Biodistribution and Tumor Targeted Accumulation of Anti-CEA-loaded Iron Nanoparticles.

INTRODUCTION: Active targeting of tumors by nanomaterials favors early diagnosis and the reduction of harsh side effects of chemotherapeuticals. METHOD: We synthesized magnetic nanoparticles (64 nm; -40 mV) suspended in a magnetic fluid (MF) and decorated them with anti-carcinoembryonic antigen (MFCEA; 144 nm; -39 mV). MF and MFCEA nanoparticles were successfully radiolabeled with technetium-99m (99mTc) and intravenously injected in CEA-positive 4T1 tumor-bearing mice to perform biodistribution studies. Both 99mTc-MF and 99mTc-MFCEA had marked uptake by the liver and spleen, and the renal uptake of 99mTc-MFCEA was higher than that observed for 99mTc-MF at 20h. At 1 and 5 hours, the urinary excretion was higher for 99mTc-MF than for 99mTc-MFCEA. RESULTS: These data suggest that anti-CEA decoration might be responsible for a delay in renal clearance. Regarding the tumor, 99mTc-MFCEA showed tumor uptake nearly two times higher than that observed for 99mTc-MFCEA. Similarly, the target-nontarget ratio was higher with 99mTc-MFCEA when compared to the group that received the 99mTc-MF. CONCLUSION: These data validated the ability of active tumor targeting by the as-developed antiCEA loaded nanoparticles and are very promising results for the future development of a nanodevice for the management of breast cancer and other types of CEA-positive tumors.

Antifungal activity of Copaíba resin oil in solution and nanoemulsion against Paracoccidioides spp.

Paracoccidioidomycosis (PCM) is a disease caused by fungi of the genus Paracoccidioides. The disease is responsible for high rates of premature deaths and socioeconomic repercussions. The limitations of antifungal agents against PCM have motivated the search for new compounds. In our ongoing exploration of Cerrado plants as potential sources of new antifungal agents, we selected Copaifera langsdorffii oil (Copaíba resin oil) in order to explore its bioactive potential and test a formulation to increase oil stability and solubilization employing Pluronic F-127 to obtain the nanoemulsion of the oil. We aim at testing both Copaíba resin oil and its nanoemulsion against four species of the Paracoccidioides genus. We performed cytotoxicity test in Balb/C3T3 cells, hemolytic activity and interaction of Copaíba resin oil and Copaíba resin oil nanoemulsion (CopaPlu) with the antifungal agents such as amphotericin B, co-trimoxazole, and itraconazole. Moreover, the Copaíba resin oil was analyzed by mass spectrometry to identify its chemical profile. Eventually, a new methodology to prepare the nanoemulsion is presented. The Copaíba resin oil and CopaPlu nanoemulsion inhibited Paracoccidioides sp. growth efficiently, and no cytotoxicity or hemolytic effect was observed at minimum inhibitory concentration (MIC). When combined with amphotericin B, Copaíba resin oil and its nanoemulsion showed an additive effect with reduction of MIC values. The Copaíba resin oil and CopaPlu nanoemulsion is a promising antifungal agent against Paracoccidioides.

Genotoxic and mutagenic assessment of iron oxide (maghemite-γ-Fe2O3) nanoparticle in the guppy Poecilia reticulata.

The environmental risk of nanomaterials (NMs) designed and used in nanoremediation process is of emerging concern, but their ecotoxic effects to aquatic organism remains unclear. In this study, the citrate-coated (maghemite) nanoparticles (IONPs) were synthesized and its genotoxic and mutagenic effects were investigated in the female guppy Poecilia reticulata. Fish were exposed to IONPs at environmentally relevant iron concentration (0.3 mg L-1) during 21 days and the animals were collected at the beginning of the experiment and after 3, 7, 14 and 21 days of exposure. The genotoxicity and mutagenicity were evaluated in terms of DNA damage (comet assay), micronucleus (MN) test and erythrocyte nuclear abnormalities (ENA) frequency. Results showed differential genotoxic and mutagenic effects of IONPs in the P. reticulata according to exposure time. The IONP induced DNA damage in P. reticulata after acute (3 and 7 days) and long-term exposure (14 and 21 days), while the mutagenic effects were observed only after long-term exposure. The DNA damage and the total ENA frequency increase linearly over the exposure time, indicating a higher induction rate of clastogenic and aneugenic effects in P. reticulata erythrocytes after long-term exposure to IONPs. Results indicated that the P. reticulata erythrocytes are target of ecotoxicity of IONPs.

Genotoxic and histopathological biomarkers for assessing the effects of magnetic exfoliated vermiculite and exfoliated vermiculite in Danio rerio.

Magnetic exfoliated vermiculite is a synthetic nanocomposite that quickly and efficiently absorbs organic compounds such as oil from water bodies. It was developed primarily to mitigate pollution, but the possible adverse impacts of its application have not yet been evaluated. In this context, the acute toxicity of magnetic exfoliated vermiculite and exfoliated vermiculite was herein assessed by genotoxic and histopathological biomarkers in zebrafish (Danio rerio). DNA fragmentation was statistically significant for all groups exposed to the magnetic exfoliated vermiculite and for fish exposed to the highest concentration (200mg/L) of exfoliated vermiculite, whereas the micronucleus frequency, nuclear abnormalities and histopathological alterations were not statistically significant for the fish exposed to these materials. In the intestinal lumen, epithelial cells and goblet cells, we found the presence of magnetic exfoliated vermiculite and exfoliated vermiculite, but no alterations or presence of the materials-test in the gills or liver were observed. Our findings suggest that the use of magnetic exfoliated vermiculite and exfoliated vermiculite during standard ecotoxicological assays caused DNA damage in D. rerio, whose alterations may be likely to be repaired, indicating that the magnetic nanoparticles have the ability to promote genotoxic damage, such as DNA fragmentation, but not mutagenic effects.