Study On Functional Modification Of Polypyrrole Film And Its Biological Properties

Polypyrrole(PPy)has been used as biomaterials for its high electrical conductivity,stablity under physiological environment and good biocompatibility.However,it usually needs to be modified according to different application requirements.In this work,we proposed to use plasma immersion ion implantation and doping with graphene to modify the PPy films,explored the effects of these two modification methods on the biological properties of modified PPy films and the related mechanisms.The main results obtained are as follows:1.PPy films were deposited on the surface of biomedical titanium by electrochemical polymerization technology and treated by oxygen plasma immersion ion implantation(O-PIII).The results obtained showed that antibacterial abilities of modified PPy films against Escherichia coli(E.coli)were enhanced due to O-PIII,and it became more evident with the increasing of implantation time,which might be ascribed to the improved hydrophilicity and change of sample surface charge from negative to positive.The similar results could not be found from Staphylococcus aureus(S.aureus)which might be related to different cell membrane structure.Meanwhile,O-PIII could improve the biocompatibility of PPy films.2.The surface roughness of PPy films increased after O-PIII,which promoted the light absorption capacity of the modified PPy films.Under the irradiation of near-infrared light with a wavelength of 808 nm,the antibacterial abilities of modified PPy films against E.coli and S.aureus both enhanced significantly.3.Electrochemical reduction PPy-graphene oxide(ER-PPy-GO)composite films were deposited on the surface of biomedical titanium by electrochemical polymerization deposition and electrochemical reduction.The composite films exhibited slight antibacterial effects against E.coli,but no obvious antibacterial abilities against S.aureus was observed.The composite films could induce the secretion of alkaline phosphatase of rat bone marrow mesenchymal stem cells(rBMSCs),no promoting effects on the secretion of cellular collagen and mineralization of extracellular matrix were observed.