Development of double porous poly (ε - caprolactone)/chitosan polymer as tissue engineering scaffold.

Polymer blend made from poly(ε - caprolactone)/chitosan (PCL/CHT) offers interesting opportunities for biological applications. The paper presents a new way to fabricate PCL/CHT double-porosity (macrovoids with interconnected microporosity) membrane materials from a chemical optimization of the solvent and non-solvent phases and from a modified phase inversion technique. By varying the PCL/CHT proportion, it is shown that it is possible to improve the chemical and physical properties of the CHT carbohydrate polymer.

Double porous poly (Ɛ-caprolactone)/chitosan membrane scaffolds as niches for human mesenchymal stem cells.

In this paper, we developed membrane scaffolds to mimic the biochemical and biophysical properties of human mesenchymal stem cell (hMSC) niches to help direct self-renewal and proliferation providing to cells all necessary chemical, mechanical and topographical cues. The strategy was to create three-dimensional membrane scaffolds with double porosity, able to promote the mass transfer of nutrients and to entrap cells. We developed poly (Ɛ-caprolactone) (PCL)/chitosan (CHT) blend membranes consisting of double porous morphology: (i) surface macrovoids (big pores) which could be easily accessible for hMSCs invasion and proliferation; (ii) interconnected microporous network to transfer essential nutrients, oxygen, growth factors between the macrovoids and throughout the scaffolds.

Tunable Microstructured Membranes in Organs-on-Chips to Monitor Transendothelial Hydraulic Resistance.

Tissue engineering is an interdisciplinary field, wherein scientists from different backgrounds collaborate to address the challenge of replacing damaged tissues and organs through the fabrication of functional and transplantable biological structures. Because the development and optimization of tissue engineering strategies rely on the complex interaction of cells, materials, and the physical-chemical tissue microenvironment, there is a need for experimental models that allow controlled studies of these aspects. Organs-on-chips (OOCs) have recently emerged as models that capture the complexity of human tissues in a controlled manner, while including functional readouts related to human organ physiology.

Influence of the Counterion Nature on the Stability Sequence of Hydrophobic Latex Particles.

The aggregation kinetics of negatively charged polystyrene latex particles in the presence of monovalent electrolytes have been investigated. The inferred coagulation critical concentrations were compared to establish the stability sequence. With the same representative co-ions, this sequence is reversed when using kosmotrope sodium and chaotrope potassium cations.

Wet air oxidation of formic acid using nanoparticle-modified polysulfone hollow fibers as gas-liquid contactors.

Catalytic wet air oxidation (CWAO) using membrane contactors is attractive for remediation of aqueous pollutants, but previous studies of even simple reactions such as formic acid oxidation required multiple passes through tubular ceramic membrane contactors to achieve high conversion. This work aims to increase single-pass CWAO conversions by using polysulfone (PS) hollow fibers as contactors to reduce diffusion distances in the fiber lumen. Alternating adsorption of polycations and citrate-stabilized platinum colloids in fiber walls provides catalytically active PS hollow fibers.

Use of lanthanide-grafted inorganic nanoparticles as effective contrast agents for cellular uptake imaging.

The improvement of commonly used Gd3+ -based MRI agents requires the design of new systems with optimized in vivo efficacy, pharmacokinetic properties, and specificity. To design these contrast agents, two parameters are usually considered: increasing the number of coordinated water molecules or increasing the rotational correlation time by increasing molecular weight and size. This has been achieved by noncovalent or covalent binding of low-molecular weight Gd3+ chelates to macromolecules or polymers.