Layer-by-layer assembled PEI-based vector with the upconversion luminescence marker for gene delivery.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Gene Therapy

Background:

• Upconversion luminescence (UCL) markers offer advantages over traditional fluorescence, including deeper tissue penetration and reduced autofluorescence.
• Poly(ethylene imine) (PEI) is a common nonviral gene-delivery vector but exhibits cytotoxicity.
• Developing safer and more effective nonviral gene-delivery systems is crucial for biomedical applications.

Purpose of the Study:

• To construct a novel upconversion luminescence (UCL) gene-delivery nonviral vector.
• To reduce the cytotoxicity of poly(ethylene imine) (PEI) in gene-delivery systems.
• To evaluate the efficacy and safety of the developed UCL gene-delivery vector for theranostic applications.

Main Methods:

• Layer-by-layer self-assembly of upconversion nanoparticles (UCNPs) with PEI.
• Aqueous modification of PEI using citric acid (CA) to reduce cytotoxicity.
• Surface assembly of PEI on UCNPs for enhanced vector construction.
• Assessment of vector stability, DNA binding affinity, photostability, and cytotoxicity.

Main Results:

• The constructed nonviral vector exhibits excellent photostability and strong DNA binding.
• The modified PEI demonstrates reduced cytotoxicity compared to unmodified PEI.
• The vector shows good stability under physiological and serum conditions.
• The UCL gene-delivery vector effectively visualizes gene delivery.

Conclusions:

• A novel, low-toxicity UCL gene-delivery nonviral vector was successfully constructed using UCNPs and modified PEI.
• The developed vector demonstrates superior photostability and stability, making it suitable for gene delivery.
• This UCL-based vector holds significant potential as a theranostic carrier for biomedical applications.