A polydopamine-coated LAPONITE®-stabilized iron oxide nanoplatform for targeted multimodal imaging-guided photothermal cancer therapy

The development of theranostic nanoplatforms with accurate diagnosis and effective therapy performance is crucial for precision medicine applications. Herein, we developed a novel targeted theranostic nanoplatform for magnetic resonance (MR) and photoacoustic (PA) imaging-guided photothermal therapy of cancer cells overexpressing sialic acid (SA). Firstly, LAPONITE® (LAP)-stabilized Fe3O4 nanoparticles (NPs) with a high r2 relaxivity were synthesized by a coprecipitation method, and then polydopamine (PDA) was coated to improve the photothermal effect and PA contrast effect, followed by the modification of PEGylated phenylboronic acid (PEG–PBA) to introduce tumor-targeting specificity into SA-overexpressed cancer cells. The formed LAP–Fe3O4@PDA–PEG–PBA NPs show excellent biocompatibility and photothermal conversion efficiency under near-infrared laser irradiation and are able to be used for dual modal MR/PA imaging of a xenografted tumor model and induce complete eradication of tumors after NIR laser treatment. In summary, LAP–Fe3O4@PDA–PEG–PBA NPs could be theranostic nanoplatforms for sensitive MR/PA imaging and effective photothermal therapy of SA-overexpressed tumors.