The assessment of biocompatibility and cytotoxicity of materials plays a critical role in materials development, ensuring safe and effective utilization in medical and biomedical applications. This enables the development of innovative solutions that are not only technologically advanced but also compatible with biological systems . The cytotoxicity assessment was carried out according to the ISO 10993-5, by indirect contact of copolymer extracts with the cells. The cell viability results for L292 mouse fibroblast cell line after exposure to copolymer extracts for 24h are represented in Figure . The red color dashed line marked at 70% is the cytotoxicity threshold according to ISO10993-5. In general, all the copolymers indicated cell viability higher than 70%, which indicates good biocompatibility of the materials. Those results were also comparable with negative control (PCL) confirming their suitability for biomedical applications. Overall, new segmented PBS-DLS copolymers of variable segmental composition and modified with PEG showed high cytocompatibility similar to our previous in vitro and also in vivo studies of PBS-DLS modified with hydroxyapatite .