Abstract:
The selective capture of low abundance cells of interest from complex biological fluids, and their subsequent efficient, undamaged release into a clean buffer, is critical for early detection in medical diagnostics. That approach requires highly selective methodologies that target the extremely rare cells of interest and reject the contaminating non-specific cells and debris. Current methods reporting high sensitivity are not rapid, and those methods reporting clinically acceptable processing and turn-around times are not yet effective. The aim of this research was to contribute towards the goal of effective capture and release of rare circulating cancer cells. It is these cells that present a threat to establish secondary, and often fatal growths. In previous research from the Polymer Biointerface Centre group, an electrospun electrochemical substrate was developed and tested for exosome capture and release. The methodology involved using a commercially available aptamer as the probe. Here, the work is extended to cell capture. While cell lines were maintained in good health and tested positively for the target proteins of interest, attempts at their successful capture on the aptamer-labelled electrospun substrate and subsequent release exposed the limitations of this approach. This led to deeper investigations of both the substrate and the aptamer, where methods of validating successful aptamer-substrate binding and aptamer-cell recognition were tested. In parallel, modified Herceptin antibodies as probes were also investigated, with HER2-positive cell lines. Challenges in utilising biological probes, namely aptamers and antibodies, attached to gold-coated substrates for cell capture and subsequent release, are discussed.
