Using a biocompatible diazidecrosslinker to fabricate a robust polyelectrolyte multilayer film with enhanced effects on cell proliferation

Due to the noncovalent interactions between the layers of polyelectrolyte films, the layer-by-layer assembled multilayered films always face the challenge of low film stiffness and chemical stability under extreme conditions. To handle this issue, we incorporated 4,4′-diazostilbene-2,2′-disulfonic acid disodium salt (DAS) as a crosslinker and subsequently photocrosslinked the layers of a poly(allylamine hydrochloride)/catalase multilayered film. The results showed that DAS could stabilize the prepared film in a manner similar to the traditional cross-linker glutaraldehyde. The multilayered film showed good biocompatibility with a positive effect on cell proliferation. Therefore, by using the commercially available DAS crosslinker, we provide a synthesis-free and biocompatible method to stabilize polyelectrolyte multilayers for broad and significant applications in biological fields, e.g., varying crosslinking density to adjust the mechanical strength of biomaterials, stabilizing susceptible biofilms, or introducing functional groups onto cell membranes.