Investigation of foldable characteristics and C2C12 cell viability in stimuli-responsive pNIPAM hydrogel matrices

Stimuli-responsive structures have emerged as pioneering tools by integrating responsiveness to external stimuli into traditional 3D processes. This advancement offers numerous advantages across various fields, with tissue engineering particularly benefiting from incorporating biomimetics into its manufacturing process. By utilizing thermo-responsive bio-hydrogels, which can transform their properties and shapes in response to external stimuli, tissue engineering can potentially overcome significant challenges in producing 3D bio-scaffolds. In this study, we conducted preliminary investigations into the potential of poly (N-isopropyl acrylamide) (pNIPAM)-based hydrogels as substrates for C2C12 cells and evaluated their folding behaviour under different temperatures. We formulated a base composition of pNIPAM hydrogel and examined its suitability as thin substrates for cell sheet production and thicker substrates for potential 3D scaffolding. Our findings revealed that cells adhered and developed on thin hydrogel layers, achieving full confluence while maintaining metabolic activity comparable to those cultured on standard substrates. However, this behaviour was not replicable on thicker pNIPAM substrates due to their low stiffness, an extensive property that needs improvement. In conclusion, our current pNIPAM composition shows strong potential for printing hydrogels to be used as cell substrates for cell sheets, eliminating the need for enzymes in cell detachment. While it also demonstrates promise for application as a 3D scaffold, enhancements in stiffness are necessary to fully realize this potential.