Biomimetic Electrospun Self-Assembling Peptide Scaffolds for Neural Stem Cell Transplantation in Neural Tissue Engineering

Spinal cord regeneration using stem cell transplantation is a promising strategy for regenerative therapy. Stem cells transplanted onto scaffolds that can mimic natural extracellular matrix (ECM) have the potential to significantly improve outcomes. In this study, we strived to develop a cell carrier by culturing neural stem cells (NSCs) onto electrospun 2D and 3D constructs made up of specific crosslinked functionalized self-assembling peptides (SAPs) featuring enhanced biomimetic and biomechanical properties. Morphology, architecture, and secondary structures of electrospun scaffolds in the solid-state and electrospinning solution were studied step by step. Morphological studies showed the benefit of mixed peptides and surfactants as additives to form thinner, uniform, and defect-free fibers. It has been observed that β-sheet conformation as evidence of self-assembling has been predominant throughout the process except for the electrospinning solution. In vitro NSCs seeded on electrospun SAP scaffolds in 2D and 3D conditions displayed desirable proliferation, viability, and differentiation in comparison to the gold standard. In vivo biocompatibility assay confirmed the permissibility of implanted fibrous channels by foreign body reaction. The results of this study demonstrated that fibrous 2D/3D electrospun SAP scaffolds, when shaped as micro-channels, can be suitable to support NSC transplantation for regeneration following spinal cord injury

Multiparametric in vitro and in vivo analysis of the safety profile of self-assembling peptides

Abstract Self-assembling peptides (SAPs) have gained significant attention in biomedicine because of their unique properties and ability to undergo molecular self-assembly driven by non-covalent interactions. By manipulating their composition and structure, SAPs can form well-ordered nanostructures with enhanced selectivity, stability and biocompatibility. SAPs offer advantages such as high chemical and biological diversity and the potential for functionalization. However, studies concerning its potentially toxic effects are very scarce, a limitation that compromises its potential translation to humans. This study investigates the potentially toxic effects of six different SAP formulations composed of natural amino acids designed for nervous tissue engineering and amenable to ready cross-linking boosting their biomechanical properties. All methods were performed in accordance with the relevant guidelines and regulations. A wound-healing assay was performed to evaluate how SAPs modify cell migration. The results in vitro demonstrated that SAPs did not induce genotoxicity neither skin sensitization. In vivo, SAPs were well-tolerated without any signs of acute systemic toxicity. Interestingly, SAPs were found to promote the migration of endothelial, macrophage, fibroblast, and neuronal-like cells in vitro, supporting a high potential for tissue regeneration. These findings contribute to the development and translation of SAP-based biomaterials for biomedical applications

Flame Retardant Finishing for Textiles

State of the art and perspectives on chemicals and techniques which have been developed in textile finishing for conferring flame retardant properties to natural and synthetic fibres are discussed in this review. An overview on the mechanism of combustion and fire retardancy is reported as well as the chemistry of flame retardants action, the different available types and their uses. The chemistry of molecules used to improve fire retardancy is discussed along with their thermal stabilities and flame-retardant properties. Simplified assumptions about the gas and condensed phase processes of flaming combustion provide relationships between the chemical structure of polymers and fire behaviour, which can be used to design fire-resistant textile materials. Moreover, an overview of currently accepted test methods on textile fabrics to quantify burning behaviour is reported. Finally, as a consequence of increasing commercial demands in terms of cost effectiveness coupled with increasing concerns about the environmental and general toxicological character of flame retardant additives, some consideration is also given to both the novel approaches of the chemistry of antimony-free and halogen free flame retardants and to attempts at increasing the efficiency of known chemistry to enhance char formation by intumescent action