Improved paramagnetic liposomes for MRI visualization of pH triggered release.
Elena Torres1, Francesco Mainini, Roberta Napolitano
1Department of Chemistry IFM and Molecular & Preclinical Imaging Centers, University of Torino, Via Nizza 52, 10126, Torino, Italy.
Summary
Paramagnetic pH-sensitive liposomes visualize drug delivery and release using MRI. These novel liposomes release imaging agents at acidic pH, enabling MRI visualization of drug release processes in preclinical studies.
Area of Science:
- Nanomedicine
- Biomedical Imaging
- Drug Delivery
Background:
- Paramagnetic liposomes offer potential for in vivo imaging.
- Visualizing drug release dynamics is crucial for therapeutic monitoring.
- Current MRI contrast agents have limitations in dynamic process visualization.
Purpose of the Study:
- To assess the in vitro utility of paramagnetic pH-sensitive liposomes (pSLs) as MRI imaging tools.
- To visualize drug delivery and release processes using Magnetic Resonance Imaging (MRI).
- To develop novel nanomedicines for enhanced MRI applications.
Main Methods:
- Formulation of pH-sensitive liposomes using POPE and THS.
- Loading liposomes with paramagnetic complexes like Gadoteridol.
- Investigating Gadoteridol release at pH 5.5 and its effect on MRI relaxivity.
- Developing stealth pSLs with PEG chains via cleavable disulfide bridges.
Main Results:
- pSLs demonstrated fast and complete Gadoteridol release at pH 5.5.
- Liposome aggregation and imaging reporter leakage enhanced MRI visualization.
- Probe size significantly influenced release kinetics.
- Stealth pSLs showed pH-dependent release, contingent on PEG removal.
Conclusions:
- The developed liposomal formulation shows promise for visualizing drug delivery and release.
- These pSLs can serve as effective imaging tools for in vivo MRI preclinical studies.
- The pH-sensitive release mechanism offers a novel approach for targeted MRI contrast agent delivery.
