Biological aspects of the polylactide-based composite materials application in orthopedics

Background. Patients with malignant bone and joint tumors often require reconstructive surgery for osteosynthesis or arthrodesis. The design of the implant can be realized by 3D printing using biodegradable materials with shape memory effect, which will facilitate operative access and reduce the risk of reoperation.Aim. The study aimed to evaluate the mechanical properties, biocompatibility and biological activity of polylactide (PLA) with hydroxyapatite (HA) and silicon dioxide (SiO2) produced by extrusion and 3D printing to identify prospects for the development of implants based on them for osteoreconstructive surgeries.Materials and methods. Materials based on PLA with the addition of 10, 15 and 20 % HA and SiO2 were obtained by extrusion. These materials were 3D-printed to produce samples that underwent a compression test. Their extracts obtained after incubation of the samples in fetal calf serum for 30 days were examined. Biocompatibility was assessed by the level of hemolysis and cytotoxicity of the extracts, as well as stimulation of oxidative stress. The effects of the extracts on cell adhesion and intensity of multipotent mesenchymal stromal cells colonization on the surface of both intact and biodegraded samples were studied separately.Results. The addition of HA and SiO2 to PLA did not significantly increase hemolysis and cytotoxicity compared to pure PLA. However, incubation with extracts of samples containing 20 % stimulated an increase in oxidative stress in leukocytes, and inhibited cell adhesion. Samples with 10 and 15 % HA maximally stimulated cell colonization on the sample surface.Conclusion. Materials based on PLA with 10 and 15 % HA combine high strength, biocompatibility, biodegradability and effective osteoconductivity, which makes them promising candidates for implants for osteoreconstruction and arthrodesis.