In vivo tracing of immunostimulatory raw starch microparticles after mucosal administration.

Raw starch microparticles (SMPs) proved efficient antigen carriers with adjuvant properties when administered via the mucosal route; however, the underlying mechanisms associated with this bioactivity are unknown. In the present study, we explored the mucoadhesion properties, fate, and toxicity of starch microparticles after mucosal administration. Nasally administered microparticles were mainly retained in nasal turbinates, reaching the nasal-associated lymphoid tissue; this step is facilitated by the ability of the microparticles to penetrate through the mucous epithelium. Likewise, we found intraduodenally administered SMPs on the small intestinal villi, follicle-associated epithelium, and Peyer's patches. Furthermore, under simulated gastric and intestinal pH conditions, we detected mucoadhesion between the SMPs and mucins, regardless of microparticle swelling. SMPs' mucoadhesion and translocation to mucosal immune responses induction sites explain the previously reported role of these microparticles as vaccine adjuvants and immunostimulants.

Cancer Progression Is not Different in Mice of Different Gender Inoculated With Cells of the Triple-Negative 4T1 Breast Cancer Model.

Background: Breast cancer in men is a rare and poorly studied disease, and its treatment is based on women breast cancer studies. However, clinical outcome is not the same in men and women. Basic studies and clinical trials in animal models provide detailed information on cancer, origin, development, cell signaling pathways, sites of metastasis, and target molecules. It is necessary to explore the biology of breast cancer in male animal models that allow observing their similarity. Methods: The triple-negative 4T1 breast cancer model was developed in both male and female mice and studied weekly during 4 weeks. For that, twenty 8-week-old female and male BALB/c mice were used. Sixteen mice (eight males and eight females) were inoculated into the second left thoracic mammary pad with 20,000 4T1 cells, resuspended in 20 µL phosphate-buffered saline (PBS). All samples were processed for immunodetection, characterized histopathologically and immunohistochemically. Results: In this work, we describe the development of a triple-negative 4T1 breast cancer model in male BALB/c mice. Breast tumors were characterized histopathologically at different time points and corresponded to a moderately differentiated invasive ductal carcinoma, estrogen receptor ER-/progesterone receptor PR-/human epidermal growth factor receptor 2 HER2-/Ki67+, with histological grade II (moderately differentiated; a solid mass with occasional duct formation and moderate to severe nuclear pleomorphism), infiltrating the adipose and muscular tissue, and metastasis to lungs. From the results, we did not observe differences in the time of tumor development, necrosis, color change of tumor tissue, and lung metastasis between male and female mice. Even though we did not find histological differences, response to treatment and molecular signaling may be different. Conclusions: The histogenesis of male breast tumors was similar to that of female BALB/c mice. The histological and immunohistochemical characteristics of male tumors also match the features reported for stage IV human breast cancer of men and women. The murine male breast cancer model described here can be a significant tool to explore the molecular mechanisms involved in male breast cancer tumorigenesis and metastasis and may bring new approaches for clinical treatment of triple-negative breast cancer in men.

Antimicrobial and cytotoxic activity of green synthesis silver nanoparticles targeting skin and soft tissue infectious agents.

Combining traditional medicine with nanotechnology therefore opens the door to innovative strategies for treating skin and soft tissue infections (SSTIs) and also contributes to the fight against the rise of antimicrobial resistance. Acanthospermum australe (Loefl.) Kuntze is a medicinal plant used by indigenous peoples in northeastern Argentina to treat SSTIs. Spherical and stable silver nanoparticles (AgNPs) of 14 ± 2 nm were synthesized from the aqueous extract of A. australe and silver nitrate. The antimicrobial activity against main species causing SSTIs and cytotoxicity on peripheral blood mononuclear cells of AgNP solution and its synthesis components were evaluated. Compared to its synthesis components, AgNP solution showed greater antimicrobial activity and lower cytotoxicity. The antimicrobial activity of AgNPs was due to the silver and not to the metabolites of the aqueous extract present on the surface of the nanoparticles. The plant extract played an important role in the formation of stable AgNPs and acted as a modulator of cytotoxic and immune responses.

Mexican hawthorn (Crataegus gracilior J. B. Phipps) stems and leaves induce cell death on breast cancer cells.

Diverse molecules with cytotoxic activity against cancer cells have been isolated from the polar extracts of different parts of various hawthorn species that grow around the world. In Mexico, hawthorn (Crataegus gracilior) is popularly consumed, but its content of anticancer substances has never been evaluated. Because antitumor substances have been identified in polar and nonpolar extracts of many plants, we evaluated the cytotoxic activity against breast cancer cells of petroleum ether, ethanol, and water extracts of the leaves and stems of C. gracilior. In contrast to other hawthorn species that contain anti-tumor substances in polar extracts, the petroleum ether extract (but not the ethanol or water extracts) of C. gracilior had cytotoxic properties (IC50 < 50 µg/mL) inducing cell death by apoptosis. Two compounds reportedly having cytotoxic activity were identified by mass spectrometry in the petroleum extract of C. gracilior: ß-sitosterol and tocopherol. Results suggest that he cytotoxic and pro-apoptotic effects of the petroleum ether extract of C. gracilior could be exerted by the joint activity of ß-sitosterol and tocopherol, possibly in combination with of other minor compounds. Because hawthorn is widely consumed in Mexico and Latin America its potential use as a functional food warrants further investigation.

UV-Vis spectroscopic quantification of residual acetone during the development of nanoparticulate drug delivery systems.

Methods for nanoparticles preparation often employ organic solvents in order to solubilize the non-polar constituents of the final nanostructures. In the research process, nanoparticles are assayed as aqueous suspensions in several cases, so that an excessive residual concentration of the organic solvent needs to be avoided since may lead to undesired secondary effects during biological tests. Despite the importance, residual solvent concentration is rarely determined, making necessary the development of quantification methods suitable for this purpose. Acetone is frequently used in drug delivery systems preparation, being capable to exert significant toxicities both, in vitro and in vivo. Thus, a simple and inexpensive UV-Vis spectrophotometric method is proposed to directly determine acetone from nanoparticles suspensions employing its reaction with vanillin. Central composite designs were employed to correct and optimize the quantification method, which was then validated according to international guidelines. The optimized method resulted accurate, precise, and linear in the range of 10-50 µg/mL, with an R2 of 0.998 and limits of detection and quantification of 2.6 and 7.8 µg/mL, respectively. The effect of several surfactants employed during nanoparticles preparation was not detrimental to the method. The proposed procedure can be successfully applied to directly quantify acetone from nanoparticles suspensions.

Cytotoxic effect of Semialarium mexicanum (Miers) Mennega root bark extracts and fractions against breast cancer cells.

The root bark of Semialarium mexicanum (Miers) Mennega (cancerina) is traditionally used in Mexico to treat cancer. However, there are no studies supporting its use. We evaluated whether S. mexicanum root bark induces cytotoxicity in breast cancer cells to determine if it has potential applications in the treatment of this disease. Extracts of S. mexicanum root bark in petroleum ether, ethanol, and water were obtained by ultrasound-assisted extraction. MTT and WST-1 assays were used to evaluate the cytotoxicity of the extracts toward breast cancer cells (MDA-MB-231 and MCF7), non-tumorigenic breast-derived cells (MCF 10A), and peripheral blood mononuclear cells (PBMCs). For the extract with greatest cytotoxicity, induction of apoptosis and oxidative stress were determined using flow cytometry. The extract was fractionated, and the cytotoxicity of its fractions was evaluated with the four cell types. The fractions were also analyzed by HPLC. Only the petroleum ether extract was cytotoxic for all cell types (MDA-MB-231 > MCF 10A/MCF7 > PBMCs). Cell death occurred by apoptosis, which could be associated with the induction of oxidative stress. Two fractions that were highly cytotoxic for breast cancer cells were obtained from this extract (IC50 ≤ 4.15 µg/mL for the most active fraction at 72 h). The MCF 10A cells were less affected, while PBMCs were not affected after 72 h of treatment. Pristimerin was identified in both fractions and may be partially responsible for the cytotoxic effect. These results suggest that S. mexicanum root bark has a potential application in breast cancer treatment.

Soybean agglutinin-conjugated silver nanoparticles nanocarriers in the treatment of breast cancer cells.

Silver nanoparticles (AgNPs) induce diverse cell-death mechanisms, similar to those promoted by anticancer chemotherapeutics; however, they have not been tested in vivo because their action is not limited to cancer cells. Therefore, in vivo evaluations of their effectiveness should be developed with targeting systems. Breast cancer shows changes in the sugar expression patterns on cell surfaces, related to cancer progression and metastases; those changes have been identified previously by the specific binding of soybean agglutinin (SBA). Here is proposed the use of SBA to target the AgNP activity in breast cancer. For that, the present work reports the synthesis of AgNPs (3.89 ± 0.90 nm) through the polyol method, the generation of AgNP nanocarriers, and the bioconjugation protocol of the nanocarrier with SBA. The free AgNPs, the AgNP nanocarriers, and the SBA-bioconjugated AgNP nanocarriers were tested for cytotoxicity in breast cancerous (MDA-MB-231and MCF7) and non cancerous (MCF 10A) cells, using the MTT assay. AgNPs demonstrated cytotoxic activity in vitro, the non cancerous cells (MCF 10A) being more sensible than the cancerous cells (MDA-MB-231 and MCF7) showing LD(50) values of 128, 205, and 319 µM Ag, respectively; the nanoencapsulation decreased the cytotoxic effect of AgNPs in non cancerous cells, maintaining or increasing the effect on the cancer-derived cells, whereas the SBA-bioconjugation allowed AgNP cytotoxic activity with a similar behavior to the nanocarriers. Future experiments need to be developed to evaluate the targeting effect of the SBA-bioconjugated AgNP nanocarriers to study their functionality in vivo.

Encapsulation efficiency of CdSe/ZnS quantum dots by liposomes determined by thermal lens microscopy.

In this study the encapsulation of core shell carboxyl CdSe/ZnS quantum dots (QDs) by phospholipids liposome complexes is presented. It makes the quantum dots water soluble and photo-stable. Fluorescence self-quenching of the QDs inside the liposomes was observed. Therefore, the thermal lens microscopy (TLM) was found to be an useful tool for measuring the encapsulation efficiency of the QDs by the liposomes, for which an optimum value of 36% was determined. The obtained limit of detection (LOD) for determining QDs concentration by TLM was 0.13 nM. Moreover, the encapsulated QDs showed no prominent cytotoxicity toward Breast cancer cells line MDA-MB-231. This study was supported by UV-visible spectroscopy, high resolution transmission electron microscopy (HRTEM) and dynamic light scattering measurements (DLS).

Physico-chemical, nutritional and infrared spectroscopy evaluation of an optimized soybean/corn flour extrudate.

A central composite design using RMS (Response Surface Methodology) successfully described the effect of independent variables (feed moisture, die temperature and soybean proportion) on the specific parameters of product quality as expansion index (EI), water absorption index (WAI), water solubility index (WSI) and total color difference (ΔE) studied. The regression model indicated that EI, WAI, WSI and ΔE were significant (p < 0.05) with coefficients of determination (R(2)) of 0.7371, 0.7588, 0.7622, 0.8150, respectively. The optimized processing conditions were obtained with 25.8 % feed moisture, 160 °C die temperature and 58 %/42 % soybean/corn proportion. It was not found statistically changes in amino acid profile due to extrusion process. The electrophoretic profile of extruded soybean/corn mix presented low intensity molecular weight bands, compared to the unprocessed sample. The generation of low molecular weight polypeptides was associated to an increased in In vitro protein digestibility (IVPD) of the extrudate. The FTIR spectra of the soybean/corn mix before and after extrusion showed that the α-helix structure remained unchanged after extrusion. However, the band associated with ß-sheet structure showed to be split into two bands at 1624 and 1640 cm(-1) . The changes in the ß-sheet structures may be also associated to the increased in IVPD in the extruded sample.

Extraction, stability, and separation of betalains from Opuntia joconostle cv. using response surface methodology.

Betalains were extracted and analyzed from Opuntia joconostle (the prickly pear known as xoconostle in Mexico). For the extraction, two solvent systems were used, methanol/water and ethanol/water. A three-variable Box-Behnken statistical design was used for extraction: solvent concentration (0-80%, v/v), temperature (5-30 °C), and treatment time (10-30 min). The extraction and stability of betalains from xoconostle were studied using response surface methodology (RSM). Techniques such as UV-vis, column chromatography, and HPLC were employed for the separation and analysis of the main pigments present in the extracts. Maximum pigment concentration (92 mg/100 g of fruit) was obtained at a temperature of 15 °C and a time of 10 min for methanol/water (20:80), whereas maximum stability of the pigment was observed at pH 5 and a temperature of 25 °C. HPLC chromatograms showed the main betalains of the xoconostle characterized were betalain, betanidin, and isobetalain.