One-Step Preparation of Fe3O4/Nanochitin Magnetic Hydrogels with Remolding Ability by Ammonia Vapor Diffusion Gelation for Osteosarcoma Therapy

Chitin, a kind of second abundant natural saccharide, has great potential in biomedical applications. Here, chitin nanofibers combined with magnetic nanoparticles, a magnetic hydrogel, was prepared in one step by mixing Fe ions with partially deacetylated chitin nanofibers (DEChNs) and physically coagulating in an ammonia gas bath. The storage modulus of the prepared magnetic DEChN (M-DEChN) hydrogels reached 5507 Pa and could be remolded by adjusting the pH value assisted with an ultrasound treatment. In addition, the M-DEChN hydrogels showed an assignable heating behavior in alternating electromagnetic fields (AMFs), and the temperature of the M-DEChN was adjustable by controlling the content of magnetic particles inside. Benefiting from the remote heating ability, the biocompatible magnetic hydrogel showed thermoablation ability to osteosarcoma cells both in vitro and in vivo. These kinds of M-DEChN hydrogels show great application prospects in killing cancer cells.