β-Cyclodextrin-Grafted Polypyrrole–Rhodamine B Nanoplatforms for Drug Delivery and Image-Guided Photothermal Therapy In Vitro

Synergetic therapeutic study using multifunctional nanoplatforms has been developed as an innovative modality for effective cancer treatment to improve the clinical efficiency of anticancer drugs and reduce severe off-target side effects. Herein, an artificial nanoplatform (denoted as PPy-RhB-PDA-CD-LA) was prepared by grafting β-cyclodextrin (β-CD) derivatives and lactobionic acid (LA) on the surface of rhodamine B (RhB)-doped polypyrrole nanoparticles (PPy-RhB NPs) using polydopamine (PDA) as the intermediate linker. Doxorubicin (DOX) was selected and successfully loaded onto the nanoplatforms with a high loading content of 327 mg/g. Furthermore, significant NIR light-triggered release of DOX was observed in a weak acidic tumor microenvironment. The nanoplatform exhibited superior photostability with a high photothermal effect of 51.7% under irradiation by a 808 nm laser and a competent temperature sensitivity (SR is 1.44% °C^-1) under a single wavelength excitation. MTT assay against SMMC-7721 cells clearly illustrated that the nanoplatform had low cytotoxicity at a high level (200 μg/mL) after 24 h and high therapeutic efficacy of chemo-phototherapy. Thus, it is highly promising for use in biomedical applications.