Abstract: BACKGROUND: Neural catheterization repair of peripheral nerve defects is a research hotspot in the field of biomedical engineering, but the autologous nerve graft repair method as the gold standard has limitations, so there is an urgent need for a method that can replace autologous nerve grafting to repair peripheral nerve defects.
OBJECTIVE: To observe the degradation characteristics and biological toxicity of the new domestic polyglycolic acid neural catheters.
METHODS: (1) Degradation performance: PBS was added to the test tubes of the blank control group. PBS and new domestic polyglycolic acid neural catheter were added to the test tubes of the fluid exchange group, with PBS changed every 3 days. PBS and the new domestic polyglycolic acid neural catheter were added to the test tubes of the non-fluid exchange group, without changing the fluid. All three groups of test tubes were placed in a 37℃ incubator, and the pH value of the fluid in the test tubes was checked weekly. (2) Cell experiments: Human fibroblasts were cultured in two groups: the control group received simple culture medium, and the experimental group received culture medium containing an extract of the new domestic polyglycolic acid neural catheter. Cell compatibility of the nerve conduit was assessed by cell morphology, CCK-8 assay, scratch assay, and Transwell assay. (3) In vivo histocompatibility: The new domestic polyglycolic acid neural catheter and the imported neural catheter were implanted between the biceps femoris and gluteus maximus muscles of SD rats, respectively, to evaluate the degradation characteristics and biotoxicity of the neural catheters. 
RESULTS AND CONCLUSION: (1) In vitro degradation experiments showed that, with fluid exchange, the degradation of the new domestic polyglycolic acid neural catheter had little effect on the pH of the surrounding fluid. Without fluid exchange, the degradation of the new domestic polyglycolic acid neural catheter lowered the pH of the surrounding fluid. (2) Cells in both groups showed good growth, with normal cell morphology and volume. CCK-8 assay showed that the new domestic polyglycolic acid neural catheter did not affect the proliferation of human fibroblasts. Scratch and Transwell assays showed that the new domestic polyglycolic acid neural catheter did not affect the migration of human fibroblasts. (3) The degradation of the new domestic polyglycolic acid neural catheter was similar to that of the imported neural catheter. Hematoxylin-eosin staining showed that the new domestic polyglycolic acid neural catheter had no significant effect on the major organs of rats. Masson staining showed that the tissues surrounding the neural catheter in both groups of rats were normal, with no inflammatory cell infiltration observed. (4) The results indicate that the new domestic polyglycolic acid neural catheter has good degradability and no biotoxicity. 

Key words: polyglycolic acid, polyglycolic acid neural catheter, autologous nerve grafting, peripheral nerve defects, in vitro degradation, in vivo implantation