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Keratin-based biomaterials can be considered as the beneficial platform for designing suitable wound dressers. One of the most common natural materials that are composed of keratin and lipid is snakes shed skin. In this new study, shed skin of two different Omani snakes; Bitis arietans snake (Puff adder, "P") and Telescopus dhara snake (Arabian Cat snake, "C"); were examined as wound dresser. The presence of lipid and keratin were assessed using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR). 3- Layered filamentous morphology of the P shed skin and the 3-layered compact structure of C shed skin were analyzed by Scanning Electron Microscopy (SEM). X-Ray powder Diffraction (XRD) analysis proved two main peaks corresponding to the α-helix and β-sheet of the protein. Crystallinity index (CI) of P and C shed skins were obtained from XRD peaks 42.85 and 28.57%. The in vivo and histopathological results indicated that skin reconstruction was effectively improved under P shed skin treatment as compared with negative and positive control (PC) and C groups. Superior histopathological scores were the beneficial properties of P group over the positive control. The synergistic effect of natural extracellular matrix-mimicking structure and keratin beneficial proteins for wound healing could develop a natural substrate for wound healing in the clinical setting. [ABSTRACT FROM AUTHOR]

The incidence of connective tissue diseases such as systemic lupus erythematous (SLE), in adult patients with sickle cell disease (SCD), appears to be increasing. The exact causes underlying this increased risk are still unknown, but a link with B regulatory (Breg) cells is possible as these cells suppress inflammatory responses, and maintain tolerance. Quantitative and qualitative analyses of circulating Breg cells were performed in a cohort of SCD patients with SLE, and their levels were correlated with key soluble mediators promoting autoreactive B cells. We demonstrated that levels of Breg cells were significantly decreased in SCD patients with SLE compared to patients with SCD only or healthy controls. Functional analysis of Breg cells from SCD patients with SLE revealed impairments in IL-10 production that correlated with lower levels of STAT3 phosphorylation, without abnormal expression of IL-10 receptor on Breg cells. On the other hand, BAFF levels were substantially elevated in SCD patients with SLE, but not significantly associated with Breg cell levels. Collectively, these results indicated numerical and functional deficits of Breg cells in SCD patients with SLE and their capacity to maintain tolerance and control inflammation is imbalanced, which leads to the development of autoimmune responses. [ABSTRACT FROM AUTHOR]

[Display omitted] • A three-layered scaffold based on Chitosan and Alginate, were developed. • DC and AV were characterized and loaded as separate layers. • The scaffold represented adequate porosity, water uptake and degradation properties. • The in vitro results revealed the excellent biocompatibility of the scaffold. • The in vivo performance of the scaffold promoted the tissue regeneration. The aim of this study was to evaluate a bioactive multilayer wound dressing, based on chitosan and alginate. To enhance healing potential, Dracaena Cinnabari and Aloe Vera were loaded as separate layers into the scaffold. The bare and bioactive multilayered scaffolds were fabricated by an iterative layering freeze-drying technique. Following of topographical, chemical, and physical assessment, the performance of the scaffolds was evaluated in vitro and in vivo. The results revealed adequate attachment, and proliferation of human foreskin fibroblasts, indicating excellent biocompatibility of the bioactive scaffold. In vivo , the performance of the multi-layered scaffold loaded with the bioactive materials was comparable with Comfeel plus®. The wounds treated with the bioactive scaffold exhibited superior hypergranulation, fibroblast maturation, epithelization, and collagen deposition, with minimal inflammation, and crust formation. It is concluded that the synergism of extracellular matrix-mimicking multi-layered scaffolding with Aloe Vera and Dracaena Cinnabari could be considered as a supportive wound dressing. [ABSTRACT FROM AUTHOR]