Fig. 3

TA-loaded hydrogel is biocompatible with cells from healthy and arthritic human joints. a–d Primary human chondrocytes or synoviocytes from healthy donors or RA patients were incubated in a 96-well transwell plate in medium, PBS, or in medium with 50 µl blank hydrogel (Blank gel), 50 µl TA-loaded TG-18 hydrogel (TA gel), DMSO (equivalent to 50 µl hydrogel) or free drug (Free TA, equivalent to 50 µl TA-loaded TG-18 hydrogel) added to the upper chamber of the transwell. After 24, 48, and 72 h of incubation, metabolic activity was determined by XTT assay. e Representative fluorescence microscopy images after live/dead staining of primary human chondrocytes or synoviocytes from healthy donors or RA patients incubated for 72 h in medium or medium with blank hydrogel (Blank gel) or TA-loaded TG-18 hydrogel (TA gel) added to the upper chamber of the transwell (Scale bar: 400 µm). Viable cells stain green with calcein-AM, whereas dead cells stain red with ethidium homodimer-1. Data in a–d are means ± SD of technical repeats (n = 3, experiment performed at least twice)