{Reference Type}: Journal Article {Title}: Chitosan composite with mesenchymal stem cells: Properties, mechanism, and its application in bone regeneration. {Author}: Kudiyarasu S;Perumal MKK;Renuka RR;Natarajan PM; {Journal}: Int J Biol Macromol {Volume}: 0 {Issue}: 0 {Year}: 2024 Jul 1 {Factor}: 8.025 {DOI}: 10.1016/j.ijbiomac.2024.133502 {Abstract}: Bone defects resulting from trauma, illness or congenital abnormalities represent a significant challenge to global health. Conventional treatments such as autographs and allografts have limitations, leading to the exploration of bone tissue engineering (BTE) as an alternative approach. This review aims to provide a comprehensive analysis of bone regeneration mechanisms with a focus on the role of chitosan-based biomaterials and mesenchymal stem cells (MSCs) in BTE. In addition, the physiochemical and biological properties of chitosan, its potential for bone regeneration when combined with other materials and the mechanisms through which MSCs facilitate bone regeneration were investigated. In addition, different methods of scaffold development and the incorporation of MSCs into chitosan-based scaffolds were examined. Chitosan has remarkable biocompatibility, biodegradability and osteoconductivity, making it an attractive choice for BTE. Interactions between transcription factors such as Runx2 and Osterix and signaling pathways such as the BMP and Wnt pathways regulate the differentiation of MSCs and bone regeneration. Various forms of scaffolding, including porous and fibrous injections, have shown promise in BTE. The synergistic combination of chitosan and MSCs in BTE has significant potential for addressing bone defects and promoting bone regeneration, highlighting the promising future of clinical challenges posed by bone defects.