In Vivo Evaluation of the Biocompatibility of Biodegradable Shape-Memory Polymers (BSMP)

Objective: This paper evaluates the in vivo biocompatibility for biodegradable shape-memory polymers (BSMP) invented by the authors. Methods: Acute general toxicity testFthe leach liquor of BSMP and equal volume normal saline were injected into the mice’s abdominal cavity of experimental and control groups respectively,and the toxicity effects on the mice were observed within 72 hours.Hemolysis testFAnticoagulated blood of rabbit was added into the leach liquor of BSMP, normal saline and distilled water in 3 groups,and MTT method was used to detect A value in 3 groups. Effect on fracture healing test: A defect was made in the femur of rabbits. The BSMP was used to repair the defect. And the type and ultrastructure of the cells in various stages’ callus or surrounding the callus were observed. Subcutaneous implantation testFthe BSMP was implanted subcutaneously in rats and the histology observation was performed at 2, 4, 8, 12 and 24 weeks.Results: Acute general toxicity test showed that the mice in 2 groups were in good physical condition and had no respiratory depression,paralysis,convulsion,and death.The hemolysis rate was 1.24% and was lower than the GB-T 14233.2-2005 level (5%). Effect on fracture healing test showed that the bone cells grew into the BSMP 24 weeks after operation. The Subcutaneous implantation test showed simulated tissue observation after 8 weeks. Conclusion: The biodegradable shape-memory polymers (BSMP) provides good biocompatibility in vivo.