The polymers have {TAIL ~ a controlled degree} of hydrophobicity with a corresponding controlled degree of erosion in {HEAD ~ an aqueous or a biological environment} of use 
The polymers have { TAIL ~ a controlled degree } of hydrophobicity with a corresponding controlled degree of erosion in { HEAD ~ an aqueous or a biological environment } of use
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH