A 3D Printable Electroconductive Biocomposite Bioink Based on Silk Fibroin-Conjugated Graphene Oxide

Abstract

Reduced graphene oxide (rGO) has wide application as a nanofiller in the fabrication of electroconductive biocomposites due to its exceptional properties. However, the hydrophobicity and chemical stability of rGO limit its ability to be incorporated into precursor polymers for physical mixing during biocomposite fabrication. Moreover, until now, no suitable rGOcombining biomaterials that are stable, soluble, biocompatible, and 3D printable have been developed. In this study, we fabricated digital light processing (DLP) printable bioink (SGOB1), through covalent reduction of graphene oxide (GO) by glycidyl methacrylated silk fibroin (SB). Compositional analyses showed that SGOB1 contains approximately 8.42% GO in its reduced state. Our results also showed that the rGO content of SGOB1 became more thermally stable and highly soluble. SGOB1 hydrogels demonstrated superior mechanical, electroconductive, and neurogenic properties than (SB). Furthermore, the photocurable bioink supported Neuro2a cell proliferation and viability. Therefore, SGOB1 could be a suitable biocomposite for neural tissue engineering.

Conductive biocomposite hydrogels with multiple biophysical cues regulate schwann cell behaviors

“…It has been previously reported that GO may demonstrate certain cytotoxicity due to hydrophobic interaction with cell membranes and subsequent extraction of membrane cholesterol and phospholipids. 45 However, this phenomenon has not been observed in our experiments. One possible explanation is that the hydrophobic GO was successfully incorporated into polymeric networks, thereby enhancing its biocompatibility.…”

Graphene Oxide–Protein-Based Scaffolds for Tissue Engineering: Recent Advances and Applications

“…However, the roughness induced by the carbonaceous flakes favored the protein absorption capacity and, at the same time, improved cell adhesion and proliferation in comparison with neat protein-based scaffolds. Ajiteru et al [146] were the first to develop a 3D printable bioink formulation based on an SF-conjugated rGO structure that, after photocuring, exhibited similar mechanical and electrical properties to those of the spinal tissue. The ability of the bionanocomposite to support the viability and proliferation of Neuro2a cells makes it a suitable candidate for the development of neural tissue engineering platforms.…”

Next Evolution in Organ‐Scale Biofabrication: Bioresin Design for Rapid High‐Resolution Vat Polymerization

“…[ 203 ] Recently, Ajiteru et al. [ 204 ] developed a printable bioresin for neural tissue engineering, through covalent reduction of graphene oxide (GO) by glycidyl methacrylated silk fibroin. The resin was capable of printing complex shapes as shown in Figure 10a.…”

“…Reproduced with permission. [ 204 ] Copyright 2020, ACS Publications, b) i–iv) Cell distribution inside the Sil‐MA hydrogels. The Sil‐MA hydrogels with i) a design of the letter HL (the logo of Hallym University), ii) a shape of human brain were printed out with PKH67‐labeled cells only, iii) the Sil‐MA hydrogels with the letter HL, and iv) a shape of winding trachea were printed out with PKH67‐labeled cells (green) and PKH26‐labeled cells (red); (from left to right) CAD images, printed images, fluorescence images by (i) confocal or (ii–iv) single plane illumination microscopy (SPIM) microscope, and merged images of fluorescence and CAD images.…”