Local delivery of FTY720 in mesoporous bioactive glass improves bone regeneration by synergistically immunomodulating osteogenesis and osteoclastogenesis.

The addition of osteoimmunology drugs to bone repair materials is beneficial to bone regeneration by regulating the local immune microenvironment. Fingolimod (FTY720) has been reported to be an osteoimmunology drug that promotes osteogenesis. However, there is no ideal biomaterial for the sustained release of FTY720 in the bone defect areas. In the present work, FTY720 loaded mesoporous bioactive glass (FTY720@MBGs) was successfully prepared based on the mesoporous properties of MBGs and electrostatic attraction. FTY720 achieved a sustained release for 7 days. The in vitro study found that FTY720@MBGs could synergistically promote osteogenesis and inhibit osteoclastogenesis due to their ability to promote macrophages toward the M2 phenotype. The in vivo study confirmed that FTY720@MBGs could significantly improve bone regeneration. This study provides new strategies for designing smart cell-instructive biomaterials that can play a role in all bone healing processes from early inflammation to bone reconstruction.