Self-assembly of paramagnetic amphiphilic copolymers for synergistic therapy.

Engineering nanoparticles (NPs) with multifunctionality has become a promising strategy for cancer theranostics. Herein, theranostic polymer NPs are fabricated via the assembly of amphiphilic paramagnetic block copolymers (PCL-b-PIEtMn), in which IR-780 and doxorubicin (DOX) were co-encapsulated, for magnetic resonance (MR) and near infrared fluorescence (NIRF) imaging as well as for photo thermal therapy (PTT)-enhanced chemotherapy. The synthesized amphiphilic paramagnetic block copolymers demonstrated high relaxivity (r1 = 7.05 mM-1 s-1). The encapsulated DOX could be released with the trigger of near infrared (NIR) light. In vivo imaging confirmed that the paramagnetic NPs could be accumulated effectively at the tumor sites. Upon the NIR laser irradiation, tumor growth was inhibited by PTT-enhanced chemotherapy. The advantages of the reported system lie in the one-step convergence of multiple functions (i.e., imaging and therapy agents) into a one delivery vehicle and the dual mode imaging-guided synergistic PTT and chemotherapy. This study represents a new drug delivery vehicle of paramagnetic NPs for visualized theranostics.