SE455103B - CARRIER FOR IMMOBILIZATION OF BIOLOGICALLY ACTIVE ORGANIC MATERIAL, WHICH IS MADE BY COMBINED PARTICLES OF A POROS SINTRAD GLASS FIBER MATERIAL - Google Patents

Description

455 10 15 20 25 30 35 103 no ~ aau 2 In this context, it may be mentioned that in the logical wastewater treatment is known to use filters of mineral wool, where for example reference can be made to NO application document 147,639 and SE patent application 7308380-O.

These are essentially mineral wool mats construction quality but in the present context too high permeability and unsatisfactory dimensional stability.

Fiberglass filter bodies are also known within technology, but these are not sintered glass fiber matrices, without the filter body being held together by a polymeric binder, such as an acrylate resin. Such a structure is unsuitable for the intended use invention, since the polymeric binder can be act on the biologically active material, partly in the position of dense, compressed filter bodies can float out and block the pores so that a homogeneous and uniform porosity is not obtained.

In addition, it is known from U.S. Patent 4,404,291 and DE patent 3,103,751 that for e.g. absorption of liquids and as carriers for cataracts lytically active materials, use a porous, sintered low density material. According to this prior art a non-porous, powdered starting material is sintered together consisting of glass, glass-ceramic material or conventional ceramic material, in order to obtain the final porous, sintered material. Porosity of the material in this case only the cavities between the sintered ones the powder particles.

The present invention has for its object to provide come a new carrier for immobilization of biological active material, which carrier is solid, inert, has good fofm stability, high internal total area, is uniform and complete open, has a homogeneous and adjustable porosity and a structural turn, which is characterized by smooth and softly rounded interior surfaces.

The above object is achieved by the carrier according to the invention consists of a porous shaped body consisting of 10 15 20 25 30 35 455 103 3 of joined particles of a porous, sintered glass fiber matrix with a density of 20-2000 kg / m3, whereby they the sintered glass fibers in the particles have an original diameter of 0.3-100 μm, and that the particles at their beat points with each other are held together by binding obtained in connection with the carbonization of organic binder.

Between the joined particles a channel is formed. system, which allows fluid flow and thus good liquid contact with the individual particles. The particles inner pore walls are formed by solid fiberglass "beams" with well-defined diameters, which are sintered in contact the points. By such sintering, a glassy fiber matrix with three-dimensional grid or mesh structure, which have smooth, homogeneous and softly rounded inner surfaces, which ket provides high strength and rigidity and is extremely suitable with regard to the transport of substrates and products. Glass- the fiber matrix is further characterized by being flexible performed with extremely fine pores without therefore opening it the pore structure is lost. This unlike others methods of producing porous glass. As an example can be mentioned that in the most common methods the pores take the form of spherical cavities, which are connected to each other via narrow openings. By a different production principle the pores form comparatively closed channels, which are obtained read by selective acid solution of a phase in a multiphase glass mixture. With common powder sintering methods are obtained a low volume pores. At fine pore dimensions becomes in addition, a significant portion of the closed type pores.

A sintered glass fiber matrix means that the original the glass fibers at an elevated temperature are compressed negative pressure so that the fibers at their points of contact melts to form a uniform matrix. The sin- The trade fiberglass matrix forms a three-dimensional network plants with a regular open structure with high gas and fluid permeability. Blocks consisting of sintered glass fiber matrix is then decomposed into particles or discs. 455 l0 15 20 25 30 35 103 4 _, Due to the fact that the wearer according to the composition consists of joined, porous particles are obtained so to speak double porosity, namely partly an "external" porosity, partly an "inner" porosity. With external porosity refers to the ratio between the cavity volume which formed between the joined particles and the carrier total volume, while internal porosity refers to the ratio between the pore volumes of the joined, porous particles and their total volume.

This is an important and distinctive fact for the wearer according to the invention that it by its composition exhibits both an external porosity and an internal porosity, wherein the internal porosity is mainly used for one safe and interference-free immobilization of the biological active material, such as an enzyme, while the outer the porosity contributes to an effective contact between it biologically active material and the fluid on which it is intended to work to thereby achieve an optimal reaction and efficient removal of formed products ter.

The internal porosity of the sintered glass fibers the matrix particles are generally determined by the density of the matrix and.the diameter of the fibers used. at a density corresponding to that of the glass used, a whole is obtained compact and non-porous matrix, which is outside the frame for the present invention. In general, particulate matter The particles in the carrier according to the invention have a density in the range 20-2000 kg / m3, preferably 300-2000 kg / m3, wherein a density in the range 1500-2000 kg / m3 is particular preferred.

The average diameter of the glass fibers used to prepare the sintered particles in the carrier according to the invention is generally in the range 0.3-100 μm, preferably 0.5-3 μm, with a fiber diameter of 0.5-3 μm particularly preferred. In general, they are smaller the fiber diameters make it possible to obtain particles with fine pores while maintaining the favorable three-dimensional 10 15 20 25 30 35 455 103 5 the network structure is maintained. In this respect, a fiber diameter less than about S pm particularly favorable. Couple- tickles with fine pores and open mesh structure are preferred in the invention, since they are particularly well suited to immobilize biologically active material with small dimension, such as enzymes and bacteria, while efficient transport of substrates and products possible is done.

As indicated above, the pore size of them is determined the sintered particles in the carrier according to the invention of the density of the particles and the diameter of the fibers that used to produce the particles. By appropriate selection of these parameters, the desired pore size can thus be play is obtained in the particles. Conveniently have the particles according to the invention a pore size of at most about 20 μm, usually about 1-2 pm. It is preferred that the pore size is in the range 1-15 μm, with a pore size of approx 5-10 pm is especially preferred. For the sake of clarity it should be mentioned here that by the term "porstor1ek" is meant the diameter of a circular pore which has the same transverse incision area as the pores of the sintered particles.

The specified pore size further refers to the mean value of all the pores of the particles. The spread around this however, the mean value of the individual pore size is quite small if fibers of the same diameter are used for preparation of the particles.

As stated earlier, the particles in the carrier according to the invention of a sintered glass fiber matrix. The composition of the glass used is not critical except that the glass must of course be such that it is possible to fiber. It is thus possible within the scope of the invention to vary the particles ice cream composition in many ways. Although the shape of the porous, sintered glass fiber the matrix is not critical and can be varied on countless way, however, it is preferred that it be originally u 455 10 15 20 25 30 35 1.14; - 103 6 placed in the form of a flat disc. Such a disc is obtained simply by performing the sintering of the glass fiber matrix between two press plates at elevated pressure and temperature.

The finished board can be of any thickness, but preferably unfortunately, the thickness is in the range 0.05-5 cm, preferably 0.05-2 cm. The finished disc is then disassembled obtaining fragments or regular paragraphs with an average diameter of about 0.005-5 cm, preferably 0.005-0.05 cm. With the expression "average diameter" refers to the diameter of a sphere of equal volume as the fragment or paragraph in question. Frag- The elements can also have the shape of slices with a thickness of 0.02-0.5 cm. By diameter is meant average the disk width.

After sintering, the fiberglass matrix should form into blocks thus comminuted into particles, each of which consists of a three-dimensional network structure. Through his structural structure, these have high mechanical strength.

They thus have a good tolerance against stacking in a column or to be subjected to stresses by mechanical agitation.

Before use according to the invention, they are joined together a three-dimensional network structure in connection with nisation of an organic binder. This is done appropriately so that the glass fiber matrix particles are brought together dissolved to the desired structure, for example in a form after the organic binder is added, eg in form of liquid monomer for the organic binder or, in the case of thermoplastic binders, in the form of molten binders average. When the structure has been impregnated with binder or binder monomer this is made to solidify respectively polymerize so that a solid, self-supporting structure is obtained held. The structure thus obtained is then heated, preferably in air, for "carbonization" of the organic the binder, which then essentially disappears completely from the free particle surfaces of the structure, but mediates one binding effect at the adjacent or adjacent particles horizontal contact surfaces, so that it is originally loose LT) 10 is 20 25 30 35 455 103 7 the joined structure forms a firmly cohesive unit with open structure, which consists of joined particles of porous, sintered glass fiber matrix, which particles at their points of contact with each other are related to organic binder. It must thus be special it is noted that despite the fact that the structure as a whole has been soaked with the organic binder the binder is removed during the carbonization, essentially completely from the particulate matter. the free surfaces of the larvae. Some clogging of the particles pores are thus not caused by the organic binder, without the finished carrier having the above indicated, advantageous combination of external and internal porosity.

The organic binder used in the invention is suitably an organic polymeric binder.

Without thereby limiting the invention thereto, as examples of preferred polymeric binders are mentioned acrylate plastics, such as polymethacrylate and polymethylmethyl acrylates, including monomers to form them polymers; vinyl acetate plastics such as polyvinyl acetate; and vinyl acetal plastics, such as polyvinyl acetal and vinyl butyral.

Very complicated shapes (tubes, spirals etc) can be obtained through an alternative and relatively simple manufacturing procedure. In this case, the par- the articles with highly viscous liquid polymer (e.g. urethane -dimethacrylate or the reaction product of bisphenol-A and glycidyl methacrylate (BIS-GMA)) which stick together the particles. The grain mass can now be given the desired shape. The shape can be initially fixed by at least the superficial the polymer is brought to cure. This can happen for example by heating or irradiating with UV radiation or visible light. The curing method is determined of which initiators and accelerators have been added according to prior art. It thus formed and (possibly) fixed body is subsequently heated, possibly after embedding in refractory material, to a temperature high enough to achieve e 455 105 10 15 20 25 30 35 8 an adhesion of the grains in their contact points.

The conditions for carbonization of the polymer binder are not critical, except that the temperature does not may be so high that the softness of the glass fiber matrix particles point is exceeded and the particles soften as a result that the pores of the particles collapse. The temperature at carbonation of the binder must always be maintained a sufficiently low temperature for the glass fiber matrix to the pores of the particles must be kept intact. Generally can be said that a suitable temperature range is at about 50 ° C, preferably at about 50 ° C, wherein about 600 ° C is a currently particularly preferred temperature peratur.

The atmosphere used in the carbonation is not critical and may conveniently be air.

The time for carrying out the carbonation shall be: be sufficient to completely carbonize it organic binder, and a time of about 15-60 min is generally satisfactory. In most cases is a time of about 30 minutes is sufficient.

As previously described, fiberglass matrix the porosity of the particles, i.e. the internal porosity of the carrier, regulated within wide limits by regulating fiber diameter and sintering pressure. Correspondingly, can the external porosity of the carrier is controlled by appropriate choice of the dimensions of the glass fiber matrix particles. As mentioned, the sintered, porous glass fiber material tris in particles with an average diameter of about 0.005-5 cm, preferably about 0.005-0.05 cm. Normally it is preferred that the particles have a relatively narrow grain size distribution, ie all the particles have in essentially the same average diameter, in order to by creating a carrier with a substantially homogeneous exterior porosity. However, there is nothing to stop, if so it would be desirable to mix particles with different average diameter to thereby achieve 10 15 20 25 30 35 455 105 9 a carrier with varied external porosity. It is too possible to build up the carrier layer by layer with different particle sizes so that the outer porosity the density is substantially homogeneous in each individual layer, but varies from layer to layer.

As stated above, the production of the carrier conveniently by the glass fiber matrix particles joined loosely in a form, after which the organic the binder is added. The use of a form med- for the possibility of varying the shape of the carrier in many ways methods such as disc shape, spherical shape, cylindrical shape, cubic shape or the like.

When using the carrier according to the invention first mobilizes the current, biologically active material alet, such as an enzyme, in the carrier, by e.g. impregnated with a solution or dispersion of the active the material. Is this a microorganism suspension coming it is then sucked up as by a sponge and can thereby after developing through the formation of microcolonies in the structure. The carrier with immobilized active material is then ready for use, eg to implement an enzyme-catalyzed chemical reaction. The carrier can thereby have the shape of aggregates or pieces, as simply down in the reaction medium, which may be a substrate solution for the enzyme. When the carrier is brought into rate of the reaction medium starts the reaction and leads to facilitate and accelerate the reaction, the reaction the medium is suitably stirred. When the reaction is complete or proceeded to the desired stage, the carrier is separated from the reaction medium by filtration or by that the carrier pieces are simply taken up from the reaction medium. the medium.

In another type of use of the carrier according to the invention has the shape of a disc or plate.

The thickness of the carrier disc can be varied as desired, however is preferably in the range 0.05-2 cm. The carrier disc "- 455 103 10 15 20 25 30 35 10 can otherwise have any shape, eg circular, elliptical, or polygonal, such as rectangular or square.

In a manner similar to that described above, immobilize first the biologically active material in the carrier plate by, for example, impregnating the board with a solution or dispersion of the active material, after which the carrier disk is ready for use, eg for an analytical task.

The fluid to be affected by the immobilized the biologically active material is then brought into contact with the carrier plate, for example by allowing the fluid to flow through the disc. An example of this is a substrate solution, flowing through a carrier disk, in which an enzyme is immobilized. The reaction can be carried out batchwise, however can also be performed continuously by inserting the carrier plate over the cross section of a tubular reactor, so that the reagent the fluid (eg a substrate solution) passes through the disc thickness. With appropriate combination of fluid overpressure and density of the carrier material can significantly quantities are forced through the carrier. About the reagent fluid shall be subjected to several successive reactions, such as several consecutive enzymatic reactions, this can be easily done by arranging several carrier plates at a suitable distance and in succession after each others in the tubular reactor, each individual carrier plate is provided with immobilized active material (enzyme) for each reaction. In this way can extremely compact and efficient biotechnological systems are created.

From the above description it will be appreciated that the invention provides one for immobilization of biological active material intended carrier with highly desirable and advantageous properties, such as high dimensional stability and strength, an open, lattice-like structure, with a well-defined and reproducible, uniform porosity and pore size. Furthermore, the carrier is inert to the future biologically active materials and their reactive 1:., lll 10 15 20 25 30 35 ; 4 "v- Ü ß <5 455 103 ll products while having an affinity for real estate biologically active materials.

The surface of the glass can be given positive groups by silane sering. The composition of the glass can be varied, trace elements can be incorporated which by ion exchange with the environment can affect the living conditions of microorganisms.

Other advantages of the glass structure are its hydrophilic character (facilitates substrate absorption, etc.) and its good mechanical and thermal properties. Through the good ones the mechanical properties are protected, for example, housed cells against influence during stirring or when stacking in column.

The carrier also does not decompose by the action of cells under the division or influence of internal pressure in connection with gas-forming reactions. The thermal stability provides resistance to high process temperatures and sterilization serbability. The specified method for producing porous glass in the form of a three-dimensional mesh structure has the advantage of providing a completely open structure with one high pore volume and large internal total area, which structure does not contain spherical, fully or partially enclosed spaces.

This provides the best conditions for substrate and product transport through the carrier medium. The method possible do, provided that the fibers have a diameter less than 5 μm, in addition to the production of extreme fine-pore (fine-mesh) structures with pores, the genome of which average diameter is less than 10 μm, with retention of stated benefits. This is not possible with anyone another previously described method. From an efficiency point of view it is especially desirable that the pore size is about 5 times cell size but not greater than 10 times the same. As carriers of microorganisms are therefore fine-pore structures médïpor sizes less than 10 μm, especially those with pores in the range of 3-10 μm, especially desirable.

Pore sizes smaller than 3 μm, on the other hand, are optimal in connection with enzyme processes while pore sizes larger than 10 μm are desirable in connection with the cultivation of e.g. door cells. a »01014

Claims (8)

4: - r- DI) 10 15 20 25 30 'iUá 12 PATENTKRAV Carrier for immobilizing biologically active organic material, characterized in that it consists of a porous shaped body consisting of joined particles of a porous, sintered glass fiber matrix with a density of 20-2000 kg / m 3, the sintered the glass fibers in the particles have an initial diameter of 0.3-100 μm, and that the particles at their points of contact with each other are joined together with a bond obtained in connection with carbonization of organic binder. Carrier according to claim 1, characterized in that the average pore diameter of the porous particles is at most 20 μm. Carrier according to Claim 1 or 2, characterized in that the porous particles have an average diameter of 0.005-5 cm, preferably 0.005-0.05 cm. Carrier according to Claim 1 or 2, characterized in that the porous particles have the shape of discs with a thickness of 0.02-0.5 cm. Carrier according to any one of the preceding claims, characterized in that the binder is a carbonized organic polymeric binder. Carrier according to Claim 5, characterized in that the binder consists of carbonized polyacrylate, polyvinyl acetate or polyvinyl acetate. Carrier according to one of the preceding claims, characterized in that the shaped body consists of a disc with a thickness of 0.5-5 cm. Carrier according to one of the preceding claims, characterized in that in the shaped body the spaces between the joined porous particles form a completely open pore system. ii: