The baseline metabolic activity (A) and insulin secretory response to a glucose challenge (B) of encapsulated cells following coating with 12-layers of the designated coating formulations. The effect of 12-L coatings on oxidative cell health was measured via reduced:oxidized glutathione (GSH:GSSG) ratio (C), total glutathione (D), and oxidized glutathione (E). Grey dashed line: untreated controls. Two-way and one-way ANOVA with Tukey's post-hoc test: ****p < 0.0001, ***p < 0.001, **p < 0.01, and *p < 0.05, where * represents differences between groups, Δ compares 12-L coatings to 0-L beads, and γ compares groups with same alginate MW and varying pH of CONP.