on the outermost surface of the gold flat sugar type polymer fine particles. That is, it is considered that a large number of protrusions were formed as a result of nonuniform growth of acrylonitrile on the surface of the polymer fine particles as in the pattern formation seen during nonuniform growth of crystals.

Next, the composition of the quaternary copolymer of acrylonitrile and styrene was changed, and the shape of the obtained fine particles was examined. The composition was controlled by changing the composition of the monomer used in the reaction. Unreacted monomer was completely removed by centrifugation and dialysis. The yield was about 20-60%, which was lower than that of a general system. This is thought to be due to the low reactivity of acrylonitrile. All the polymer fine particles showed high water dispersion stability that did not settle for more than one week after dispersion in water and kept a colloidal state. Composition to the total amount of monomers of acrylonitrile fixing the composition of the total macromonomer 0.7%, was varied are shown the following _{C AN} to 0.00-0.99, quaternary against repeating units before acrylonitrile units polymer in composition _{F AN} in could be controlled to the respective 0.00-0.90. The weight average molecular weight was sufficiently high at 5.2 × 10 ⁴ -1.6 × 10 ⁵ . The molecular weight distribution was 6.1-7.2, which was wider than in the case of general radical copolymerization, but this was due to the large difference in reactivity between styrene and acrylonitrile, and the molecular weight of these two monomers and macromonomer being different from each other. It seems to be caused by a large difference. Table 1 _{C AN} indicates monomer composition and quaternary copolymer composition and yield in the 0.66-0.92.

FIG. 6 shows a figure in each binding energy region obtained by X-ray photoelectron spectroscopy (XPS). This figure shows that carbon, nitrogen, and oxygen are all present on the surface of the fine particles. Since oxygen is present only in the macromonomer and nitrogen is present only in acrylonitrile, it can be seen that at least these two monomer units are present in the fine particle index plane. In addition, Table 1 shows the elemental composition on the surface of the fine particles obtained from the peak area in this figure. Ratio of carbon atoms of oxygen atoms has a value of _0.50-0.69, it was not dependent on _{C AN.} The oxygen atom is not present only in two macromonomer, these macromonomers is independent of C _AN, it is always considered to be a state of covering the fine particle resurfacing. On the other hand, the ratio of carbon atoms of the nitrogen atom represents a value of _0.31-0.15, showed a small tendency due to the phenomenon of _{C AN.} This indicates that the composition of the acrylonitrile microparticle resurface is affected by _CAN as well as the bulk composition.

Changing the C _AN Figure 7 shows the TEM photograph of polymer microparticles created. F _AN was found to have the form also of non-spherical in all cases in the case of 0.49-0.66. As shown in the left diagram of FIG. 7, F _AN = 0.66 is not uniform in shape, and it is expected that the shape effect on the material sorption of fine particles is not uniform. However, it can be seen that as the number of _fans increases, the shape becomes more uniform. In particular, as shown in the right diagram of FIG. 7, it was found that fine particles having a single shape similar to coronavirus can be obtained when F _AN = 0.49. The size was found to be about 300 nm from TEM and dynamic light scattering, and was slightly larger than the virus. The fine particles consisting only of styrene and macromonomer were completely spherical and had no protrusions. On the other hand, fine particles were not obtained only from acrylonitrile and macromonomer. This indicates that all of styrene, acrylonitrile and macromonomer must be absent in order to produce surface functional confetti type fine particles. When _FAN is 0.66 or more, by using a macromonomer composition of greater than 0.7% or by using a polyethylene macromonomer having a molecular weight of greater than 1740, confetti having a size of 200 nm or less Type nanoparticles could be created.

  Here, instead of styrene, for example, styrene derivatives, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylnaphthalene derivatives, 9-vinylanthracene, vinylanthracene derivatives, vinylpyrene and derivatives thereof, vinylphenanthrene and derivatives thereof, vinylbiphenyl and Derivatives thereof, vinyl terphenyl and derivatives thereof, vinyl quaterphenyl and derivatives thereof, vinyl quinkephenyl and derivatives thereof, vinyl triphenyl and derivatives thereof, vinyl perylene and derivatives thereof, vinyl carbazole and derivatives thereof, vinylated nucleobases and derivatives thereof Derivatives, vinyl stilbene and its derivatives, vinyl benzophenone and its derivatives, vinyl pyridine and its derivatives, vinyl pyrazine and its derivatives, vinyl Azine and its derivatives, vinyl thiophene and its derivatives, vinyl pyrrole and its derivatives, vinyl benzoxazole and its derivatives, vinyl benzothiazole and its derivatives, vinyl benzimidazole and its derivatives, vinyl benzotriazole and its derivatives, vinyl coumarin and its derivatives , Vinyl quinoline and its derivatives, vinyl fluorescein and its derivatives, vinyl porphyrin and its derivatives, vinyl chlorophyllin and its derivatives, other pigments with a vinyl group, etc. I just need it.

  Further, instead of acrylonitrile, acrylamide and its derivatives, acrylic acid esters and its derivatives, N-vinylacetamide, N-vinylalkylamides, vinylpyrrolidone, vinylpyrrolidinone, vinyl ethers, and the like have solubility in water and ethanol. Any monomer that is higher than styrene and lower in polymerization reactivity than styrene may be used.

In general, pattern formation by non-uniform crystal growth occurs depending on time. Therefore, by changing the reaction time in a system of C _{AN =} 0.66 from 1 hour to 24 hours, operating polymerization was investigated the structure and physical properties of the obtained polymer microparticles, respectively. All the polymer fine particles showed high water dispersion stability that did not settle for more than one week after dispersion in water and kept a colloidal state. Table 2 shows the measurement results. A result of measuring the _{F AN} of the produced polymer particles in each polymerization time ¹ H NMR method showed a value of 0.53-0.56, was almost constant value irrespective of the time. Moreover, the yield was 29-56%, and showed an upward trend until 3 hours, but thereafter was almost constant. This indicates that the polymerization was almost completed in 3 hours.

  FIG. 8 shows the reaction time dependence of the surface element composition determined by XPS. The ratio N / C of nitrogen atoms to carbon atoms on the surface of the fine particles measured by XPS was 0.10 to 0.13 and was almost constant regardless of time. Further, the ratio O / C of oxygen atoms to carbon atoms was 0.29 to 0.62, and showed an upward trend with the reaction time up to 12 hours. This indicates that the surface composition of the macromonomer is increasing. The increase in the surface composition of the macromonomer even though the increase in yield stopped in 3 hours indicates that the macromonomer inside the fine particles moves to the vicinity of the surface with time. On the other hand, no increase in O / C was observed after 12 hours.

The results of the shape of the polymer fine particles was taken by TEM at the time of changing C _{AN =} 0.66 systems a reaction time of from 1 hour to 24 hours is shown in FIG. Changes in the size of the protrusions formed on the particle surface were observed by changing the composition of the polymerization solvent. The shape of the polymer particles prepared in 1 hour was a sphere, but small protrusions were seen in the one prepared in 2 hours, and then the protrusions grew as the reaction time increased, forming a confetti shape. The process of being done was observed. It was also found that the number of protrusions after 2 hours did not change at all even when the reaction time changed.

  From the photograph of FIG. 9, the size of the protrusion was calculated as a semi-elliptical sphere, and the total volume was calculated. The change with volume reaction time is shown in FIG. According to this figure, it was found that the volume increased monotonically with the reaction time. Taking into account that the polymerization has been completed in 3 hours, it can be seen that the growth of protrusions is not directly related to the increase in the number of polymer chains. Further, it is slightly different from the trend of increasing the surface composition of the macromonomer assumed from FIG.

  The average value of the ratio between the height of the protrusion and the full width at half maximum when the sharpness of the protrusion was regarded as a semi-elliptical sphere was calculated from the photograph of FIG. 9, and the reaction time dependency was plotted in FIG. The sharpness showed a tendency to increase with the reaction time up to 12 hours, but did not increase thereafter. Taking into account that the polymerization has been completed in 3 hours, it can be seen that the sharpness is not directly related to the increase in the number of polymer chains. On the other hand, it can be seen from FIG. 9 that the tendency to increase the surface composition of the macromonomer is quite similar. That is, it is considered that the macromonomer is strongly involved in the increase in the sharpness of the protrusion.

FIG. 12 shows a scanning electron micrograph (SEM, Hitachi S-4100H SEM) of polymer fine particles polymerized for 3 hours at C _AN = 0.66. The sample was coated with a gold film having a thickness of about 20 nm immediately before the measurement using a sputtering method. As can be seen from the photograph, the shape of the polymer fine particles synthesized under these conditions shows that the protrusions are regularly arranged in hexagonal form. In this case, as shown in the schematic diagram shown at the bottom of FIG. 13, the size of the polymer fine particles was 390 nm, the diameter of the base of the protrusion was 50 nm, and the distance between the apexes of the protrusion was 80 nm. Thus, it was found that if appropriate reaction conditions were selected, confetti sugar-type polymer fine particles having a regular protrusion arrangement could be produced uniformly.

  FIG. 13 schematically shows the process of forming the protrusions. It is considered that styrene, which is the most reactive monomer, is preferentially polymerized at the initial stage of polymerization shorter than one hour of reaction time, and a polymer chain having a considerably high styrene composition is formed. In this case, since polystyrene is not required as a polymerization solvent, it is considered that polymer chains are precipitated to form a lyophobic nucleus. At the polymerization time of 1 hour, the reaction is still ongoing, and the formation of spherical polymer fine particles with high water dispersion stability has been confirmed. It is thought that the water dispersion stability is improved. At a polymerization time of 2 hours, the reaction is still ongoing, and formation of confetti-type polymer fine particles having small protrusions with high water dispersion stability has been confirmed. At this point, since the acrylonitrile unit and the macromonomer have high solvent affinity, it is considered that the shell is formed so as to cover the periphery of the nucleus formed by the styrene unit. At the polymerization time of 3 hours, the reaction was completed, and formation of gold flat sugar-type fine polymer particles with sufficiently large protrusions with high water dispersion stability was confirmed. XPS further increased the amount of macromonomer present on the fine particle surface. Has also been confirmed. At this time, the regular arrangement of protrusions was also confirmed. That is, it can be seen that the protrusions grew simultaneously with the progress of the polymerization. Since the surface composition of acrylonitrile is known to be constant after 1 hour from XPS, it is considered that the macromonomer has a large effect on the growth of protrusions. After 4 hours, the sharpness of the protrusions becomes large despite the completion of the polymerization. Therefore, when the macromonomer existing inside the shell jumps further to the outside due to its extremely high solvent affinity, the solvent is removed. By calling into the shell, it is thought that only that part of the shell swells. This is considered to be the mechanism of protrusion formation. Swelling encourages further macromonomer shells to jump out of the shell, which further swells. This promotes the vertical growth of the protrusion shell. This is thought to increase the sharpness of the protrusions. Over 12 hours, the macromonomer no longer jumped out of the shell, and the protrusions increased in size uniformly and the sharpness became constant. It is considered that the same macromonomer jumps out at the time of 1-3 hours, but at this time, the polymerization proceeds at the same time. Accordingly, since the swollen protrusion portion has active molecular motion, the polymerization proceeds more easily than the other portions. That is, at this time, in addition to swelling, an increase in the molecular chain amount also has an effect on the growth of protrusions.

  In addition to the combination of styrene, acrylonitrile and macromonomer, the combination of monomers for producing surface-functional confetti type polymer fine particles is not only a combination of styrene, acrylonitrile and macromonomer, but also a monomer having high hydrophobicity and a fast radical polymerization reaction rate (monomer 1). Is a monomer having a moderate radical polymerization reaction rate lower than that of monomer 1 (monomer 2), a macromonomer having extremely high affinity for the polymerization solvent (monomer 3), and a macromonomer having a polymerization solvent affinity having a certain degree of higher affinity (functional monomer). Monomer 4) A combination of one or more monomers of four or more types may be used. However, when the monomer 3 also has the properties of the monomer 4, it may be able to be synthesized only by a combination of the monomer 1, the monomer 2 and the monomer 3 alone.

  The monomer 1 is specifically a monomer having a structure in which an aromatic ring such as a styrene derivative is directly bonded to a vinyl group, and the monomer 2 has a polar group such as an acrylic monomer and has a single double bond or triple bond. Monomer 3 is an oligomer with a very high solvent affinity, such as polyethylene glycol monomethacrylate, which has a vinyl group and a molecular weight that does not inhibit the radical polymerizability of the vinyl group, such as polyethylene glycol monomethacrylate. The monomer 4 has a certain degree of solvent affinity, such as a methacrylic acid oligomer whose terminal is modified with a vinyl group, and has a physical reactivity such as a chemically reactive functional group, a charged functional group, and a hydrogen bond. This is similar to an oligomer having at least one functional group selected from functional groups having interactive properties.

  From the mechanism shown above, it is expected that the affinity between the macromonomer and the solvent is important in protrusion formation. Therefore, polymer fine particles were synthesized by changing the volume ratio of water to ethanol in the solvent, and the structure and shape were investigated. A TEM photograph of these fine particles is shown in FIG. It has been found that gold-peeled polymer fine particles are obtained when the water composition of the solvent is 20 mol% or more and less than 60 mol%. The number of protrusions increased with the water composition of the solvent, the protrusion size decreased with the water composition of the solvent, and the distance between protrusions also decreased with the water composition of the solvent. As a result, the specific surface area reached more than twice that of spherical fine particles having no projection of the same size.

  It was found that all the fine particles had a sufficiently high dispersion stability with no precipitation at all when left in an aqueous dispersion state for about one week. On the other hand, as a result of investigating the sedimentation property by centrifuging the aqueous dispersion of each microparticle at 9000 rpm for 10 minutes under a gentle condition in which the spherical polymer microparticles do not settle, all settled and are excellent in sediment recovery. I found out. Moreover, it was shown that the colloidal dispersibility can be controlled by controlling the shape even if there is no difference in the size of the fine particles, since it becomes easy to settle as the protrusion size increases.

  In order to investigate the surface immobilization ability of ovalbumin, which is often used as an antigen model substance, on the surface of the polymer fine particles, ovalbumin, a condensation dehydrating agent, and gold plain sugar type polymer fine particles having a carboxylic acid on the surface are mixed in a HEPES buffer. When the reaction was carried out at 4 ° C. for 25 hours, the amount of ovalbumin immobilized per mol of carboxylic acid was several times to several tens of times higher than that of spherical polymer particles under any concentration condition. It was. This indicates that the shape of the confetti type has a remarkably high ability to immobilize the substance on the surface.

  In the case of a water volume composition of 60-100%, it has been found that confetti type polymer fine particles having a diameter of less than 200 nm can be synthesized. These microparticles are equivalent in shape and size to viruses having protrusions such as coronavirus, and can be used as the highest performance drug transport sustained release carrier, pathological condition capture carrier, gene introduction carrier, and diagnostic agent carrier.

  An example of a one-step production method for surface-functional confetti type polymer fine particles will be described. Dissolve styrene, acrylonitrile, macropolymer end-polymerizable polyethylene glycol, functional macromonomer and radical initiator azobis (isobutyronitrile) in water / ethanol mixed solution, and stir until the mixture becomes transparent Then, free radical polymerization was performed by heating after vacuum degassing. It was confirmed visually that the turbidity of the reaction solution increased with time. The white turbidity of the reaction solution indicates that the dispersion polymerization occurred smoothly. Unreacted monomer was removed by dialysis after the reaction. The polymer fine particles of the product thus obtained showed high water dispersion stability that kept the colloidal state without settling for more than one week after dispersion in water. Here, the functional macromonomer is a chemically reactive functional group and a negatively charged functional group, a macromonomer having a carboxylic acid that is also a negatively charged functional group, one-end styrylated polymethacrylic acid, a chemically reactive functional group that is positively charged One-end styrylated polyvinylamine or one-end styrylated polyallylamine which is a macromonomer having an amino group which is also a functional group, and one-end styrylated poly (styrene-4-yl) which is a macromonomer having a sulfonic acid which is a negatively charged functional group. Sodium sulfonate) or sodium polyvinyl sulfonate, a chemically reactive functional group and a negatively charged functional group, one-end styrylated poly (dimethylaminopropylacrylamide) having a tertiary amine group, and a negatively charged functional group 4 One-end styrylated poly (styrene-4-triethylammonium) with secondary amine groups Bromide), refers to a hydrogen-bonding functional group in which one terminal styryl polyacrylamide which is a macromonomer having an amide group, one terminal styryl poly having a thermal response has an amide group (N- isopropylacrylamide).

  Here, the charged composition of acrylonitrile with respect to all monomers is 0.66 mol%. Polymerization was carried out with a macromonomer charge composition of 0.7 mol% with respect to all monomers, but it may be 2 mol% or less. Moreover, although the composition of the functional macromonomer with respect to all the macromonomers was polymerized at 30 mol%, it may be 30 mol% or less. The composition of water in the water ethanol mixed solvent was 20% by volume. The polymerization time was 6 hours

  As a result of analyzing the primary structure by proton nuclear magnetic resonance, infrared spectroscopy, and gel permeation chromatography methods using aqueous dispersions of these products and powders obtained by freeze-drying them as samples, quaternary It was found that a copolymer was obtained.

  As a result of measuring the quaternary copolymer in a water-dispersed state with a laser diffraction scattering particle size distribution measuring apparatus manufactured by Beckman Coulter, it was found that a unimodal peak was obtained and fine particles were formed. The particle size was 280 ± 38 nm, and the particle size distribution was almost monodispersed.

  As a result of observing the fine particles with a TEM and SEM, it was found that the polymer particles of the confetti type were obtained. Since the particle size was the same as in the water dispersion state, it is considered that polymer fine particles having the same shape are dispersed in the water dispersion state.

  RAS and XPS revealed that each functional group was accumulated on the surface.

  An example of a method for controlling the protrusion size of the surface-functional confetti type polymer fine particles will be described. Styrene, acrylonitrile, end-polymerizable polyethylene glycol monomethacrylate, which is a macromonomer, one-end styrylated polymethacrylic acid having a carboxylic acid, which is a functional macromonomer, and azobis (isobutyronitrile), which is a radical initiator, in water / ethanol It dissolved in the mixed solution, stirred until the mixed solution became transparent, vacuum degassed, and then heated to carry out free radical polymerization. It was confirmed visually that the turbidity of the reaction solution increased with time. The white turbidity of the reaction solution indicates that the dispersion polymerization occurred smoothly. Unreacted monomer was removed by dialysis after the reaction. The polymer fine particles of the product thus obtained showed high water dispersion stability that kept the colloidal state without settling for more than one week after dispersion in water.

  Here, the monomer charge composition and the solvent composition are the same as those shown in Example 1. The polymerization time was varied from 1 hour to 24 hours.

  The aqueous dispersion of these products and the powder obtained by freeze-drying this were used as samples, and the structure of the quaternary copolymer and the formation of fine particles were confirmed by the method shown in Example 1. It was also confirmed that carboxylic acid was accumulated on the surface.

  As a result of observing the fine particles with TEM and SEM, it was found that polymerized fine particles of confetti type were obtained after a polymerization time of 2 hours. It was found that the protrusion size increased with the reaction time, and the sharpness could be controlled.

  When the polymerization time was 3 hours, a large number of fine particles having hexagonal protrusions were present.

  An example of a method for controlling the number of protrusions of the surface-functional confetti type polymer fine particles will be described. Styrene, acrylonitrile, end-polymerizable polyethylene glycol monomethacrylate, which is a macromonomer, one-end styrylated polymethacrylic acid having a carboxylic acid, which is a functional macromonomer, and azobis (isobutyronitrile), which is a radical initiator, in water / ethanol It dissolved in the mixed solution, stirred until the mixed solution became transparent, vacuum degassed, and then heated to carry out free radical polymerization. It was confirmed visually that the turbidity of the reaction solution increased with time. The white turbidity of the reaction solution indicates that the dispersion polymerization occurred smoothly. Unreacted monomer was removed by dialysis after the reaction. The polymer fine particles of the product thus obtained showed high water dispersion stability that kept the colloidal state without settling for more than one week after dispersion in water.

  Here, the monomer charge composition and the polymerization time are the same as those shown in Example 1. The composition of water in the water ethanol mixed solvent was changed from 0 to 100% by volume.

  Using the aqueous dispersion of these products and the powder obtained by freeze-drying this as a sample, the structure of the quaternary copolymer was confirmed by the method shown in Example 1 to confirm the formation of fine particles. It was also confirmed that carboxylic acid was accumulated on the surface.

  A TEM photograph of the fine particles is shown in FIG. It has been found that gold-peeled polymer fine particles are obtained when the water composition of the solvent is 20 mol% or more and less than 60 mol%. The number of protrusions increased with the water composition of the solvent, the protrusion size decreased with the water composition of the solvent, and the distance between protrusions also decreased with the water composition of the solvent. As a result, the specific surface area reached more than twice that of spherical fine particles having no projection of the same size.

  As a result of investigating the sedimentation property by centrifuging the aqueous dispersion of each fine particle at 5000 rpm for 10 minutes, it was found that sedimentation tends to occur as the protrusion size increases. This indicates that the colloidal dispersibility can be controlled by controlling the shape even if there is no difference in the size of the fine particles.

  Even when the water composition of the solvent was 60 mol% or more, gold-peeled polymer fine particles were obtained, but the protrusion size was extremely small, and the particle size was smaller than 300 nm.

  Since the specific surface area of the polymer fine particles having the shape of a gold-peeled sugar having a functional group and a large number of protrusions on the surface is large, the substance sorption ability is remarkably high, and it is easily settled by centrifugation. In addition, molecules effective for medical treatment such as drugs, antibodies, antigens, and DNA can be immobilized using functional groups on the surface, so that drug delivery carriers, drug controlled release carriers, virus capture carriers, gene transfer It can be used as a self-organizing polymer fine particle carrier that can be used in a wide range of fields such as carriers for carriers and diagnostic agents, and has higher performance than conventional products. Moreover, the polymer fine particles can be easily manufactured in one step using a free radical dispersion copolymerization method, and furthermore, the size and shape can be easily controlled, so that the energy saving property is excellent and the industrial production is possible. It is advantageous.

  Total reflection (ATR) Fourier transform infrared spectroscopic spectrum of dried powder of gold-peeled sugar type polymer fine particles Proton nuclear magnetic resonance spectrum ( ¹ H NMR)   Transmission electron micrograph of TEM   Low angle reflection (RAS) infrared spectroscopic spectrum of the surface of gold flat sugar type polymer fine particles   Wide-angle X-ray diffraction pattern (WAXD) of the whole and surface of confetti type polymer fine particles   X-ray photoelectron spectroscopy (XPS) of gold-peeled polymer fine particles   Dependence of monomer composition on transmission electron micrographs of gold-peeled sugar polymer particles   Reaction time dependence of surface elemental composition of confetti type polymer fine particles   Polymerization time dependence of transmission electron micrographs of confetti type polymer fine particles.   Polymerization time dependence of protrusion volume of gold-peeled sugar polymer particles   Polymerization time dependence of the sharpness of protrusions of konpei sugar-type polymer particles   Scanning electron micrograph (SEM) of gold-peeled polymer particles   Formation mechanism of protrusions of confetti type polymer fine particles   Polymerization solvent composition dependence of transmission electron micrographs of konpei sugar-type polymer particles.

Claims (11)

It has at least one kind of a chemically reactive functional group, a charged functional group, or a functional group having a physical interaction property such as a hydrogen bond on the surface, and is characterized by a shape like a confetti having a large number of protrusions on the surface. Polymer fine particles and composition thereof The fine polymer particle according to claim 1, wherein the protrusions are regularly arranged. Polymer fine particles characterized in that the diameter of the sphere part excluding the protrusions is 200 nanometers or less, and has a shape of a confetti-like shape having a large number of protrusions on the surface. 2. A method for producing polymer fine particles and a composition thereof according to claim 1, characterized in that a plurality of monomers having greatly different solubility and polymerization rate in the polymerization solvent of these polymers are produced in one step as starting materials. A large number of polymer fine particles shown in claim 1 are produced in a uniform shape by using, as a starting material, a plurality of monomers having greatly different solubility and polymerization rate of the polymer in a polymerization solvent. How to make 3. The method for producing polymer fine particles according to claim 2, wherein a plurality of monomers having greatly different solubility and polymerization rate in the polymerization solvent of the polymer are produced in a single step as a starting material. 4. The method for producing polymer fine particles according to claim 3, wherein a plurality of monomers having greatly different solubility and polymerization rate in the polymerization solvent of the polymer are produced as a starting material in one step. 5. A method for controlling the size and shape of polymer fine particles according to claim 4, wherein the polymerization conditions are variously changed. Polymeric fine particles of confetti-like shape having a large number of protrusions obtained from styrene, acrylonitrile, terminally polymerizable polyethylene glycol and one or more other functional macromonomers as starting materials, and compositions thereof 10. The method for producing polymer fine particles and a composition thereof according to claim 9, wherein the polymer fine particles and the composition thereof are produced in one step using styrene, acrylonitrile, terminal polymerizable polyethylene glycol and one or more other functional macromonomers as starting materials. The method of controlling the size and shape of the polymer fine particles according to claim 10, wherein the polymerization conditions are variously changed.