Facile synthesis of Fe3O4 photothermal nanoparticles coated with poly-3,4-dihydroxybenzaldehyde for improved photothermal therapy of cancer cells

Given the significant rise in the number of individuals diagnosed with cancer, the management of cancer therapy has become a prominent concern in society and a formidable task in human health care. Photothermal therapy has garnered significant interest in cancer treatment because of its exceptional efficacy and minimal invasiveness. Thus, current research mainly focuses on developing biocompatible materials with excellent photothermal properties. Therefore, we synthesized Fe3O4 nanoparticles coated with poly-3,4-dihydroxybenzaldehyde (Fe3O4@PDBA) where 3,4-dihydroxybenzaldehyde was covalently polymerized onto the surface of Fe3O4. The induction of PDBA leads to a dramatical improvement in the photothermal properties of Fe3O4. Besides, the thickness of the PDBA shell layer is also a key factor in the photothermal performance and various physicochemical properties of Fe3O4@PDBA and the photothermal performance of Fe3O4@PDBA increases with increasing thickness of the PDBA shell. Additional structural characterization of the products, DFT calculations of the UV-Vis absorption spectra and the HOMO-LUMO gap under the simple model of the polymer, and product identification by the use of H1NMR, MS, and other techniques were performed. Through multiple characterizations, the reaction solution color and UV-Vis absorption spectra were essentially consistent with the computed findings. The calculations confirm that the polymerization process of PDBA is progressively red-shifted and the absorption is gradually enhanced in the NIR region. Fe3O4@PDBA exhibited strong cytotoxicity against cancer cells (Hela, 98.0 %) in vitro photothermal treatment. Hence, Fe3O4@PDBA exhibits superior photothermal characteristics, targeting, biocompatibility (99.0 %), and degradability, which brings about significant potential for photothermal cancer therapy. [Display omitted] •New poly-3,4-dihydroxybenzaldehyde photothermal agent.•DFT calculates the maximum absorption wavelength redshift to match the actual test.•Strong photothermal and degradation properties.•Excellent biocompatibility and cancer cell killing ability.