Microstructured polyethylene terephthalate (PET) for microsieving of cancer cells

The paper describes a simple and cheap method of manufacturing microsieves through laser technology. The microsieves were used to capture live cancer cells in vitro. The problem of capturing live circulating cancer cells from the patient's blood (a liquid biopsy) in an efficient manner still remains unresolved. The process of drilling microsieves was optimized by using a copper foil with a thickness of 25 mu m. The target microsieves were manufactured from polyethylene terephthalate (C10H8O4)(n) (PET) - a thermoplastic polymer from the polyester group. Fifty laser pulses with the energy of 22 mu J for drilling each hole were applied. The total number of the cancer cells captured by the microsieve was calculated by using SEM images. More than 82.5% of DU 145 human prostate cancer cells (HTB-81 ATCC) was captured in the microsieves. The most interesting phenomenon observed by the SEM imaging was the adhesion of live cancer cells to the microsieve material within the drilled holes. The cancer cells had a smaller diameter than the holes in the microsieve; therefore, their capture by adhesion forces may resolve the problem involved in the filtration of unfixed, live cells.