Exposure to bisphenol A: current levels from food intake are toxic to human cells.

In the present work, cell lines of different origin were exposed to BPA levels from food intake reported elsewhere. Specifically, we used an in vitro assay to determine cytotoxicity of BPA in three cell lines: MCF7 (breast cancer), PC3 (prostate cancer) and 3T3-L1 (mouse fibroblast). Cytotoxic effects were observed at concentrations higher than 50 µg/mL which is above the involuntary exposure level of BPA described before in fresh, canned and frozen foods and beverages. Furthermore, medial inhibitory concentrations (IC50) of 85.17 µg/mL and 88.48 µg/mL were observed for PC3 and 3T3-L1, respectively, and a slightly lower IC50 of 64.67 µg/mL for MCF7. These results highlight BPA's toxicity potential at current levels from food intake. The cell line-dependent divergent response to BPA reported herein is discussed.

The enzymatic poly(gallic acid) reduces pro-inflammatory cytokines in vitro, a potential application in inflammatory diseases.

Cytokines like IL-6, TNF-α, and IL-1ß are important mediators of inflammation in many inflammatory diseases, as well as in cellular processes like cell proliferation and cell adhesion. Finding new molecules that decrease cell proliferation, adhesion (inflammatory infiltrate), and pro-inflammatory cytokine release could help in the treatment of many inflammatory diseases. The naturally derived poly(gallic acid) (PGAL), produced enzymatically from gallic acid in aqueous medium, is a non-toxic, thermostable multiradical polyanion that is antioxidant and has potential biomedical uses. Experimental evidence has demonstrated that PGAL reduces pro-inflammatory cytokines, which are the target of some inflammatory diseases. PGAL decreased IL-6, TNF-α, and IL-1ß production in human monocytes exposed to PMA without affecting cell viability. Additionally, PGAL reduced cell proliferation by affecting the transition from the S phase to the G2 phase of the cell cycle. Cell adhesion experiments showed that PMA-induced cell adhesion was diminished with the presence of PGAL, particularly at a concentration of 200 µg/mL. These properties of PGAL show a potential use for treating inflammatory diseases, such as psoriasis or arthritis.

Development of an antimicrobial and antioxidant hydrogel/nano-electrospun wound dressing.

A nanocomposite based on an antibiotic-loaded hydrogel into a nano-electrospun fibre with antimicrobial and antioxidant capacities is investigated. The material is composed of nanofibres of enzymatic PCL grafted with poly(gallic acid) (PGAL), a recently developed enzyme-mediated hydrophilic polymer that features a multiradical and polyanionic nature in a helicoidal secondary structure. An extensive experimental-theoretical study on the molecular structure and morphological characterizations for this nanocomposite are discussed. The hydrogel network is formed by sodium carboxymethylcellulose (CMC) loaded with the broad-spectrum antibiotic clindamycin. This nano electrospun biomaterial inhibits a strain of Staphylococcus aureus, which is the main cause of nosocomial infections. The SPTT assay demonstrates that PGAL side chains also improve the release rates for this bactericide owing to the crosslinking to the CMC hydrogel matrix. The absence of hemolytic activity and the viability of epithelial cells demonstrates that this nanocomposite has no cytotoxicity.

Poly(gallic acid)-coated polycaprolactone inhibits oxidative stress in epithelial cells.

Enzymatic mediated poly (gallic acid) (PGAL), a stable multiradical polyanion with helicoidal secondary structure and high antioxidant capacity, was successfully grafted to poly(ε-caprolactone) (PCL) using UV-photo induction. PCL films were prepared with several levels of roughness and subsequently grafted with PGAL (PCL-g-PGAL). The results on the full characterization of the produced materials by mechanical tests, surface morphology, and topography, thermal and crystallographic analyses, as well as wettability and cell protection activity against oxidative stress, were adequate for tissue regeneration. The in vitro biocompatibility was then assessed with epithelial-like cells showing excellent adhesion and proliferation onto the PCL-g-PGAL films, most importantly, PCL-g-PGAL displayed a good ability to protect cell cultures on their surface against reactive oxygen species. These biomaterials can consequently be considered as novel biocompatible and antioxidant films with high-responsiveness for biomedical or tissue engineering applications.

A simple method for mitochondrial respiration and calcium uptake assessment in pollen tubes.

Key mitochondrial processes are known to be widely conserved throughout the eukaryotic domain. However, the scarce availability of working materials may restrict the assessment of such mitochondrial activities in several working models. Pollen tube mitochondrial studies represent one example of this, where tests have been often restricted due the physical impossibility of performing experiments with isolated mitochondria in enough quantities. Here we detail a method to measure in situ mitochondrial respiratory chain activity and calcium transport in tobacco pollen tubes. •Digitonin-mediated plasmalemma permeabilization allows efficient assessment of mitochondrial respiration and calcium uptake.•This method allows quick, reliable and portable measurements from low to high cellular densities, versus methods requiring intracellular calcium reporters.

One-solvent extraction of astaxanthin from lactic acid fermented shrimp wastes.

Free astaxanthin one-solvent extractions with ethanol, acetone, and liquid 1,1,1,2-tetrafluoroethane from raw and lactic acid fermented (ensilaged) shrimp residues were investigated. The total carotenoid recovery from ensilaged shrimp wastes was higher than that from non-ensilaged ones as assessed by HPLC analyses. Acetone gave the highest extraction yields of free astaxanthin with up to 115 microg/g of material. Moreover, liquid tetrafluoroethane is reported for the first time in a successful one-solvent extraction of carotenoids from shrimp.

Cytoprotective effect of the enzyme-mediated polygallic acid on fibroblast cells under exposure of UV-irradiation.

The poly(gallic acid), produced by laccase-mediated oxidation of gallic acid in aqueous media (pH5.5) to attain a novel material with well-defined molecular structure and high water solubility (500mg/mL at 25°C), has been investigated to understand its potential biological activities. In this regard, a biomedical approach based on cytoprotective effect on human fibroblast cells exposed to UV-irradiation in the presence of the polymer has been demonstrated. The results also shows that 200µg/mL of poly(gallic acid) inhibits the growth and migration of dermal fibroblasts and cancer cell lines without affecting cell viability. Poly(gallic acid) pretreatment with 10µg/mL protects dermal fibroblasts from UV induced cell death and additionally, the cytoprotective effect reduce ROS presence in the cells. This property can be correlated with the antioxidant power (IC50 of 23.5µg/mL) of this novel material, which was ascertained by electronic paramagnetic resonance spectroscopy and spectrophotometrically. Additionally, the antimicrobial activity of this material was corroborated with the inhibition of Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 29212) strains (MIC=400mg/mL) common bacteria found in hospitals.

Environmental epigenomics: Current approaches to assess epigenetic effects of endocrine disrupting compounds (EDC's) on human health.

Environmental Epigenomics is a developing field to study the epigenetic effect on human health from exposure to environmental factors. Endocrine disrupting chemicals have been detected primarily in pharmaceutical drugs, personal care products, food additives, and food containers. Exposure to endocrine-disrupting chemicals (EDCs) has been associated with a high incidence and prevalence of many endocrine-related disorders in humans. Nevertheless, further evidence is needed to establish a correlation between exposure to EDC and human disorders. Conventional detection of EDCs is based on chemical structure and concentration sample analysis. However, substantial evidence has emerged, suggesting that cell exposure to EDCs leads to epigenetic changes, independently of its chemical structure with non-monotonic low-dose responses. Consequently, a paradigm shift in toxicology assessment of EDCs is proposed based on a comprehensive review of analytical techniques used to evaluate the epigenetic effects. Fundamental insights reported elsewhere are compared in order to establish DNA methylation analysis as a viable method for assessing endocrine disruptors beyond the conventional study approach of chemical structure and concentration analysis.

Review on the worldwide regulatory framework for biosimilars focusing on the Mexican case as an emerging market in Latin America.

The global biopharmaceutical market is worth over $100 billion USD. Nearly 90% of these products will lose their patent in the next ten years, leading to the commercialization of their subsequent versions, known as 'biosimilars'. Biosimilars are much more complex molecules than chemically synthesized generics in terms of size, structure, stability, microheterogeneity, manufacture, etc. Therefore, a specific regulatory framework is needed in order to demonstrate their comparability with innovative products, as well as their quality, safety and efficacy. The EU published the first regulatory pathway in 2005 and has approved 14 biosimilars. Mexico has recently developed a clear regulatory pathway for these products. Their legal basis was established in Article 222 Bis of General Law of Health in 2009, clear specifications in the Regulation for Health Goods in 2011, and further requirements in the Mexican Official Norm NOM-EM-001-SSA1-2012. The aim of this review is to summarize the regulatory pathways for biosimilars in the world with a special focus on Mexican experience, so as contribute to the development of regulations in other countries.

Evaluation of the effects and interactions of mixing and oxygen transfer on the production of Fab' antibody fragments in Escherichia coli fermentation with gas blending.

Fermentations carried out at 450-L and 20-L scale to produce Fab' antibody fragments indicated a serious problem to control levels of dissolved oxygen in the broth due to the large oxygen demand at high cell densities. Dissolved oxygen tension (DOT) dropped to zero during the induction phase and it was hypothesised that this could limit product formation due to inadequate oxygen supply. A gas blending system at 20-L scale was employed to address this problem and a factorial 2(2) experimental design was executed to evaluate independently the effects and interaction of two main engineering factors: agitation rate and DOT level (both related to mixing and oxygen transfer in the broth) on Fab' yields. By comparison to the non-gas blending system, results in the gas blending system at same scale showed an increase in the production of Fab' by 77% independent of the DOT level when using an agitation rate of 500 rpm level and by 50% at an agitation rate of 1,000 rpm with 30% DOT. Product localisation in the cell periplasm of >90% was obtained in all fermentations. Results obtained encourage further studies at 450-L scale initially, to evaluate the potential of gas blending for the industrial production of Fab' antibody fragments.