Comparative study on antibody immobilization strategies for efficient circulating tumor cell capture

Area of Science:

• Biotechnology
• Nanotechnology
• Medical Diagnostics

Background:

• Circulating tumor cells (CTCs) are rare but clinically significant biomarkers.
• Efficient isolation of CTCs requires highly sensitive and specific technologies.
• Antibody immobilization strategies critically impact microfluidic-based CTC capture systems.

Purpose of the Study:

• To evaluate and compare different antibody immobilization methods for CTC capture.
• To assess the impact of immobilization techniques on CTC capture efficiency and selectivity.
• To optimize microfluidic systems for improved CTC isolation.

Main Methods:

• Assessed two covalent and two bioaffinity antibody immobilization methods on SiO2 surfaces and microfluidic channels.
• Utilized anti-epithelial cell adhesion molecule (EpCAM) as the capture antibody.
• Employed MCF-7 (EpCAM+) and CCRF-CEM (EpCAM-) cell lines to evaluate capture efficiency and selectivity.

Main Results:

• Bioaffinity immobilization with streptavidin-glutaraldehyde linker yielded the highest CTC capture efficiency.
• Covalent EDC-NHS reaction offered comparable efficiency with improved time and cost-effectiveness.
• All tested methods demonstrated high selectivity for EpCAM-expressing CTCs.
• EDC-NHS immobilization within microfluidic channels proved effective for high-efficiency, selective CTC capture.

Conclusions:

• Antibody immobilization strategy is crucial for effective CTC isolation in microfluidic devices.
• Both bioaffinity and optimized covalent methods can achieve high CTC capture efficiency and selectivity.
• The EDC-NHS covalent method in microfluidic channels presents a practical approach for CTC isolation.