Effect of sulfated chitosan hydrogel on vascularization and osteogenesis.

Bone regeneration and vascularization have presented a clinical challenge for decades. Considering the importance of stem cells, such as mesenchymal stem cells (MSCs), in bone regeneration, endothelial progenitor cells (EPCs) are crucial during bone repair. This paper presented sulfated chitosan (SCS)-based hydrogel scaffolds to accelerate bone tissue regeneration, vascularization enhancement, and improve bone repair. Thus, these scaffolds played a crucial role in the regeneration of blood vessels, with the increased presentation of epithelial progenitors and immune cells in this microenvironment. In vivo experiments showed that the biological impact of SCS was critical for angiogenesis and vascularization, in conjunction with bone morphogenetic protein-2 (BMP-2) and MSCs. Therefore, the BMP-2-/hydrogel system established in this study promoted angiogenesis, stimulated MSC proliferation, and enhanced bone tissue formation. In addition, this paper highlighted the angiogenic role of SCS in creating a micro-environment for effective bone repair and provides insight into the future development of new bone regeneration material.