Fig. 4.

Effect of 25 μM L-histidine (His) on the release of green fluorescent protein (GFP) in its standard form (GFP-std; circles), supercharged negative (GFP-neg; squares), or supercharged positive (GFP-pos; triangles) following injection into hydrogels composed of 1 mg/mL Col1/0.5 mg/mL HA or 1 mg/mL Col1. (A) Release over 24 h. (B) Magnified release data over the first 5 h. Mean +/− standard deviation. GFP-std Col1, n = 4. GFP-std Col1/HA, n = 6. GFP-neg Col1, n = 4. GFP-neg Col1/HA, n = 6. GFP-pos all series, n = 4. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)