Laboratory Assessment of the Polylactide Bone Implants Impact on Rats at Different Observation Terms

The article deals with the issues of laboratory assessment of the effect of biodegradable implants based on polylactide when inserted into the femoral bone of experimental rats at different observation periods. Implants used composite material only based on polylactide, as well as based on polylactide, hydroxyapatite and tricalcium phosphate. Materials and Methods. Experimental animals (n = 40) had a bone defect in the diaphysis region of the femur. The first group of rats (n = 20) carried out an implantation of a composite material made of polylactide, the second group (n = 20) took the material made of polylactide, hydroxyapatite and tricalcium phosphate. We studied glycoproteins, sialic acids, chondroitinsulfates, ALT and AST, alkaline phosphatase, γ-glutamyltranspeptidase, bilirubin, urea and creatinine in blood serum of the rats at 30, 90, 180 and 360 days after implantation. Results and Discussion. The content of glycoproteins was increased by 39.9 %, chondroitin sulfates – by 67.1 %, alkaline phosphatase activity – by 67.4 %, compared to the control group, after 30 days of implanting the composite material based on polylactide. After 90 days, the content of glycoproteins was reduced by 30.6 % compared to the 30th day of implantation and did not differ from the indicator in the control group. The content of chondroitinsulfates decreased by 12.0 %, alkaline phosphatase activity – by 24.9 % compared to the 30th day of implantation and remained elevated compared to the control group. The biochemical parameters of the liver and kidney functional state did not change during follow-up after implantation. The content of glycoproteins in the group of rats, which had been implanted composite material, based on polylactide, hydroxyapatite and tricalcium phosphate, increased by 29.0 %, chondroitinsulfates – by 46.8 %, alkaline phosphatase activity – by 47.1 % compared with the control group. At 90 days, the content of glycoproteins decreased by 21.3 %, chondroitinsulfates – by 18.0 %, alkaline phosphatase activity – by 15.7 % compared with the 30th day after implantation. Biochemical markers of kidney and liver during the experiment were not altered compared to the control group of animals. It was also found that in rats of both groups at 180 and 360 days after implantation, the content of biochemical parameters in blood serum did not differ from the control group. However, it should be noted that the content of glycoproteins at 30 days after implantation in the first group of rats was higher by 8.4%, chondroitin sulfates and alkaline phosphatase activity – by 13.8 % compared to those in second group. For 90 days, content only chondroitin sulfate content was increased by 22.3 % compared to the 30th day after implantation. Conclusions. Thus, the regenerative-inflammatory process in the bone tissue was better in the second group of rats, which used a composite material based on polylactide, hydroxyapatite and tricalcium phosphate as an implant in comparison with using polylactide as an implant.