Synthesis and crosslinking of collagen using 4-3,4,5-tris(oxiran-2-ylmethoxy)benzamido)benzenesulfonic acid for the development of robust metal-free leather.

The leather manufacturing sector is actively pursuing organic alternatives to replace the utilization of inorganic tanning chemicals such as chromium, zirconium, and aluminum due to concerns over their environmental impact. Although glutaraldehyde has been considered a feasible alternative, it still falls short in providing the leather with greater tensile properties and is also considered to be toxic. In this study, we report the synthesis of a sulfonated gallic acid-based epoxide (GSE) and evaluate its performance as a metal-free tanning compound. The synthesized compound was subjected to comprehensive characterization using FTIR (functional group), ESI-MS (molecular weight), and NMR (chemical environment) spectroscopy. Furthermore, the leather treated with GSE demonstrated organoleptic and physical properties that were comparable to those achieved with glutaraldehyde tanning systems. SEM analysis of the GSE-tanned leather exhibited a homogeneous distribution pattern, confirming the stability of the collagen. In addition, the hydrothermal stability temperature of leather crosslinked with epoxide was found to be 83 ± 2 °C. The wastewater generated from the GSE tanning process exhibited a BOD to COD ratio of 0.35 ± 0.04, indicating its high treatability. The results showed that the GSE tanning system provided better tanning efficiency and improved crosslinking and thermal stability without the use of metal salts. Furthermore, the use of GSE as a tanning agent offers several advantages, such as easy availability, biodegradability, and low toxicity, making it a sustainable and environment-friendly option for the leather industry.

Ferulic acid loaded microspheres reinforced in 3D hybrid scaffold for antimicrobial wound dressing.

Here we report the preparation of biomimetic fibrin/chitosan/keratin hybrid scaffolds with a synergistic combination of ferulic acid loaded silica microspheres for antimicrobial wound dressing applications. The infrared and X-ray powder diffraction studies confirm the homogenous nature of the prepared hybrid scaffolds without any major interactions between the constituents. The developed hybrid scaffolds show good thermal, porosity, compression and water uptake properties. Scanning electron microscopic analysis shows that the as-synthesized ferulic acid loaded silica microspheres exhibit an average size of 35 ± 10 µm and also exposes the smooth surface with interconnected porosity in the prepared hybrid scaffolds. The incorporated ferulic acid loaded silica microspheres hybrid scaffolds show effective antimicrobial activity against the common wound pathogens. In vitro NIH3T3 fibroblast cell culture and drug release studies reveal that the prepared hybrid scaffolds have enhanced cell proliferation and adhesion with a prolonged drug release for about 72 h. In vitro wound healing and actin cytoskeleton analysis reveal that the incorporated ferulic acid loaded silica microspheres in fibrin/chitosan/keratin hybrid scaffolds facilitates cell growth and migration to damaged area through cell-cell interactions. These results suggest that the prepared hybrid scaffolds with ferulic acid loaded silica microspheres have great potential for soft tissue engineering applications particularly for the treatment of chronic and infected wounds.