Characterizations of the strain-stiffening property and cytotoxicity in the self-assembled polyampholyte hydrogel

Strain-stiffening is a mechanical response that mimics the behavior of biological tissues. In this study, we fabricated and characterized P(TM co SA-CAA) hydrogel. These hydrogels were referred to as SA, 0.75 SA + 0.25 CAA, 0.5 SA + 0.5 CAA, 0.25 SA + 0.75 CAA, and CAA. Scanning electron microscopy of the hydrogel revealed that the nanofibrillar networks were homogeneously and compactly connected. Notably, the addition of SA-CAA led to remarkable improvement (of 260 kPa and over fourfold) in the elastic modulus and elongation at the break point. The best strain-stiffening was observed for the 0.5 SA + 0.5 CAA hydrogel. Additionally, the investigation of P(TM co SA-CAA) hydrogel mechanism viability and proliferation revealed no toxicity. The strain-stiffening property of P(TM co SA-CAA) facilitates the adhesion of cells. These results suggest that the strain-stiffening of self-assembled P(TM co SA-CAA) hydrogels may be appealing for biomedical applications.