Formulation of O-carboxymethyl chitosan with magnesium phosphate cement promotes in vitro / in vivo angiogenesis and osteogenesis related to the TRPM7 channel in bone regeneration

Despite the abundant evidence on the biodegradability of K-struvite (KMgPO 4 & sdot; 6H 2 O) that promotes bone regeneration, the cell-related surface bioactivity still stays low owing to the absence of organic components. O - Carboxymethyl chitosan ( O -CMC) is a glycosaminoglycan-mimetic with outstanding biocompatibility, biodegradability and solubility, which has been successfully used in tissue engineering and regenerative medicine (TERM). In this study, we incorporated O -CMC into K-struvite to prepare hybrid scaffolds (OMPCs) with increasing biphasic contents. We found that O -CMC improved the physicochemical properties, in vitro/vivo biocompatibility, and enzymatic biodegradability of K-struvite, resulting in enhanced in vitro/vivo angiogenesis and osteogenesis via the proper release of Mg 2 + . In addition, we found differential expression of transient receptor potential cation channel member 7 (TRPM7) within the endothelial and osteoblast lineages, triggering the phosphorylation of the PI3K/Akt and MEK/ERK signaling pathways, respectively. In summary, it can be concluded that the biphasic addition of O -CMC is a viable method for improving the surface bioactivity of Kstruvite to accelerate bone regeneration.