Figure 7.

Impact of blue (450 nm) and NIR (850 nm) light treatment on the metabolic activity of human dermal fibroblasts when exposed to dermal tissue oxygen levels (approx. 2%). (A) Fluorescence counts (Alamar Blue) measured in reticular and papillary fibroblasts (facelift, female, 64 yo) in low (2%) and high (20%) oxygen levels. No strong change in Alamar fluorescence count is apparent. (B) Relative cell counts of human dermal fibroblasts (reticular and papillary) after light treatment in hypoxic conditions (2% oxygen). Cells were grown in 35-mm individual dishes and treated with light once a day for three consecutive days. Cell counting was performed 24 h after last treatment. Material originating from two different donors was included in the experiment (N = 2, reticular and papillary, 3 repeats, 12 counts per bar). (C) Relative metabolic activity of human papillary fibroblasts in response to 30 J.cm⁻² at 450 nm in low and high environmental oxygen levels (N = 2, papillary and 3 replicates). (D) Relative metabolic activity of human reticular fibroblasts in response to 20 J.cm⁻² at 850 nm in low and high environmental oxygen levels (N = 2, reticular and 3 replicates). Irradiance levels were 50 mW.cm⁻² (450 nm) and 80 mW.cm⁻² (850 nm).