Figure 1.

Conceptual illustration of four generations of NanoVelcro Assay developed by UCLA team. The 1^st generation NanoVelcro chip [45,46], composed of silicon nanowire substrate (SiNS) in conjunction with an overlaid microfluidic chaotic mixture, was created for CTC capture and enumeration. The 2^nd Gen NanoVelcro-LMD (laser microdissection) chip [33-35] was designed for the isolation of captured CTC. The 3^rd generation ThermoResponsive NanoVelcro chip [37,38] utilized temperature driven conformation change of polymer brushes to achieve the capture and release of viable CTCs at 37°C and 4°C, respectively. The 4^th gen Sweet Chip [39] utilized the competitive binding of sorbitol to phenylboronic acid (PBA) to gently release captured CTC was intact molecular integrity.