Sustained Protein Therapeutics Enabled by Self-healing Nanocomposite Hydrogels for Non-invasive Bone Regeneration
Bone tissue engineering based on stem cells, growth factors and bioactive scaffolds has presented an appealing but challenging approach for rehabilitation of patients with bone defects. A versatile system with capability of easy operation and precise protein delivery in specific location is attractive for enhancing bone regeneration. Here, we develop a non-invasive delivery system based on injectable and self-healing nanocomposite hydrogels for sustained protein release, which has the potential to improve the current orthopedic strategy. Specifically, laponite (LAP) nanoplatelets are able to accelerate the gelation process by reason of hydrogen bonds with polysaccharide matrices, endowing hydrogels with superior mechanical and rheological behaviors, along with better injectability and self-healing ability. Attractively, the strong static binding between LAP nanoplatelets and bone morphogenetic protein-2 (BMP-2) can form stable LAP@BMP-2 complexes. The results indicate that the complexes effectively preserve intrinsic bioactivity of BMP-2 and prolong release period for more than four weeks. Moreover, hydrogel incorporating with LAP@BMP-2 complexes synergistically boost cell spreading, proliferation activity and osteogenesis both in vitro and in vivo, as compared to that with LAP or BMP-2 alone. Overall, this study proposes a valid platform for protein therapeutics and non-invasive bone repair.