Ultrasound-Augmented Phase Transition Nanobubbles for Targeted Treatment of Paclitaxel-Resistant Cancer

Paclitaxel (PTX) resistance in most epithelial ovarian cancers (EOCs) with increasing membrane expression of mucin 16 (MUC16) is mediated by the Toll-like receptor-myeloid differentiation factor 2/myeloid differentiation factor 88 (TLR4-MD2/MyD88) signaling pathway. 6-Shogaol (6S), an α,β-unsaturated carbonyl compound with lipophilic property, can block PTX-induced formation of the TLR4-MD2 complex that activates the MyD88/NF-κB signaling pathway. Herein, to improve the effectiveness of 6S, augment the sensibility of PTX, and enhance the targeting ability of PTX-resistant cancer therapies, we report a class of 6S-loaded phase transition nanobubbles conjugated with the MUC16 antibody (6S@NBs-MUC16A), which can enhance the sensitivity of PTX to EOC cells through ultrasound-controlled targeted-delivery of 6S. The 6S@NB-MUC16A could enhance the targeting efficiency and organizational distribution of 6S in MyD88⁺ EOC area, and the 1 MHz ultrasound can be used as an initiator to trigger the "explosion" of nanobubbles and promote the 6S release. Furthermore, in vivo assessment results indicate that ultrasound-augmented 6S@NB-MUC16A can significantly improve the response of EOC to PTX and the inhibition ratio of tumor growth compared to the control-treated with PTX alone, and exhibit less toxicity to the critical organs. The ultrasound-augmented 6S@NB-MUC16A with less cytotoxicity could be a potentially useful nanosystem to surmount PTX resistance in EOC, which provides potential possibilities for the applications in the biological field.