The Study On Preparation And Characterization Of Polypyrrole/Poly (L-Lactide) Electro-Active Composite And Its Biocompatibility

In the clinical application of bone implants there are still some problems related to the imperfectness of osseointegration of implants with bone tissue .How to improve the combination intensity implant-bone interface and realize better osseointegration is still a challenge we design and reshape the implant material. Electricity micro-circumstance is one of important circumstances that osteoblasts live,which has important signification for bone regeneration and reintegrate under simulating. Electrical conductivity polypyrrole (PPy) has some special quality different from general high molecular material for medicine using. These characteristics include:â‘ it has remarkable conductivity,â‘¡its biocompatibility with respect to mammalian cells has been tested in recent years,â‘¢its properties impart the electrochemically controlled release ability .The ideal bone implant material will not only be bioactive, biocompatible and osseoinductive but also make response receiving outer stimulation to regulate cell attachment, proliferation, differentiation and mineralization. Considering functional design of bone implant material, we prepare PPy/PLA electro-active composite by chemical oxidation. We expect implant material that is provided with biocompatibility, mechanical stability and electro-bioactive, as well as respond outer microelectric circumstance stimulation , enhance chemical banding of implant-bone interface and improve success ratio of bone implant technique.There are five major parts in this research.(1) Designing electric equipment which can not only place material to test electrical conductivity, but also plant cell into little chamber. And constructing a system of ten channels can export direct current stimulation.(2) PPy/PLA electro-active composite containing 10% PPy were prepared by chemical oxidation,testing micro-morphology of material interface,chemical component and electrical conductivity stability. The result display PPy micro-domain distribute in PLA and composite has perfect electric conductivity stability.(3) The primary osteoblasts were cultured from calvarium of new-born SD rats by tissue piece culture method. The cultured osteoblasts have typical biology behavior by identifying in morphology and Von Kossa staining. Three to six numbers osteoblsts were more adaptive to use in vitro experiment by measuring Alkaline phosphatase(ALP) activity of one to seven numbers.