Tuning the Bandgap of Photo-Sensitive Polydopamine/Ag₃PO₄/Graphene Oxide Coating for Rapid, Noninvasive Disinfection of Implants

Abstract

Bacterial infection and associated complications are threats to human health especially when biofilms form on biomedical devices and artificial implants. Herein, a hybrid polydopamine (PDA)/Ag3PO4/graphene oxide (GO) coating is designed and constructed to achieve rapid bacteria killing and eliminate biofilms in situ. By varying the amount of GO in the hybrid coating, the bandgap can be tuned from 2.52 to 2.0 eV so that irradiation with 660 nm visible light produces bacteria-killing effects synergistically in concert with reactive oxygen species (ROS). GO regulates the release rate of Ag+ to minimize the cytotoxicity while maintaining high antimicrobial activity, and a smaller particle size enhances the yield of ROS. After irradiation with 660 nm visible light for 15 min, the antimicrobial rates of the PDA/Ag3PO4/GO hybrid coating against Escherichia coli and Staphylococcus aureus are 99.53% and 99.66%, respectively. In addition, this hybrid coating can maintain a repeatable and sustained antibacterial efficacy. The released Ag+ and photocatalytic Ag3PO4 produce synergistic antimicrobial effects in which the ROS increases the permeability of the bacterial membranes to increase the probability of Ag+ to enter the cells to kill them together with ROS synergistically.

Corrosion Motivated ROS Generation Helps Endow Titanium with Broad‐Spectrum Antibacterial Abilities

“…Besides, it should steadily work. However, most available ROS generating systems must be activated by electric, ultraviolet or visible light, their ROS producing abilities will gradually fade away after the external supplier is turned off, limiting their application in clinic, since external stimuli can hardly pass through human tissue to reach the implant surfaces, so the ROS cannot continuously produced. Self‐motived ROS generation systems are therefore highly desirable.…”

Size‐Transformable Metal–Organic Framework–Derived Nanocarbons for Localized Chemo‐Photothermal Bacterial Ablation and Wound Disinfection

“…Hence, novel and efficient antibacterial materials and strategies are urgently needed to reduce the dependence on antibiotic treatments . In recent years, abundant kinds of antibacterial materials and strategies have been developed, which not only include chemotherapies by using diverse small molecules, quaternary ammonium polymers, and bactericidal metal ions (Ag 2+ , Zn 2+ , and Cu 2+ ions), but also consist of photothermal‐ or photodynamic‐based sterilization via production of massive heating or reactive oxygen species . However, the antibacterial materials with a single bactericidal model are usually difficult to achieve high efficiency or 100% disinfection, especially at low concentrations; meanwhile, it is also easy to cause bacterial resistance during sterilization processes…”

Highly Effective and Noninvasive Near‐Infrared Eradication of a Staphylococcus aureus Biofilm on Implants by a Photoresponsive Coating within 20 Min

“…[15][16][17][18][19] Near-infrared light-induced hyperthermia for combating bacteria based on photothermal conversion agents is one of the most attractive emerging methods and can destroy bacteria via various thermal effects, such as breakdown of the cell membrane or denaturation of proteins/enzymes. [15][16][17][18][19] Near-infrared light-induced hyperthermia for combating bacteria based on photothermal conversion agents is one of the most attractive emerging methods and can destroy bacteria via various thermal effects, such as breakdown of the cell membrane or denaturation of proteins/enzymes.…”