Laminin entactin

SIA of laminin nanofibers was performed based on previously published methods.^{21 -23 (link)} Briefly, 25 mm diameter glass coverslips (Thermo Fisher Scientific) were spincoated with 10 wt% solution of PIPAAm (Polysciences) in 1-butanol at 6,000 RPM for 105 seconds. PDMS stamps were then incubated with laminin in sterile DI water at a concentration of 50 μg/mL for 45 min, washed 2 times in DI water to remove excess laminin, and dried under stream of nitrogen (Fig. 1a). The laminin types used all from EHS tumor were (i) >95% pure entactin free laminin 111 (Lam95, Corning^® ultrapure laminin, product #354239), (ii) >90% pure entactin free laminin 111 (Lam90, Corning^® laminin, product #354232) and (iii) >90% pure laminin 111 and entactin complex (Lam+E, Corning^® laminin/entactin, product #354259). The laminin coated PDMS stamps were brought into conformal contact with the PIPAAm coated coverslips for 10 min to create arrays of 200 × 20 μm laminin rectangles on the PIPAAm surface (Fig. 1b). Next, patterned coverslips were placed in a 35 mm petri dish and laminin nanofibers were released by adding 800 μL of 40°C, DI water and allowing it to cool to room temperature, through the lower critical solution temperature of PIPAAm resulting in the dissolution of the PIPAAm (Fig. 1c).