Triple-functional bone adhesive with enhanced internal fixation,bacteriostasis and osteoinductive properties for open fracture repair

At present,effective fixation and anti-infection implant materials represent the mainstay for the treatment of open fractures.However,external fixation can cause nail tract infections and is ineffective for fixing small fracture fragments.Moreover,closed reduction and internal fixation during the early stage of injury can lead to potential bone infection,conducive to bone nonunion and delayed healing.Herein,we designed a bone adhesive with anti-infection,osteogenic and bone adhesion fixation properties to promote reduction and fixation of open fractures and subsequent soft tissue repair.It was prepared by the reaction of gelatin(Gel)and oxidized starch(OS)with vancomycin(VAN)-loaded mesoporous bioactive glass nanoparticles(MBGNs)covalently cross-linked with Schiff bases.Characterization and adhesion experiments were conducted to validate the successful preparation of the Gel-OS/VAN@MBGNs(GOVM-gel)adhesive.Meanwhile,in vitro cell experiments demonstrated its good antibacterial effects with the ability to stimulate bone marrow mesenchymal stem cell(BMSCs)proliferation,upregulate the expression of alkaline phosphatase(ALP)and osteogenic proteins(RunX2 and OPN)and enhance the deposition of calcium nodules.Additionally,we established a rat skull fracture model and a subcutaneous infection model.The histological analysis showed that bone adhesive enhanced osteogenesis,and in vivo experiments demonstrated that the number of inflammatory cells and bacteria was significantly reduced.Overall,the adhesive could promote early reduction of fractures and antibacterial and osteogenic effects,providing the foothold for treatment of this patient population.

Bioactive calcium and mangnesium phosphate bone adhesive for enhanced vascularization and bone regeneration

Bone adhesive is a promising material for the treatment of bone fractures,which is helpful for the fast and effective reduction and fixation of broken bones.However,the existing adhesives bond weakly to bone tissues,and are non-absorbable,or hard to cure under wet conditions.Herein,inspired by the cement-based adhesive used in the industry field,we report a bioactive calcium and magnesium phosphate bone adhesive(MPBA)with the properties of facile preparation,robust adhesion,and bioactive.MPBA is equipped with similar strength to cancellous bones and shows reliable bonding performance for various interfaces,such as Ti6Al4V,Al2O3,and poly(ether-ether-ketone).MPBA achieves excellent bonding ability for the above interfaces with the bonding strengths of 2.28±0.47,2.32±0.15,and 1.44±0.38 MPa,respectively.Besides,it also shows reliable fixation ability for bovine bone surfaces.The bonding behavior to materials and bones suggests that MPBA could be used for both fracture treatment and implant fixation.Meanwhile,MPBA possesses good biological activity,which could promote the vascularization process and osteogenic differentiation.Finally,in vivo experiments confirmed MPBA can effectively restore bone strength and promote bone regeneration.