Fine neurite patterns from photocrosslinking of cell-repellent benzophenone copolymer

We have synthesized photocrosslinkable benzophenone copolymer, Poly(St-co-MBz), and fabricated cell-repellent patterns of Poly(St-co-MBz) on covalently bound poly-D-lysine (PDL) layer via the photocrosslinking. We have successfully obtained fine grid line pattern with line width of 3 μm and fine neurite, presumably axon, patterns with excellent pattern fidelity. We found that benzophenone unit can be crosslinked under the exposure of UV (with the intensity of ∼77 mW/cm² at 280 nm and ∼60 mW/cm² at 365 nm) without photo-oxidative damage to PDL, poly-L-lysine, and polyethyleneimine.