75% ethanol disinfection preserves biocompatibility and mechanical properties of swim bladder for cardiovascular applications

To evaluate the effects of 75% ethanol on the disinfection efficacy, biocompatibility, extracellular matrix (ECM) integrity, and mechanical properties of swim bladders from Hypophthalmichthys nobilis, a promising biomaterial for cardiovascular applications. Swim bladders were immersed in 75% ethanol for 30, 60, or 120 minutes, followed by phosphate-buffered saline (PBS) rinsing. Disinfection efficacy was assessed using bacterial cultures; cytotoxicity and blood compatibility were evaluated using CCK-8 assays and hemolysis tests. The decellularization efficiency, ECM integrity, and mechanical properties were analyzed through histological staining, DNA quantification, and uniaxial tensile test. 75% ethanol effectively disinfected the swim bladder with minimal cytotoxicity and good hemocompatibility. Histological staining demonstrated preservation of collagen fibers, elastin, and glycosaminoglycans (GAGs), indicating minimal impact on the ECM structure. The uniaxial tensile test revealed that ethanol immersion caused tissue dehydration and increased stiffness, but these effects were reversible after PBS rinsing, with mechanical properties returning to baseline. DNA content and tissue thickness normalized following PBS washing, suggesting that ethanol did not impair decellularization. 75% ethanol is an effective disinfectant for swim bladder biomaterials, preserving biocompatibility, ECM structure, and mechanical properties after rinsing. These findings support the use of swim bladder-derived scaffolds in cardiovascular tissue engineering applications.