Figure 3.

Viability and growth of A549 cells on the hydrogels. (I) Surface of (A) Collagen-HG and (B,C) Collagen/mucin-HG; SEM. (II) Growth of A549 cells during a 48-h incubation period. The viability was determined by the MTT assay system. (III) Comparative photo image of the surface of (A) Collagen-HG, (B) Collagen/mucin-HG, and (C) Collagen/mucin/polyP-HG; SEM. In the polyP-containing matrix, nanoparticles of sizes between 50 and 100 nm have been formed from polyP and MgCl₂. (IV) Already after microscopical inspection of the cells, after staining with calcein, a strong difference in the density of the cells between cultures onto Collagen-HG (A) and Collagen/mucin-HG (B) in comparison to Collagen/mucin/polyP-HG (C) is apparent. (V) Growth of A549 cells on the three different matrices during a 48-h incubation period. The cells were seeded onto Collagen-HG (collagen: 5 mg/mL) alone or supplemented with mucin (100 µg/mL) or additional also with polyP (1 to 100 µg/mL). After an incubation period of 48 h, the viability was assessed using the MTT assay. The values are expressed as absorbance values at 550 nm. The number of parallel experiments was 10. Data are means ± SD (* p < 0.05).