Опыт разработки погружных изделий для остеореконструкции с эффектом памяти формы и антибактериальной активностью на основе полилактида/гидроксиапатита

Experience in the development of immersible osteoarthritis devices with shape memory and antibacterial activity based on a polylactide/hydroxyapatite

Background. Based on the results of evaluating the mechanical and strength characteristics and studying various aspects of biological activity, a composite material based on polylactide and hydroxyapatite (PLA/HA) is considered a promising component of shape-memory implants for osteoreconstructive surgeries. Aim. To evaluate the response of laboratory animals to the implantation of PLA/HA-based implant samples, as well as the potential for their use as a platform for the local administration of antibacterial agents. Materials and methods. Experimental samples were manufactured in the form of surgical staples from a PLA/HA composite material containing 15 % mass fraction of impurities by weight of hydroxyapatite in the form of 90 nm needle-shaped nanoparticles. To study biocompatibility and biodegradation in vivo, the staples were implanted subcutaneously in mice. After 50 days, the samples were removed, their weight changes were assessed, and histological tissue sections in the area of contact with the implants were examined. To explore the potential of using PLA/HA as a platform for local delivery of an antibacterial drug, 35 μg of an amoxicillin/clavulanic acid mixture was applied to the surface of the samples, followed by washing. The loaded samples were then placed on Mueller–Hinton agar seeded with Escherichia coli and Staphylococcus aureus. After 20 hours of incubation, the presence of zones of inhibition of colony formation around the samples and disks was assessed. Results. The shape memory effect was achieved by heating the samples, resulting in the closure of the initially open fixation clips. Although no significant change in sample weight was observed during their residence in the animals, histological examination of the surrounding tissue revealed signs of their initial biodegradation in vivo. No massive infiltration of tissue in the contact area by inflammatory cells, characteristic of an acute inflammatory response, was detected. However, isolated foreign body giant cells and isolated macrophages, lymphocytes, and neutrophils were observed in some samples. Microbiological studies demonstrated an inhibitory effect on the growth of E. coli and S. aureus colonies around the samples. Conclusion. The obtained results demonstrated the biocompatibility of PLA/HA with a hydroxyapatite content of 15 % mass fraction of impurities by weight, as its implantation did not induce an acute inflammatory reaction or rejection in experimental animals. Furthermore, it was demonstrated that products made from this material can be used as a platform for the local delivery of antibacterial agents. © 2025, ABV-press Publishing House. All rights reserved.