Confined electrophoretic deposition of uniformly dispersed nanoparticles-integrated hydrogels with enhanced mechanical and enzyme-like properties for antibacterial therapy

Nanoparticle-integrated hydrogels leverage favorable properties of both hydrogels and nanoparticles to create new functional materials for attractive applications. However, traditional integrated approaches can not guarantee the uniformity and full exposure of incorporated nanoparticles, resulting in unsatisfactory performance. In this work, the integrated hydrogel network uniformly deposited with MnSiO₃ nanoparticles (defined as MnSiO₃ based E-gels) has been successfully prepared by a confined electrophoretic deposition (EPD) strategy. The density of cross-linking points and the electrostatic attraction effects of the hydrogel network at the cathode significantly affect the deposition behavior of nanoparticles. The confined EPD strategy exhibits extensive versatility and convenience, enabling the ultra-uniform deposition of a series of nanoparticles (Ag, ZnO, NiO, Fe₃O₄, MoS₂, MnO₂, CuO and ZIF-8) with positive charges within the hydrogel micro-pores within one minute. Equidistant distribution of nanoparticles under the electrostatic field with better dispersity and higher binding stability exhibits significant advantages for the nano-integrated hydrogels. As expected, the mechanical strength, adhesion property, enzyme-like activity, in vitro and in vivo bacterial inhibition effects were significantly improved compared with those of the conventional hydrogels. Therefore, the E-gels prepared by the confined EPD strategy provide a promising and versatile protocol for high-efficiency integration of polymer-based hydrogel networks and functional nanoparticles for attractive applications.