Spider dragline silk composite films doped with linear and telechelic polyalanine: Effect of polyalanine on the structure and mechanical properties

Abstract

Spider dragline silks have attracted intensive attention as eco-friendly tough materials because of their excellent mechanical property and biomass-based origin. Composite films based on a recombinant spider dragline silk protein (ADF3) from Araneus diadematus were prepared by doping with linear or telechelic poly(l-alanine) (L- or T-polyA, respectively) as a reinforcing agent. Higher tensile strength and toughness of the composite films were achieved with the addition of polyA compared with the tensile strength and toughness of the silk-only film. The difference in the reinforcing behavior between L- and T-polyA was associated with their primary structures, which were revealed by wide angle X-ray diffraction analysis. L-polyA showed a tendency to aggregate in the composite films and induce crystallization of the inherent silk β-sheet to afford rigid but brittle films. By contrast, T-polyA dispersion in the composite films led to the formation of β-sheet crystal of both T-polyA and the inherent silk, which imparted high strength and toughness to the silk films.

Influence of Short-Range Scrambling of Monomer Order on the Hydrolysis Behaviors of Sequenced Degradable Polyesters

“…The structure of the random copolymer is more complex but can be confirmed by first analyzing the composition of the pentamers that are embedded. 1 H NMR spectroscopy and mass spectrometry show that the distribution in L 3 G 2 -Si is consistent with the expected 32 sequence outcomes arising from the statistical combination of protected dimers (Figure 3).…”

“…In synthetic polymer science, there are few studies of the sensitivity of bulk properties to discrete changes in monomer sequence in an otherwise sequence-controlled polymer (SCP). The degree to which sequence plays a role in the macromolecular function is well established in nature and most appreciated within the scope of biological chemistry, where it is well understood that for some biopolymers a single monomer sequencing error can dramatically affect the function, e.g., DNA, while for others, the behavior is controlled by an overall sequence pattern rather than exact monomer identity and placement, e.g., structural proteins like spider silk. − …”

Epidermal cell surface structure and chitin-protein co-assembly determine fiber architecture in the Locust cuticle

“…9). Interstrand spacing of 0.47 nm is common for beta-sheet structures as in amyloid structures, whereas spacing of 0.43 nm is common for the inter-strand spacing in silks (25)(26)(27). Other unassigned reflections with d-spacing of 0.38 nm and 0.77 nm are observed along with additional reflections in the small angle region with d-spacing of 1.5 nm and 3.4 nm (the latter already noted by Rudall et al…”

Hydrogel Preparation Methods and Biomaterials for Wound Dressing

“…It possesses low density, biodegradability and biocompatibility, and good mechanical properties, in addition, it has the ability to self-assemble into materials that are suitable as cell culture matrices [ 124 , 125 , 126 ]. The functionalized recombinant spider silk proteins expressed in bacteria hold great potential for the development of advanced biomaterials in the field of tissue engineering [ 115 , 127 ]. The wound dressing made by Chouhan et al using recombinant spider silk protein (4RepCT) not only stimulated cell proliferation but also provided antibacterial effects, thereby improving the wound healing process [ 128 ].…”