Study Of The Highly Efficient Capture And Controllable Release Of Circulating Tumor Cells

Circulating tumor cells (CTCs) show great importance in tumor detection and tumor metastasis. However, they are extremely rare in peripheral blood. Thus, it is urgent to develop a highly effective and reliable platform to capture and recycle CTCs. In this thesis, we have developed a method based on arrays of gold nanowires (AuNWs) to capture target tumor cells (human acute lymphoblastic leukemia cells, CEM) with high efficiency using K562 cells (human chronic myelogenous leukemia cells) as the control cells. We also developed a simple method to release the captured cells based on electrochemistry desorption by electrochemical reduction of S-Au bonds. The contents of this thesis are as follows:1. Fabrication of gold nanowires arrays for cancer cells captureAuNWs were fabricated by electrochemical deposition with porous anodic alumina (PAA) membrane as the template and the deposition current and time was adjusted to control the length and regularity of the AuNWs. The capture efficiency of target cells captured by aptamer modified AuNWs was far more higher than that of target cells captured by aptamer modified gold plated glass and non-target cells captured by aptamer modified AuNWs. The results demonstrate that AuNWs can promote the interaction of cells with the substrate and aptamer has high specificity to the target.2. The release of captured cells with high efficiency on a simply home-made gold electrode by electrochemical desorptionA gold plated glass was used as the cell capture electrode. The aptamer and PEG modified on this capture electrode were used to capture target cells and eliminate the nonspecific adsorption of cells on the electrode surface. After cell capture a negative potential was applied to break the Au-S bond, resulting in the release of captured cells from the capture electrode surface. The releasing process is very quick and efficient, and does not show significant effect on cell viability, which makes it applicable in CTCs isolation and study of CTCs’electrochemical property.