RESUMEN
Magnetic nanoparticles offer multiple utilization possibilities in biomedicine. In this context, the interaction with cellular structures and their biological effects need to be understood and controlled for clinical safety. New magnetic nanoparticles containing metallic/carbidic iron and elemental silicon phases were synthesized by laser pyrolysis using Fe(CO)5 vapors and SiH4 gas as Fe and Si precursors, then passivated and coated with biocompatible agents, such as l-3,4-dihydroxyphenylalanine (l-DOPA) and sodium carboxymethyl cellulose (CMC-Na). The resulting magnetic nanoparticles were characterized by XRD, EDS, and TEM techniques. To evaluate their biocompatibility, doses ranging from 0â»200 µg/mL hybrid Fe-Si nanoparticles were exposed to Caco2 cells for 24 and 72 h. Doses below 50 μg/mL of both l-DOPA and CMC-Na-coated Fe-Si nanoparticles induced no significant changes of cellular viability or membrane integrity. The cellular internalization of nanoparticles was dependent on their dispersion in culture medium and caused some changes of F-actin filaments organization after 72 h. However, reactive oxygen species were generated after exposure to 25 and 50 μg/mL of both Fe-Si nanoparticles types, inducing the increase of intracellular glutathione level and activation of transcription factor Nrf2. At nanoparticles doses below 50 μg/mL, Caco2 cells were able to counteract the oxidative stress by activating the cellular protection mechanisms. We concluded that in vitro biological responses to coated hybrid Fe-Si nanoparticles depended on particle synthesis conditions, surface coating, doses and incubation time.
RESUMEN
Iron oxide nanoparticles are promising candidates for theranostics in cancer, that aims to achieve in one-step precise tumor imaging by magnetic resonance, and targeted therapy through surface attached anti-cancer drugs. The aim of this study was to investigate in preclinical setting the biocompatibility of new iron oxide-based nanoparticles that were coated with L-DOPA for improved dispersion in biological media. These nanostructures (NPs) were designed for biomedical applications as contrast agents and/or drug carriers. We investigated the effect exerted in vitro by NPs and L-DOPA on the viability and proliferation of normal mouse L929 fibroblasts. NPs exhibited good biocompatibility against these cells. Moreover, L-DOPA contained in NPs sustained fibroblasts proliferation and/or limited anti-proliferative effects of naked nanoparticles. In the animal study, C57BL/6 mice were injected intraperitoneally with a single dose of NPs (approximately 125 mg/kg body weight). We followed up hematological and histological parameters for one, three and seven days after NPs administration. Results indicated that NPs possibly induced local inflammation and consequent recruitment of peripheral lymphocytes, whilst the decrease of platelet counts may reflect tissue lesions caused by NPs. The histopathological study showed mild to moderate alterations in the hepatocytes, splenic and renal cells, while the brain parenchyma only presented nonspecific congestive changes. Taken altogether, the preclinical study indicated that the new iron oxide nanoparticles coated with L-DOPA were biocompatible against fibroblasts and had a convenient toxicological profile when administered intraperitoneally in a single dose to C57BL/6 mice. Accordingly, the proposed nanostructure is a promising candidate for imaging and treating dispersed peritoneal tumors.
