Non-Invasive On-Off Fluorescent Biosensor for Endothelial Cell Detection.

Area of Science:

• Biomedical Engineering
• Molecular Biology
• Cell Biology

Background:

• Endothelial cells (ECs) play critical roles in vascular health and disease.
• Current methods for EC detection often require immunostaining, which can be invasive and time-consuming.
• There is a need for rapid, specific, and non-invasive tools for live EC detection.

Purpose of the Study:

• To develop a novel genetically encoded fluorescent protein-based biosensor (FPB) for specific and rapid detection of living endothelial cells (ECs).
• To enable direct, visual, and non-invasive monitoring of ECs in live biological systems.
• To establish a powerful tool for live EC research with potential applications in disease diagnosis and treatment.

Main Methods:

• Development of a turn-on fluorescent protein biosensor, LV-EcpG, incorporating a high-affinity peptide (E12P) for EC recognition.
• Utilizing phage display technology to obtain the E12P peptide with specific binding affinity for ECs.
• Engineering a turn-on enhanced green fluorescent protein (EGFP) with linker peptides to create a genetically encoded FPB with an 'on-off' switching mechanism.

Main Results:

• The LV-EcpG biosensor demonstrated specific binding to endothelial cells (ECs).
• The 'on-off' switching mechanism ensured fluorescence activation only upon EC binding, enabling direct and visual detection.
• The biosensor exhibited multicolor imaging capabilities, enhancing its utility for live EC research.
• LV-EcpG proved to be a powerful tool for non-invasive live EC detection.

Conclusions:

• LV-EcpG is a novel, genetically encoded fluorescent protein-based biosensor for specific, rapid, and non-invasive detection of living endothelial cells.
• The biosensor's specificity and visual output make it valuable for live EC research.
• LV-EcpG holds significant potential for advancing the diagnosis and treatment of cardiovascular diseases and tumor angiogenesis.