Alternatively, other targeting devices may be used such as attachment of {HEAD ~ the amplifier} to a porphyrin or {TAIL ~ other tumor} seeking moiety 
to
Alternatively , other targeting devices may be used such as attachment of { HEAD ~ the amplifier } to a porphyrin or { TAIL ~ other tumor } seeking moiety
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH