Near-Infrared Polymeric Nanoparticles with High Content of Cyanine for Bimodal Imaging and Photothermal Therapy

The discovery and synthesis of theranostic nanomedicines with high loading of imaging and therapeutic agents is challenging. In this work, a polymer assembling strategy was used to make nanoparticles with exceptionally high loading of theranostic agent. As an example, poly(heptamethine) was synthesized via multicomponent Passerini reaction, and then assembled into nanoparticles in the presence of poly(ethylene glycol)2k-block-poly(d,l-lactide)2k (PEG-PLA) with high heptamethine loading (>50%). The formed nanoparticles could be used for bimodal bioimaging and photothermal therapy. The bimodal bioimaging provided complementary message about biodistribution, and photothermal treatment inhibited the growth of cervical carcinoma upon laser irradiation. This assembly of polymers formed by imaging and therapeutic agents opens new possibilities for the construction of multifunctional nanomedicines.