In other embodiments of the invention, {TAIL ~ the active agent} comprises {HEAD ~ a paramagnetic element} 
In other embodiments of the invention , { TAIL ~ the active agent } comprises { HEAD ~ a paramagnetic element }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD