Table 2 Initial slope of the temperature variation with time, ΔT/δt, SAR deduced using the formula SAR = (ΔT/δt)⋅(Cv/XFe), where Cv = 4.2 J/gK is the specific heat capacity of water and XFe is the magnetosome concentration, and temperature increase measured over the whole magnetic session, ΔT. ΔT/δt, SAR and ΔT were measured for magnetosomes suspended in water (2 mg of magnetosomes in 100 µl of water or 40 µg of magnetosomes in 2 µl of water), magnetosomes after cellular internalization in vitro, and magnetosomes administered to U87-Luc intracranial tumors and exposed to one MS (MS1), two MS (MS2), three MS (MS3), four MS (MS4), five MS (MS5), six to fifteen MS (MS6 to MS15)
Magnetosome in water suspension (2 mg/100 μl) | Magnetosome in water suspension (40 μg/2 μl) | Magnetosome incubated with U87-Luc cells during 24 h | MS1 (in vivo) | MS2 in vivo | MS3 in vivo | MS4 in vivo | MS5 in vivo | MS6 to MS15 in vivo | |
|---|---|---|---|---|---|---|---|---|---|
∆T/δt (°C/s | 5.9 ± 1.5 | 0.27 ± 2.8×10−2 | 9.5 × 10−3 ± 1.8 × 10−3 | 2.2 × 10−2 ± 7.1 × 10−3 | 1.1 × 10−2 ± 4.4 × 10−3 | 1.1 × 10−5 ± 5.5 × 10−7 | 1.1 × 10−5 ± 5.5 × 10−7 | 1.1 × 10−5 ± 5.5 × 10−7 | 0 |
SAR (W/gFe) | 1234 ± 307 | 57 ± 6 | 57 ± 11 | 4.7 ± 1.5 | 2.5 ± 1 | 2 × 10−3 ± 10−4 | 2 × 10−3 ± 10−4 | 2 × 10−3 ± 10−4 | 0 |
∆T (°C) | 95 ± 8 | 33 ± 3 | 7.4 ± 0.7 | 4 ± 1 | 1.7 ± 1 | 0.4 ± 0.4 | 0.4 ± 0.4 | 0.4 ± 0.4 | 0 |