Synthesis and characterization of biomimetic polymeric material based on poly(D, L-lactic acid) modifications

A novel poly(lactic acid) (PLA) based biomimetic polymeric material was prepared by bulk modification as follows. Firstly, maleic anhydride groups were introduced to the side chain of PLA by way of melt free radical copolymerization using benzoyl peroxide as an initiator. Then, to neutralize the acidic degrading products of PLA, aliphatic diamine was introduced to the side chain of PLA by the N-acylation of anhydrides with-NH₂. On this basis, in order to endow PLA with bioactivity and biospecificity, adhesive peptide arg-gly-asp-ser (RGDS) were grafted onto the backbone of PLA by using carbodiimide as condensating agent. In this paper, MALLS, FTIR and XPS were used to characterize the synthetic biomimetic material and rhodamine-carboxyl interaction method, ninhydrin reaction and amino acid analyzer were used to determine the content of maleic anhydride, diamine and RGDS, respectively. The results demonstrated that, in the context of remaining main chain structure of PLA, the content of RGDS is 5.12 μmol/g by the developed synthetic method, which provides theoretical and technical supports for further detecting biocompatibility of this material and finally applications in biomedical field.