pH-triggered echogenicity and contents release from liposomes.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Drug Delivery Systems

Background:

• Liposomes are crucial lipid nanoparticles for delivering therapeutic agents to cancer cells.
• Current pH-sensitive liposomes require complex lipid modifications.
• Lysosomal acidity is a known trigger for drug release.

Purpose of the Study:

• To develop a novel pH-sensitive liposome system without specialized lipid synthesis.
• To utilize in situ gas bubble generation for triggered content release.
• To enhance anticancer drug delivery and enable ultrasound imaging.

Main Methods:

• Liposomes were engineered to encapsulate a pH-responsive precursor generating gas bubbles.
• Atomic force microscopy was used to study liposomal structural changes at reduced pH.
• Doxorubicin-loaded liposomes were targeted to pancreatic cancer cells overexpressing folate receptors.
• Ultrasound was applied to assess its effect on drug release and cell viability.

Main Results:

• The novel liposomes demonstrated pH-sensitive content release triggered by acidic environments.
• Gas bubble generation led to rapid liposomal disruption and drug release.
• Ultrasound application significantly enhanced the release of encapsulated doxorubicin.
• Targeted liposomes combined with ultrasound reduced pancreatic cancer cell viability by 14%.

Conclusions:

• This strategy offers a new method for creating pH-sensitive liposomes using a precursor-based approach.
• The gas bubble generation mechanism provides efficient and triggered drug release.
• The echogenic nature of the liposomes allows for ultrasound-guided therapy, improving cancer treatment efficacy.