Assessing the degradation profiles of a thermoresponsive polyvinyl alcohol (PVA)-based hydrogel for biomedical applications

Primary challenges associated with the design and success of polymeric biomedical devices are generally related to the control of the biomaterial in terms of degradability characteristics, sufficient processability characteristics, and required mechanical strength that may be altered during sterilization or manufacturing procedures. Polyvinyl alcohol-based thermoresponsive biomaterials provide a distinct advantage for biomedical applications as their physiochemical properties can be easily modified according to their desired use. In this work, we evaluated the thermal degradation characteristics of a polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/polyvinylpyrrolidone (PVP) hydrogel that undergoes a steam sterilization autoclave cycle at 121(degrees)C to induce fluid-like behavior. FTIR was used to characterize the evolution of the area of the carbonyl region between 1800 and 1525 cm(-1). The carbonyl area increased at temperatures beyond 121(degrees)C which were used to accelerate the onset of degradation during both thermal oxidation and pyrolysis. The change in the carbonyl region was shown to correlate with respect to both temperature and time of exposure. The carbonyl region increased significantly in the presence of oxygen at temperatures above 150(degrees)C. Despite showing signs of thermal degradation at temperatures exceeding 150(degrees)C, our biomaterial was shown to be stable at 121(degrees)C during thermal degradation testing. Furthermore, bulk property analysis showed the hydrogel's mechanical and swelling properties were preserved even after being subject to multiple autoclave cycles beyond what would be experienced during a sterilization or clinical procedure.