Strontium Ranelate Incorporated Enzyme-Cross-Linked Gelatin Nanoparticle/Silk Fibroin Aerogel for Osteogenesis in OVX-Induced Osteoporosis

Osteoporosis is a wide-range disease with negative impact on bone defects healing. Strontium ranelate (SR) has promising osteogenic potential for its dual function on stimulating osteoblasts and inhibiting osteoclasts activity. However, it has limitations for its dose-dependent effect and side effects on systemic application. Here, a sequentially crosslinking strategy including enzyme-crosslinking through tyrosinase from mushroom and physical folding is acquired to create SR loaded gelatin nanoparticle/silk fibroin aerogel (abbreviated as S/G-Sr-MT) with drug release controlling capacity. The results showed successful enzyme-crosslinking, excellent spatial structure and enhanced mechanical of S/G-Sr-MT. Evenly Sr2+ loading and stable release with markedly inhibited initial burst release was detected. Biomineralization investigation showed rapid deposition of hydroxyapatite on the surface of S/G-Sr-MT. In vitro, spreading morphology and higher osteogenic gene expression of MC3T3-E1 seeded on S/G-Sr-MT were...