One is a cell delivery agent for delivering a biologically active protein or {HEAD ~ peptide} to {TAIL ~ a cell} as described above 
One is a cell delivery agent for delivering a biologically active protein or { HEAD ~ peptide } to { TAIL ~ a cell } as described above
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH