i used stereolithography to make up my hydrogel specimen, with pegda(80%) peg (15%)
irgacure 2959(0.5%) and water, using uv light 405nm for curing 5 minutes, and i am sure that the hydrogel is successfully cured, which have enough stress. Then i preserved my hydrogel in a dry box that is sealed and light-proof. However, my cell test always tell me that the hydrogel is harmful to cell. Can comebody tell me if my process have any problem or how can i improve my experiment?