Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide (e.g., dextran) containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom.

Abstract: New water-dispersible or water-soluble sulphonated polyesters with a number molecular mass lower than 20000, exhibiting a sulphur weight content of the order of 0.5 to 10% and a hydroxyl functional group content, expressed as OH equivalent/kg of polymer, higher than 0.2. They may be employed as antisoiling and/or antiredeposition agents and optionally detergents in detergent compositions, in rinsing, softening or antisoiling treatment compositions, for washing with or without pretreatment, rinsing, softening or the antisoiling treatment of textiles, especially those polyester-based.

Abstract: The present invention relates to biodegradable PHA copolymers comprising at least two randomly repeating monomer units. The present invention further relates to a plastic article comprising a biodegradable copolymer, wherein the biodegradable copolymer comprises at least two randomly repeating monomer units (RRMU) wherein the first RRMU has the structure wherein R1 is H, or C1 or C2 alkyl, and n is 1 or 2; the second RRMU has the structure and wherein at least 50% of the RRMUs have the structure of the first RRMU. The present invention further relates to an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet comprising a film comprising a PHA of the present invention and an absorbent core positioned between the topsheet and the backsheet.

Abstract: There are provided amphiphilic biodegradable block copolymers comprising polyethylenimine (PEI) as a hydrophilic block and aliphatic polyesters as a hydrophobic block, which can form various size of polymer aggregates and have very low critical micelle concentration, approximately 10−3 g/l in comparison with low-molecular-weight micelle, and self-assembled polymer aggregates formed from the block copolymers in aqueous milieu, which can be applied to solubilization of insoluble drug and a delivery system of proteins, genes or drugs.

Abstract: This invention deals with an absorbable, gel-forming composition for multifaceted prevention of post-operative surgical adhesion through a plurality of physico-pharmacological modes, comprising a solution of one or more bioactive compounds in a liquid copolymeric vehicle made by end-grafting one or more cyclic monomer onto a polyalkylene glycol. More specifically, the bioactive drugs can display one or more pharmacological activity associated with antiangiogenic, antineoplastic, anti-inflammatory, and anti-proliferative effects.

Abstract: The present invention is a water-responsive blend of a polylactide and a polyvinyl alcohol. The present invention includes films and personal care articles comprising a blend of a polyvinyl alcohol and a polylactide and includes a method of making such films and articles and a method of varying the water responsiveness of such films and articles. In a preferred embodiment, the compositions, films and articles comprise a blend of polyvinyl alcohol and modified polylactide. The compositions and films described herein are useful as a component in flushable and degradable articles.

Abstract: A stereospecific poly(lactic acid) is isotactic poly(lactic acid) having a number average molecular weight ranging from 10,000 to 200,000 grams per mole, with, on average, an equal number of poly (R) and poly (S) blocks where each block contains an average of 5 to 50 monomer units. Product was prepared by polymerizing rac-lactide in the presence of racemic catalyst consisting of: and the corresponding S-enantiomer or in the presence of racemic catalyst consisting of: and the corresponding S-enantiomer, wherein R is C1-C4 alkyl which is straight chain or branched.

Abstract: Crosslinked compositions formed from water-insoluble copolymers are disclosed. These compositions are copolymers having a bioresorbable region, a hydrophilic region and at least two cross-linkable functional groups per polymer chain. Crosslinking of these polymers can be effected in solution in organic solvents or in solvent-free systems. If crosslinking occurs in a humid environment, a hydrogel will form. If crosslinking occurs in a non-humid environment, a xerogel will form which will form a hydrogel when exposed to a humid environment and the resulting crosslinked materials form hydrogels when exposed to humid environments. These hydrogels are useful as components in medical devices such as implantable prostheses. In addition, such hydrogels are useful as delivery vehicles for therapeutic agents and as scaffolding for tissue engineering applications.

Abstract: The thermal degradation of the biodegradable bacterial polyesters poly(3-hydroxybutyrate), PHB, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHB/V produces a macromer, especially a 1000-6000 g/mol macromolecule, which contains an unsaturated end group as well as a carboxylic acid end group. The macromers may be polymerized to produce homopolymers and copolymers for different applications in which amphiphilic and biocompatible properties are required, for example, drug delivery systems.

Abstract: An improved barrier or drug delivery system which is highly adherent to the surface to which it is applied is disclosed, along with methods for making the barrier. In the preferred embodiment, the system is compliant, in that it is capable of conforming to the three dimensional structure of a tissue surface as the tissue bends and deforms during healing processes. The barrier or drug delivery systems is formed as a polymeric coating on tissue surfaces by applied a polymerizable monomer to the surface, and then polymerizing the monomer. The polymerized compliant coating preferably is biodegradable and biocompatible, and can be designed with selected properties of compliancy and elasticity for different surgical and therapeutic applications.

Abstract: Provided is a process for producing an aromatic liquid crystalline polyester comprising the steps of: charging 80 to 20 mol % of a compound represented by the following formula (I) and 20 to 80 mol % of a compound represented by the following formula (II) into a reaction vessel; conducting polycondensation reaction at a temperature from 270 to 350° C. to produce an aromatic liquid crystalline polyester; discharging the aromatic liquid crystalline polyester in a molten state from the reaction vessel and solidifying; then, pulverizing the solidified polyester into particles; and heat-treating at a temperature from 200 to 310° C., The aromatic liquid crystalline polyester has improved low temperature molding processability, and the film thereof has sufficient heat-resistance and excellent gas barrier properties.

Abstract: Bioerodible polyorthoesters useful as orthopedic implants or vehicles for the sustained delivery of pharmaceutical, cosmetic and agricultural agents contain amine functionalities and &agr;-hydroxy acid-containing groups.

Abstract: The present invention provides a cationic coating composition capable of forming a coating film which is excellent in a corrosion resistance and an adhesive property and an electrodepositably coating property toward a rust preventive steel plate (zinc-plated steel plate). The cationic coating composition described above comprises as a vehicle component, a polyol-modified, amino group-containing epoxy resin prepared by reacting an epoxy resin (A) having an epoxy equivalent of 180 to 2500 with a polyol compound (B) obtained by adding caprolactone to a compound having plural active hydrogen groups and an amino group-containing compound (C).

Abstract: The present invention is directed to a method for the direct, one-step synthesis of crystalline segmented glycolide copolymers having less than 80 percent glycolide-based sequences in the copolyester chain. The copolyester chain can also be formed using a polyether glycol as the initiator for the ring-opening copolymerization of glycolide and other cyclic monomers to form highly hydrophilic materials.

Abstract: This invention is to provide a macromolecular solid electrolyte exhibiting high ion conductivity even at low temperatures and a polymer used therefor. This invention relates to a polymer formed of structural units represented by the following formula (1): wherein R represents a linear or branched alkylene residue of 1 to 4 carbon atoms; X− represents a deprotonated residue of an acid; Y+ represents a cation of a nitrogen-containing compound; Z represents a residue of a monoethylenically unsaturated compound; m represents a number of average addition mols of a branched chain bound to the structural unit, —(RO)—, forming a main chain and is in the range of 2 to 20; n is in the range of 3 to 500; and p is in the range of 0 to 2, and macromolecular solid electrolyte comprising the polymer as an essential component.

Abstract: A class of biopolymer including sulfur in the form of a thioester in the polymer backbone or a thioether in the polymer side chains has been developed. These are preferably produced by fermentation of bacteria with appropriate sulfur containing substrates, which are incorporated by a broad spectrum polyhydroxyalkanoate (“PHA”) polymerase. The sulfur-containing PHAs allow various applications and uses in industry. Representative embodiments of the applications of the sulfur-containing PHAs include their uses in the packaging industry, medicine, pharmacy, agriculture or food industry, as active agents or as coatings, packaging, or carriers.

Abstract: A method for producing a microbial polyester by culturing a microorganism being capable of producing a poly hydroxyalkanoate polyester in a culture medium containing 1-hexene as a sole carbon source.

Abstract: Microorganisms capable of synthesizing novel polyhydroxyalkanoate having 3-hydroxythienylalkanoic acid as monomer unit, using thienylalkanoic acid as a stock are cultured on a culture medium containing thienylalkanoic acid, and the polyhydroxyalkanoate produced in the cultured cell is extracted and

Abstract: Thermally stable polymers comprising chain members derived from at least one 1,3-dihydroxybenzene moiety and at least one aromatic dicarboxylic acid moiety, said polymer being substantially free of anhydride linkages linking at least two mers of the polymer chain, are prepared using an interfacial method comprising the steps of: (a) combining at least one 1,3-dihydroxybenzene moiety and at least one catalyst in a mixture of water and at least one organic solvent substantially immiscible with water; (b) adding to the mixture from (a) a controlled stoichiometric ratio of at least one acid chloride and at least one base while maintaining the pH between about 4 and about 8.5, and (c) adjusting the pH of the reaction mixture to a value in the range of about 7 and about 9 following complete addition of acid chloride, and stirring the reaction mixture for a time sufficient to destroy any anhydride linkages in the polymer chain.

Abstract: The present invention is directed to a method for reducing waste accumulation by using an environmentally degradable disposable material. The disposable material, which includes a hydroxycarboxylic acid-containing polymer, degrades hydrolytically during operative and disposal stages in a controlled manner such that the disposal degradation rate of the material is accelerated relative to the operative degradation rate of the material.

Abstract: A process for preparing a polyhydroxycarboxylic acid having a weight average molecular weight of 50,000 to 1,000,000, which comprises a crystallizing step comprising (A) a step of heating pellets of a polyhydroxycarboxylic acid having a weight average molecular weight of 2,000 to 100,000 under stirring to a temperature from glass transition point or higher to a melting point or lower and heating until a defined result is attained, and (B) a step of heating the polyhydroxycarboxylic acid to a temperature of solid phase polycondensation reaction temperature, and a solid phase polycondensation reaction step of reacting the crystallized polyhydroxycarboxylic acid at an endothermic start temperature or lower of an endothermic peak as recognized upon temperature elevation analysis of the crystallized polyhydroxycarboxylic acid by using a differential scanning calorimeter.

Abstract: Hydrogels of polymerized and crosslinked macromers comprising hydrophilic oligomers having biodegradable monomeric or oligomeric extensions, which biodegradable extensions are terminated on free ends with end cap monomers or oligomers capable of polymerization and cross linking are described. The hydrophilic core itself may be degradable, thus combining the core and extension functions. Macromers are polymerized using free radical initiators under the influence of long wavelength ultraviolet light, visible light excitation or thermal energy. Biodegradation occurs at the linkages within the extension oligomers and results in fragments which are non-toxic and easily removed from the body. Preferred applications for the hydrogels include prevention of adhesion formation after surgical procedures, controlled release of drugs and other bioactive species, temporary protection or separation of tissue surfaces, adhering of sealing tissues together, and preventing the attachment of cells to tissue surfaces.

Abstract: The present invention provides novel hydrogel-forming, self-solvating, absorbable polyester copolymers capable of selective, segmental association into compliant hydrogels upon contacting an aqueous environment. Methods of using the novel polyester copolymers of the invention in humans are also disclosed for providing a protective barrier to prevent post-surgical adhesion, treatment of defects in conduits such as blood vessels, and controlled release of a biologically active agent for modulating cellular events such as wound healing and tissue regeneration or therapeutic treatment of diseases such as infection of the periodontium, dry socket, bone, skin, vaginal, and nail infections.

Abstract: A method for producing a biologically degradable polyhydroxyalkanoate coating in the form of an elastomeric film, wherein an aqueous dispersion of polyhydroxyalkanoate or a mixture of polyhydroxyalkanoate is prepared and the dispersion is applied to the surface to be coated, after which water is made or allowed to evaporate to obtain a polyhydroxyalkanoate film, the film formation taking place at a temperature lower than the melting point of the polyhydroxyalkanoate, wherein the polyhydroxyalkanoate is a Pseudomonas polyhydroxyalkanoate other than a polymer or copolymer of &bgr;-hydroxyvalerate or &bgr;-hydroxybutyrate, without requiring additional steps to render the film elastomeric.

Abstract: Crosslinked compositions formed from a water-insoluble copolymer are disclosed. These compositions are copolymers having a bioresorbable region, a hydrophilic region and at least two crosslinkable functional groups per polymer chain. These compositions are able to form hydrogels in aqueous environments when crosslinked. These hydrogels are good sealants for implantable prostheses when in contact with an aqueous environment. In addition, such hydrogels can be used as delivery vehicles for therapeutic agents.

Abstract: Microorganisms capable of synthesizing novel polyhydroxyalkanoate having 3-hydroxythienylalkanoic acid as monomer unit, using thienylalkanoic acid as a stock are cultured on a culture medium containing thienylalkanoic acid, and the polyhydroxyalkanoate produced in the cultured cell is extracted and

Abstract: The present invention provides a process for producing polyhydroxycarboxylic acids which comprises subjecting at least one hydroxycarboxylic acid or oligomer thereof to polycondensation in the presence of an alkali metal compound, an alkaline earth metal compound, or a compound of a metal of Group IIIb of the periodic table. The polyhydroxycarboxylic acids obtained by the process have a weight-average molecular weight of 30,000 or above and are useful as biodegradable plastics for food-wrapping films, drug delivery systems, etc.

Abstract: Carboxyl functional polyester resins obtainable by reaction of: a) at least a compound of the formula  wherein a≧1, and wherein R1 and R2 each may represent an alkyl group having from 1 to 4 carbon atoms or wherein R1 and R2 may form together with the group —CH—(CH2)x—CH˜ a cycloalkyl group and preferably 1,4-cyclohexane dicarboxylic acid (A1), mixed with smaller molar amounts of monoglycidyl esters of &agr;,&agr;-branched carboxyl acids containing from 5 to 19 carbon atoms in the acid moiety (A2), and b) at least one compound B comprising one primary- or secondary hydroxyl group and one tertiary aliphatic carboxyl group, and c) optionally one diol compound C, and d) optionally a dihydroxymonocarboxylic acid compound D, and e) optionally a trihydroxyalkane (E1) or tetrahydroxyalkane (E2), the molar ratio of compounds A1:(C+A2):B:D:E1:E2, being, (X+Y+1):Y:2:X:Q:P, wherein X ranges from 0 to 8, Y ranges from 1 to 8, Q ranges from 0 to 3 and w

Abstract: A hydrogel forming system which comprises a hydrophobic macromer with unsaturated group terminated ends and a hydrophilic polymer which is a polysaccharide containing hydroxy groups which are reacted with unsaturated group introducing compound, is convertible by free radical polymerization to form a hydrogel containing a three dimensional crosslinked polymer network containing hydrophobic and hydrophilic components. Preferably, the hydrophobic polymer is prepared by reacting the hydroxyls of a diol obtained by converting hydroxy of terminal carboxylic acid group of poly(lactic acid) to aminoethanol group, with an unsaturated group introducing compound which is acryloyl chloride or isocyanate having an unsaturated group at one end of the molecule.

Abstract: Rigid-rod monomers and polymers are provided for use in applications such as rapid prototyping, composites and adhesives. The monomers can be photocured through the end groups and then thermally post cured through the acetylene groups. The result is a highly crosslinked polymer having an effective glass transition temperature well above 200° C.

Abstract: A hot melt adhesive composition can be made using a polyester derived from 2-hydroxy-propanoic acid (lactic acid). A biodegradable/compostable thermoplastic resin can be formulated into a hot melt adhesive using a lower molecular weight material as a tackifying resin. The adhesive material can be made pressure sensitive and can be made entirely biodegradable by combining the polyester polymer with other biodegradable/compostable ingredients. The biodegradable/compostable adhesive material can be used as a substitute for non-biodegradable materials made from commercial polymers that resist attack by bacteria, fungi and other microbial populations. The resulting adhesive composition can be used in a variety of applications such as packaging and for the manufacture of disposable articles which are made from degradable materials. The entire disposable article can be made from adhesives and structural materials that are fully biodegradable/compostable.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.

Abstract: Disclosed is a select class of liquid crystalline polyesters and molding compositions comprising the polyesters and glass fiber. The liquid crystalline polyesters consist essentially of (1) diacid residues consisting essentially of (i) cyclohexanedicarboxylic acid residues and (ii) other diacid residues selected from terephthalic acid residues, 2,6-naphthalene-dicarboxylic acid residues, or a mixture thereof; (2) diol residues consisting essentially of hydroquinone residues, 4,4′-biphenol residues or a mixture thereof; and, optionally, (3) p-hydroxybenzoic acid residues. In the above definition, the moles of diol residues are equal to the moles of diacid residues and the total of the (1), (2) and (3) mole percentages is equal to 100. The liquid crystalline polyesters have melting points determined by differential scanning calorimetry equal to or less than 360° C.

Abstract: An improved barrier or drug delivery system which is highly adherent to the surface to which it is applied is disclosed, along with methods for making the barrier. In the preferred embodiment, the system is compliant, in that it is capable of conforming to the three dimensional structure of a tissue surface as the tissue bends and deforms during healing processes. The barrier or drug delivery systems is formed as a polymeric coating on tissue surfaces by applied a polymerizable monomer to the surface, and then polymerizing the monomer. The polymerized compliant coating preferably is biodegradable and biocompatible, and can be designed with selected properties of compliancy and elasticity for different surgical and therapeutic applications.

Abstract: The invention relates to a lactic acid residue containing polymer composition and product having improved stability and to methods for the preparation and use thereof. The lactic acid residue containing polymer preferably includes a polylactide polymer having a number average molecular weight of between about 25,000 and about 200,000, lactide, if present at all, present in a concentration of less than 0.5 wt % based on the weight of the composition, and deactivating agents. Articles which can be manufactured from the lactic acid residue containing polymer composition include fibers, coated paper, films, moldings, and foam.

Abstract: A soft hydrogel containing a triblock copolymer and water is disclosed. The copolymer has formula (I): X-G-Y, wherein G is a non-hydroxylated hydrophilic linear polymer block containing p repetitive units, where p is a number from 10 to 150, each of X and Y is a polyester block containing m and n repetitive units, respectively, and the ratio (m+n)/p is high enough for said copolymer to be water-insoluble, said ratio (m+n)/p being selected in such a way that adding water to a solution of the copolymer in a water-miscible organic solvent leads to the formation of a soft hydrogel capable of retaining an amount of water at least as great as the weight of said copolymer. Said hydrogel is suitable for retaining and gradually releasing hydrophobic substance and/or hydrophilic macromolecules, including drugs.

Abstract: A gas barrier polymer composition with active hydrogen functionality is provided. The polymer may be prepared by reacting a solution of organic diacid containing at least one active hydrogen group and diglycidyl ether in the presence of an optional catalyst. The pressure, temperature, and time parameters of the reaction are preferably regulated to prevent degradation and subsequent incorporation of degradation products of organic diacid containing at least one active hydrogen group into the gas barrier polymer composition. A formulation of the gas barrier polymer composition and a carrier may be used to coat plastic materials, containers, and preforms. The gas barrier polymer composition may also be employed in a method of making multilayer packaging materials or container preforms. The multilayer packaging materials or preforms can be used to make containers useful in packaging gas sensitive substances.

Abstract: The invention relates to biodegradable polycondensates, to the production of said polycondensates, and to their use for releasing specific substances. The polycondensates are derived from at least three components chosen from the following group: a) dianhydrohexites b) bivalent (polyvalent) organic carboxylic acids and c) polyvalent organic carboxylic acids which, in addition to two carboxylic acid functions, have at least one other, optionally capped, i.e., OH and/or COOH function.

Abstract: A method is provided for isolating and purifying PHA from microbial or plant biomass that contains PHA. The method includes the step of extracting PHA from the biomass using at least one solvent while simultaneously subjecting the biomass to a filtration process to remove cells. In a preferred embodiment of the method, an aqueous slurry of the biomass is directly extracted by diafiltration using an organic solvent. In a preferred diafiltration process, an aqueous slurry of microbial cells comprising PHA is recirculated through a filtration membrane, wherein the membrane has a pore size sufficiently small to reject individual cells or such aggregates of cells as may exist in the slurry.

Abstract: The present invention provides an olefin-based block copolymer that has an olefin block that is substantially saturated and at least one (poly)ester or (poly)ether block. The olefin-based block copolymer of the invention can be prepared by reacting a liquid hydroxyl-functional, saturated or substantially saturated olefin polymer with a chain-extension reagent that is reactive with hydroxyl groups and will polymerize in a head-to-tail arrangement of monomer units. The olefin-based block copolymer of the invention can be used to prepare an adhesion promoter that provides excellent adhesion of subsequent coating layers to olefinic substrates like TPO and superior properties as compared to previously used adhesion promoters containing chlorinated polyolefins.

Abstract: To increase the melt strength and increase high shear thinning of a polyester composition, a polar chain terminator that contains a nonionic group or an ionic group neutralized with a counterion is added at a level of 0.05 to 20 mole percent. Optionally, up to 2.0 mole percent of a tri-functional or greater branching agent is added to the polyester composition. Optionally, up to 30 mole percent of a polar midchain difunctional monomer that contains a nonionic group or an ionic group neutralized with a counterion is added. The polyester composition is based on 100 mole percent diacid component and 100 mole percent glycol component.

Abstract: A process for the continuous production of substantially purified lactide and lactide polymers from lactic acid or an ester of lactic acid including the steps of forming crude polylactic acid, preferably in the presence of a catalyst means in the case of the ester of lactic acid, to form a condensation reaction by-product and polylactic acid, and depolymerizing the polylactic acid in a lactide reactor to form crude lactide, followed by subsequent purification of the crude lactide in a distillation system. A purified lactide is then polymerized to form lactide polymers.

Abstract: The invention is directed to self-assembling, polymer-based delivery systems for proteins. The delivery systems comprises an active agent and a polyol ester of the invention, having a linear polyol containing six or more hydroxyl groups as a central backbone and biodegradable hydroxy carboxylic ester groups attached to the central backbone.

Abstract: The present invention is directed to a method for reducing waste accumulation by using an environmentally degradable disposable material. The disposable material, which includes a hydroxycarboxylic acid-containing polymer, degrades hydrolytically during operative and disposal stages in a controlled manner such that the disposal degradation rate of the material is accelerated relative to the operative degradation rate of the material.

Abstract: An aliphatic polyester film comprising, as a main component, a polylactic acid having a reduced viscosity (&eegr;sp/C) of not less than 0.50 dl/g and not more than 2.50 dl/g, wherein the film has a thermal shrinkage in the longitudinal direction at 120° C. of not more than 5.0% is provided. The aliphatic polyester film of the present invention is provided which is useful as a packaging film and an adhesive tape, superior in hand tearability, twist retention, processability and film forming property, and which is biodegradable when placed in a natural environment.

Abstract: Crosslinked compositions formed from water-insoluble copolymers are disclosed. These compositions are copolymers having a bioresorbable region, a hydrophilic region and at least two cross-linkable functional groups per polymer chain. Crosslinking of these polymers can be effected in solution in organic solvents or in solvent-free systems. If crosslinking occurs in a humid environment, a hydrogel will form. If crosslinking occurs in a non-humid environment, a xerogel will form which will form a hydrogel when exposed to a humid environment and the resulting crosslinked materials form hydrogels when exposed to humid environments. These hydrogels are useful as components in medical devices such as implantable prostheses. In addition, such hydrogels are useful as delivery vehicles for therapeutic agents and as scaffolding for tissue engineering applications.

Abstract: An aliphatic polyester is provided which is manufactured by a process comprising a step of hydrolyzing cellulose so as to form D-glucose, a step of forming gluconolactone represented by the formula (II) from the D-glucose, and a step of performing ring-opening polymerization of the gluconolactone so as to form an aliphatic polyester represented by the formula (I).

Abstract: This invention relates to compositions comprising a polycarbonate, polyester or polyketone which is subject to oxidative, thermal and/or light-induced degradation, or their mixtures and blends, and at least one benzofuran-2-one type compound, to the use thereof for stabilising polycarbonate, polyester or polyketone or their mixtures or blends against oxidative, thermal and/or light-induced degradation, as well as to a process for stabilising these plastic materials.

Abstract: The present invention relates to a resin composition for foam, which is used as a packing cushioning material, and an object thereof is to provide said composition which has biodegradability and is made from a principal raw material, lactic acid capable of contributing to the protection of global environment. The object can be attained by a resin composition having biodegradability and expandability, comprising a high-molecular weight polylactic acid having a melt viscosity of 0.01 to 50 in terms of a melt index value (MI), characterized in that said resin composition is prepared by compounding 0.1 to 5% by weight of at least one compound, which is selected from a polyisocyanate having an isocyanate group of not less than 2.0 equivalents/mol, an epoxy compound having an epoxy group of more than 2.0 equivalents/mol and an acid anhydride having an anhydrous carboxyl group of more than 2.

Abstract: Hydrogels of polymerized and crosslinked macromers comprising hydrophilic oligomers having biodegradable monomeric or oligomeric extensions, which biodegradable extensions are terminated on free ends with end cap monomers or oligomers capable of polymerization and cross linking are described. The hydrophilic core itself may be degradable, thus combining the core and extension functions. Macromers are polymerized using free radical initiators under the influence of long wavelength ultraviolet light, visible light excitation or thermal energy. Biodegradation occurs at the linkages within the extension oligomers and results in fragments which are non-toxic and easily removed from the body. Preferred applications for the hydrogels include prevention of adhesion formation after surgical procedures, controlled release of drugs and other bioactive species, temporary protection or separation of tissue surfaces, adhering of sealing tissues together, and preventing the attachment of cells to tissue surfaces.