Surface modification by 2-methacryloyloxyethyl phosphorylcholine coupled to a photolabile linker for cell micropatterning

This report describes a new surface-treatment technique for cell micropatterning. Cell attachment was selectively controlled on the glass surface using a photochemical reaction. This strategy is based on combining 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, which is known to reduce non-specific adsorption, and a photolabile linker (PL) for selective cell patterning. The MPC polymer was coated directly on the glass surface using a straightforward surface modification method, and was removed by ultraviolet (UV) light illumination. All the surface modification steps were evaluated using static water contact angle measurements, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), measurements of non-specific protein adsorption, and the cell attachment test. After selective cleavage of the MPC polymer through the photomask, cells attached only to the UV-illuminated region where the MPC polymer was removed, which made the hydrophilic surface relatively hydrophobic. Furthermore, the size of the MC-3T3 E1 cell patterns could be controlled by single cell level. Stability of the cell micropatterns was demonstrated by culturing MC-3T3 E1 cell patterns for 5 weeks on glass slide. The micropatterns were stable during culturing; cell viability also was verified. This method can be a powerful tool for cell patterning research.