| Background: The regeneration capacity of bone is very powerful,however,the critical-sized bone defect caused by traumatic fractures,tumor resection,and congenital malformation probably not heal.The common treatment for the large bone defect in clinic is various bone grafts.Regardless of the type of bone graft,there are obvious disadvantages.Even autologous bone graft,the gold standard of bone transplantation,still has drawbacks such as infection,donor site pain,and long operation time.In addition,due to tissue availability,it is far from meeting clinical needs.Therefore,it is necessary to find new substitutes for natural bone grafts in clinical practice.Methods: Bone tissue engineering is a promising strategy,which is aiming to develop replacement for bone transplantations in vitro and overcome the defects of natural bone grafts.The core of bone tissue engineering is to establish a system with the capable of bone regeneration.Based on this,we firstly loaded resveratrol(Res),a drug which could promote osteogenic differentiation and bone formation,into the solid lipid nanoparticles(SLNs)with slow-release effect,and found out the optimal concentration of Res-SLNs for BMSCs.Then we encapsulated the Res-SLNs in injectable and photo-crosslinked gelatin methacryloyl hydrogel by physical blending to prepare Res-SLNs/GelMA scaffold,which could dually release Res and promote bone regeneration in large bone defects.Results: The characterization of Res-SLNs and drug screening experiments showed that the Res-SLNs had excellent sustained release property and the concentration of Res-SLNs at 1 μM had the strongest effect on promoting osteogenic differentiation.The effect of different Res-SLNs/GelMA hydrogel scaffolds on the osteogenic differentiation of BMSCs showed 0.02% w/v Res-SLNS/GelMA hydrogel had the best promoting osteogenic capacity and could accelerate the healing of bone defects.Conclusions: All in all,0.02% w/v Res-SLNs/GelMA hydrogel is an appropriate release system for Res with good biocompatibility,bone osteoconduction,and osteoinduction,which could significantly promote bone regeneration. |
