Plasma surface modification of electrospun fibers for adhesion-based cancer cell sorting

Abstract

Personalized cancer therapies drive the need for devices that rapidly and accurately segregate cancer cells from solid tumors. One potential sorting strategy is to segregate populations of cells based on their relative strength of adhesion. To investigate the effect of surface hydrophilicity and cell phenotype on adhesion, primary human breast skin fibroblasts and keratinocytes and MCF-7 breast cancer cells were seeded onto air and CF₄ plasma-treated nanofibers followed by exposure to three shear stresses (200, 275 and 350 dynes per cm²) 1 hour after inoculation. No difference in strength of adhesion was measured in either fibroblasts or keratinocytes on either plasma treated-surface: all exhibited >60% of the initial cell count after a 5 minute exposure to 350 dynes per cm² of shear stress. In contrast, a significant difference between relative strength of adhesion on air versus CF₄ plasma-treated surfaces was observed for MCF-7 cells: 26% and 6.6% of cells remained on the air and CF₄ plasma-treated surfaces, respectively. The ability to sort this cancer cell line from two non-cancerous primary human cells was evaluated by inoculating a mixture of all three cell types simultaneously onto CF₄ treated nanofibers followed by 1 hour of culture and exposure to 350 dynes per cm² shear stress. The majority of MCF-7 cells were removed (0.7% remained) while a majority of fibroblasts and keratinocytes remained adhered (74 and 57%). Post-sorted MCF-7 viability and morphology remained unchanged, preserving the possibility of post-separation and analysis. These data suggest that the plasma treatment of electrospun scaffolds provides a tool useful in sorting cancer cells from a mixed cell population based on adhesion strength.