Preparation of Feather Keratin Hydrolyzate‐Gelatin Composites and Their Graft Copolymers

Fabrication of dual layered biocompatible herbal biopatch from biological waste for skin - tissue regenerative applications

A dual layered herbal biopolymeric patch (biopatch) with enhanced wound healing efficiency and skin mimicking functions was fabricated for skin-tissue regenerative applications. In this study, hoof keratin (KE) extracted from biological waste and gelatin (GE) was employed for KE-GE biosheet fabrication using a simple casting method. Further, the top layer of the fabricated KE-GE biosheet was coated with bioactive Matricaria recutita (Chamomile flower) extract (CH) with gelatin through an electrospraying method. The optimized dual layered herbal biopatch (KE-GE/GE-CH) exhibits strong physiochemical (FTIR, XRD TG-DTA), mechanical (tensile strength) and biological (in vitro and in vivo) studies. Moreover, the morphology (SEM) of soft mimetic biopatch possesses excellent cell-material interaction and cell proliferation which accelerates the wound healing process. Biopatch demonstrates a proven degradation profile with good swelling features to achieve more than 80% herbal drug release in 96 h. Antimicrobial properties also reveal the potential activity of biopatch against bacterial microbes. In addition, in vitro cell viability using NIH 3T3 fibroblast cell lines and in vivo investigations revealed that the biopatch is non-cytotoxic, increases collagen deposition and shows rapid reepithelialization at the wound site as a potential wound dressing. We anticipated that the biological hoof keratin and bioactive herbal extract coated biopatch could serve as a desirable wound dressing candidate to suit various skin tissue regenerative applications.

Keratin: dissolution, extraction and biomedical application

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.

Comparative study of some physico-chemical characteristics of osteoporotic and normal human femur heads

OBJECTIVE

To compare some of the physico-chemical properties of osteoporotic and normal femur heads -- a sample study.

MATERIALS AND METHODS

The organic and inorganic parts of human normal (healthy) (N), osteoporotic (OP) femur heads and were separated using conventional methods and their physico-chemical characteristics were compared using infrared spectroscopy (IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM).

RESULTS

The data revealed that the extra crosslinking had taken place between the intramolecular alpha chains of collagen of OP bone. This was confirmed by IR spectroscopy and TGA studies. XRD data of the inorganic part of N have shown well-resolved peaks compared to OP revealing the decreased crystallinity in the osteoporotic bone.

CONCLUSIONS

The extra intramolecular crosslinking of OP bone collagen molecules increases its fragility. The crystallinity of inorganic phase is less in OP and this may be the reason for its brittleness.