Development of a diagnostic polymersome system for potential imaging delivery

Area of Science:

• Biomaterials Science
• Nanotechnology
• Diagnostic Imaging

Background:

• Current soft tissue visualization methods require enhancement for improved diagnostic accuracy.
• Developing multifunctional nanocarriers is crucial for advanced imaging techniques.
• Polymersomes offer a versatile platform for encapsulating various imaging agents.

Purpose of the Study:

• To develop a dual-imaging diagnostic polymersome system for enhanced soft tissue visualization.
• To simultaneously embed a near-infrared fluorophore (Cy5.5) and a paramagnetic probe (gadolinium, Gd(III)).
• To evaluate the imaging performance and safety of the developed polymersomes.

Main Methods:

• Self-assembly of lipid-containing copolymer (poly(acrylic acid-co-distearin acrylate)) in aqueous solution.
• Loading of Cy5.5 via hydrophobic association and Gd(III) via electrostatic complexation into polymersomes.
• Characterization of polymersome properties, payload confinement, colloidal stability, and in vitro/in vivo imaging performance.

Main Results:

• Successfully developed Cy5.5/Gd(III)-loaded polymersomes (CGLPs) with high loading efficiencies (Cy5.5 ca 74%, Gd(III) 83%).
• CGLPs demonstrated excellent payload confinement, reduced aggregation, and superior contrast enhancement in MR imaging (15-fold higher relaxivity than Magnevist).
• In vivo studies showed comparable MR contrast to Magnevist with a 5-fold lower Gd dose and excellent NIR imaging contrast at tumor sites with no observed toxicity.

Conclusions:

• The developed CGLPs are a promising dual-imaging nanodevice for soft tissue visualization.
• The system offers superior MR relaxivity and efficient NIR imaging capabilities.
• CGLPs present a non-toxic, advanced diagnostic tool with significant potential in medical imaging.