A pH-Responsive Theranostic Nanoprobe for Ultrasonic-Triggered Eradication of Helicobacter pylori In Vivo Under Magnetic Resonance Imaging Guiding.

Abstract

The prevailing antibiotic-based eradication strategy for the carcinogenic bacterium of Helicobacter pylori (H. pylori) is compromised by its low efficacy and substantial side effects. In this study, a pH-responsive theranostic nanoprobe integrating magnetic resonance imaging (MRI) and sonodynamic therapy (SDT) modules is developed to achieve efficient and safe H. Pylori elimination. The theranostic nanoprobe is constructed by coating manganese porphyrin (MnTCPP) doped hollow mesoporous iron oxide nanoparticle (HMIN) with a pH-responsive, H. pylori-targeting polymer. In this nanoprobe, MnTCPP functions as both a sonosensitizer and a paramagnetic enhancer, while HMIN serves as both a drug carrier and a superparamagnetic quencher. Upon the pH-mediated activation at the H. pylori-infected gastric sites in murine model, the MnTCPP released from HMIN around bacteria switched ON the MRI signal for bacterial localization. This imaging capability guided ultrasonic-triggered ¹O₂ generation from MnTCPP with maximum spatial accumulation. As a result, the H. pylori are effectively eradicated in situ through spatiotemporally controlled and targeted SDT, without bacterial drug resistance and imbalance of intestinal flora, showing a promising alternative strategy for treating H. pylori infection.