Thylakoid-based photosynthetic hydrogel for dual-phase ROS regulation in infected wounds

Area of Science:

• Biomaterials Science
• Photodynamic Therapy
• Wound Healing
• Oxidative Stress Management

Background:

• Reactive oxygen species (ROS) have a dual role in infected wounds, aiding pathogen clearance but causing oxidative stress.
• Traditional photodynamic therapy (PDT) is limited by hypoxia and cannot manage later-stage oxidative stress.
• Existing treatments struggle to dynamically address the changing needs of infected wound environments.

Purpose of the Study:

• To develop a self-oxygenating photodynamic hydrogel for enhanced infected wound management.
• To overcome hypoxia limitations in PDT by generating oxygen in situ.
• To mitigate oxidative stress and promote wound healing through antioxidant properties.

Main Methods:

• Co-encapsulation of spinach-derived thylakoids and Chlorin e6 (Ce6) in a methacrylated gelatin (GelMA) hydrogel matrix.
• Utilizing thylakoids as a photosynthetic oxygen engine under 660 nm irradiation to produce oxygen.
• Employing thylakoids for ROS scavenging, independent of light, to reduce oxidative stress.

Main Results:

• The developed hydrogel (GCT) continuously generated oxygen, alleviating hypoxia and boosting Ce6-mediated ROS production for antibacterial PDT.
• Thylakoids effectively scavenged ROS, reducing oxidative stress in host cells and promoting angiogenesis and tissue repair.
• The system demonstrated efficient bacterial eradication and facilitated a comprehensive wound healing process.

Conclusions:

• A novel thylakoid-based photosynthesis-coupled PDT system was successfully developed for infected wound management.
• This strategy effectively addresses the dynamic needs of infected wounds by combining oxygen generation and ROS scavenging.
• The GCT hydrogel represents a significant advancement in photodynamic therapy for promoting whole-process wound healing.