Research of degradation and biocompatibility of polyglycolic acid nerve conduct
10.3760/cma.j.cn441206-20231028-00064
- VernacularTitle:聚乙醇酸神经导管的降解和生物相容性研究
- Author:
Haiwei SUN
1
;
Zeming BAI
;
Chunhui LI
;
Kai TAO
Author Information
1. 北部战区总医院干部病房一科,沈阳 110016
- Keywords:
Polyglycolic acid(PGA) nerve conduit;
Peripheral nerve injury;
Degradation;
Biocompatibility;
Rat
- From:
Chinese Journal of Microsurgery
2024;47(4):443-449
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the characteristics and data related to the degradation and biocompatibility of the domestically procuded polyglycolic acid (PGA) nerve conduit.Methods:This study was conducted in the Department of Burns and Plastic Surgery, the Northern Theater General Hospital between January and August 2022. PGA nerve conduits were immersed in 15 ml normal saline for in vitro experiments of degradation. The experimental period was 12 weeks. The pH of the immersion solution were tested weekly and the rates of mass loss were calculated. The in vitro experiments for biocompatibility were conducted in both of the experimental group and the control group. In the experimental group, a DMEM solution containing 10% of fetal bovine serum was used as the extraction medium, and domestically produced PGA nerve conduit was immersed in the extraction medium in the control group. An extraction medium was firstly prepared for a controlled extraction time of 72 hours±2 hours at 37 ℃±1 ℃. The pH of both experimental and control groups were tested at 24, 48 and 72 hours. The 72-hour extracts of both experimental and control groups were used to prepare the single cell suspension. The single cell suspension containing the cultured RSC 96 were separately seeded into 96-well plates for Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, to observe the effect of PGA nerve conduits on the proliferation of RSC 96. Then RSC 96 were incubated for 24 hours with the extracts of both experimental and control groups. The effect of PGA nerve conduits on the migration of RSC 96 was observed with Transwell assay. Twenty-four adult male SD rats were used and divided into experimental group and control group, with 12 rats per group, for the in vivo study of degradation and biocompatibility. Rats in the experimental group were implanted with domestically produced PGA nerve conduits, and Neurotubes, a US made nerve conduit, were implanted in the rats of control group. The PGA nerve conduits were implanted in a bluntly prepared gap between the biceps femoris muscle and the gluteus maximus muscle of the right hind limb of rats for the in vivo degradative experient. The degradation and biocompatibility of the PGA nerve conduit were evaluated by means of gross observation, tests of blood routine, liver and kidney functions and histological examinations at 2, 4, 8 and 12 weeks after implantation. SPSS 19.0 software was used for statistical analysis of the experimental data, and the results were expressed as Mean±SD. T test was used for inter-group comparison and Turkey method was used for intra-group and inter-group comparison. P<0.05 was used to determine whether the difference was statistically significant. Results:The rate of in vitro degradation was found at 1.470%±0.026% in week 4, and thereafter, a gradually accelerated degradation rate was observed and at a 32.180%±0.040% of degradation rate in week 12. The pH of the immersion solution decreased slowly in the first 2 weeks, with the pH at 6.200±0.061 in week 2. The pH then suddenly dropped to 3.930±0.118 in week 3, and then decreased slowly, with a pH 2.560±0.003 in week 12. Both MTT and Transwell experiments showed that the extract of PGA nerve conduits had no effect on the proliferation and migration of RSC 96, nor a significant difference existed in comparison with the corresponding control groups ( P>0.05). The experiments of in vivo degradation of PGA nerve conduits showed that the nerve conduits in both experimental and control groups had good support at week 2 after implantation. At weeks 4-12 after implantation, the nerve conduits in both groups gradually softened and collapsed, but the conduits were in one piece and not broken. The blood routine, liver and kidney functions showed no statistically significant difference between the 2 groups over the same period, and between each time point within the groups and the groups before implantation ( P>0.05). No obvious abnormal appearance of livers and kidneys was found in the rats sacrificed at each observation time point. Also, there was no obvious degeneration and necrosis of the muscle tissue around the conduits in the 2 groups, and no obvious inflammatory cells infiltration was found from the histological examinations. Morphology of the muscle tissue remained normal. Conclusion:Domestically produced PGA nerve conduit is fund good in both of biocompatibility and biodegradability. It is safe and reliable, and it provides a basis for the further experients in repair of nerve defects.
