Porous tantalum-composited gelatin nanoparticles hydrogel integrated with mesenchymal stem cell-derived endothelial cells to construct vascularized tissue .

The ideal scaffold material of angiogenesis should have mechanical strength and provide appropriate physiological microporous structures to mimic the extracellular matrix environment. In this study, we constructed an integrated three-dimensional scaffold material using porous tantalum (pTa), gelatin nanoparticles (GNPs) hydrogel, and seeded with bone marrow mesenchymal stem cells (BMSCs)-derived endothelial cells (ECs) for vascular tissue engineering. The characteristics and biocompatibility of pTa and GNPs hydrogel were evaluated by mechanical testing, scanning electron microscopy, cell counting kit, and live-cell assay. The BMSCs-derived ECs were identified by flow cytometry and angiogenesis assay. BMSCs-derived ECs were seeded on the pTa-GNPs hydrogel scaffold and implanted subcutaneously in nude mice. Four weeks after the operation, the scaffold material was evaluated by histomorphology. The superior biocompatible ability of pTa-GNPs hydrogel scaffold was observed. Our results suggested that 28 days after implantation, the formation of the stable capillary-like network in scaffold material could be promoted significantly. The novel, integrated pTa-GNPs hydrogel scaffold is biocompatible with the host, and exhibits biomechanical and angiogenic properties. Moreover, combined with BMSCs-derived ECs, it could construct vascular engineered tissue . This study may provide a basis for applying pTa in bone regeneration and autologous BMSCs in tissue-engineered vascular grafts.