Analysis of the immune response using FTIR spectroscopy in mothers and their newborns with different vaccination schemes for COVID-19.

The SARS-CoV-2 outbreak has provoked more than 6 million deaths worldwide. The scarcity of effective treatments and its virulence converted the vaccines into an essential tool to face it. The most used vaccines were the mRNA, adenovirus vector, and inactivated whole-virus. However, nowadays, infants aged < 6 months are not eligible for any vaccines against COVID-19, and their immunization relies on passive immunity. In this research, we investigated the humoral and cellular immune response generated on newborns of SARS-CoV-2 vaccinated mothers with mRNA or viral vector (VV) vaccine employing Fourier transformed infrared (FTIR) spectroscopy in saliva samples. For this purpose, saliva samples of newborns and their mothers were collected; the population was divided into two groups, VV and mRNA, which were subdivided into three subgroups: before pregnancy (BP), at the first (FTP) and second (STP) trimesters of pregnancy. The samples were analyzed using FTIR spectroscopy, and the bands associated with the humoral and cellular immune responses, such as IgG, IgA, and IFN-γ were analyzed. The integrated areas were calculated and compared to elucidate the quantity of those immunoglobins and the cytokine. Likewise, the correlation of the humoral and cellular immune response between the newborns and their mothers and the correlation between cellular and humoral immune response was also evaluated. The VV vaccine produced a significant humoral and cellular immune response in newborns and their mothers when they received it at the STP compared with the mRNA vaccine, evidencing statistical significance. However, no correlation was observed between newborns and their mothers when the vaccine was applied in this trimester of pregnancy. When administered BP, the mRNA vaccine generated more humoral immunity in newborns and their mothers. Nevertheless, compared with the VV vaccine, it only showed statistical significance in the mothers, highlighting that IgG showed a moderate positive correlation between the newborns and their mothers.

Food grade titanium dioxide accumulation leads to cellular alterations in colon cells after removal of a 24-hour exposure.

Titanium dioxide food grade (E171) is one of the most used food additives containing nanoparticles. Recently, the European Food Safety Authority indicated that E171 could no longer be considered safe as a food additive due to the possibility of it being genotoxic and there is evidence that E171 administration exacerbates colon tumor formation in murine models. However, less is known about the effects of E171 accumulation once the exposure stopped, then we hypothesized that toxic effects could be detected even after E171 removal. Therefore, we investigated the effects of E171 exposure after being removed from colon cell cultures. Human colon cancer cell line (HCT116) was exposed to 0, 1, 10 and 50 µg/cm2 of E171. Our results showed that in the absence of cytotoxicity, E171 was accumulated in the cells after 24 of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization. After the removal of E171, colon cells were cultured for 48 h more hours to analyze the ability to restore the previously detected alterations. As we hypothesized, the removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.

Differential response of immobile (pneumocytes) and mobile (monocytes) barriers against 2 types of metal oxide nanoparticles.

BACKGROUND: Inhaled nanoparticles (NPs) challenges mobile and immobile barriers in the respiratory tract, which can be represented by type II pneumocytes (immobile) and monocytes (mobile) but what is more important for biological effects, the cell linage, or the type of nanoparticle? Here, we addressed these questions and we demonstrated that the type of NPs exerts a higher influence on biological effects, but cell linages also respond differently against similar type of NPs. DESIGN: Type II pneumocytes and monocytes were exposed to tin dioxide (SnO2) NPs and titanium dioxide (TiO2) NPs (1, 10 and 50 µg/cm2) for 24 h and cell viability, ultrastructure, cell granularity, molecular spectra of lipids, proteins and nucleic acids and cytoskeleton architecture were evaluated. RESULTS: SnO2 NPs and TiO2 NPs are metal oxides with similar physicochemical properties. However, in the absence of cytotoxicity, SnO2 NPs uptake was low in monocytes and higher in type II pneumocytes, while TiO2 NPs were highly internalized by both types of cells. Monocytes exposed to both types of NPs displayed higher number of alterations in the molecular patterns of proteins and nuclei acids analyzed by Fourier-transform infrared spectroscopy (FTIR) than type II pneumocytes. In addition, cells exposed to TiO2 NPs showed more displacements in FTIR spectra of biomolecules than cells exposed to SnO2 NPs. Regarding cell architecture, microtubules were stable in type II pneumocytes exposed to both types of NPs but actin filaments displayed a higher number of alterations in type II pneumocytes and monocytes exposed to SnO2 NPs and TiO2 NPs. NPs exposure induced the formation of large vacuoles only in monocytes, which were not seen in type II pneumocytes. CONCLUSIONS: Most of the cellular effects are influenced by the NPs exposure rather than by the cell type. However, mobile, and immobile barriers in the respiratory tract displayed differential response against SnO2 NPs and TiO2 NPs in absence of cytotoxicity, in which monocytes were more susceptible than type II pneumocytes to NPs exposure.

Toxicity of engineered nanomaterials with different physicochemical properties and the role of protein corona on cellular uptake and intrinsic ROS production.

The Organisation for Economic Co-operation and Development has listed thirteen engineered nanomaterials (ENM) in order to investigate their toxicity on human health. Silicon dioxide (SiO2) and titanium dioxide (TiO2) are included on that list and we added indium tin oxide (ITO) nanoparticles (NPs) to our study, which is not listed on OECD suggested ENM to be investigated, however ITO NPs has a high potential of industrial production. We evaluate the physicochemical properties of SiO2 NPs (10-20 nm), TiO2 nanofibers (NFs; 3 µm length) and ITO NPs (<50 nm) and the impact of protein-corona formation on cell internalization. Then, we evaluated the toxicity of uncoated ENM on human lung epithelial cells exposed to 10 and 50 µg/cm2 for 24 h. TiO2 NFs showed the highest capability to adsorb proteins onto the particle surface followed by SiO2 NPs and ITO NPs after acellular incubation with fetal bovine serum. The protein adsorption had no impact on Alizarin Red S conjugation, intrinsic properties for reactive oxygen (ROS) formation or cell uptake for all types of ENM. Moreover, TiO2 NFs induced highest cell alterations in human lung epithelial cells exposed to 10 and 50 µg/cm2 while ITO NPs induced moderated cytotoxicity and SiO2 NPs caused even lower cytotoxicity under the same conditions. DNA, proteins and lipids were mainly affected by TiO2 NFs followed by SiO2 NPs with toxic effects in protein and lipids while limited variations were detected after exposure to ITO NPs on spectra analyzed by Fourier Transform Infrared Spectroscopy.

Generalidades y aplicaciones de las células madre / Generalities and applications of the stem cells

Una célula madre (CM) es capaz de dividirse indefinidamente y diferenciarse en distintos tipos de células especializadas, no sólo morfológicamente sino también de forma funcional. A finales del siglo XX los histoembriólogos Boveri y Haeckel acuñaron el término de células madre (CM). Atendiendo a su origen, las CM se clasifican en embrionarias y adultas, en tanto que de acuerdo a su potencial y capacidad de diferenciación se clasifican en: totipotenciales, pluripotenciales, multipotenciales y unipotenciales. Dentro de las características principales de las CM se encuentran a) autorrenovación, debida a la actividad de la telomerasa; b) potencialidad, que es la capacidad de diferenciarse en otro tipo celular; c) baja inmunogenicidad, debido a una baja expresión del complejo principal de histocompatibilidad I (MHC I) y carencia de la expresión de MHC II. Las principales investigaciones que se han desarrollado con CM han sido con la finalidad de diferenciarlas in vitro hacia otros tejidos como: páncreas, condrocitos y cardiomiocitos, entre otros, con el objetivo de llegar a ser una fuente de reemplazo celular. Sin embargo, tienen otras aplicaciones, como el vehículo terapéutico de genes para enfermedades monogénicas o como vehículo de terapias antitumorales, además de la tecnología de CM pluripotentes inducidas (iPSC) que ha permitido evaluar la toxicidad en diversos fármacos.

A stem cell (SC) is capable to divide indefinitely and differentiate into several specialized cell types, not only morphologically but also functionally. The term of SC emerged at the late twentieth century, by histologists and embryologist Boveri and Haecker. According to their origin the SC are classified in embryonic and adult, while according to their potential and differentiation capacity, they are classified in: totipotential, pluripotential, multipotential and unipotential. The main SC features are: a) self-renewal, which is due to the telomerase activity; b) pluripotentiallity, which is their ability to differentiate into other cell types; c) low immunogenicity, due to the low expression of the major histocompatibility complex I (MHC I) and lack expression of MHCII. The major SC works have been developed with aimed to differentiate the SC in vitro to other tissues such as pancreas, chondrocytes and cardiomyocytes among others, in other to become a cell replacement source; however, there are other applications such as gene therapy vehicle for monogenic diseases, or as a vehicle for antitumor therapies. In additions, the induced pluripotent stem cells (iPSC) technology has allowed human toxicity evaluation of various drugs.