Biodegradable magnesium incorporated microspheres enable immunomodulation and spatiotemporal drug release for the treatment of osteonecrosis of the femoral head

Functionalization of biomimetic mineralized collagen for bone tissue engineering

“…There is a risk of uncontrolled release of growth factor (GF) and leakage to other areas of the body after the MC with adsorbed GF by immersion is implanted in the body [ 125 ]. The polymers have excellent bioactivity and biodegradability, and can be processed into injectable hydrogels [ 126 , 127 ], microcapsules [ 128 ], and microspheres [ [129] , [130] , [131] , [132] ] with certain mechanical strength. By surrounding the AF surface with biodegradable materials, we can regulate the release thereof [ 48 , 133 ], and the sequential release of AFs can be realized.…”

“…For example, poly (lactide- co -glycolide) (PLGA) can release rhBMP-2 better than alginate [ 134 ], while alginate can realize the space-time controlled release of VEGF and maintain biological activity for a long time [ [135] , [136] , [137] ]. Furthermore, by incorporating magnesium particles into PLLA microspheres, the release of BMP-2 can be manipulated, achieving spatiotemporal co-release of magnesium and BMP-2 from the microspheres [ 132 ]. Functionalized mineralized collagen (FMC) can be obtained by injecting active factor (AF)-loaded hydrogel into MC composite or mixing AF-loaded microspheres with MC raw material.…”