Grießinger, JA; Bonengel, S; Partenhauser, A; Ijaz, M; Bernkop-Schnürch, A (2017). "Thiolated polymers: Evaluation of their potential as dermoadhesive excipients". Drug Dev. Ind. Pharm. 43 (2): 204–212. doi: 10.1080/03639045.2016.1231809. PMID 27585266. S2CID 19045608.

Ponrasu et al. [ 102] investigated hydrogel scaffolds composed of morin, psyllium, and keratin (PSH + KER + MOR) as a potential biomaterial that supports skin wound healing in diabetic Wistar rats. They noted that, cell viability was similar (around 82%) in all three groups: PSH + KER, PSH +KER + 0.5% MOR, and PSH + KER + 1% MOR after 48-h observation. Antimicrobial studies showed that MOR scaffolds had a bacteriostatic effect against S. aureus. On the other hand, PSH + KER hydrogels showed poor properties against gram-negative bacteria ( E. coli). In vivo wound healing process in diabetic rats was observed in every 4-day interval. Animal studies showed that PSH + KER + MOR scaffold treatment significantly reduced the re-epithelialization time and enhanced the rate of wound contraction by accelerating collagen synthesis in diabetic rats compared to controls. RRPs are Unilever suggested retail prices only, it is at the discretion of the individual retailers to set the actual price.Lee, Chang-Hun; Kim, Min-Sung; Chung, Byung Min; Leahy, Daniel J; Coulombe, Pierre A (July 2012). "Structural basis for heteromeric assembly and perinuclear organization of keratin filaments". Nature Structural & Molecular Biology. 19 (7): 707–715. doi: 10.1038/nsmb.2330. PMC 3864793. PMID 22705788.

During a keratin treatment, the keratin molecules penetrate the hair cortex, providing deep nourishment and repair. This can result in improved hair gloss, softness, and manageability.Keratin is a protein that can be found in your hair, skin and nails – in fact, your hair is composed primarily of keratin (approximately 95%). It helps both to protect the outer layer of each of your hair strands, as well as give them strength from an inner core within. But when your hair suffers any damage – either physically, chemically or from environmental factors like the sun – it loses some of its natural keratin, which exposes the hair’s cortex, leaving it weaker and more prone to additional damage. So, how do keratin treatments work? Hyperkeratosis can have a range of symptoms. However, all symptoms will involve an area of rough or patchy skin that feels different from the surrounding skin. Biocompatibility can be defined as the ability of materials to interact with host cells without causing systematic and local cytotoxicity, mutagenesis, carcinogenicity, allergic reactions, or inflammation [ 61]. Several in vitro studies on different cell lines have been shown that keratin biomaterials are biocompatible and support cell growth [ 62, 63, 64]. Yamauchi et al. [ 65] proposed that keratin-coated substrate has shown better L929 fibroblasts attachment and growth compared to the ones coated with collagen. Park et al. [ 66] have also reported that keratin extracted from human hair is more effective in healing wounds due to the almost complete regeneration of epithelial cells. Sadeghi et al. [ 67] examined carboxymethyl cellulose (CMC)-human hair keratin hydrogel with controlled clindamycin in vitro on mouse fibroblasts. They showed that increasing the content of keratin in CMC hydrogel not only lowered water vapor transmission rate to a suitable range for wound healing but also improved the water stability of CMC hydrogel. The in vitro release study indicated that clindamycin was released slower in samples containing higher keratin. Higher keratin content led to better cellular attachment, proliferation, and spreading. Summarizing, the addition of keratin into the carboxymethyl cellulose improves their properties compared with pure CMC samples. Itakura, Eijun; Tamiya, Sadafumi; Morita, Keisuke; Shiratsuchi, Hideki; Kinoshita, Yoshiaki; Oshiro, Yumi; Oda, Yoshinao; Ohta, Shigeru; Furue, Masutaka; Tsuneyoshi, Masazumi (September 2001). "Subcellular Distribution of Cytokeratin and Vimentin in Malignant Rhabdoid Tumor: Three-Dimensional Imaging with Confocal Laser Scanning Microscopy and Double Immunofluorescence". Modern Pathology. 14 (9): 854–861. doi: 10.1038/modpathol.3880401. PMID 11557780.

Ramezani M, Shamshiri A, Zavattaro E, et al. Immunohistochemical expression of P53, Ki-67, and CD34 in psoriasis and psoriasiform dermatitis. Biomedicine (Taipei). 2019;9(4):26. doi:10.1051/bmdcn/2019090426 Earland C, Blakey PR, STELL JGP (1962) Molecular orientation of some keratins. Nature 196:1287–1291 Freeman, D. (2002). Corns and calluses resulting from mechanical hyperkeratosis. American Family Physician, 65(11), 2277-2280Keratin biomaterials have been in use for decades, yet they are seemingly new to the field. Keratin is a global class of biological material, which represents a group of cysteine-rich filament-forming proteins [ 1, 2]. It is the major component of hair, wool, hooves, nails, feathers, and horns are one of the most abundant and underexploited protein sources [ 3]. Their complex hierarchical structure, such as filament-matrix composition at nano-level and polypeptide chains, create a robust wall for protection against heat stress, pathogen invasions (particularly through the skin), and mechanical damage [ 1, 2, 4]. Keratins and keratinous materials are subdivided into two different classes of secondary structures of protein: alpha ( α)-keratin and beta ( β)-keratin [ 4]. Moreover, keratins are the protein that forms a shielding layer for the epidermal appendages and, thereby, imparting an important role in protection. Keratin genes account for most of the intermediate filament genes in the human genome, making up the two largest sequence homology groups: keratins type I, also called acidic keratins; and keratins type II, called neutral-basic keratins [ 1, 2, 4]. In particular, keratin helps make the cells in hair, skin, and nails stronger and more resilient and helps reduce damage to the tissues from friction. Dhouailly D, Cong X, Manabe M, Schermer A, Sun TT (1989) Expression of hair-related keratins in a soft epithelium: subpopulations of human and mouse dorsal tongue keratinocytes express keratin markers for hair-, skin- and esophageal-types of differentiation. Exp Cell Res 181:0–158 Another study, performed by Batzer et al. [ 110], describes the use of keratin-based wound products on refractory wounds. In this study, 45 chronic wounds of mixed etiologies presenting in 31 patients were treated with a solid keratin matrix (Keramatrix ®) and a liquid keratin gel (Keragel ®) wound dressing (Keraplast Technologies, San Antonio, TX, USA). They showed that topical keratin products Carrots are high in vitamin A. Half a cup of raw carrots provides 459 mcg of vitamin A, which is 51% of the recommended DV.

Earland C, Blakey PR, Stell JGP (1962) Studies on the structure of keratin IV. The molecular structure of some morphological components of keratins. Bba. Biochim Biophys Acta 56:268–274 Specific types of keratin, such as K31, which is a major protein found in human hair, play a crucial part in maintaining the hair’s strength. Xiao XL, Hu JL, Gui XT, Qian K (2017) Shape memory investigation of alpha-keratin fibers as multi-coupled stimuli of responsive smart materials. Polymers 9:87 To reach their mature stage, epidermis must be fully matured by E. 18.5, and KCs with terminal differentiation become enucleated corneocytes, which form the outermost layer with complete barrier function. Researchers have discovered that the expression of K10 in the ectopic cell cycle can inhibit cell cycle progression and proliferation and thus encourage terminal differentiation of keratinocytes. Transcription factors play a significant role in the regulation of keratin synthesis, controlling the rate at which it is synthesized. Extensive research has been conducted on the regulation of K5 and K14, two key keratins that form the cytoskeletal IF network in mitotically active basal cells. K14 is limited to cells in the basal layer, whereas K10 is induced in differentiated cells at the spinous layer and is maintained throughout the cell. In keratinocytes, the transcription factor C/EBP* was forced to inhibit growth, but it also increased K1 and K10 expression, but it had no effect on Lor or Inv. Low calcium levels were detected in Cebpb-deficiency mice, but not in high calcium levels that turned on K10 expression. Thiolated polymers (= thiomers) can form disulfide bridges with cysteine substructures of keratins getting covalently attached to these proteins. [25] Thiomers exhibit therefore high binding properties to keratins found in hair, [26] on skin [27] [28] and on the surface of many cell types. [29] Filament formation [ edit ]

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Lin et al. [ 22] examined keratin biomaterial extracted from human hair in vitro and in vivo. They showed that the obtained biomaterial is biodegradable, biocompatible, and supported human adipose stem cells (hASCs) adhesion, proliferation, and differentiation. In vivo investigation performed on ICR mice showed that keratin scaffolds with hASCs shortened healing time accelerated epithelialization and promoted wound remodeling in comparison with the keratin-scaffolds-only group, hASCs-only group, and control. On the whole, keratin scaffolds possess appropriate pore size and good cytocompatibility and can be further applied in the field of regenerative medicine. Hieronymus TL, Witmer LM, Ridgely RC (2006) Structure of white rhinoceros (Ceratotherium simum) horn investigated by X-ray computed tomography and histology with implications for growth and external form. J Morphol 267:1172–1176