Fig. 10.

a) A programmed biomimetic design boosts bone growth in HA and SF scaffolds, enabling precise BMP-2 release for enhanced osteogenesis. Reproduced with permission [130]. Copyright 2016, American Chemical Society. b) A multi-layered biphasic calcium phosphate (BCP) scaffold is designed for programmed release of BMP-2. This design aims to prevent the initial burst release and instead promote a controlled release during the osteogenic cells' differentiation phase. Reproduced with permission [131]. Copyright 2021, Elsevier BV. c) A cell-free bone tissue engineering system using a SF/nanohydroxyapatite (nHAp) scaffold was created. This system embeds low doses of BMP-2 and VEGF, which are released in a controlled way to support bone formation and vascularization. Reproduced with permission [133]. Copyright 2017, Royal Society of Chemistry. d) rhBMP-2 bonded to mesoporous bioglass nanoparticles (MBGNs) forms a GelMA/MBGNs-rhBMP-2 hydrogel for staged release: initial rhBMP-2 release for early bone healing, followed by calcium and silicon ion release for sustained osteogenesis. Reproduced with permission [135]. Copyright 2020, American Chemical Society. e) DFO and DEX synergistically promote osteogenic differentiation through the Wnt/β-catenin pathway. Their combined release from EFM leads to enhanced vascularized bone regeneration in rat skull defects. Reproduced with permission [136]. Copyright 2022, John Wiley and Sons Ltd. f) A smart hydrogel programmed for on-demand, pulsatile and sustained release of PTH, enhanced with magnetic actuation to improve osteogenesis in critical-sized defects. Reproduced with permission [138]. Copyright 2023, American Chemical Society.