Fig. 2.

Characterization of plasmonic hydrogels as cellular scaffolds. (a) SEM images show HeLa-EGFP or C3H/10T1/2-fLuc cells cultured for 1 day within hydrogels containing 0.03 mg mL⁻¹ HGNPs. (b) Graphs show metabolic activities of cells encapsulated within hydrogels containing different doses of HGNPs, at the indicated times of culture. (c) Release of fbg-AF546 to the medium in cultures of C3H/10T1/2-fLuc cells entrapped in hydrogels containing the indicated doses of HGNPs. The data are expressed as the percentage of the fluorescence measured in the media from hydrogels lacking HGNPs cultured for 1 day, which was given the arbitrary value of 100 (b and c). Each value represents the mean ± SD. HeLa-EGFP cells were encapsulated within hydrogels containing 0.03 mg mL⁻¹ HGNPs (d and e) or the indicated doses of HGNPs (f) and cultured for 24 h. Constructs were treated with rapamycin and exposed (+) or not (−) to NIR irradiation at 44 mW mm⁻² for 5-20 min (d), 20 min (e) or 10 min (f), and cultured further for 24 h. Biomappings of top-view (tv) or cross section (cs) of hydrogels show calcein-violet stained cells in blue (e) or EGFP-expressing cells in green (d and f). Graph shows the relative area concentric to the spot of laser incidence comprising cells that express (Activation) or do not express (Death) EGFP in tv images. Values are relative to the total surface area of the hydrogel, which was given the arbitrary value of 100.