Fluorogenic pH-sensitive polydiacetylene (PDA) liposomes as a drug carrier.

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Sustained-release is a key challenge for liposomal drug carriers in clinical use.
• Current liposomes often struggle with controlled drug release profiles.
• Developing advanced carriers is essential for improved therapeutic outcomes.

Purpose of the Study:

• To develop novel fluorogenic pH-sensitive polymerized liposomes.
• To investigate the drug release properties of these liposomes at varying pH levels.
• To evaluate the therapeutic efficacy and drug release monitoring capabilities of the developed liposomes.

Main Methods:

• Fabrication of unilamellar liposomes using polydiacetylene (PDA) lipids (PCDA, DOPE, PHC) and ampicillin.
• Characterization of liposome size distribution changes in response to pH reduction from 7 to 4.
• Analysis of ampicillin release kinetics using High-Performance Liquid Chromatography (HPLC).
• Assessment of therapeutic effect via E. coli plaque assays and fluorescent imaging.

Main Results:

• Liposome size increased significantly (approx. 20-fold) as pH decreased, indicating fusion and polymerization.
• Cross-linking of PDA lipids effectively prevented premature drug leakage.
• Rapid and near-complete ampicillin release (74.4%) achieved within 4 hours at acidic pH.
• Successful visualization of drug release at the therapeutic site using fluorescent PDA liposomes.

Conclusions:

• Novel pH-sensitive polymerized liposomes offer a promising platform for controlled drug delivery.
• The rapid drug release at acidic pH addresses limitations of existing liposomal carriers.
• These liposomes demonstrate potential for effective therapeutic applications and real-time drug release monitoring.