Electrohydrodynamic Bubbling: An Alternative Route to Fabricate Porous Structures of Silk Fibroin Based Materials

Abstract

Conventional fabrication techniques and structures employed in the design of silk fibroin (SF) based porous materials provide only limited control over pore size and require several processing stages. In this study, it is shown that, by utilizing electrohydrodynamic bubbling, not only can new hollow spherical structures of SF be formed in a single step by means of bubbles, but the resulting bubbles can serve as pore generators when dehydrated. The bubble characteristics can be controlled through simple adjustments to the processing parameters. Bubbles with diameters in the range of 240-1000 μm were fabricated in controlled fashion. FT-IR characterization confirmed that the rate of air infused during processing enhanced β-sheet packing in SF at higher flow rates. Dynamic mechanical analysis also demonstrated a correlation between air flow rate and film tensile strength. Results indicate that electrohydrodynamically generated SF and their composite bubbles can be employed as new tools to generate porous structures in a controlled manner with a range of potential applications in biocoatings and tissue engineering scaffolds.

On the Routines of Wild-Type Silk Fibroin Processing Toward Silk-Inspired Materials: A Review

“…Gel formation may also be promoted by increasing silk concentration in solution . Recently, CO 2 ‐assisted synthesis of RSF hydrogels by gas bubbling and 3D, 2D, or standalone RSF structures by electrohydrodynamic (EHD) bubbling were reported …”

“…[92,102] Recently, CO 2 -assisted synthesis of RSF hydrogels by gas bubbling and 3D, 2D, or standalone RSF structures by electrohydrodynamic (EHD) bubbling were reported. [103,104] The virtual insolubility of (R)SF-derived materials in aqueous media is a crucial property at the end of production, since in most cases their application will involve contact with water or water-based solutions. It is directly related to crystallinity of a fibroin.…”

Silk fibroin for vascular regeneration

“…Porous silk fibroin scaffolds. Despite electrospinning method, 3D porous silk fibroin scaffolds can also be produced using many other methods like freeze‐drying (Zhu et al, ), salt‐leaching (Kim et al, ; Yan et al, ), freeze‐thaw (Nazarov et al, ), electrohydrodynamic bubbling (Ekemen et al, ), rapid prototyping (Ghosh et al, ), and other facile method using n ‐butanol (Cao et al, ). Porous scaffolds (as shown in Fig.…”

Biofabrication of Gelatin Tissue Scaffolds with Uniform Pore Size via Microbubble Assembly

“…It is possible to overcome the disadvantages of both conventional and rapid prototyping methods with recently developed versatile and robust techniques of microbubble generation. Bottom‐up fabrication approach of tissue scaffolds with microbubbles allows precise control of a very narrow pore size distribution . The technique is simple, fast, and does not require a template or a complex setup.…”