2.7. Biocompatibility Testing (Cell Viability Assay)

The cytotoxic effect of the produced membranes on HFF-1 was evaluated in vitro following ISO 10993-5 and ISO 10993-12. The membranes were first sterilized by UV irradiation over 30 min, and then immersed in the cell medium for 24 h (the extraction ratio of dBAM and M1-1 is 6 cm²/mL and M1-3 is 3 cm²/mL). Therefore, the membranes were removed and the extraction medium was referred to conditioned medium. The HFF-1 was incubated with the conditioned medium in humidified incubator for 24 h. The control group was incubated with the normal cell medium. Cell viability was measured using the MTT method at specified time points. Briefly, 0.5 mg/mL MTT solution (100 μL) was added to the cell culture plates for staining living cells for 4 h. Afterwards, the MTT was removed and 100 μL DMSO was added to the culture plates, incubating for 15 min. Subsequently, the results were tested at 570 nm with Microplate reader (Bio-Rad 680).