Multi-functional near-infrared fluorescent polymer dot-siRNA for gene expression regulation.

Area of Science:

• Biotechnology
• Nanomedicine
• Molecular Biology

Background:

• Gene expression regulation is vital for cellular functions; its misregulation leads to disease.
• Current gene silencing methods like antisense inhibition and CRISPR-Cas9 have limitations in specificity, toxicity, and usability.
• Targeted gene silencing offers therapeutic potential for various diseases.

Purpose of the Study:

• To design and characterize a nanomaterial-based tool for efficient gene silencing in eukaryotic cells.
• To develop a polymer dots (Pdots)-based nanoplatform for delivering gene-specific small interfering RNA (siRNA).
• To enable simultaneous visualization of siRNA delivery and gene expression inhibition.

Main Methods:

• Synthesized polymer dots (Pdots) with specific size and zeta potential characteristics.
• Functionalized Pdots with Gapdh siRNA (Pdot-siRNA) and characterized their size, zeta potential, and optical properties (visible and NIR emission).
• Treated primary mouse brain microvascular cells with Pdot-Gapdh siRNA to assess cellular uptake and gene silencing efficacy via immunolabeling.

Main Results:

• Pdots and Pdot-siRNA exhibited distinct size and zeta potential values, with dual emission peaks in visible and near-infrared ranges.
• Uniform cellular uptake of Pdot-siRNA was observed in mouse brain microvascular cells.
• Significant reduction in Gapdh immunolabeling intensity indicated successful gene silencing.

Conclusions:

• The Pdot-siRNA nanoplatform provides a novel and effective strategy for targeted gene expression inhibition.
• This approach allows for simultaneous visual monitoring of siRNA delivery, enhancing experimental control and understanding.
• The Pdot-siRNA system demonstrates potential for broad applications in basic research and therapeutic interventions with minimal toxicity and high efficiency.