Hybrids of Iron-Filled Multiwall Carbon Nanotubes and Anticancer Agents as Potential Magnetic Drug Delivery Systems: In Vitro Studies against Human Melanoma, Colon Carcinoma, and Colon Adenocarcinoma

Table 1

⁵⁷Fe Mössbauer spectroscopy parameters for Fe@MWCNTs and Fe@O-MWCNTs at room temperature [47, 48].

Sample/phase	C (%)	S (mm/s)	(mm/s)	B (T)	Г (mm/s)
Fe@MWCNTs
-Fe	40	−0.10	—	—	0.18
-Fe	34	0.01	—	33.0	0.18
	26	0.20	0.03	20.6	0.28
Fe@O-MWCNTs
-Fe	42	−0.09	—	—	0.17
-Fe	53	0.00	—	33.2	0.17
	5	0.14	0.18	21.0	0.27

C (%): relative contribution of various iron phases to the absorption cross section; it corresponds to iron abundancies as particular phases; S (mm/s): spectral shift versus shift of -Fe at room temperature; Δ (mm/s): electric quadrupole splitting; B (T): magnetic hyperfine field; Γ (mm/s): absorber line width. Errors for all values are of the order of unity for the last digit shown.