The hydrogel matrix comprises about 3 to {HEAD ~ about 150 mM} of {TAIL ~ polar amino acids} 
of
The hydrogel matrix comprises about 3 to { HEAD ~ about 150 mM } of { TAIL ~ polar amino acids }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL