Controlled Scaffold Platform Designs on Nasopharyngeal Carcinoma Cell Separation

Abstract

Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic disease occurring in the nasopharynx. For early diagnosis or treatment, it is useful to separate invasive nasopharyngeal carcinoma (NPC43) cells from epithelial (NP460) cells. However, the lack of proper in vivo models significantly hinders the systematic study of NPC. In this study, an in vitro two-layer scaffold platform was developed to mimic the extracellular matrix of the tissue. Three precisely controlled factors were designed to investigate how topographic cues affected migration of NP460 and NPC43 cells, including overlay angles between the top and bottom layers, various top layer thicknesses, and surface topography of the bottom layer ridges. These designs offered different surface contact areas for cells to probe and form focal adhesions as they migrated on the platforms. As NP460 and NPC43 cells respond differently to the surrounding microenvironments, most NPC43 cells could move into the 10 µm wide trenches while NP460 cells stayed on the 40 µm wide top layer ridges. Over 90% separation efficiency was achieved on platforms with the top layer being perpendicular to the bottom layer, 15-µm thick top layer, and grating on the bottom layer ridges.

Enhancing Nasopharyngeal Carcinoma Cell Separation with Selective Fibronectin Coating and Topographical Modification on Polydimethylsiloxane Scaffold Platforms

“…The increased hydrophilicity of the plasma-treated surfaces would enhance cell attachment [18]. Consistent with previous findings, NP460 cells moved faster than NPC43 cells on the scaffold platforms [25,26]. After the plasma treatments of the platforms, NP460 and NPC43 cells had similar migration speeds compared to cells on untreated platforms, as shown in Figure 2a.…”

“…As shown in the Supplementary video S1a, with FN selectively coated on the top layer sidewalls and bottom layers, more NP460 and NPC43 cells were able to migrate into the 10 µm wide trenches by stretching their lamellipodia or long protrusions to contact the sidewalls of the trenches. Some cells could further move to the bottom layer since the bottom layer was also coated with FN, which was seldom observed in our previous studies [5,14,25,26]. However, the selective coating of the platforms enhanced both NP460 and NPC43 cell traversing capabilities.…”

“…Aspect ratio is defined as the ratio between the major and minor axes of a best-fitted ellipse generated via the ImageJ software based on the outline of the cell. Statistical comparisons between It can be seen that NP460 cells had sheet-like lamellipodia, while NPC43 cells had long protrusions in all directions with vesicles on the cell surface [26]. To quantify the cell morphological change for cells spread on different plasma-treated platforms, the aspect ratio of NP460 and NPC43 cells was calculated, as shown in Figure 3c.…”

“…The fabrication details for the biomimetic scaffold platforms were described previously [5,25,26]. Briefly, grating patterns were transferred onto a silicon (Si) wafer via photolithography and dry etching and coated with a thin anti-sticking hydrophobic layer of trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane (FOTS) to form the Si stamp.…”

“…The ECM functions as a complex scaffold for cells in the tissue, encompassing varied physical dimensions and surface properties that influence NPC cell migration and traversing behaviors. Previous studies have demonstrated the influential role of topographical features in the ECM in guiding cell migration, with a focus on controlling the dimensions and layouts of 3D PDMS scaffold platforms to realize the NPC cell separation [25][26][27][28][29]. The concept of utilizing these topographical features to direct cell adhesion, seeding, viability, and migration on two-dimensional surfaces has been well established [9,18,20,22,[30][31][32].…”