A review on new bio-based constituents for natural fiber-polymer composites

Keratinous materials such as wool, feathers and hooves are tough unique biological co-products that usually have high sulfur and protein contents A high cystine content (7–13%) differentiates keratins from other structural proteins, such as collagen and elastin Dissolution and extraction of keratin is a difficult process compared to other natural polymers, such as chitosan, starch, collagen, and a large-scale use of keratin depends on employing a relatively fast, cost-effective and time efficient extraction method Keratin has some inherent ability to facilitate cell adhesion, proliferation, and regeneration of the tissue, therefore keratin biomaterials can provide a biocompatible matrix for regrowth and regeneration of the defective tissue Additionally, due to its amino acid constituents, keratin can be tailored and finely tuned to meet the exact requirement of degradation, drug release or incorporation of different hydrophobic or hydrophilic tails This review discusses the various methods available for the dissolution and extraction of keratin with emphasis on their advantages and limitations The impacts of various methods and chemicals used on the structure and the properties of keratin are discussed with the aim of highlighting options available toward commercial keratin production This review also reports the properties of various keratin-based biomaterials and critically examines how these materials are influenced by the keratin extraction procedure, discussing the features that make them effective as biomedical applications, as well as some of the mechanisms of action and physiological roles of keratin Particular attention is given to the practical application of keratin biomaterials, namely addressing the advantages and limitations on the use of keratin films, 3D composite scaffolds and keratin hydrogels for tissue engineering, wound healing, hemostatic and controlled drug release

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Keratin: dissolution, extraction and biomedical application

Traditional, state-of-the-art and renewable thermal building insulation materials: An overview

https://hal.umontpellier.fr/hal-03243158/document

Nanofibers as new-generation materials: From spinning and nano-spinning fabrication techniques to emerging applications

Bio-based fertilizers: A practical approach towards circular economy.

Wool keratin-polypropylene composites: Properties and thermal degradation

The development of nanocellulose has attracted significant interest in the last few decades due to its unique and potentially useful features. Novel nanocelluloses boost the strongly expanding field of sustainable materials and nanocomposites. Their potential areas of application include reinforcing agents in nanocomposites, paper, biodegradable films, barriers for packaging, stabilizing agents in dispersions for technical films and membranes, additives in food, texturing agents in cosmetics, and medical devices such as wound dressings and bioactive implants. This review organizes current knowledge on the isolation of microfibrillated and nanofibrillated cellulose from plant sources. Details of the extraction of fibrils from cellulose are reviewed. In addition, the terms cellulose “microfiber” and cellulose “nanofiber” are formally defined and distinguished. Key Terms Microfibrillated Cellulose, Nanocellulose, Nanocomposites, Nanofibril Isolation

Preparation of Nanocellulose: A Review

Wool fibers were submitted to “green hydrolysis” with superheated water in a microwave reactor, in view of the potential exploitation of keratin-based industrial and stock-farming wastes. The liquid fraction was separated by filtration from the solid fraction, which consists mainly of small fragments of wool fibers and other insoluble protein aggregates. The liquid fraction contains free amino acids, peptides and low molecular weight proteins, with a small amount of cystine and lanthionine, and has a different secondary structure when compared with keratins extracted from wool via reductive or oxidative methods. Cleavage of the cystine disulfide bonds without the use of harmful, often toxic, reductive or oxidative agents allows the extraction of protein material from keratin wastes, offering the possibility of larger exploitation and valorization.

Microwave-assisted chemical-free hydrolysis of wool keratin

Management of waste wool is a problem related to sheep farming and butchery in Europe. Since the primary role of European flock is meat production, sheep are crossbreds not graded for fine wool production. Their wool is very coarse and contains a lot of kemps (dead fibres), so that it is practically unserviceable for textile uses, and represents a by-product which is mostly disposed off. Green hydrolysis using superheated water is an emerging technology to turn waste wool into amendment-fertilizers for the management of grasslands and other cultivation purposes. In this way wool keratin (the wool protein) is degraded into simpler compounds, tailoring the release speed of nutrients to plants. Wool, when added to the soil, increases the yield of grass grown, absorbs and retains moisture very effectively and reduces run off of contaminants such as pesticides. Moreover, the closed-loop cycle grass–wool–grass is an efficient form of recycling, because the wool-grass step is solar powered and grazing sheep increases soil carbon sequestration on grasslands and fertilisation, if not over-used, can enhance the carbon sequestration rate. Economical results of using hydrolysed wool as a fertilizer are expected from the increase of the management yield and the extension of the pasture lands that may contribute to employment and profit of sheep farming, increase European sheep population, and reduce European dependency of imported meat which is forecast to rise in the next years.

Green Hydrolysis as an Emerging Technology to Turn Wool Waste into Organic Nitrogen Fertilizer

Keratin from wool fibers was extracted with different extraction methods, for example oxidation, reduction, sulfitolysis, and superheated water hydrolysis.Different samples of extracted keratin wer...

Alessia Patrucco

Papers

Wool keratin-polypropylene composites: Properties and thermal degradation

Preparation of Nanocellulose: A Review

Microwave-assisted chemical-free hydrolysis of wool keratin

Green Hydrolysis as an Emerging Technology to Turn Wool Waste into Organic Nitrogen Fertilizer

Physicochemical properties of keratin extracted from wool by various methods