The aim of the study was to evaluate the potential of manganese‑zinc ferrite nanoparticles (MZF NPs) as a novel negative magnetic resonance imaging (MRI) contrast agents for 4T1 (mouse mammary carcinoma) and L929 (murine fibroblast) cell lines.
MZF NPs and its suitable coating, polyethylene glycol (PEG) via covalent bonding, were investigated under in vitro condition. The cytotoxicity of MZF NPs was tested by 3‑(4,5‑dimethyl thiazolyl‑2)‑2,5‑diphenyltetrazolium bromide assay after 12 and 24 h of incubation. To evaluate the potential of MZF NPs as T2 MRI nanocontrast agent, images were obtained from phantom containing different Fe concentrations and T2 relaxivity (r2) was measured. The viability of both 4T1 breast cancer and L929 murine fibroblast cell lines incubated with different Fe concentrations.
In vitro T2‑weighted MRI showed that signal intensity of 4T1 cells was lower than that of L929 as control cells. T2‑weighted MRI showed that signal intensity of MZF NPs enhanced with increasing concentration of NPs. The values of 1/T2 relaxivity (r2) for coated MZF NPs with PEG found to be 85.5 mM−1 s−1 which is higher than that of commercially clinical used (Sinerem) MRI contrast agent.
The results showed that MZF NPs have potential to detect breast cancer cells (4T1) and also have high contrast resolution between normal (L929) and cancerous cells (4T1) which is a suitable nanoprobe for T2‑weighted MR imaging contrast agents.