Enhanced Control of Liposomal Drug Release by Drug-Aptamer Complexes

Area of Science:

• Biotechnology
• Materials Science
• Pharmacology

Background:

• Conventional diffusion-controlled drug delivery systems (DDS) often exhibit initial burst release, leading to systemic toxicity and shortened efficacy.
• Liposomes, a common type of DDS, face challenges in controlling drug release rates and duration of action.

Purpose of the Study:

• To investigate the enhancement of liposomal drug delivery systems (DDS) by incorporating aptamers that specifically bind to encapsulated drugs.
• To evaluate the impact of aptamer-drug affinity on drug release kinetics and in vivo efficacy.

Main Methods:

• Liposomes were engineered to encapsulate drugs, with some formulations including aptamers designed for specific drug binding (Lipo-Apt).
• The release profiles of various hydrophilic molecules (tetrodotoxin, serotonin, kanamycin) from Lipo-Apt and conventional liposomes were analyzed.
• In vivo studies assessed the duration of local anesthesia using tetrodotoxin-loaded Lipo-Apt injected into the sciatic nerve of rats.

Main Results:

• Aptamer incorporation into liposomes (Lipo-Apt) effectively slowed the release of small, hydrophilic molecules.
• A single injection of tetrodotoxin-loaded Lipo-Apt in rats provided a 6.6-day nerve blockade, a fourfold increase compared to liposomes alone.
• The Lipo-Apt system demonstrated a 26-fold improvement over the aptamer-drug complex alone and reduced systemic toxicity, allowing for higher drug doses.

Conclusions:

• Aptamer-modified liposomes (Lipo-Apt) represent a promising strategy for advanced drug delivery, offering enhanced control over drug release.
• This approach significantly extends the duration of therapeutic effect and mitigates systemic toxicity associated with conventional DDS.
• Lipo-Apt technology holds potential for improving the efficacy and safety of various drug delivery applications.