Self-assembly behavior of the keratose proteins extracted from oxidized Ovis aries wool fibers

Keratose Self-Cross-Linked Wound Dressing for Iron Sequestration in Chronic Wounds

Chronic wound diseases affect a large part of the world population, and therefore, novel treatments are becoming fundamental. People with chronic wounds show high iron and protease levels due to genetic disorders or other comorbidities. Since it was demonstrated that iron plays an important role in chronic wounds, being responsible for oxidative processes (ROS generation), while metalloproteinases prevent wound healing by literally "eating" the growing skin, it is crucial to design an appropriate wound dressing. In this paper, a novel bioactive dressing for binding iron in chronic wounds has been produced. Wool-derived keratose wound dressing in the form of films has been prepared by casting an aqueous solution of keratoses. These films are water-soluble; therefore, in order to increase their stability, they have been made insoluble through a thermal cross-link treatment. Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA) analyses clarified the structure and the properties of the keratose wound dressing films. The capability of this new biomaterial in iron sequestration has been investigated by testing the adsorption of Fe3+ by inductively coupled plasma-optical emission spectrometry (ICP-OES). The results suggest that the keratose cross-linked films can adsorb a large amount of iron (about 85% of the average amount usually present in chronic wounds) following pseudo-second-order kinetics and an intraparticle diffusion model, thus opening new perspectives in chronic wound care. Furthermore, the QSAR Toolbox was applied for conducting in silico tests and for predicting the chemical behavior of the C-Ker-film. All of the data suggest that the keratose bioactive dressing can significantly contribute to wound healing by mechanisms such as iron depletion, acting as a radical scavenger, diminishing the proteolytic damage, acting as a substrate in place of skin, and, finally, promoting tissue regeneration.

Physicochemical and thermomechanical performances study for Timahdite sheep wool fibers application in the building's insulation

The present research focuses on the development and thermomechanical characterization of unfired solid bricks based on clay (white and red) and Timahdite sheep wool, which are local, durable, abundant, and economical materials. As this clay material is incorporated with sheep wool in the form of yarn multi-layers in opposite directions. It achieves good thermal and mechanical performance and a lightness of these bricks as acquired progress. This new method of reinforcement offers significant thermo-mechanical performance for the composite for thermal insulation in sustainable buildings. Several physicochemical analyses to characterize the raw materials were used. Thermomechanical measurements to characterize the elaborated materials. The wool yarn effect was significant on the mechanical behavior of the developed materials at 90 days, with flexural strength from 18 to 56% for the white clay. And 8-29% for the red one. Decrease in compressive strength from 9 to 36% for the white clay and 5-18% for the red one. These mechanical performances are accompanied by thermal conductivity gain ranging from 4 to 41% for the white and 6-39% for the red for wool fractions: 6-27 g. This green multi-layered bricks from abundant local materials with optimal thermo-mechanical properties, qualified for the intended use for thermal insulation and energy efficiency in the construction and development of local economies.

Halogen Bonded Chiral Emitters: Generation of Chiral Fractal Architecture with Amplified Circularly Polarized Luminescence

Self-assembled chiroptical materials have attracted considerable attention due to their great applications in wide fields. During the chiral self-assembly, it remains unknown how achiral molecules can affect the assembly process and their final chiroptical performance. Herein, we report an achiral molecule directed chiral self-assembly via halogen bonds, exhibiting not only an unprecedented chiral fractal architecture but also significantly amplified circularly polarized luminescence (CPL). Two axially chiral emitters with halogen bond sites co-assemble with an achiral 1,4-diiodotetrafluorobenzene (F₄ DIB) and well-ordered chiral fractal structures with asymmetry amplification are obtained. The enhancement of the dissymmetry factors of the assemblies was up to 0.051 and 0.011, which was approximately 100 folds than those of the corresponding molecules. It was found that both the design of the chiral emitter and the highly directional halogen bond played an important role in hierarchically chirality transfer from chiral emitters to the micrometer scale chiral fractal morphology and amplified dissymmetry factors. We hope that this strategy can give a further insight into the fabrication of structurally unique featured highly efficient chiroptical materials.

Ionic Nanocomplexes of Hyaluronic Acid and Polyarginine to Form Solid Materials: A Green Methodology to Obtain Sponges with Biomedical Potential

We report on the design, development, characterization, and a preliminary cellular evaluation of a novel solid material. This material is composed of low-molecular-weight hyaluronic acid (LMWHA) and polyarginine (PArg), which generate aqueous ionic nanocomplexes (INC) that are then freeze-dried to create the final product. Different ratios of LMWHA/PArg were selected to elaborate INC, the size and zeta potential of which ranged from 100 to 200 nm and +25 to -43 mV, respectively. Turbidimetry and nanoparticle concentration analyses demonstrated the high capacity of the INC to interact with increasing concentrations of LMWHA, improving the yield of production of the nanostructures. Interestingly, once the selected formulations of INC were freeze-dried, only those comprising a larger excess of LMWHA could form reproducible sponge formulations, as seen with the naked eye. This optical behavior was consistent with the scanning transmission electron microscopy (STEM) images, which showed a tendency of the particles to agglomerate when an excess of LMWHA was present. Mechanical characterization evidenced low stiffness in the materials, attributed to the low density and high porosity. A preliminary cellular evaluation in a fibroblast cell line (RMF-EG) evidenced the concentration range where swollen formulations did not affect cell proliferation (93-464 µM) at 24, 48, or 72 h. Considering that the reproducible sponge formulations were elaborated following inexpensive and non-contaminant methods and comprised bioactive components, we postulate them with potential for biomedical purposes. Additionally, this systematic study provides important information to design reproducible porous solid materials using ionic nanocomplexes.