A simple fabricated microfluidic chip for rapid capture of circulating tumor cells

Abstract

Due to their portability, affordability and high sensitivity, microfluidic systems have become promising technologies to develop point-of-care (POC) diagnostics. A major challenge in microfluidic system fabrication is to integrate multiple microfluidic components in a simple way and construct microfluidic systems in a rapid, inexpensive manner. Here we investigated the design and fabrication of rapid capture of circulating tumor cells (CTCs) without the need for a cleanroom facility. The device contains is composed of a polydimethylsiloxane (PDMS) layer and a double-sided adhesive film (DSA). The microfluidic channels on the DSA film were simply fabricated using a laser prototyping technique. PDMS was chosen as the support layer to facilitate sample injection and avoid leakage. The microfluidic chip fabrication takes less than one minute without employing expensive lithographic methods. Design changes of fluidic channel can be made by ProE software, and which is applicable to rapid prototyping of microfluidic devices. The PDMS base and a glass cover slip were then assembled via the DSA. Before assembling the chip, glass cover was cleaned with ethanol using sonication. Then, it was washed with distilled water and dried under nitrogen gas. After cleaning steps, the glass cover was plasma treated for 60 seconds (100 mW, 1% O2, 60 s). Next, specific antibody was pre-immobilized on the bottom of the microchannel and then bound with FITC-labeled detection antibodies to generate fluorescent signals. Then, the inlet with cell suspension solution was connected to a syringe pump which controlled the fluid velocity, flow rates was adjusted from 2 to 8 μL/min. Using this device, a high tumor cell capture efficiency of 92% was achieved at a flow velocity of 2 μL/min. In this paper, a new technique is described to reduce fabrication time and cost, and shows considerable promise for the translation to a rapid point-of-care diagnostic device for the detection of CTCs. © 2014 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.