Manipulating mammalian cell morphologies using chemical-mechanical polished integrated circuit chips

Area of Science:

• Biomaterials Science
• Surface Science
• Cell Biology

Background:

• Integrated circuits offer precisely engineered surfaces for biological applications.
• Tungsten (W) and silicon oxide (SiO2) are common materials in microelectronics.
• Controlling cell adhesion and alignment on engineered surfaces is crucial for tissue engineering and biosensors.

Purpose of the Study:

• To investigate the alignment and immobilization of mammalian (Vero) cells on tungsten chemical-mechanical polished integrated circuit surfaces.
• To determine the influence of tungsten line geometry on cell orientation and adhesion.
• To assess the reusability of these surfaces for cell culture.

Main Methods:

• Fabrication of ultra-flat silicon oxide surfaces with embedded micro- and nano-scale tungsten lines.
• Deposition and microscopy-based observation of Vero cell adhesion and morphology.
• Analysis of cell orientation relative to tungsten line width and spacing.
• Development of a model to explain cell behavior based on surface topography.

Main Results:

• Vero cells exhibited a strong preference for tungsten over silicon oxide, with up to 99% adhesion on tungsten.
• Cells elongated and aligned along tungsten lines, with alignment sensitivity to line width and spacing.
• High alignment (93%) observed on 10 μm lines, reduced alignment (~22%) on 0.18 μm lines.
• Model confirmed cell rearrangement to maximize contact with tungsten features.

Conclusions:

• Tungsten micro/nano-structures on polished integrated circuits effectively guide mammalian cell alignment and immobilization.
• Cellular response is predictable based on geometric parameters of the patterned surfaces.
• The engineered surfaces are reusable, retaining their cell alignment capabilities after cleaning.