Composite Microfluidic Petri Dish-Chip (MPD-Chip) without Protein Coating for 2D Cell Culture

Abstract

Hydrophilicity is a requisite attribute for the 2D cell culture substrate's surface, facilitating cell adhesion and spreading. Conventional poly(dimethylsiloxane) (PDMS) microfluidic chips necessitate protein coatings to enhance hydrophilicity; however, this approach is afflicted by issues of transient efficacy, interference with cell analysis, and high costs. This paper presents a protein-free microfluidic chip, termed a "microfluidic Petri dish-chip (MPD-chip)", integrating PDMS as the cover and a tissue culture-treated (TC-treated) Petri dish as the substrate. Microstructures are hot-embossed onto the Petri dish substrate using a silicon mold. This meticulous replication process serves to establish stable flow field dynamics within the chip. A simplified method for irreversible bonding, utilizing plasma activation and silylation, is proposed for affixing the PDMS cover onto the microstructured Petri dish substrate. The prepared composite chip exhibits remarkable tightness, boasting a notable bond strength of 2825 kPa. Furthermore, the composite microfluidic chip demonstrates the capability to withstand flow velocities of at least 200 μL/min, effectively meeting the required injection standards for both cell suspension and culture medium. SH-SY5Y and HeLa cells are cultured dynamically in the MPD-chip and control groups. Outcomes encompassing normalized cell density, cell adhesion area, and cell viability metrics unequivocally highlight the superiority of the MPD-chip in facilitating long-term two-dimensional (2D) cell cultures.