Figure 4. Two different ECM ligands are presented simultaneously to aggregated β-cells.

(A–C) Confocal images of MIN6 β-cells (green) co-seeded with laminin-coated (red) and fibronectin-coated (blue) microparticles. The relative amount of each population of particle incubated with the MIN6 cells was varied prior to seeding at ratios of (A) 25% laminin coated microparticles and 75% fibronectin-coated microparticles (1LN:3FN), (B) 50% laminin-coated microparticles and 50% fibronectin-coated microparticles (1LN:1FN), and (C) 75% laminin-coated microparticles and 25% fibronectin-coated microparticles (3LN:1FN). Images are composite stacks of 50 images taken at 2 μm intervals and scale bars represent 100 μm. (D) Total number of particles, both laminin- and fibronectin-coated, incorporated per aggregate as a function of particle seeding condition. Significantly fewer particles are incorporated in the 3LN:1FN microparticle seeding condition (p<0.05 using one-way ANOVA). (E) Average number of microparticles from each population of incorporated per aggregate as a function of seeding conditions. White bars represent number of laminin-coated microparticles incorporated per aggregate and black bars represent number of fibronectin-coated microparticles per aggregate. n ≥ 25 aggregates were measured for each seeding condition. * denotes significant difference between the number of particles of each kind incorporated for a given seeding condition, and # represents statistically significant number of particles incorporated compared to other seeding conditions for that type of particle. All statistical significances were determined using a p<0.05 and student’s t-test.