摘要:
Electrospun biodegradable poly(ester-amide) fabric is especially suitable as a scaffold for tissue engineering and to incorporate drug for burn or wound healing treatment to accelerate healing, or to prevent tissue adhesion after surgery.
摘要:
The invention provides biodegradable, cationic compositions based on cationic α-amino acid-containing PEA, PEUR and PEU polymers for use in preparation of non-viral gene transfer compositions. In the invention gene transfer compositions a poly nucleic acid is condensed with the polymer to form a soluble unit wherein the electrical charge of the poly nucleic acid is neutralized by the polymers. The invention gene transfer compositions can be used to transfect target cells by contact with the target cells.
摘要:
Injectable drug laden microspheres are obtained from unsaturated functionalized polyhydric alcohol ester of polyester by a method comprising dissolving the unsaturated functionalized ester in a hydrophobic organic solvent, dissolving drug and/or biologically active agent in water, admixing the two solutions to form water-in-oil emulsion, forming an aqueous solution of stabilizer, admixing the water-in-oil emulsion and the stabilizer solution to form water-in-oil-in-water emulsion, and evaporating the organic solvent.
摘要:
Injectable hydrogel microspheres are prepared by forming an emulsion where hydrogel precursors are in a disperse aqueous phase and polymerizing the hydrogel precursors. In a preferred case, the hydrogel precursors are poly(ethylene glycol) diacrylate and N-isopropylacrylamide and the continuous phase of the emulsion is an aqueous solution of dextran and a dextran solubility reducer. The microspheres will load protein, e.g., cytokines, from aqueous solution.
摘要:
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. Agent can be entrapped in the polymer network, e.g., drugs, macromolecules or synthetic or natural polymers, for controlled release therefrom. In one embodiment, a vascular stent is coated with hydrogel with therapeutic agent entrapped therein.
摘要:
Biodegradable hydrogels are formed by photocrosslinking dextran-maleic acid monoesters in which the average degree of substitution of each glucose unit of each &agr;-D-glucopyranosyl of dextran by maleic acid ranges from 0.60 to 1.6 and which have a weight average molecular weight ranging from 40,000 to 80,000 on a dextran basis. The hydrogels at pH 7 have maximum swelling ratios ranging from 500 to 1,500 percent. The hydrogels are characterized by increase in swelling ratio as average degree of substitution increases. The hydrogels are useful, for example, for drug delivery and solubility enhancers of drugs, as protective encapsulators of viruses used in gene therapy, and for conventional uses of hydrogels.
摘要:
A controlled release doxorubicin containing composition comprises doxorubicin physically entrapped in a dextran-methacrylate biodegradable hydrogel. The composition provides a rapid initial release of doxorubicin over a period of 5 to 7 hours followed by slow release. Increased degree of substitution in the dextran methacrylate decreases cumulative doxorubicin release. The composition provides higher cumulative release in acid pH (e.g., the stomach) than at physiological pH at lower degrees of substitution. The composition allows administration alternatives to the bolus intravenous and continuous intravenous methods of administration now used for doxorubicin. The composition can be prepared without the use of heat (which can result in heat destruction of doxorubicin) and is prepared without chemical cross-linker such as glutaraldehyde and the toxicity associated therewith.