Chitosan-Based Transdermal Microneedles for Synergistic Sono-Photodynamic Antibacterial Therapy

Area of Science:

• Biomaterials Science
• Nanotechnology
• Infectious Diseases

Background:

• Bacterial biofilms impede wound healing, causing inflammation and antimicrobial resistance.
• Conventional antibiotics face challenges due to overuse and resistance.
• Novel strategies are needed to overcome biofilm-associated infections.

Purpose of the Study:

• To design and fabricate a dual-mode responsive delivery system for synergistic sono-photodynamic therapy (SPDT).
• To evaluate the antibacterial efficacy of the system against standard and drug-resistant bacterial strains and biofilms.
• To assess the biocompatibility of the developed system.

Main Methods:

• Fabrication of chitosan (CS) and oleanolic acid (OA) composite microneedles encapsulating chlorin e6 (Ce6).
• In vitro evaluation of antibacterial activity under combined laser and ultrasound irradiation.
• Cytocompatibility assays using normal fibroblast cells.

Main Results:

• The CS-OA composite microneedles (C_SO_AC@MN) efficiently delivered Ce6 for SPDT.
• The system demonstrated potent antibacterial activity against Staphylococcus aureus, Escherichia coli, and drug-resistant strains.
• Effective disruption of pre-formed biofilms was observed due to reactive oxygen species generation.
• Good biocompatibility was confirmed at effective antibacterial concentrations.

Conclusions:

• The developed microneedle system offers an integrated strategy for combating biofilm-associated bacterial infections.
• Synergistic sono-photodynamic therapy shows significant potential for treating complex wound infections.
• This approach holds promise for clinical translation in wound care and infection management.