Phase Transformations of Liquid Drops Containing Mineral Dust and Organic Compound (Citric Acid)

International audienc

Drop size distribution monitoring of oil-in-water emulsions in SMX+ static mixers: Effect of operating and geometrical conditions

International audienceStatic mixers provide enhanced mixing via a motionless element inside a rigid pipe, and are widely used for continuous mixing and blending in industry. This study focuses on the emulsification of a silicon oil-in-water system stabilized by a surfactant through SMX+ ® static mixers involving no mass transfer between the two phases. The experiments covered a large domain of dispersed fraction from dilute conditions (5 %vol.) up to concentrated ones (60 %vol.) close to phase inversion and three different viscosities from 20 to 350 mPa s with transitional or turbulent flow regimes. The number of static mixers was studied until a constant drop size distribution monitored at line with a video probe was obtained. With the considered flow rates, only the five first SMX+ elements were necessary to achieve a complete drop breakup and coalescence equilibrium, the following ones only causing a supplementary pressure drop. The influence of the number of SMX+ and energy dissipation rate was found to be of first order 2 compared to the volume fraction or viscosity of the dispersed phase. According to the large amount of data, it was possible to establish a new form of a Middleman correlation dedicated to this type of mixer of new generation. The formula takes into account the number of static mixers besides other hydrodynamic and physicochemical parameters

Development and structural characterization of a novel nanoemulsion for oral drug delivery

International audienc

Design and validation of a custom-made system to measure transepithelial electrical impedance in human corneas preserved in active storage machine

Corneal epithelial barrier represents one of the major limitations to ocular drug delivery and can be explored non-invasively through the evaluation of its electrical properties. Human corneas stored in active storage machine (ASM) could represent an interesting physiological model to explore transcorneal drug penetration. We designed a new system adapted to human corneas preserved in ASM to explore corneal epithelial barrier function ex-vivo. A bipolar set-up including Ag/AgCl electrodes adaptors to fit the corneal ASM and a dedicated software was designed and tested on freshly excised porcine corneas (n = 59) and human corneas stored 14 days in ASM (n = 6). Porcine corneas presented significant and proportional decrease in corneal impedance in response to increasing-size epithelial ulcerations and acute exposure to benzalkonium chloride (BAC) 0.01 and 0.05%. Human corneas stored 14 days in ASM presented a significant increase in corneal impedance associated with the restoration of a multi-layer epithelium and an enhanced expression of tight junctions markers zonula occludens 1, claudin 1 and occludin. These results support the relevance of the developed approach to pursue the exploration and development of human corneas stored in ASM as a physiological pharmacological model

Femtosecond Laser Cutting of Human Crystalline Lens Capsule and Decellularization for Corneal Endothelial Bioengineering

The bioengineering of corneal endothelial grafts consists of seeding in vitro cultured corneal endothelial cells onto a thin, transparent, biocompatible, and sufficiently robust carrier which can withstand surgical manipulations. This is one of the most realistic alternatives to donor corneas, which are in chronic global shortage. The anterior capsule of the crystalline lens has already been identified as one of the best possible carriers, but its challenging manual preparation has limited its use. In this study, we describe a femtosecond laser cutting process of the anterior capsule of whole lenses in order to obtain capsule discs of 8 mm diameter, similar to conventional endothelial grafts. Circular marks made on the periphery of the disc indicate its orientation. Immersion in water for 3 days is sufficient to completely remove the lens epithelial cells and to enable the seeding of corneal endothelial cells, which remain viable after 27 days of culture. Therefore, this method provides a transparent, decellularized disc ready to form viable tissue engineered endothelial grafts