Skin substitutes based on gellan gum with mechanical and penetration compatibility to native human skin.

The study reports on a simple system to fabricate skin substitutes consisting of a naturally occurring bacterial polysaccharide gellan gum. Gelation was driven by the addition of a culture medium whose cations induced gellan gum crosslinking at physiological temperature, resulting in hydrogels. Human dermal fibroblasts were incorporated in these hydrogels and their mechanical, morphological, and penetration characteristics were studied.

Antimicrobial and physicochemical characterization of 2,3-dialdehyde cellulose-based wound dressings systems.

Biobased and biodegradable films were prepared by physically mixing 2,3-dialdehyde cellulose (DAC) with two other biopolymers, zein and gelatin, in three different proportions. The antimicrobial activities of the composite blends against Gram-positive and Gram-negative bacteria increase with the increase of DAC content. Cell viability tests on mammalian cells showed that the materials were not cytotoxic.

Polysaccharide-based skin scaffolds with enhanced mechanical compatibility with native human skin.

We report a custom-made technique to synthesize process-convenient skin scaffolds by tuning the mechanical properties of hydrogels based on a few naturally occurring polysaccharides to match the rheological properties of previously established benchmarks, i.e., the ex vivo native human skins.

Custom-made rheological setup for in situ real-time fast alginate-Ca gelation.

There is a growing interest in the in situ gelation of the alginate-Ca system due to its remarkable applications. In this work, we record and evaluate the fast gelation kinetics of alginate-Ca using a custom-made rheometric setup. This enables us to inject CaCl into the alginate while we perform the rheological measurements.

Nonlinear rheological behavior of gelatin gels: In situ gels and individual gel layers filled with hard particles.

Hypothesis: Previously, we examined the impact of two preparation procedures on the mechanical properties of native gelatin gels. In this work, we extend our research by considering hard spherical particles as fillers. We expect that the presence of these fillers significantly affects the viscoelastic response.

Crosstalk of Cellulose and Mannan Perception Pathways Leads to Inhibition of Cellulase Production in Several Filamentous Fungi.

It is essential for microbes to acquire information about their environment. Fungi use soluble degradation products of plant cell wall components to understand the substrate composition they grow on. Individual perception pathways have been well described.

Nonlinear rheological behavior of gelatin gels: In situ gels and individual layers.

The gelation procedure and the gelation time of gelatin gels may lead to apparently similar materials, however, with different rheological fingerprints under small and large oscillatory shear deformations. Here, in the first paper of this series, gelation of 3 and 5% w/w gelatin solutions at 5 °C was performed in situ on the rheometer plate and in custom-made casting modules to obtain individual gel layers. Large amplitude oscillatory shear (LAOS) tests were performed.

Nonlinear viscoelastic properties of native male human skin and in vitro 3D reconstructed skin models under LAOS stress.

This work discusses the first set of rheometric measurements carried out on commercially accessible juvenile and aged skin models under large amplitude oscillatory shear deformations. The results were compared with those of native male whole human and dermis-only foreskin specimens, catering to a few ages from 0.5 to 68 years, including specimens from a 23-year-old male abdomen.

Shear Banding in 4:1 Planar Contraction.

We study shear banding in a planar 4:1 contraction flow using our recently developed two-fluid model for semidilute entangled polymer solutions derived from the generalized bracket approach of nonequilibrium thermodynamics. In our model, the differential velocity between the constituents of the solution allows for coupling between the viscoelastic stress and the polymer concentration. Stress-induced migration is assumed to be the triggering mechanism of shear banding.

Linear viscoelastic and microstructural properties of native male human skin and in vitro 3D reconstructed skin models.

The study reports first ever account of measurements of linear viscoelastic moduli under small amplitude oscillatory shear deformations, for commercially available juvenile and aged in vitro 3D reconstructed skin models. The results were compared with those of native male whole human and dermis-only foreskin samples, catering to a wide age group from 0.5 to 68 years, including samples from a 23-year-old male abdomen.