pH-Responsive and Chemiluminescent Carboxyethyl Chitosan Nanocarriers for Intelligent Targeted Phototherapy Sterilization

Abstract

The development of nanotechnology provides hope for precision sterilization, but traditional physical encapsulation of drugs and non-targeted treatments is prone to drug leakage and non-specific damage. Besides, traditional fluorescence imaging is subject to autofluorescence interference and non-specific damage caused by continuous excitation. Herein, we report a pH-/H 2 O 2activated and self-luminous nanosphere for intelligent bacteriatargeting and self-reported imaging-guided precision phototherapy sterilization. pH-responsive porphyrin derivative-grafted carboxymethyl chitosan (CMC-PC-N) was designed and synthesized as bacterial microenvironment-responsive nanocarriers and phototherapeutic agents. Peroxyoxalate (CPPO), a H 2 O 2 -responsive chemiluminescence substrate, was further employed as a built-in initiator for self-reported imaging and self-assembled with CMC-PC-N to form the nanosphere by nanoprecipitation (CPPO@ CMC-PC-N). Hydrophilicity of the nanosphere increases in the bacterial acidic microenvironment due to the protonation of N atoms in CPPO@CMC-PC-N, resulting in the dissociation of nanospheres and the rapid release of CPPO. As a result, the formed positively charged CMC-PC-N targets bacteria by electrostatic adsorption. Meanwhile, the reaction of the released CPPO with endogenous H 2 O 2 activates the fluorescence of the porphyrin to achieve self-report imaging. Also, precision phototherapy sterilization is further activated by external irradiation under imaging guidance. The microenvironment-triggered disassembly, rapid CPPO release, and self-luminous properties integrated with good biocompatibility ensure CPPO@CMC-PC-N intelligent bacteriatargeting, self-report imaging with non-background interference, and efficient phototherapy sterilization with negligible side effects.

Functionalized Mesoporous Polydopamine Nanocarrier with Near-Infrared Laser-Trigged NO Release and Photothermal Effects for the Killing of Pathogenic Bacteria

“…The past few decades have witnessed rapid advances in nanomaterials, which provide new opportunities to address the challenges of bacterial infections. Nanomaterial-based strategies are considered to be promising tools against pathogenic bacteria due to their enhanced efficacy and therapeutic index. − The antimicrobial mechanisms of nanomaterials, such as generating ROS, , are different from those of common antibiotics.…”