Hydrogen Bond-Mediated Supramolecular Polymeric Nanomedicine with pH/Light-Responsive Methotrexate Release and Synergistic Chemo-/Photothermal Therapy

Complete cancer cure and healing are still difficult, owing to its complexity and heterogeneity. Integration of supramolecular forces, for example, hydrogen bonds (H-bonds), to anti-cancer nanomedicine affords new scaffolds for biomedical material decoration, featuring the advantages of dynamic property and easier processability. Here, we target the construction of H-bond-mediated supramolecular polymer micelles, loaded with a chemotherapeutic drug along with a photothermal agent for synergistic chemo-/photothermal therapies (CT/PTT). To do so, we design and synthesize an amphiphilic ABA-type triblock copolymer, bearing H-bonding moiety (barbiturate, Ba) within the middle hydrophobic B block. The presence of pendant Ba moieties within the hydrophobic core promotes the loading capability of methotrexate (MTX) and transportation stability, benefitting from the formation of specific Ba/MTX H-bonding interactions. IR780, a photothermal agent, concomitantly encapsulated via hydrophobic interactions, facilitates the development of a synergistic CT/PTT modalities, where MTX can be released on demand owing to the dissociation of Ba/MTX H-bonding interactions induced by elevated temperature. Such H-bonding nanomedicine possesses enhanced drug loading capacity and transport performance and can also trigger stimuli-responsive drug release in the tumor zone. We believe that H-bonded nanomedicines provide a fine toolbox that is conducive to attaining biomedical requirements with remarkable values in theranostics that are highly promising in clinical applications.