A Microfabricated Wet-Spinning Apparatus To Spin Fibers of Silk Proteins. Structure−Property Correlations

Abstract

A microfabricated spinneret is described that is capable of spinning meters of fibers from solutions containing as little as 10 mg of purified protein. Using the spinneret, regenerated Bombyx mori fibers were made using various processing parameters. A log-linear relationship was found between the maximum stress sustained by the regenerated fibers and their diameters. Solid state 13 C NMR was used to determine the effects of spinneret diameter and postspinning draw ratio on the secondary structure of the alanine residues in the silk protein. The relationship between the secondary structure of the alanine residues and the maximum stress of the silks was also examined. The results suggest that a relatively high fraction of the alanine residues in the silks must be in the -sheet conformation (>65%) in order to produce the highest stress fibers. However, the fraction of alanine residues in the -sheet conformation does not uniquely determine the maximum stress of a fiber; it is suggested that orientation of these -sheets is also an important parameter.

A microfluidic cell for studying the formation of regenerated silk by synchrotron radiation small- and wide-angle X-ray scattering

“…3,5,[14][15][16] Our aim is to mimic silk protein aggregation in a microfluidic environment and to obtain microstructural information by SR-SAXS/WAXS techniques. Silk producing microfluidic devices made of silicon 17 or polydimethylsiloxane 18 ͑PDMS͒ are, however, not optimized for in-situ X-ray scattering studies requiring a high transparency and a low scattering background. A microfluidic cell optimized for X-ray scattering during silk fibroin aggregation made of glass will be described in the current article.…”

Silk Fibroin Nanofiber. Electrospinning, Properties, and Structure

“…Up to date, some attempts to artificially spin silk protein fibers have been reported. [16][17][18][19][20] There has also been a preliminary report of electrospun spider silk nanofibers. 19 In the present paper, we describe how we have adapted the electrospinning process to fabricate an engineered matrix composed of SF nanofibers for use in tissue engineering scaffolds or wound dressings.…”

Environment-Induced Silk Fibroin Conformation Based on the Magnetic Resonance Spectroscopy

“…The resonance peak at 5 ~ 25 ppm in Fig. 2(B) for the C of Ala residue can distinguish the helix form from the -sheet form (Liivak et al, 1998). The lineshape of the peak can be deconvoluted into four components, Silk I at 17.0 ± 0.5 ppm and Silk II at 20.0 ±0.5 ppm, as well as transition state components, Silk I-like at 15.0 ± 0.5 ppm and Silk II-like at 21.5 ± 0.5 ppm Zong et al, 2004).…”