Fabrication and characterization of a novel crosslinked human keratin-alginate sponge.
Human hair keratins have been explored for biomedical applications because of their abundance, bioactivity and processability. However, pure keratin templates have poor mechanical properties, which limit their practical relevance. Herein, we described a novel composite sponge, consisting of human hair keratins chemically crosslinked with alginate using 1-ethyl-3-dimethylaminopropyl carbodiimide hydrochloride, with improved mechanical properties. Fourier transform infrared spectroscopy (FTIR) and free amine group quantification using ninhydrin revealed a maximum crosslinking index of 82.1 ± 1.3%. With increasing alginate proportions, the sponges exhibited increased tensile strength, tensile modulus and compression modulus at maximum values of 10.3 ± 1.92 kPa, 219.07 ± 52.39 kPa and 191.48 ± 32.89 kPa, respectively. The crosslinked sponges also demonstrated water vapour transmission rates comparable to commercial wound dressings. Meanwhile, sponges with higher proportions of keratin showed lower water uptake capacities and higher degradation rates by proteinase K, in comparison with sponges with higher proportions of alginate. Higher proportions of keratin on coated two-dimensional surfaces and in three-dimensional sponges resulted in more attachment and improved proliferation of L929 fibroblasts, verifying the bioactive role of keratin in the composites. In addition, subcutaneous implantation of the keratin-alginate sponges into C57BL/6NTac mice over 4 weeks showed no significant immunological reaction and minimal formation of fibrotic capsules. Furthermore, the sponges supported cellular infiltration, neo-tissue formation and vascularization in vivo. These findings demonstrated the feasibility of producing crosslinked human hair keratin-alginate sponges, with tuneable physical and mechanical properties, which are cell compliant in vitro and biocompatible in vivo, suggesting their potential for clinically relevant exploitations. Copyright © 2016 John Wiley & Sons, Ltd.
School of Materials Science and Engineering, Nanyang Technological University, Singapore.
Pietradewi
P
Hartrianti
School of Materials Science and Engineering, Nanyang Technological University, Singapore.
Luong T H
LTH
Nguyen
School of Materials Science and Engineering, Nanyang Technological University, Singapore.
Julianto
J
Johanes
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
Siaw Meng
SM
Chou
School of Biological Sciences, Nanyang Technological University, Singapore.
Pengcheng
P
Zhu
School of Biological Sciences, Nanyang Technological University, Singapore.
Nguan Soon
NS
Tan
National Skin Centre, Singapore.
Mark Boon Yang
MBY
Tang
School of Materials Science and Engineering, Nanyang Technological University, Singapore.
Kee Woei
KW
Ng
D000464:Alginates / Q000737:chemistry* / Q000494:pharmacology*; D000818:Animals; D020723:Glucuronic Acid / Q000737:chemistry / Q000494:pharmacology; D006197:Hair / Q000737:chemistry*; D006603:Hexuronic Acids / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D007633:Keratins / Q000737:chemistry* / Q000494:pharmacology*; D051379:Mice
D000464:Alginates; D006603:Hexuronic Acids; D007633:Keratins; D020723:Glucuronic Acid
3D scaffold; alginate; crosslink; hair keratin; mechanical properties; sponge