Microfluidic Determination of Distinct Membrane Transport Properties between Lung Adenocarcinoma Cells CL1-0 and CL1-5.

The cell membrane permeability of a cell type to water (Lp) and cryoprotective agents (Ps), is the key factor that determines the optimal cooling and mass transportation during cryopreservation. The human lung adenocarcinoma cell line, CL1, has been widely used to study the invasive capabilities or drug resistance of lung cancer cells. Therefore, providing accurate databases of the mass transport properties of this specific cell line can be crucial for facilitating either flexible and optimal preservation, or supply. In this study, utilizing our previously proposed noncontact-based micro-vortex system, we focused on comparing the permeability phenomenon between CL1-0 and its more invasive subline, CL1-5, under several different ambient temperatures. Through the assay procedure, the cells of favor were virtually trapped in a hydrodynamic circulation to provide direct inspection using a high-speed camera, and the images were then processed to achieve the observation of a cell's volume change with respect to time, and in turn, the permeability. Based on the noncontact nature of our system, we were able to manifest more accurate results than their contact-based counterparts, excluding errors involved in estimating the cell geometry. As the results in this experiment showed, the transport phenomena in the CL1-0 and CL1-5 cell lines are mainly composed of simple diffusion through the lipid bilayer, except for the case where CL1-5 were suspended in the cryoprotective agent (CPA) solution, which also demonstrated higher Ps values. The deviated behavior of CL1-5 might be a consequence of the altered expression of aquaporins and the coupling of a cryoprotective agent and water, and has given a vision on possible studies over these properties, and their potential relationship to invasiveness and metastatic stability of the CL1 cell line.