Modified Research Of Nano-bone Adhesive

Objective: With more and more high-energy damage,it brings some trouble to clinical treatment for fracture.The treatment of grievous comminuted fracture is still a challenge in the field of orthopeadics at present.Nowadays,bone tissue engineering technology combines with common medical glue to research nano-bone adhesive in clinical treatment of comminuted fracture and bone nonunion has become the forefront of international biotechnology research in the field of a new hot spot.We focus on the modified research of n-butyl cyanoacrylate,which mixed with nano-hydroxyapatite/poly L-lactic acid(Nano-HA/PLLA),to improve the adhesive strength and reduce the degradation rate.We believe that the performance of bone adhesive used in clinic will be perfected with the development and research of adhesive.Methods: 1.The preparation of nano-bone biological adhesive(1)Observed that n-butyl cyanoacrylate mixed with nano-HA/PLLA powders react immediately or not.(2)Compared with the strength of bone adhesives with different concentration through the three-point bending test.(3)Found out the optimal ratio of bone adhesive by statistical analysis.2.The cytotoxicity experiment Human bone marrow mesenchymal stem cells(h BMSCs)were cultured with the extracting solution of common medical glue and nano-bone biological adhesive.At 1~5 days,the proliferation of cells was detected by MTT cell toxicity test everyday.3.Animal experiment(1)Selected 40 rabbits to make the models of bilateral ulnar fracture.For each rabbit,the fractures were fixed with nano-bone biological adhesive on the right,and common medical glue or without any glue on the left respectively.(2)After surgery,X-ray performed at 2nd week,4th week and 8th week and histological observed at 2nd week and 4th week.Results: 1.The preparation of nano-bone biological adhesive(1)After shaking the nano-bone biological adhesive,it could become suspension without sediment.The viscosity didn't change with the increase of powder concentration.(2)The bonding time of adhesive with different concentration was not significant difference.When the nano-HA/PLLA's concentration was 10 mg/m L,it could reach the largest average strength.2.The cytotoxicity experiment Both the extracting solution of nano-bone biological adhesive and common medical glue had some cytotoxicity compared with pure medium.Though the cell survival rate in experimental groups was lower,it could still grow well and showed good compatibility.3.Animal experiment Nano-bone biological adhesive can promote the healing of fracture obviously in the early compared with common medical glue.It can be degraded completely for 4 weeks in vivo.Conclusion: 1.When the concentration of nano-HA/PLLA is 10 mg/m L,it can reach the largest average strength.2.The cytotoxicity of nano-bone biological adhesive is not higher than common medical glue,on the contrary,it may even lower.3.The nano-bone biological adhesive as a new bone biomaterials for repairing bone fracture in clinic will promot fracture healing in the early without delaying the healing of fracture.