A glimpse in critical attributes to design cutaneous film forming systems based on ammonium methacrylate

A film forming system based on Eudragit\uae RL (EuRL) was designed aiming to evidence the relevance of formulative variables on the following critical attributes: film forming rate, outward stickiness, Young modulus (Y) and in vitro drug skin permeation. Different solvent mixtures (acetone and isopropanol in the range from 10:90 to 40:60 v/v), polymer concentrations (10-30 % w/w), and plasticizer types and concentrations (triacetin or tributyl citrate, up to 50% of EuRL) were evaluated. EuRL dissolved in 80/20 or 70/30 v/v isopropanol/acetone mixtures at the concentration of 20% and plasticized with tributyl citrate (20 or 30% with respect to polymer) gave films with negligible stickiness and Y lower than 3 MPa. This value should assure an intimate and prolonged contact with the skin since it was significantly lower than Y of human stratum corneum (55 MPa). The optimized formulations were able to sustain the skin permeation of ibubrofen, ketoprofen and flurbiprofen and evidenced the importance of each formulative variable. In particular, relatively slow solvent evaporation rate can determine an initial \u201cburst\u201d effect and can influence the drug permeation in the initial hours. Conversely, when the solvent evaporation rate is not discriminant, the thermodynamic activity remains the main parameter driving the skin permeation

YihQ is a sulfoquinovosidase that cleaves sulfoquinovosyl diacylglyceride sulfolipids

Sulfoquinovose is produced by photosynthetic organisms at a rate of 1010 tons per annum and is degraded by bacteria as a source of carbon and sulfur. We have identified Escherichia coli YihQ as the first dedicated sulfoquinovosidase and the gateway enzyme to sulfoglycolytic pathways. Structural and mutagenesis studies unveiled the sequence signatures for binding the distinguishing sulfonate residue and revealed that sulfoquinovoside degradation is widespread across the tree of life

Normal Mouse Intestinal Epithelial Cells as a Model for the in vitro Invasion of Trichinella spiralis Infective Larvae

It has been known for many years that Trichinella spiralis initiates infection by penetrating the columnar epithelium of the small intestine; however, the mechanisms used by the parasite in the establishment of its intramulticellular niche in the intestine are unknown. Although the previous observations indicated that invasion also occurs in vitro when the infective larvae are inoculated onto cultures of intestinal epithelial cells (e.g., human colonic carcinoma cell line Caco-2, HCT-8), a normal readily manipulated in vitro model has not been established because of difficulties in the culture of primary intestinal epithelial cells (IECs). In this study, we described a normal intestinal epithelial model in which T. spiralis infective larvae were shown to invade the monolayers of normal mouse IECs in vitro. The IECs derived from intestinal crypts of fetal mouse small intestine had the ability to proliferate continuously and express specific cytokeratins as well as intestinal functional cell markers. Furthermore, they were susceptible to invasion by T. spiralis. When inoculated onto the IEC monolayer, infective larvae penetrated cells and migrated through them, leaving trails of damaged cells heavily loaded with T. spiralis larval excretory-secretory (ES) antigens which were recognized by rabbit immune sera on immunofluorescence test. The normal intestinal epithelial model of invasion mimicking the natural environment in vivo will help us to further investigate the process as well as the mechanisms by which T. spiralis establishes its intestinal niche

Mono-dispersed Functional Polymeric Nanocapsules with Multi-lacuna via Soapless Microemulsion Polymerization with Spindle-like α-Fe2O3Nanoparticles as Templates

The mono-dispersed crosslinked polymeric multi-lacuna nanocapsules (CP(St–OA) nanocapsules) about 40 nm with carboxylic groups on their inner and outer surfaces were fabricated in the present work. The small conglomerations of the oleic acid modified spindle-like α-Fe2O3nanoparticles (OA–Fe2O3) were encapsulated in the facile microemulsion polymerization with styrene (St) as monomer and divinyl benzene (DVB) as crosslinker. Then the templates, small conglomerations of OA–Fe2O3, were etched with HCl in tetrahydrofuran (THF). The surface carboxylic groups of the crosslinked polymeric multi-lacuna nanocapsules were validated by the Zeta potential analysis