Cross-linked vegetable oil with covalently loaded dexamethasone: linear drug release for osteogenic induction of hBMSCs in vitro

A novel covalently dexamethasone-conjugated drug release system based on cross-linked vegetable oil (DEX-CVs) was designed and prepared by simple curing reaction of modified vegetable oil and dexamethasone phosphomonoester (DEX-P) without any toxic catalyst and initiator. UV and HPLC analysis confirmed that the dexamethasone (DEX) drug could be released linearly with high purity by adjusting the component ratios. The analysis of the model reaction indicated that DEX-P in the optimized DEX-CV (A4) was mainly covalently conjugated in the cross-linked vegetable oil network by cyclic phosphotriester bond, and the selective hydrolysis induced the pure release of dexamethasone drug. Finally, the low cytotoxicity and successful osteogenic differentiation effect of A4 on human bone marrow mesenchymal stem cells (hBMSCs) was corroborated by the detection of MTT analysis, ALP activity, staining experiments and some gene expressions, which provided the promising applications in drug release areas and bone tissue engineering.