Single-step formulation of levodopa-based nanotheranostics – Strategy for ultra-sensitive high longitudinal relaxivity MRI guided switchable therapeutics
Nanotheranostics (combined diagnosis and therapy) is emerging as the integral part of future therapeutic strategy. However, developing and fabrication of nanotheranostic module involves multistep processes and always faces formulation challenges. The complexity involved during its multi-step formulations hinders them from reproducible industrial production and clinical translation. Therefore, a facile synthesis for multifunctional nanotheranostics is critical to its translational success. In this present report, we have developed a one-pot facile strategy to prepare MRI-visible photothermal theranostic switchable module (T-SWITCH). These nanoparticles are synthesized through polymerization of levodopa together with the reduction of KMnO4 in presence of silk sericin for the formation of manganese dioxide particles within T-SWITCH. The synthesized T-SWITCH showed uniform size distribution around 100 nm with high longitudinal relaxivity coefficient (r1) up to 61.94 mM-1s-1. The reported r1 of T-SWITCH is exceedingly higher than any previously reported manganese-based contrast agents with first-rate in vitro and in vivo contrast enhancement capability. T-SWITCH can be activated to switch its therapeutic mode by near-infrared light (NIR). It exhibited strong excitable absorption in the safer and biological NIR window between 650~900nm. We have validated the significant efficacy of T-SWITCH anti-cancer therapeutic efficacy both in vitro and in vivo through switchable photothermal therapy.