Light-Triggered Pheophorbide A-Based Protamine-Cinnamon Liposomes for Synergistically Enhanced Antibacterial Activity...

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Antimicrobial Research

Background:

• Liposomes have limitations in targeting and responsiveness for natural antibacterial agents.
• Photosensitizers often suffer from poor sustainability and low delivery efficiency.
• Developing advanced delivery systems is crucial for enhancing natural antibacterial agent efficacy.

Purpose of the Study:

• To develop an intelligent, light-triggered liposome system for synergistic co-delivery of natural antibacterial agents.
• To utilize Pheophorbide A as a phototrigger for controlled release of a protamine-cinnamon extract complex.
• To optimize the system for improved targeting, stability, and on-demand antibacterial activity.

Main Methods:

• Systematic optimization of photosensitized liposome preparation.
• Characterization of liposome properties including encapsulation efficiency, particle size, PDI, and zeta potential.
• In vitro release studies under red light irradiation and stability assessments.
• Antibacterial efficacy testing against Escherichia coli and Staphylococcus aureus.

Main Results:

• Photosensitized liposomes achieved >70% encapsulation efficiency and excellent colloidal stability.
• Light-triggered release showed a cumulative rate of 89.91% within 72h, ~4x higher than conventional liposomes.
• Liposomes maintained structural integrity for 56 days at 4°C and 25°C.
• Light-dependent antibacterial efficacy demonstrated lower MIC and enhanced activity against E. coli and S. aureus.

Conclusions:

• The developed light-triggered liposome system offers an intelligent, on-demand delivery mechanism for natural antibacterial agents.
• This system significantly expands the application potential of protamine and cinnamon extract.
• Enhanced antibacterial efficacy, stability, and controlled release were achieved, addressing limitations of conventional systems.