i) a linear polymer selected from {TAIL ~ the group} consisting of linear hydrophobic biodegradable polymers and linear {HEAD ~ non degradable hydrophilic polymers} 
i ) a linear polymer selected from { TAIL ~ the group } consisting of linear hydrophobic biodegradable polymers and linear { HEAD ~ non degradable hydrophilic polymers }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD