Folate receptor-targeted quantum dot liposomes as fluorescence probes

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Materials Science

Background:

• Folate receptors (FRs) are overexpressed in various cancer cells, making them a promising target for cancer diagnosis and therapy.
• Quantum dots (QDs) offer unique optical properties for bioimaging, but their application can be limited by stability and targeting issues.
• Liposomes provide a versatile platform for drug/agent delivery and can be functionalized for targeted applications.

Purpose of the Study:

• To prepare novel FR-targeted liposomes encapsulating hydrophilic Cadmium Telluride (CdTe) quantum dots (QDs).
• To evaluate these QD-loaded liposomes as luminescence probes for live cancer cell imaging.
• To assess the targeting efficacy, stability, and cytotoxicity of the developed imaging agents.

Main Methods:

• Hydrophilic CdTe QDs were synthesized in an aqueous phase.
• FR-targeted QD liposomes were prepared by hydrating a lipid thin film with CdTe suspension.
• Characterization involved UV-visible and fluorescence spectroscopy, particle size, and zeta potential analysis.
• Targeting and imaging capabilities were tested on HeLa cancer cells; cytotoxicity was assessed via cell incubation.

Main Results:

• FR-targeted QD liposomes exhibited spherical morphology, high fluorescence yield, and excellent photochemical stability.
• The liposomes showed good cancer cell targeting ability and minimal cytotoxicity.
• Average particle size was approximately 105 nm with a narrow size distribution.
• Liposomes maintained size and QD integrity after 11 months of storage at 4°C.

Conclusions:

• FR-targeted CdTe QD liposomes are effective luminescence probes for cancer cell imaging.
• These targeted liposomes can be internalized via FR-mediated endocytosis, enabling specific tumor cell targeting.
• The developed agents show potential for long-term monitoring and imaging of tumor cells and tissues.