Defect Engineering of Bi2S3-x@PDA/CuS Z-Scheme Heterojunction for Enhanced Sonodynamic and Chemodynamic Cancer
Yufeng Feng1, Yingshu Li1, Xiaoxiao Yan1
1Key Laboratory For Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Guangxi Key Laboratory of Chemistry and Molecular Engineering of Medicinal Resources, University Engineering Research Center for Chemistry of Characteristic Medicinal Resources (Guangxi), School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, China.
Abstract:
Although bismuth sulfide (Bi2S3) with a narrow bandgap shows great promise for sonodynamic therapy (SDT), its efficacy is limited by a low reactive oxygen species (ROS) quantum yield due to the rapid recombination of electron and hole pairs. Herein, a sulfur-vacancy-rich Bi2S3-x@PDA/CuS (BPC) Z-scheme heterojunction is rationally designed by coating Bi2S3-x nanorods with polydopamine (PDA) (denoted as Bi2S3-x@PDA) via in situ polymerization of dopamine hydrochloride and CuS nanoparticles growing on the Bi2S3-x@PDA surface to overcome this challenge. This design synergistically integrates sulfur-vacancy engineering and a Z-scheme heterostructure to regulate the electronic properties of Bi2S3, dramatically enhancing charge separation and boosting ROS production for potent SDT. Crucially, the BPC heterojunction simultaneously remodels the tumor microenvironment; it functions as a Fenton-like nanozyme to generate hydroxyl radical (•OH) for chemodynamic therapy while using sono-excited holes to consume overexpressed glutathione, thereby amplifying intratumoral oxidative stress. Surface functionalization with hyaluronic acid (HA) endows the final BPC@HA nanocomposite with excellent physiological stability, biocompatibility, and active cancer-cell targeting capabilities. As a result, in vivo studies confirmed that BPC@HA dramatically suppresses tumor growth through these combined properties. This study presents a powerful paradigm for engineering multifunctional sonosensitizers that overcome both intrinsic material limitations and extrinsic biological barriers in cancer therapy.
