Mussel-Inspired Electroactive and Antioxidative Scaffolds with Incorporation of Polydopamine-Reduced Graphene Oxide for Enhancing Skin Wound Healing

Abstract

Wound repair and tissue regeneration are complex processes that involve many physiological signals. Thus, employing novel wound dressings with potent biological activity and physiological signal response ability to accelerate wound healing is a possible solution. Herein, inspired by mussel chemistry, we developed a polydopamine (PDA)-reduced graphene oxide (pGO)-incorporated chitosan (CS) and silk fibroin (SF) (pGO-CS/SF) scaffold with good mechanical, electroactive, and antioxidative properties as an efficient wound dressing. First, pGO with good dispersibility and cell affinity was obtained upon reduction by PDA under alkali conditions. Second, pGO was dispersed into a CS/SF mixture, and then CS and SF chains were dual-cross-linked by poly­(ethylene glycol) diglycidyl ether and glutaraldehyde to obtain a pGO-incorporated gel. Finally, the gel underwent a freeze-dry process to obtain the pGO-CS/SF scaffold. Owing to PDA reduction and functionalization, pGO in the scaffold plays important roles for the performances of the scaffolds. First, the pGO acts as nanoreinforcement to enhance the mechanical properties of the scaffold by combining the dual-cross-linked CS/SF network. Second, the uniformly distributed pGO in the scaffolds comprises a well-connected electric pathway, which can provide a channel for the transmission of electrical signals in the scaffold. Moreover, pGO in the scaffolds serves as an antioxidant agent to scavenge reactive oxygen species (ROS) and therefore terminates excessive ROS oxidation. In vitro studies show that electroactive pGO-CS/SF scaffolds can respond to electrical signals and promote cytological behavior. In addition, the pGO-CS/SF scaffolds can reduce cellular oxidation by removing excessive ROS. The in vivo full-thickness skin defect model demonstrates that the electroactive and antioxidative pGO-CS/SF scaffold can efficiently enhance wound healing. In summary, the pGO-CS/SF scaffold is a promising wound dressing because of its ability to promote physiological electrical signal transmission for cell growth and reduce ROS oxidation, resulting in an improved wound regeneration effect.

Structure and properties of PVA/silk fibroin hydrogels and their effects on growth behavior of various cell types

“…Therefore, the content of silk fibroin in PVA hydrogel may be one of the factors that affect cell morphology. Although silk fibroin hydrogels are beneficial for stem cell growth and differentiation [20,21], and silk fibroin composite scaffolds are also widely studied, such as silk fibroin/chitosan/graphene oxide scaffolds [22] and silk fibroin/chitosan/bioactive glass nanoparticle scaffolds [23]. These studies indicated that the composition and content of silk fibroin in composite scaffolds play an important role in cell morphology and behavior.…”

Polydopamine/silver hybrid coatings on soda-lime glass spheres with controllable release ability for inhibiting biofilm formation

“…Finally, the fitting results of C 1s, N 1s, and O 1s of PDA-Ag-HF/GSs (Fig. 3f-h) show that the C 1s spectrum can be fitted to four peaks at 284.77, 285.94, 286.6 and 288.52 eV, corresponding to the carbon skeleton (C-C), amino group (C-N), phenolic hydroxyl group (C-OH), and carbonyl group (C=O) on PDA, respectively [24]. The peaks at 399.90 and 402.34 eV on the N 1s spectrum represent amide and the amino groups (-NH 2 ), respectively.…”

“…More importantly, the catechol functional group has a reducing ability and can form a redox balance [23]. Such excellent performances make DA widely used in many fields such as biomedicine [24] and the environment [18].…”

Hybrid Bilayer PLA/Chitosan Nanofibrous Scaffolds Doped with ZnO, Fe3O4, and Au Nanoparticles with Bioactive Properties for Skin Tissue Engineering

“…There are numerous studies showing that the application of external stimuli improves various cell behaviors and accelerates tissue regeneration among which direct current stimulation can be named [28,[33][34][35][36][37][38][39]. The use of DC has been proven to improve the proliferation of various cell types including L929.…”

“…However, the biosafety for metal oxides is higher than for metals thus to increase the conductivity of the material, they can be used in the higher dose. Obtained results showed that the nanoparticles-doped scaffolds exhibit ability to be used for cells stimulation using direct current of low voltage [28,[33][34][35][36][37][38][39]. named [28,[33][34][35][36][37][38][39].…”