Rapid Photoinduced Self-Healing, Controllable Drug Release, Skin Adhesion Ability, and Mechanical Stability of Hydrogels Incorporating Linker-Modified Gold Nanoparticles and Nanogels

Appropriately modified thermoresponsive hydrogels, such as poly(<i>N</i>-isopropylacrylamide) hydrogels, bring an opportunity for a variety of biomedical applications. Incorporating compounds with different properties into poly(<i>N</i>-isopropylacrylamide) hydrogels offers opportunities to enhance their mechanical, self-healing ability, adhesiveness, thermal responsiveness, and drug release capabilities. In this study, we investigated the influence of Au-sulfur interactions on the properties of the poly(<i>N</i>-isopropylacrylamide) hydrogels after introducing <i>N,N'</i>-bis(acryloyl)cystine (a newly synthesized cross-linker), modified gold nanoparticles, and a p(NIPAm-BISS) nanogel into the hydrogel matrix. Our findings demonstrated that poly(<i>N</i>-isopropylacrylamide) hydrogels with these compounds exhibited higher mechanical strength (65% tensile stress and 25% elongation), faster thermal responsiveness, controllable self-healing [85% recovery after 2 min, using a NIR laser (800 nm, 0.75 W)], skin adhesiveness, and enhanced drug release (0.08 mg·mL^-1, a 93% improvement). These results may contribute to advancements in the design of temperature-responsive hydrogels tailored for specific biomedical needs, such as targeted drug delivery with the use of a NIR laser and tissue engineering.