Erythrocyte-platelet hybrid membranes coating polypyrrol nanoparticles for enhanced delivery and photothermal therapy.

Polypyrrole nanoparticles (PPy NPs) have been extensively studied for photothermal therapy (PTT) of tumors because they can generate heat upon near-infrared (NIR) irradiation. Developing non-toxic, self-targeting and long-circulating PPy biomaterials to maximize photothermal effects remains challenging. Here, we show that PPy NPs camouflaged with fusing red blood cells (RBC) and platelet (PLT) membranes can kill tumor cells under direct near infrared irradiation (NIR). The resulting RBC-PLT hybrid membrane-coated PPy NPs (PPy@[R-P] NPs) possess characteristics of both RBC and PLT, exhibiting long circulation times and self-targeting properties. After administration of PPy@[R-P] NPs via tail vein, tumor vessels were injured by photothermal stimulation under NIR laser exposure, which induced a large amount of microthrombosis. Due to the existence of PLT membranes, a large number of PPy@[R-P] NPs were successfully recruited to the microthrombosis sites. As a result, the distribution of nanomaterials in the tumor tissues was improved, and excellent photothermal treatment was achieved. The resulting PPy@[R-P] NPs may contribute to anti-tumor PTT.