Near-infrared image-guided delivery and controlled release using optimized thermosensitive liposomes
David C Turner1, Delaram Moshkelani, Colby S Shemesh
1Department of Pharmaceutical Sciences, Mercer University, Atlanta, Georgia 30341, USA.
Pharmaceutical Research
|March 28, 2012
Summary
Optimized thermosensitive liposomes with near-infrared (NIR) dye show promise for image-guided chemotherapy. Dextran coating enhanced in vitro uptake, and NIR imaging enabled real-time monitoring of liposome delivery in vivo.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Drug Delivery Systems
Background:
- Thermosensitive liposomes offer controlled drug release triggered by temperature.
- Near-infrared (NIR) active agents can enable non-invasive imaging for tracking delivery.
- Optimizing liposome formulation is crucial for effective therapeutic delivery and imaging.
Purpose of the Study:
- To engineer optimized NIR-active thermosensitive liposomes.
- To achieve image-guided delivery of chemotherapeutic agents.
- To evaluate liposome formulation and surface coatings for enhanced performance.
Main Methods:
- Liposomes were surface-coated with polyethylene glycol or dextran.
- Differential scanning calorimetry and calcein release assays optimized liposomal release.
- Flow cytometry assessed in vitro macrophage uptake.
- Indocyanine green (ICG) was encapsulated for in vivo NIR imaging and biodistribution studies.
Main Results:
- An optimized formulation (DPPC:SoyPC:cholesterol, 100:50:30 molar ratio) was identified.
- Dextran coating showed greater in vitro macrophage uptake compared to polyethylene glycol.
- Non-invasive NIR imaging confirmed tumor accumulation and correlated well with ex vivo organ concentrations.
Conclusions:
- The optimized thermosensitive liposomes are stable at 37°C and exhibit burst release at 40-42°C.
- Dextran is a promising surface coating for thermosensitive liposomes.
- NIR imaging allows reliable, real-time monitoring of liposome biodistribution in vivo.
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