AC hysteresis
loops of (a) A@PMAO in D.I. water, (b) A@PMAO in agar, (c) A@PMAO
in PBS, (d) A@PEG20k-ST in D.I. water, (e) A@PEG20k in D.I. water,
(f) A@PEG20k in agar, and (g) A@PEG20k in PBS. (h) Experimental SAR
versus field curves corresponding to (a–g) AC loops and (i)
experimental SAR versus field curves of A@PEG20k until 40 and 60 mT
together with a simulated SAR versus field curve for FM-NPs of 23
nm. All measurements and simulations have been performed at 300 kHz
and 300 K. Measurements up to 40 mT have been carried out by AC Magnetometer-1
and up to 60 mT by AC Magnetometer-2 (see Materials
and Methods).