Characterization of the Microflow Through 3D Synthetic Niche Microenvironments Hosted in a Millifluidic Bioreactor

Background: Development of new medicines is a lengthy process with high risk of failure since drug efficacy measured in vitro is difficult to confirm in vivo. Intended to add a new tool aiding drug discovery, the MOAB-NICHOID device was developed: a miniaturized optically accessible bioreactor (MOAB) housing the 3D engineered scaffold NICHOID. The aim of our study was to characterize the microflow through the 3D nichoid microenvironment hosted in the MOAB-NICHOID device.Methods: We used computational fluid dynamics (CFD) simulations to compute the flow field inside a very fine grid resembling the scaffold microenvironment.Results: The microflow inside the multi-array of nichoid blocks is fed and locally influenced by the mainstream flow developed in the perfusion chamber of the device. Here we have revealed a low velocity, complex flow field with secondary, backward, or local recirculation micro-flows induced by the intricate architecture of the nichoid scaffold.Conclusion: Knowledge of the microenvironment inside the 3D nichoids allows planning of cell experiments, to regulate the transport of cells towards the scaffold substrate during seeding or the spatial delivery of nutrients and oxygen which affects cell growth and viability.

Precise crystal regulation and harvest by constructing confined flexible droplet crystallizer on 3D-printed sessile platform

Precise regulation of the mass-heat-momentum transfer carried great implications to the crystallization behavior in microscale droplet, which is one of the core concerns in crystal engineering. Herein, a confined flexible droplet crystallizer (CFDC) was facilely constructed on designed 3D-printed, matrix-type regular sessile platforms. Owing to the flexible morphology of CFDC, the synergized micro-flows generated by the integration of capillary flow and Marangoni flow in CFDC could be precisely controlled, which was validated from both experimental and simulative aspects. Standard cubic crystal was manufactured at the sessile platform center after evaporating an optimized CFDC (with 120° featured angle), where the synergized micro-flows created the perfect flow zone to balance the mass transfer and particle location. In addition, larger standard cubic crystal could be obtained via simply scale-up the platform (16 times) or supplementary feeding (secondary to forth feeding), manifesting great potential for high-quality crystal parallel preparation and harvest.

Analytical study of the intensification of the mass transfer process during inactivation of soybean grain in an ultrasonic installation

The article is devoted to improving the effectiveness of technological impact on soy in order to remove anti – nutritional substances from it-trypsin inhibitors and urease enzymes. This is achieved by intensifying the mass transfer during extraction by ultrasonic pulsating micro-flows and cavitation with the formation of the oxidizer hydrogen peroxide H2O2. The developed technical means provide high inactivation rates and increase the productivity of the process.

CLINICAL AND LABORATORY ANALYSIS OF THE EFFECTIVENESS OF TREATMENT OF DEEP CARIES WITH CALCIUM-CONTAINING PADS

The task of a dentist in the treatment of deep caries (pulp hyperemia) is not only to restore the integrity of the tooth, but also to stimulate the production of replacement dentin with the help of a medical pad, to ensure reliable isolation of the pulp from the toxic effects of materials. Having a wide range of different therapeutic pads, but not having methods to objectively assess the condition of the pulp, doctors have to «blindly» give preference to a particular manufacturer. In this work, based on a clinical and laboratory study, an analysis of the effectiveness of calcium-containing pads «Life» and «Dycal» – was performed. The clinical stage was performed on patients in the treatment of deep caries. Changes in the pulp microcirculation were evaluated using laser Doppler flowmetry. During histological examination, samples of tooth cuts were studied for analysis of micro-flows of the dye at the «seal-tooth» border and the depth of penetration of the dye. The clinical results are consistent with laboratory results, which can be used to draw conclusions about the benefits of the «Life» treatment pad in the treatment of deep caries.