Recombinant human hair keratin proteins for halting bleeding

Abstract

Keratins derived from human hair have been widely used for tissue engineering. However, some drawbacks relative to the traditional keratins extracts have been found: (a): difficultly controlling the amino acid composition; (b): batch to batch inconsistent quality; and (c): producing complex keratin and keratin-associated proteins (KAPs), which problems have made some studies concerning human hair keratins stagnant, especially in the mechanism studies related to hemostasis of keratins. Herein, a type-I human hair keratin of K37 and a type-II human hair keratin of K81 were heterologously expressed and firstly used for haemostatic application. SDS-PAGE analysis shows that the recombinant keratins had higher purity compared to the extracted keratins. The circular dichroism (CD) spectra of K37 and K81 suggested that the secondary structures were rich in α-helix. In addition, the recombinant keratin proteins could enhance fibrin colt formation at the site of injury and decrease the bleeding time and blood loss in liver puncture and femoral artery injury rat models. This study provides a new strategy for future works involving design and mechanism studies of keratin biomaterials.

Keratin-Associated Protein Nanoparticles as Hemostatic Agents

“…Hemostatic nanoparticles with a particular size and curvature characteristics can stop internal bleeding more efficiently due to the strong bonding between the nanoparticles and the tissue surface . Previous studies have demonstrated that keratin nanoparticles can act as hemostatic materials in several animal models, such as bleeding from rabbits and pigs, , enhanced platelet binding and activation, and facilitated fibrinogen polymerization. , Therefore, the present study aimed to evaluate the hemostatic ability of the prepared keratin-associated proteins nanoparticles (KAPNPs) from human hair.…”

“…28 Previous studies have demonstrated that keratin nanoparticles can act as hemostatic materials in several animal models, such as bleeding from rabbits and pigs, 17,29 enhanced platelet binding and activation, and facilitated fibrinogen polymerization. 18,19 Therefore, the present study aimed to evaluate the hemostatic ability of the prepared keratinassociated proteins nanoparticles (KAPNPs) from human hair. In this study, as shown in Figure 1, we extracted KAPs from the keratin mixture of human hair.…”

“…Among these candidates, keratin-based materials show better efficacy in controlling blood loss than commercialized hemostatic agents . Keratin is a protein with a unique chemical structure dominated by a rich cysteine content and is primarily found in hair, feathers, and wool. , Compared to other keratin sources, human hair keratin has been widely used in health care, − especially the hemostatic applications − due to its natural abundance at a low cost . It has been hypothesized that the hemostasis mechanism of keratin might be due to peptide motifs that act as ligands for cell surface receptors, and keratin becomes adherent to the bleeding tissue. , Receptor recognition may play some roles in the capacity of keratin to adhere and activate platelets. ,, …”

“…Interestingly, to date, the studies investigating keratin materials as hemostats are either processed without purification or derived from keratin with a molecular weight larger than 30 kDa, such as recombinant KIFs, including K37 and K81. , The role of KAPs in hemostatic evaluation of the hair-derived protein fractions has not been well understood, especially considering that no one has yet reported on prepared nanoparticles from human hair KAPs. Hemostatic nanoparticles with a particular size and curvature characteristics can stop internal bleeding more efficiently due to the strong bonding between the nanoparticles and the tissue surface .…”

“…In this study, as shown in Figure , we extracted KAPs from the keratin mixture of human hair. We assumed that the much-purified keratin mixture could take advantage of its unique physicochemical properties. , KAPNPs were then prepared through the desolvation method, with glutaraldehyde as a cross-linker. The physicochemical properties of extracted KAPs and KAPNPs were assessed.…”