Dopamine and DNA functionalized manganese whitlockite nanocrystals for magnetic resonance imaging and chemo-photothermal therapy of tumors

Multifunctional inorganic nanomaterials have opened new avenues for cancer diagnosis and therapy. However, the difficulty to functionalize them has prevented their wider application, owing to the lack of active groups on their surfaces. Here we report a novel method to functionalize manganese whitlockite (Mn-WH) with polydopamine (PDA) and hairpin DNA (hpDNA) to improve the water stability and anti-cancer effects of Mn-WH nanoparticles (Mn-WH NPs). Compared to WH NPs, the Mn-WH@PDA-hpDNA NPs exhibit better water dispersibility, high drug loading capacity, excellent photothermal performance, stable MRI imaging ability, and outstanding chemo-photothermal synergistic therapeutic potential against tumors. After intratumoral injection in nude mice, the Mn-WH@PDA-hpDNA-DOX NPs promote complete tumor ablation upon exposure to 808 laser-irradiation. The nanoparticles showed no major side effects or toxicity. Thus, these results indicate that the Mn-WH@PDA-hpDNA-DOX NPs have excellent potential as anti-cancer agents, along with excellent magnetic resonance imaging (MRI) capabilities and the reported functionalization approach provides a novel and effective strategy for the surface functionalization of inorganic nanomaterials.