Exploring rifamycin cytotoxic potential through targeted liposomal formulations.

Area of Science:

• Oncology
• Nanotechnology
• Pharmacology

Background:

• Drug repositioning offers novel therapeutic strategies for cancer treatment.
• Antibiotics with antiproliferative properties are potential candidates for cancer therapy.
• Rifamycin, an antibiotic inhibiting bacterial RNA synthesis, was investigated for its cytotoxic potential.

Purpose of the Study:

• To explore rifamycin as a potential cytotoxic agent for cancer treatment.
• To develop liposome-encapsulated rifamycin (Rf-Lp) for enhanced drug delivery.
• To evaluate the efficacy of antibody-conjugated Rf-Lp for targeted cancer therapy.

Main Methods:

• Liposomes were formulated as nanocarriers for rifamycin delivery.
• Rifamycin-loaded liposomes (Rf-Lp) were characterized for particle size, stability, and biocompatibility.
• Cytotoxic activity was assessed in various tumor cell lines and spheroids.
• Monoclonal antibody 2C5 (mAb 2C5) was conjugated to Rf-Lp for targeted delivery.

Main Results:

• Rf-Lp exhibited good physical and chemical stability and low hemolytic potential.
• Encapsulated rifamycin demonstrated cytotoxic activity against multiple tumor cell lines.
• Rf-Lp showed enhanced efficacy in a spheroids model, suggesting improved penetration.
• mAb 2C5 conjugation significantly boosted rifamycin's cytotoxic activity in specific cell lines, especially with short exposure times.

Conclusions:

• Liposome encapsulation improves rifamycin stability and release kinetics.
• Antibody-mediated targeting with mAb 2C5 enhances cellular uptake and therapeutic efficacy.
• Liposome-encapsulated, antibody-conjugated rifamycin is a promising strategy for targeted cancer therapy.