Enzymatically Degradable Electrospun Nanogel ScaffoldsPromoted in Vitro Proliferation of rADSC

Scaffolds that mimic the extracellular matrix (ECM) can promote the proliferation of stem cells. Poly­(<i>N</i>-isopropylacrylamide) (PNIPAM)/gelatin (PG) nanogel electrospun membranes were designed to replicate the hierarchical and dynamic nature of ECMs. First, PG nanogels with semi-interpenetrating network structures were synthesized by emulsion polymerization. Characterization using ¹H NMR and FTIR spectroscopies confirmed the successful incorporation of gelatin into the PNIPAM-based network. The PG nanogels were spherical with a size of 184.1–231.9 nm, and they demonstrated a thermoresponsive behavior. The rehydrated nanofibers exhibited an average diameter of 663.6 ± 50.1 nm and a Young’s modulus of 1.3 ± 0.1 MPa at 37 °C. The membrane completely degraded within 10 min of collagenase treatment. Adipose-derived stem cells from rats exhibited good proliferation on the PG membranes, with cell proliferation in the PNI50 group being 1.47 times that in the tissue culture plate (TCP) group. The PG nanofibers showed potential for stem cell expansion.