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Tuned assembly of collagen has tremendous applications in the field of biomedical and tissue engineering owing to its targeted biological functionalities. In this study, ionic liquids choline dihydrogen citrate (CDHC) and diethyl methyl ammonium methane sulfonate (AMS) have been used to regulate the self-assembly of collagen at its physiological pH by probing the assembled systems at certain concentration ratios of ionic liquids and the systems were studied using various characterization methods. Due to interaction with collagen, choline dihydrogen citrate causes delay in the collagen fibrillisation process showing no binding interactions with collagen. In contrast, diethyl methyl ammonium methane sulfonate shows crosslinking effect on collagen fibrillisation due to the electrostatic interaction with the tetrahedral hydration shell of collagen moieties. From rheological studies it was observed that the AMS treated collagen fibril at 1:1 % (w/v) has highest linear viscoelastic range, this can bear the stress under high strain compare to native collagen fibril as well as all CDHC composites. For a sustainable biomaterial or bio-scaffold, mechanical property plays pivotal role on it and from our experimental analysis we found certain composites of ionic liquid treated collagen fibrillar assembly which may act as a sustainable biomaterial or bio-scaffold. It was also evolved that, how the structure-function relationship of ionic force modulated fibrillar assembly controlling the mechanical properties of the tuned system. This self-assembled, ionic-liquid treated collagen-fibrillar system would accelerate various force modulated fibrillar network study, for mimicking the ECM and tissue engineering application. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] Systematic studies reveal rearrangement of bound water cluster of collagen due to LBG. [•] Non-covalent and covalent interactions reorder hydrogen bonding network. [•] Interconnected porous architecture of composites is LBG concentration dependent. [ABSTRACT FROM AUTHOR]

Keratin an underutilised biopolymer, with its composite structure, amino acid composition and amphoteric nature is a potential material for sorption/desorption of toxic pollutants. We hypothesized that post-fabrication functionalization of keratin over electrospun mats could solve the problem of incompatibility existing between membrane polymers and keratin, which is due to the limited dissolution capacity of keratin in solvent used for membrane preparation. Accordingly, the PEI (Polyethyleneimine)/PAN (Polyacrylonitrile) based system was fabricated in a simple and sustainable manner over which keratin was functionalized via electrostatic interaction (with PEI). The functionalized membranes were then studied for their capacity to reject a recalcitrant anionic dye, Alizarin Red S in a dead end filtration setup. The keratin functionalized over the surface significantly altered the functionality and permeability of membranes, thus resulting in an enhanced rejection capacity of 93.25% as compared to 70.18% of the unfunctionalized membrane. The synergistic effect of decreased surface roughness (physical characteristic) and electrostatic repulsion mechanism (chemical characteristic) of the system was responsible for the enhanced rejections. This study has become the first of its kind in utilizing an electrospun microfiltration membrane for dye removal via a filtration mechanism, where so far only adsorption based experiments were effective. [Display omitted] • Thermal crosslinking of PEI in PEI/PAN system yielded stable nanofibers. • Post-functionalization of keratin over membrane solved solvent compatibility issues. • Analysis of role of keratin's charge in altering rejection capacity of membrane towards a recalcitrant dye, Alizarin Red S. [ABSTRACT FROM AUTHOR]

Abstract: Collagen is usually combined with other biopolymers to enhance its physico-chemical properties for tissue engineering applications. In this study, guar gum, a non ionic plant derived polysaccharide was mixed with collagen and the effect of the same on dielectric behaviour and pore size distribution of the composites has been investigated. Circular dichroic studies show that guar gum does not bring any alteration in the conformation of the native protein. Thermoporometry result shows that by varying the concentration of guar gum, the pore size distribution of the biocomposite can be controlled. The thermal stability of biocomposite system increases as the concentration of guar gum increases and reaches a maximum of 40±0.5°C. Initiation of the polarization mechanism through the ionic charge drift on the protein-additives interfaces is affected due to the guar gum concentration, which influences the hydration shell of the protein molecule. [Copyright &y& Elsevier]

Dermatan sulfate is one of the major glycosaminoglycan (GAG) present in the animal hides, which is a waste/byproduct from meat industry. Efficient utilization of these meat industry wastes is garnering attention because these wastes render a possibility for their conversion into useful products. With the increased concerns over health, various initiatives have been developed to permit more efficient utilization of these by-products and thereby directly impacting environmental sustainability. Herein, we demonstrate for the first time an efficient and environmentally safe ionic liquid-assisted enzymatic process for the extraction of dermatan sulfate from buffalo hides. Dermatan sulfate has been extracted, separated, and purified from the GAG mixture using IL-assisted enzymatic digestions and chromatographic separations. NMR, FT-IR, and ESI-MS measurements showed typical characteristic peaks for dermatan sulfate. The advantages of this eco-friendly process adopted include i) use of fewer chemicals, ii) elimination of harsh chemicals, iii) elimination of various steps and sub-steps, iv) reduction in process time (12 h), and v) increase in extraction yield by 75% when compared to conventional enzymatic process (57%). Thus, the use of ionic liquids alongside enzymes will serve as an efficient methodology for the futuristic development of these derived GAGs for their potential applications. [Display omitted] • An efficient ionic-liquid assisted enzymatic process has been demonstrated for extraction of dermatan sulfate from buffalo hide, a by-product from meat industry. • Extracted dermatan sulfate has been purified using ion-exchange and FPLC chromatographic procedures. • Extracted dermatan sulfate has been structurally analyzed using NMR and FT-IR measurements. • The advantages of ionic-liquid assisted enzymatic process includes the use of fewer chemicals, elimination of harsh chemicals, reduction in process time (12 h) and increase in extraction yield by 75%. [ABSTRACT FROM AUTHOR]

In the present study organoclay based acrylic polymer nanocomposites were prepared via emulsion polymerization and used as filling agent for leather. The main objective of the study is to use inexpensive clay for preparation of synthetic tanning agent (syntan) for leather processing. Prepared clay/polymer nanocomposites consisting of different weight ratios of organoclay were characterized for morphological and mechanical strength properties. The results showed that surface roughness and mechanical strength of the films increased with increasing concentration of organoclay. The particle size and zeta potential analysis reveal that the clay/polymer nanocomposites (CPNs) were electrostatically stable with particle size varying between 62 and 295 nm. The leathers treated with experimental clay-polymer nanocomposite incorporated with 5 wt% clay exhibited smooth fibrillar arrangement suggesting excellent dispersion and filling properties, thus opening new avenues for efficient leather processing. The experimental leathers also exhibited better tensile strength of 28 ± 0.5 compared to control 26 ± 0.5 N/mm2 and organoleptic properties such as fullness, belly filling and softness were also improved. Thus, the preparation and application of the syntan paves a way to the sustainable approach for making leather filling agent, which is cost-effective, abundantly available and eco-friendly. Clay/polymer nanocomposites for leather application. Image 1 • Clay/polymer nanocomposites (CPNs) were prepared via emulsion polymerization. • Leathers treated with CPNs exhibited better filling on the crust leather. • CPNs pave way to the sustainable approach for making a syntan. [ABSTRACT FROM AUTHOR]