Laminin-111 Functionalization for Cell Culture

PEGLM was prepared as previously described (Fearing et al., 2019 (link); Francisco et al., 2013 (link)). Laminin-111 (LM-111, Trevigen; Gaithersburg, MD, USA) was reacted with acrylate-PEG-hydroxysuccinimide (Ac-PEG-NHS, 10 kDa, Creative PEGWorks; Winston-Salem, NC, USA) in order to form PEGLM. This solution was then dialyzed against PBS in order to remove unreacted Ac-PEG-NHS groups and PEGLM concentration was determined at 280 nm absorbance. Stiff (> 1 GPa) tissue culture surfaces (i.e., polystyrene well plates or glass chamber slides; Nunc Lab-Tek Chamber Slide Systems, Thermo Fisher Scientific; Waltham, MA, USA) were coated with the PEGLM solution (diluted with sterile PBS to a working concentration of 22.5 μg/mL). The PEGLM was allowed to adsorb to the culture surface overnight at 4 °C. The following day, the solutions were removed, and surfaces were rinsed with sterile PBS prior to inception of the experiment.