77PRed-blood-cell-membrane-enveloped magnetic nanoclusters as a biomimetic theranostic nanoplatform for bimodal imaging guided cancer photothermal therapy

Background Due to their intrinsic thermal and magnetic resonance imaging properties, magnetic nanoparticles (MNCs) have attracted more and more attention in the biomedical field. However, relatively weak photothermal conversion (PTC) efficiency and low tumor homing capacity has hampered its further application in vivo. Methods To solve these problems, we modified near-infrared (NIR) light-absorbing materials onto the surface of MNCs to increase PTC efficiency and increase MNCs tumor homing capacity by coated red blood cell (RBC) membranes. Results Our data show that after being loaded with NIR cypate molecules, the as-prepared Cyp-MNCs showed remarkably increased NIR absorbance and resultant PTC efficiency compared with the MNCs. By disguising itself, Cyp-MNCs coated with erythrocyte membranes inherit the long circulation characteristics of RBCs to improve the MNCs' tumor homing capacity. By tracking the NIR fluorescence of cypate under an in vivo fluorescence imaging system, we discovered that such Cyp-MNC@RBCs upon intravenous injection show significantly improved tumor homing capacity compared with bare cypate-loaded MNCs. The antitumor efficiency of biomimetic Cyp-MNC@RBCs was particularly prominent and was superior to biomimetic MNC@RBCs. Additionally, fluorescence and T2-weighted magnetic resonance imaging (MRI) functionalities were all retained attributable to Cyp-MNC@RBCs cores. Conclusions Our study would provide a promising procedure for other similarly enhanced photothermal treatments by increasing PTC efficincies and improving tumor-homing capacity. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.