The Preparation Of Modifed Poly (Lactic Acid) Approved To Be Material Of Drug Carrier

On the basis of my predecessor , we first prepared polyethylene glycol (PEG) grafted PLA (PPLA). PPLA was approved to be material of drug carrier and can be used as raw material for postgrafting. It is necessary for us to recognize the structure of PPLA. The infra-red (FTIR), magnetic resonance imaging (NMR), gel-filtration chromatograph(GPC) and triketohydrindene hydrate coloration were used to characterize PPLA. Then with biotin as raw material, by covalently grafting PPLA, a bioactive materials (BPLA) was obtained. The triketohydrindene hydrate coloration, magnetic resonance imaging (NMR) and contact angle were used to characterize BPLA. The anti-non-specific protein absorption property of material was tested using FITC labeled BSA. The bioactive of biotin on BPLA was tested using FITC labeled avidin.The main works and conclusions are included as follows:(1) Prepare polyethylene glycol (PEG) grafted PLA by using PLA with maleic anhydride grafted on (MPLA) and polyethylene glycol as raw material.The product was PPLA.(2) With polyethylene glycol combined PLA as control product, The infra-red (FTIR), magnetic resonance imaging (NMR), gel-filtration chromatograph(GPC) and triketohydrindene hydrate coloration were used to characterize PPLA and control product.It confirmed that during the reaction between PEG and anhydride ,the PLA backbone was degradating due to the reaction of PEG and esteratic linkage . We conformed its structure, a PEG graft PLA, in which 1 PEG connected to the tail of PLA and other 2 PEG graft on the side chain of PLA via maleic anhydride group.(3)The bulk-modification of PLA was carried out from biotin and PPLA with Dicyclohexylcarbodiimide(DCC) as a condenser, the product was BPLA.1H-NMR, triketohydrindene hydrate coloration,water contact angle, FITC-BSA and FITC-avidin was used to characterize BPLA. The results indicated that biotin was successfully grafted onto PPLA,and BPLA had the property of decreasing the non-specific protein absorption and specific bioactivity.The results exhibited that PPLA is a new drug delivery material with hydrophilic and the prominent property of decreasing the non-specific protein ab-sorption. It can act as a carrier of hydrophilic and hydrophobilic drug, because it has hydrophilic and hydrophobilic district. it will be a useful raw material for the pre-paration of bioactive molecule and will have a potential use in drug delivery.