3D Printing And Biocompatibility Study Of A New Biodegradable Occluder For Cardiac Defect

Objective to make biodegradable occluder for heart defect by three-diamensional(3D)printing technique using self-developed lactide-Sanya methyl carbonate-glycolide(PLLA-TMC-GA)three copolymer PLTG as material and evaluate its biological safety,laying a theoretical foundation for animal experiment.Methods product samples occluder by 3D printing technique using self-developed lactide-Sanya methyl carbonate-glycolide three copolymer PLTG as material;to evaluate the blood compatibility of the occluder samples by hemolysis test,dynamic blood clotting test and platelet adhesion test;to evaluate the histocompatibility by implantation experiment;to evaluate the systemic toxicity of occluder samples to animals by systemic acute toxicity test.Results Combined with the existing clinical data and reference to the parameters of previous occluder,CAD software was successfully used to design the occluder model,and the complete absorbable occluder sample was successfully produced by using the 3D printer,and the actual sample was basically consistent with the design model.The survival rates of cells in the 24 h and 48 h time point 100% occluder samples were 84.9%and 90.1% respectively,indicating that the occluder material had no obvious toxicity to the cells.The hemolysis test showed that the OD value of the negative control group was0.018,less than 0.03,and the positive control group was 0.778,which was in line with 0.8+ 0.3 limits;the hemolysis rate of the occluder sample material was 2.5%,not more than5%,indicating that the occluder had a slight damage to the red blood cell.The dynamic coagulation test showed that the downward trend of the positive control group was drastic,indicating that the positive control group had a higher activation degree to the coagulation factor,and the overall morphological trend of the material curve of the occluder sample was similar to that of the negative group,and the decreasing trend of the occluder was relatively slow with time,indicating that the occluder material was in the internal source.The activation of sexual coagulation factors is low.Platelet adhesion test showed that the platelet morphology index of the material of occluder was 2.55,and the platelet morphology index of poly(L-lactic acid)group(PLLA)was 2.74,indicating that thedeformation degree of the occluder sample material to the platelet was similar to that of the PLLA material,and even better than PLLA.In the implant test,all the animals were successfully built,the operation process was smooth,the dead animals were not found after the operation,no obvious tissue damage and necrosis were found,the experimental results were in accordance with the national standard.The body weight of the experimental mice was not obviously changed at 48 h and 72 h,indicating that the material of the occluder had no acute systemic toxicity,and the material was qualified.Conclusion The new biodegradable heart defect occluder can be made by using the lactide-Sanya methyl carbonate-glycolate polymer PLTG as the material.It can be designed and made by 3D printing technology.The new biodegradable heart defect occluder has good biocompatibility,safety and reliability,and has large animal experimental conditions.