Tantalum coating of porous carbon scaffold supplemented with autologous bone marrow stromal stem cells for bone regenerationin vitroandin vivo

Abstract

Porous tantalum metal with low elastic modulus is similar to cancellous bone. Reticulated vitreous carbon (RVC) can provide threedimensional pore structure and serves as the ideal scaffold of tantalum coating. In this study, the biocompatibility of domestic porous tantalum was first successfully tested with bone marrow stromal stem cells (BMSCs) in vitro and for bone tissue repair in vivo. We evaluated cytotoxicity of RVC scaffold and tantalum coating using BMSCs. The morphology, adhesion, and proliferation of BMSCs were observed via laser scanning confocal microscope and scanning electron microscopy. In addition, porous tantalum rods with or without autologous BMSCs were implanted on hind legs in dogs, respectively. The osteogenic potential was observed by hard tissue slice examination. At three weeks and six weeks following implantation, new osteoblasts and new bone were observed at the tantalum-host bone interface and pores. At 12 weeks postporous tantalum with autologous BMSCs implantation, regenerated trabecular equivalent to mature bone was found in the pore of tantalum rods. Our results suggested that domestic porous tantalum had excellent biocompatibility and could promote new bone formation in vivo. Meanwhile, the osteogenesis of porous tantalum associated with autologous BMSCs was more excellent than only tantalum implantation. Future clinical studies are warranted to verify the clinical efficacy of combined implantation of this domestic porous tantalum associated with autologous BMSCs implantation and compare their efficacy with conventional autologous bone grafting carrying blood vessel in patients needing bone repairing.

Effect of porous tantalum on the biological response of human peripheral mononuclear cells exposed to Porphyromonas gingivalis

“…Tissue integration requires a fine balance between the need for inflammatory signals, which are necessary for host defense but also for induction of tissue remodeling, and subsequent reduction of inflammatory reactions . In this study, PBMC incubated with PT present similar cell mitochondrial activity results ( P > .05) to the control group, confirming the maintenance of cell viability in PT presence, and the in vitro PBMC‐PT interaction results clearly indicated that PT allowed cell adherence as assessed by SEM, results that are described in previous studies …”

“…21 In this study, PBMC incubated with PT present similar cell mitochondrial activity results (P > .05) to the control group, confirming the maintenance of cell viability in PT presence, and the in vitro PBMC-PT interaction results clearly indicated that PT allowed cell adherence as assessed by SEM, results that are described in previous studies. 5,6,22 Leukocyte adhesion to implants has long been recognized as a key and primary mechanism for inflammatory reactions to the material itself. 23 The biological response also depends on the physicochemical nature of the surface and positively correlates with material surface roughness.…”

“…In this regard, the presence, in vivo, of multiple cell types in the bone microenvironment obscures the features of specific interactions per se . Although previous studies have reported that PT is biocompatible and likely not harmful because it does not exhibit any deleterious effects on different cells, its interaction with some of the first cells after implantation, such as human peripheral blood mononuclear cells (PBMC), has not been extensively studied …”

Involvement of autophagy in tantalum nanoparticle-induced osteoblast proliferation

“…12 Currently, porous Ta has been widely applied in orthopedic applications and oral implants, and studies have shown that it can highly promote the adhesion, proliferation, differentiation, and mineralization of osteoblasts in vitro 3,13,14 and in vivo. 15,16 In addition, recent studies have revealed that porous Ta combined with bone marrow stromal stem cells (BMSCs), 17 bone marrow mesenchymal stem cells (BMMSCs), 18 and fibrin 19 can better promote cell proliferation, bone integration, and regeneration. 20 Currently, a commercial PTTM-enhanced Ti dental implant is applied.…”

Stem Cells for Bone Regeneration: Role of Trophic Factors

“…The constructs generated much more new bone and blood vessels than the control calcium phosphate cement without cells [16]. Porous tantalum rods were implanted with or without autologous bone marrow stromal cells (BMSCs) on hind legs in dogs and the scaffold combined with cells enhanced new bone formation after 12 weeks of implantation [17]. These studies indicate that the combination of scaffolds with stem cells can enhance bone regeneration to greater extent.…”