Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Patent
1994-04-28
1998-11-17
Berman, Susan W.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
522 84, 522 85, 522 87, 522 88, 522 86, 522 75, 527201, 527202, 527203, 527306, 527313, 527314, 514 2, 514 3, 514 6, 514866, 514893, 514962, 514963, 424492, 424493, 424456, 424457, C08F 250, C08L 500, C08L 504, C08L 508
Patent
active
058377476
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a new form of biocompatible materials (including lipids, polycations, and polysaccharides) which are capable of undergoing free radical polymerization. The invention also relates to methods of modifying certain synthetic and naturally occurring biocompatible materials to make polymerizable microcapsules containing biological material. The invention also relates to composites of said polymerizable materials, methods of making microcapsules and encapsulating biological materials therein, and apparatus for making microcapsules containing biological cells. The present invention also relates to drug delivery systems relating to the foregoing, and bioadhesives and wound dressings made utilizing the foregoing technology.
BACKGROUND OF THE INVENTION
Over the past 10 to 15 years various combinations of ionic polymers have been tested and utilized for microencapsulation of live cells and tissues. The most widely accepted material of the prior art is polylysine alginate, particular for in vivo applications. (Dupuy, 1988(12.); Chang, 1984(3.); Braun, 1985(2.); Goosen, 1985(15.), Darquy, 1985(14.)) However, these polymers are water soluble in the form known in the prior art, and therefore have been considered to be of limited long-term stability.
Polysaccharides such as alginates have been used extensively in recent years in the food, cosmetics, pharmaceutical and biomedical industries (Smidsr.o slashed.d and Skjak-Br.ae butted.k, 1990(28.)). In the pharmaceutical and biomedical industries, their gel forming properties in the presence of multivalent cations have been exploited for the microencapsulation of cells and tissue and controlled release of drugs.
It is the combination of multivalent (generally divalent) cations, such as calcium, with the alginate, which provides the mechanical stability of the ionically crosslinked gel. However, in the physiological environment (e.g., in the transplantation of microencapsulated islets or for drug release) extracellular concentrations of monovalent cations (such as sodium ions) exceed the concentration of divalent cations (such as calcium). Under such conditions, these gels tend to lose their mechanical stability over the long term due to diffusion, leading to exchange of divalent cations for monovalent cations in the physiological fluid.
In an effort to improve the mechanical stability of these gels, chemical modifications of the alginates have been proposed (Moe et al., 1991(24.)) utilizing covalent rather than ionic crosslinking. These techniques involve the use of reagents, reaction conditions and relatively long reaction periods which, if used for the encapsulation of living tissue, are likely to prove toxic and even fatal.
Researchers have used alginate gels for the immunoisolation of transplanted tissue to treat insulin dependent diabetes (Lim and Sun, 1980(22.)). Alginates containing higher fractions of .alpha.-L-guluronic acid residues (G-content) have been determined to be more biocompatible (i.e., they do not induce a cytokine response from monocytes) than those containing a larger fraction of .beta.-D mannuronic acid residues (M-content; see Soon-Shiong et al., 199(30.)). Thus, implanted gels of alginates containing a high M-content, when implanted in rats, show extensive fibrous overgrowth at 3 weeks while high G-content alginates show no fibrous overgrowth for the same implantation period.
Thus, it would be desirable to be able to provide alginates which are covalently polymerized and are substantially more stable under physiological conditions than are prior art alginate compounds and implantation systems with alginate coats. It would also be desirable to provide alginates which may be rapidly polymerized, relative to the rate of crosslinking with prior art ionically crosslinked systems.
Previous attempts to make stable polymers for microencapsulation have met with limited success. Many of the more stable polymers appear to be relatively cytotoxic due in large part to the chemical reactivity of the monomer precursors used.
Othe
REFERENCES:
patent: 3332897 (1967-07-01), Ray-Chaudhuri
patent: 4321117 (1982-03-01), Kaetsu et al.
patent: 4605691 (1986-08-01), Balazs et al.
patent: 4654233 (1987-03-01), Grant et al.
patent: 4778880 (1988-10-01), Symes et al.
patent: 4803168 (1989-02-01), Jarvis, Jr.
patent: 4806355 (1989-02-01), Goosen et al.
patent: 4861629 (1989-08-01), Nahm
patent: 5128326 (1992-07-01), Balazs et al.
PTO Translation at J54 128482, "A Microcapsule and a Method of Manufacturing It"., Oct. 1979.
Braun et al., "The encapsulation of pancreatic islets. Investigation of insulin secretion and content in vitro" Biochim. Acta 44:143-147 (1995).
Chang, "Artificial Cells in Medicine and Biotechnology" Humana Press, 10:4-24 (1984).
Decker and Moussa, "Real-Time Kinetic Study of Laser-Induced Polymerization" Macromolecules 22:4455-4461 (1989).
Eaton, David F., "Dye Sensitized Photopolymerization" Advances in Photochemistry 13:427-487 (1986).
Harris et al., "Synthesis and Characterization of Poly(ethylene Glycol) Derivatives" J. Polym. Sci., Polym. Chem. Ed. 22:341-352 (1984).
Mathias et al., "Synthesis and Polymerization of Mono-and Divinyl Ethers of Oligooxyethylenes" J. Polym. Sci., Polym. Lett. Ed. 20:473-479 (1982).
Moe et al., "Covalently cross-linked sodium aliginate beads" Food Hydrocolloids 5:119-123 (1991).
Morrison and Boyd, "Organic Chemistry" Organic Chemistry, Allyn and Bacon, pp. 756-757 (1973).
Wu, David S., "Optical-scanner design impacts rapid laser prototyping" Laser Focus World pp. 99-106 (Nov. 1990).
Abuchowski et al., "Alteration of Immunological Properties of Bovine Serum Albumin by Covalent Attachment of Polyethylene Glycol" J. Biol. Chem. 252:3578-3581 (1977).
Braun et al., Biochim. Acta 44:143 (1985).
Chang, "Microencapsulation and Artificial Cells" Humana Press, Clifton, NJ, pp. 4-26 (1984).
Darquy and Reach "Immunoisolation of pancreatic B cells by microencapsulation" Diabetologia 28:776-780 (1985).
Decker and Moussa, Macromolecules 22:4455.
Desai and Hubbell "Solution technique to incorporate polyethylene oxide and other water-soluble polymers into surfaces of polymeric biomaterials" Biomaterials 12:144-153 (1991).
Dupuy et al., "Agarose Beads in Paraffin Oil as Interfaces to Encapsulate Living Cells. Tests of function with Islets of Langerhans" Artif. Organs 11:314 (1987).
Dupuy et al., In situ polymerization of a microencapsulating medium round living cells Journal of Biomedical Materials Research 22:1061-1070 (1988).
Eaton, Advances in Photochemistry 13:427 (1986).
Gharapetian et al., "Encapsulation of Viable Cells Within Polyacrylate Membranes" Biotech. Bioeng. 28:1595-1600 (1986).
Goosen et al., "Optimization of Microencapsulation Parameters: Semipermeable Microcapsules as a Bioartificial Pancreas" Biotechnol. Bioeng. 27:146-150 (1985).
Harris, J. Milton, "Laboratory Synthesis of Polyethylene Glycol Derivatives" JMS-Rev. Macromol. Chem. Phys. C25(3):325-373 (1985).
Harris et al., J. Polym. Sci., Polym. Chem. Ed. 22:341 (1984).
Hoyle et al., "Laser-Pulsed Photopolymerization of Methyl Methacrylate: The Effect of Repetition Rate" Macromolecules 22:3866-3871 (1989).
Iwata et al., "Evaluation of Microencapsulated Islets in Agarose Gel as Bioartificial Pancreas by Studies of Hormone Secretion in Cultrue and by Xenotransplantation" Diabetes 38(1):224-225 (1989).
Karu, T. I., "Effects Of Visible Radiation On Cultured Cells" Photochem. and Photobiol. 52:1089-1098 (1990).
Lanza et al., "Large-Scale Canine and Human Islet Isolation Using a Physiological Islet Purification Solution" Diabetes 39:309A (1990).
Lim and Sun, "Microencapsulated Islets as Bioartificial Endocrine Pancreas" Science 210:908-910 (1980).
Mathias et al., J. Polym. Sci., Polym. Lett. Ed. 20:473 (1982).
Moe et al., Food Hydrocolloids 5:119 (1991).
Morrison and Boyd, Organic Chemistry, Allyn and Bacon, p. 755 (1973).
Pitha et al., "Detergents Linked to Polysaccharides: Preparation and Effects on Membranes and Cells" Eur. J. Biochem. 94:11-18 (1979).
Sefton et al., "HEMA-MMA Copolymer For T
Desai Neil P.
Heintz Roswitha A.
Sandford Paul A.
Sojomihardjo Soebianto
Soon-Shiong Patrick
Berman Susan W.
Raymer Gregory P.
Reiter Stephen E.
Vivorx Inc.
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