Figure 4.

Lipids and pH changes alter mucus structure and microparticle distribution within mucus. Microspheres dosed to mucus were diluted in A) Maleate buffer at pH 6.5 and [Ca²⁺] = 10 mM B) Maleate buffer at [Ca²⁺] = 20 mM, C) Maleate buffer at pH 3.5, D) Fed state lipids, including model bile components phospholipid and bile salt. Mucus appears more uniform and microspheres were dispersed more homogeneously for cases A and B. Bar = 50 μm.