Various chemical, natural, or synthetic in origin, crosslinking methods have been proposed over the years to stabilise collagen fibers. However, an optimal method has yet to be identified. Herein, we ventured to assess the potential of 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate, as opposed to glutaraldehyde (GTA), genipin and carbodiimide, on the structural, physical and biological properties of collagen fibers. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate induced an intermedium surface smoothness, denaturation temperature and swelling. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate fibers had significantly higher stress at break values than the carbodiimide fibers, but significantly lower than the GTA and genipin fibers. With respect to strain at break, no significant difference was observed among the crosslinking treatments. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate fibers exhibited significantly higher cell metabolic activity and DNA concentration that all other crosslinking treatments, promoted consistently cellular elongation along the longitudinal fiber axis and by day 7 they were completely covered by cells. Collectively, this work clearly demonstrates the potential of 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate as collagen crosslinker. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 914-922, 2016.

Polyacrylonitrile?phenolic composites display excellent in-plane properties but perform poorly when out-of-plane, through-thickness properties are considered. Composite architectures with carbon nanotubes, either dispersed within the matrix or bound to a fabric, in traditional composites have the potential to alleviate this weakness. However, effective reinforcement of composites using carbon nanotubes is difficult, due to poor dispersion and interfacial stress transfer and has thus far been met with limited success and at high costs. This paper describes an innovative and cost-effective technology to improve these inferior mechanical properties by using an exceptionally stable protein, SP1, for CNT attachment to PAN fabric, forming a three-dimensional nano-reinforced structure. This work confirms remarkable improvements in interlaminar shear strength and through-thickness tensile strength of SP1/CNT-reinforced polyacrylonitrile composites.