As mentioned above, the improvement of the performance properties of PBS-based materials can be achieved by creating a composite system. To date, additives such as lignin , cellulose , chitin or hydroxyapatite (HAp) particles have been used. The last of these fillers -HAp -is a mineral with a composition similar to the mineral fraction of human bone, making it a candidate for use in bone tissue engineering . To date, several experiments have been carried out using PBS-based materials with the addition of HAp. Piotr Prowans et al. showed that the PBS-DLA composite with 30 wt% addition of hydroxyapatite nanoparticles is an attractive material for bone healing applications . In turn, GanG Li's work demonstrated that the addition of HAp nanoparticles to PBS significantly improved the proliferation and adhesion of mouse embryonic fibroblast cells to the surface of the porous biomaterial . Studies have also been carried out demonstrating the reinforcing effect of HAp nanoparticles on the mechanical properties of PBS-based materials prepared by extrusion and injection moulding methods. In all of these works, nano-sized HAp particles were used. To date, there are no reports on the influence of micro-hydroxyapatite on the broadly understood properties of PBS-based materials. Many scientific reports indicate that the particle size of the apatite filler can have a significant effect on biological, physicochemical or mechanical properties .