Abstract

Poly(n-butyl cyanoacrylate) (PBCA) is a widely used adhesive; however, its long-term stability and unpredictable biodegradation behavior under physiological conditions remain concerns for applications requiring prolonged in-body exposure. To assess its stability and preliminary biosafety under simulated physiological conditions, this study employed a combined kinetic and biological approach to systematically investigate the degradation mechanism and predict the thermal-stability lifetime of modified PBCA adhesives. Thermogravimetric measurements performed at multiple heating rates yielded an average activation energy of 109.4 kJ/mol. The degradation followed a phase-boundary-controlled mechanism with cylindrical symmetry, consistent with the R 2 model. Kinetic predictions revealed a strong temperature dependence, where the thermal-stability lifetime declined from over 473 days at 37 °C to approximately 85 days at 50 °C. Additionally, MTT assays, LIVE/DEAD staining, and cell adhesion tests using L929 fibroblasts verified the excellent cytocompatibility of PBCA adhesives, with cell viability maintained above 90%. This study provides a kinetic basis for understanding the thermal stability of PBCA and offers quantitative evidence supporting its preliminary in vitro biosafety profile, thereby informing further evaluation for implant-related biomedical use. Graphical abstract