The potential cytotoxicity or growth inhibitory effect of the PBA-DLA copolyester was investigated in cell culture, using L929 mouse fibroblasts based on ISO 1993-5. Cells (passages were kept in growth media (DMEM, 10% FBS, 2 mM L-glutamine, 100 U/ml penicillin, and 100 µg/ml streptomycin) in a T25 flask. For the experiments, a sub-confluent T25 flask of L929 cells was trypsinized and 1 × 10 4 cells per well were seeded in a 96-well plate. In parallel, a 100µm-thick film of PBA-DLA copolyester and reference material (polycaprolactone PCL CAPA® 6430) was cut into the three 6 cm 2 samples which were then sterilized in UV light for 15 minutes on each side. Next, samples of the material (n=3) were cut into smaller pieces and placed into a 24-well plate and 1 ml of medium was added to each well. The plates were then incubated for 24 hours (5% CO2, 37 °C) to allow the cells to adhere and spread, after which the media was aspirated and replaced with 100 µl of growth media containing extracts from tested materials (6 technical replicates were performed per material). Sham control was prepared by giving 100 µl of pure growth media. The plate was incubated for 24 hours and then cell viability was assessed via an inverted light microscope (Delta Optical IB-100) and resazurin viability assay using a fluorescent plate reader (Biotek Synergy HTX, excitation 540 nm, emission 590 nm). During resazurin viability assay complete growth media was added to the empty well without cells and it was considered as a blank. The obtained results were expressed as the percent of normalized cell viability (CV%) calculated using an equation .