Comparative Study of Injectable Implants Based on Microparticles of Various Biodegradable Materials in a Murine Model of Subcutaneous Implantation

A comparative study of two commercially available injectable implants based on microparticles of various biodegradable materials (calcium hydroxyapatite and cross-linked collagen) was carried out using a murine model of subcutaneous implantation. The developed experimental model showed that both implants effectively replace the volume of soft tissues. Implant resorption was accompanied by a moderate chronic inflammatory response. The implant based on calcium hydroxyapatite microparticles caused pronounced post-injection swelling at 1 day after administration and demonstrated a more pronounced migration from the injection point. For this implant, an earlier onset of the process of replacing microparticles with autologous collagen fibers, accompanying its biodegradation, was observed. The implant based on cross-linked collagen microparticles had a greater lifting effect at the injection site and retained a longer effect of skin augmentation lasting for 12 months.