The cell culture medium and hydrogel matrix include an effective amount of polar amino acids, the polar amino acids selected from the group consisting of arginine, {TAIL ~ lysine}, {HEAD ~ histidine}, glutamic acid, and aspartic acid 
The cell culture medium and hydrogel matrix include an effective amount of polar amino acids , the polar amino acids selected from the group consisting of arginine , { TAIL ~ lysine } , { HEAD ~ histidine } , glutamic acid , and aspartic acid
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH