Functionalization Of PLLA Surfaces And The Evalution Of Biocompatibility

Polylactic Acid (PLA) is one of the synthetic polymer materials which is widelyused in the research and application of tissue engineering. However, because of itsbad surface hydrophilicity and absence of natural molecule acting point, itsapplication as biomaterials was limited.First, three methods of stem grafting by Ar plasma, stem grafting by ultravioletlight and alkaline hydrolysis were used to introduce carboxyl group onto the surfaceof PLLA to improve its hydrophilicity and introduce new molecule acting point to thesurface of PLLA. And the the affection on the carboxyl group density of materialsurface, the grafting density of PAA, the surface form before and after treatment, thechange of contact-angle by different treatment conditions were studied. The resultindicated that compared with other methods, Ar plasma stem grafting inlet the mostdensity of carboxyl group.Using water-soluble carbodiimide as condensation agent, N-methylenephosphonic chitosan were covalently grafted on the PLLA-g-AA membranes tointroduce the biomacromolecules onto the surface of PLLA.The hematolysis and dynamic hemoglutination tests resulted that the functionalPLLA could significantly improve the anticoagulation of PLLA. The skeltogenous cellculture appeared that the cells were growing best on the surface modified byN-methylene phosphonic chitosan, and the cell affinity was improved in a certainextent on the surface modified by alkaline hydrolysis and acrylic acid.It is concluded that the functional PLLA with acrylic acid or N-methylenephosphonic chitosan could effectively improve the biocompatibility of PLLA.