The cytotoxicity, biocompatibility and morphological observation of bone formation traced in porous tantalum / 中华骨科杂志

ABSTRACT

Objective To investigate cytotoxicity,biocompatibility and new bone formation traced of Chinese porous tantalum,and provide experimental strategies for further clinical application.Methods The physical properties of the porous tantalum were observed by the SEM.The osteoblasts were isolated from rabbit embryo.The extract fluid from tantalum was made.The cytotoxicity and proliferation of osteoblasts compounded with porous tantalum in vitro were detected by the MTT assay.The osteoblasts were co-cultured with extract of tantalum in vitro and the morphological changes,proliferation and adhesion were observed under SEM.A total of 24 New Zealand rabbits were used to establish the model of femoral condyles with porous tantalum bars implanted.Among which 4 of them was injected with calcein and alizarin on the 5th day and the 19th day and sacrificed at 10 week postoperatively.The specimens were observed with LSCM at 488 nm and 543 nm wavelength respectively.The remained 20 animals were sacrificed successively at 2,4,8,12 weeks of implantation,then were examined by histological observation.Results The SEM showed that the pore of porous tantalum were three-dimensional connected morphology.MTT assay showed that the osteoblasts grew well in extract and no significant difference between experimental and control groups.The osteoblasts grew and spread extensively on porous tantalum.Early on co-culture,the osteoblasts attached to the surface and inner walls of material,in the later stage,the osteoblasts excreted bone matrix over the surface of porous tantalum.The animal model showed that porous tantalum was bonded closely with host bone.Hard slicing showed that new bone and capillary regenerated on tantalum-bone interface at 2,4 weeks postoperatively.The pores were full with bone tissue at 8,12 weeks.The LSCM indicated that the green and red fluorescence-labeled new bone was displayed on tantalum-bone interface,while the red zone located around the green zones.They appeared to be discontinuous at early stage,but connected with each other at the end.Conclusion The Chinese porous tantalum has good biocompatibility and no cytotoxicity.The contact osteogenesis and bone conduction exist in tantalum-bone interface,and in a time-dependent manner.