Partial Hydrolysis of Poly(2-ethyl-2-oxazoline) and Potential Implications for Biomedical Applications?

The hydrolysis of PEtOx is studied to evaluate the potential toxicity of partially hydrolyzed polymers that might interfere with its increasing popularity for biomedical applications. The hydrolysis of PEtOx is studied in the presence of digestive enzymes (gastric and intestinal) and at 5.8 M hydrochloric acid as a function of temperature (57, 73, 90, and 100 °C). It is found that PEtOx undergoes negligible hydrolysis at 37 °C and that thermal and solution properties are not altered when up to 10% of the polymer backbone is hydrolyzed. Mucosal irritation and cytotoxicity is also absent up to 10% hydrolysis levels. In conclusion, PEtOx will not decompose at physiological conditions, and partial hydrolysis will not limit its biomedical applications. Poly(2‐ethyl‐2‐oxazoline) is shown to be stable against hydrolysis under physiological conditions. Up to 10% hydrolysis may occur before the thermal and solubility properties are significantly altered. Partially hydrolyzed PEtOx with up to 10% hydrolysis does not induce slug mucosal irritation and shows no cytotoxicity, demonstrating that partial hydrolysis does not limit biomedical applications.