Most preferably, the polymer has {TAIL ~ a molecular weight} in {HEAD ~ the range} of 15 kDa to 40 kDa 
Most preferably , the polymer has { TAIL ~ a molecular weight } in { HEAD ~ the range } of 15 kDa to 40 kDa
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH