Targeted theranostics agent based on polydopamine/hyaluronic acid nanoparticles for MRI and photothermal therapy.

Theranostics based on magnetic resonance imaging (MRI) and photothermal therapy can provide high‐resolution imaging with the minimum side effect of cancer treatment. In this research, polydopamine nanoparticles (PDA‐NPs) are synthesized and functionalized with hyaluronic acid (HA) as a cancer‐targeting theranostics agent. The synthesis of PDA‐NPs with an average size of 25 nm is confirmed by field emission scanning electron microscope, and the functionalization of PDA‐NPs with HA is confirmed by ultraviolet–visible spectroscopy and Fourier transform infrared spectroscopy. The highest longitudinal relaxation rate (r1) is observed at the Fe to PDA weight ratio of 0.25 by MRI analysis. MTT results confirm that the PDA/HA‐NPs to Fe ion concentration of 6 μg mL−1 are not toxic (cell viability, 80%–95%). The result of immunocytochemistry analysis shows the binding of 78% of PDA/HA‐NPs to the human bone marrow mesenchymal stem cells with CD44 antigens. Finally, PDA/HA‐NPs are irradiated by an 808 nm laser to investigate their photothermal property. The specific absorption rate of PDA/HA‐NPs at a concentration of 0.4 mg mL−1 with an iron ratio of 0.25 is determined as 107.95 W g−1 when irradiated with a laser of 500 mW cm−2 power density. [ABSTRACT FROM AUTHOR]