In this work, we evaluated biodegradation, bioactivity, and cytotoxicity of PBS-DLS copolymers of variable segmental composition modified with PEG. The enzymatic degradation was performed with using Pseudomonas cepacia lipase over a period of 20 days, revealing that the copolymers are degraded by the enzyme at a slow rate, while the incorporation of PEG into the copolymer chains significantly accelerated the degradation process, evident from the increased mass loss and molecular weight decrease. This acceleration is attributed to the nature of hydrophilic PEG, which improved the surface wettability, allowing for easier hydrolysis and accessibility of water molecules into the copolymer structure. The molecular weight of the copolymers was also reduced after degradation tests, with the PEG modification further decreasing the Mn and Mw. The higher crystallinity of copolymers containing higher hard segments content