Manganese-Loaded Liposomes: An In Vitro Study for Possible Diagnostic Application

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Radiology

Background:

• Free manganese ions (Mn²⁺) present toxicity concerns for diagnostic imaging.
• Liposomal formulations offer a potential strategy to encapsulate and deliver manganese safely.
• Developing safer contrast agents for magnetic resonance imaging (MRI) is crucial.

Purpose of the Study:

• To investigate manganese-based liposomal formulations for diagnostic MRI applications.
• To evaluate the safety and efficacy of encapsulated manganese compounds compared to free ions.
• To assess the contrast enhancement properties of liposomal manganese formulations.

Main Methods:

• Preparation and characterization of anionic liposomes loaded with manganese chloride (MC) and manganese hippurate (MH).
• Evaluation of encapsulation efficiency using ICP-OES analysis.
• Assessment of magnetic resonance imaging (MRI) contrast properties using phantoms and human cell safety tests.

Main Results:

• High encapsulation efficiencies for both MC (99.7%) and MH (98.8%) within liposomes.
• Liposomal manganese formulations (LP-MC, LP-MH) exhibited superior contrast-to-noise ratios compared to free Mn ions at equivalent concentrations.
• The liposomal formulations demonstrated safety for use on human cells at the tested dose.

Conclusions:

• Manganese-based liposomal formulations are effective carriers for diagnostic MRI.
• These liposomes overcome the toxicity limitations of free manganese ions.
• The enhanced contrast and safety profile suggest potential for preclinical diagnostic applications.