| It is well known that polylactide (PLA) is a kind of much better biocompatible andbiodegradable polymer and is being increasingly used in medicine and organic fields.However，the high hydrophobicity limited its applications at a large scale．Poly(glycolide-lactide) and polyvinyl pyrrolidone is used to compose copolymer with polylacticacid. The hydrophilicity/hydrophobicity of the copolymers could be adjusted by changing theproportion．As the introduction of hydrophilic chain, the flexibility of the molecular chain hasimproved and effectively adjusted its mechanical properties and surface properties, whichmake it more suitable for the application of controlled drug delivery ,drug targeting systems，tissue engineering and so on．The high relative molecular weight of PLA which could be 104is synthetized by the twostep method. By researching the reaction condition, the condition of how to get a high relativemolecular of polylactic acid is obtained. The copolymer of polylactic acid is obtained by thereaction of lactide, glycolide and the polyvinyl pyrrolidone with a hydroxyl end. IR,1HNMRand GPC is used to characterize the structure of the polymer. By the determination of thedegradation performance contact angle and bibulous rate, the hydrophilic of the copolymer isbetter than polylactic acid itself.By electrostatic spinning, the superfine fibre and the fibre loaded drug were prepared withthe best technological condition, using polylactic acid, poly (glycolide-lactide) and polyvinylpyrrolidone as drug carrier and acetylsalicylic acid as model drugs. Meanwhile the controlledreleased properties of the fibre is researched. The results show that the properties of controlledreleased of the superfine fibre is very well with polylactic acid copolymer and acetylsalicylicacid by electrostatic spinning. The controlled release properties of the copolymer is better than its homopolymers. The releasing rate of medicine carrying superfine fibers was increasewith the increase of the content of medicine. |
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