Augmented Graphene Quantum Dot-Light Irradiation Therapy for Bacteria-Infected Wounds

Abstract

This paper proposes a highly efficient antibacterial system based on a synergistic combination of photodynamic therapy, photothermal therapy, and chemotherapy. Chitosan oligosaccharide functionalized graphene quantum dots (GQDs-COS) with short-term exposure to 450 nm visible light are used to promote rapid healing in bacteria-infected wounds. The GQDs undergo strong photochemical transformation to rapidly produce radical oxygen species and heat under light illumination, while the COS has an innate antimicrobial ability. Moreover, the positively charged GQDs-COS can easily capture bacteria via electrostatic interactions and kill Gram-positive and Gram-negative bacteria by multivalent interactions and synergistic effects. The antibacterial action of this nanocomposite causes irreversible damage to outer and inner bacterial membranes, resulting in cytoplasm leakage and death. The system has good hemocompatibility and low cytotoxicity and can improve the healing of infected wounds, as demonstrated by the examination of pathological tissue sections and inflammatory markers. These results suggest that GQDs anchored with bioactive molecules are a potential photo-activated antimicrobial strategy for anti-infective therapy.

Copper deposited diatom-biosilica with enhanced photothermal and photodynamic performance for infected wound therapy

“…Therefore, combination of PDT and PTT, through increasing the temperature of infection sites to enhance the catalysis rate of photosensitizers is a desired antibacterial strategy. 11,12 In the past decades, various inorganic materials, such as carbon-based nanomaterials, metal oxides, metal chalcogenides and precious metal nanoparticles, have been proven to have ROS catalytic activity; some of them exhibited both photothermal and photodynamic properties, which can eradicate different types of bacteria, even drugresistant bacteria. 13 However, the treatment performance of these nanomaterials is still restricted in vivo, because of their potential toxicity, limited catalytic ability and photothermal conversion efficiency.…”

Recent Advances in Bio‐Compatible Oxygen Singlet Generation and Its Tumor Treatment

“…Therefore, scientists hope that PDT and chemotherapy can learn from each other to form a more efficient antibacterial strategy. Mei et al [343] proposed a highly efficient antibacterial system based on a synergistic combination of PDT/PTT and chemotherapy. This nanosystem is composed of chitosan oligosaccharide coated CE6.…”

Phototherapy-based combination strategies for bacterial infection treatment

“…The heat induced by photothermal treatment can not only increase the ambient temperature of tissue to achieve antimicrobial efficacy but also increase blood flow and oxygen supply to enhance the 1 O 2 generation of photodynamic treatment, and so the multiple treatment strategy combined with photodynamic and photothermal therapy achieves a better antibacterial effect than that achieved by the individual therapies alone. For example, Zhang et al 135 utilized the intrinsic antibacterial action of chitosan oligosaccharide (COS) and the photodynamic and photothermal properties of graphene quantum dots (GQDs) to prepare COS functionalized GQDs (GQDs-COS) that exhibit multiple synergetic antibacterial activities, and could interact with negatively charged bacterial surfaces via electrostatic attraction. Additionally, under 450 nm light irradiation, GQDs-COS could simultaneously kill Gram-positive and Gram-negative bacteria via three types of antibacterial activity (photodynamic, photothermal and chemical therapy).…”