Preparation Of Poly(Lactic Acid) Nanopaticles With Drug And Layer-by-Layer Assembly

Embedded devices have become very common today in medical operations, eg, the heart surgery. During the treatment, we will encounter a very key issue that is the bodies’ abnormalities of the implant into and infection. If there is a kind of method that can reduce the abnormalities and infection, the patients will be more comfortable and the probability of success in operation will be higher. In this paper we combined the drug control and release coating with embedded devices for the purpose of drug release. According to this method, we can improve the embedded devices and the drug medical, organization compatibility and renewable will be achieved.During the experiment, poly(lactic acid)(PLA)/poly(lactide-co-glycolide)(PLGA) was made into nano-particles with drugs traped in. PLA/PLGA-nanoparticle has negative charge in the aqueous solution, so it can be used to construct Layer-by-Layer films with poly(ethyleneimine)(PEI)/chitosan (CH). In this thesis, three nanopreciation methods had been introducted, emulsion-solvent evaporation method, emulsion-solvent diffusion method, double emulsion method. According to the solubility of different drugs, corresponding methods have been chosen. The surface morphology, size, zeta potential of nano-particles and the films were monitored by UV-vis spectroscopy, SEM and TEM. Then analysis and compare the drug content(w/w)and the drug entrapment of nanoparticles and films with different drugs. Finally, chose a kind of nanoparticles and films to study the release of drug in vitro.Experimental results showed that emulsion-solvent evaporation method and emulsion-solvent diffusion method were fit for the fat-soluble drug and double emulsion method was fit for the water-soluble drug. The layer-by-layer films constructed by nanoparticles with drugs could release the drugs continuously. The drug content and drug entrapment were increasingly important in morden pharmaceutical companies. LBL technology has broad prospects in tissue engineering and genetic engineering.