Evaluation of cytotoxicity of biphasic TiO2 nanoparticles with organic surface coatings

Titanium dioxide nanoparticles (TiO2 NPs) are used in lots of human applications because of their extraordinary nano scaled properties. Particularly, due to their photoprotective properties, they are used in topical dermatologic preparation and also as white pigment. Due to these properties their use in human life is more and more frequent. Despite the fact that nano dimension brings various beneficial properties, it could bring also bad features. Therefore, in this study, we evaluated a cytotoxicity of two types of biphasic TiO2 NPs using distinct cells of epithelial origin. We found that TiO2 NPs can induce cytotoxic stress resulting in fragmentation of DNA

MALDI MSI of MeLiM melanoma: Searching for differences in protein profiles

Background Treatment of advanced cutaneous melanoma remains challenging, and new data on melanoma biology are required. The most widely accepted criteria for the prognostic evaluation of melanoma are histopathological and clinical parameters, and the identification of additional tumor markers is thus of paramount importance. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI), an important tool in cancer research, is useful for unraveling the molecular profile of melanoma. Methodology/Principal findings In this report, we used the melanoma-bearing Libechov minipig (MeLiM), a unique animal model that allows observation of the complete spontaneous regression of invasive cutaneous melanoma, to investigate i) the differences between melanoma and healthy skin protein profiles and ii) the proteins potentially involved in spontaneous regression. The MeLiM tissues were cryosected, histologically characterized, analyzed by MALDI MSI, and immunohistologically stained. Multivariate statistical analyses of the MALDI MSI data revealed ten relevant m/z ions, of which the expression levels varied significantly among the studied MeLiM tissues. These ion peaks were used to create mass ion images/maps and visualize the differences between tumor and healthy skin specimens, as well as among histologically characterized tissue regions. Conclusions/Significance Protein profiles comprising ten statistically significant mass ion peaks useful for differentiating cutaneous melanoma and healthy skin tissues were determined. Peaks at m/z 3044, 6011, 6140 and 10180 were overexpressed in melanoma compared with healthy skin tissue. More specifically, m/z 6140 was expressed at significantly (p < 0.05) higher levels in normally growing melanoma regions than in regions with early and late spontaneous regression. This study demonstrates the clinical utility of MALDI MSI for the analysis of tissue cryosections at a molecular level