PSA-Responsive Aptamer-Based Switchable Aggregates of Ultrasmall Gold Nanoparticles.

Area of Science:

• Biotechnology
• Nanotechnology
• Biomedical Engineering

Background:

• Prostate-specific antigen (PSA) is a critical biomarker for monitoring prostate cancer recurrence post-surgery.
• Existing detection methods may lack sensitivity or in vivo applicability.
• Aptamer-based nanosystems offer potential for enhanced diagnostic capabilities.

Purpose of the Study:

• To develop and optimize a PSA-responsive aptamer-based switchable aggregate system (AS2-US-AuNP-Aggregate).
• To evaluate the system's detection limits in various conditions, including blood-mimicking environments.
• To explore the potential for in vivo diagnostic applications.

Main Methods:

• Construction of ultrasmall gold nanoparticles (US-AuNPs) linked by aptamer oligomers.
• Dynamic light scattering (DLS) and extinction spectroscopy for system characterization.
• Testing PSA detection in buffers, with DNaseI, and filtered plasma.

Main Results:

• The AS2-US-AuNP-Aggregate system demonstrated selective disassembly in the presence of PSA.
• Achieved PSA detection limits of 10 fM in buffers and 1 pM in filtered plasma.
• System optimization was aided by an in silico routine.

Conclusions:

• Aptamer-based nanoparticle aggregates show significant potential for user-friendly diagnostic tools.
• The developed system exhibits high sensitivity and applicability in biologically relevant conditions.
• Further optimization strategies are discussed for advancing in vivo diagnostic applications.