Comparative study of bioactivity of collagen scaffolds coated with graphene oxide and reduced graphene oxide

Abstract

Graphene oxide (GO) is a single layer carbon sheet with a thickness of less than 1 nm. GO has good dispersibility due to surface modifications with numerous functional groups. Reduced graphene oxide (RGO) is produced via the reduction of GO, and has lower dispersibility. We examined the bioactivity of GO and RGO films, and collagen scaffolds coated with GO and RGO. METHODS:GO and RGO films were fabricated on a culture dish. Some GO films were chemically reduced using either ascorbic acid or sodium hydrosulfite solution, resulting in preparation of RGO films. The biological properties of each film were evaluated by scanning electron microscopy (SEM), atomic force microscopy, calcium adsorption tests, and MC3T3-E1 cell seeding. Subsequently, GO- and RGO-coated collagen scaffolds were prepared and characterized by SEM and compression tests. Each scaffold was implanted into subcutaneous tissue on the backs of rats. Measurements of DNA content and cell ingrowth areas of implanted scaffolds were performed 10 days post-surgery. RESULTS: The results show that GO and RGO possess different biological properties. Calcium adsorption and alkaline phosphatase activity were strongly enhanced by RGO, suggesting that RGO is effective for osteogenic differentiation. SEM showed that RGO-modified collagen scaffolds have rough, irregular surfaces. The compressive strengths of GO- and RGO-coated scaffolds were approximately 1.7-fold and 2.7-fold greater, respectively, when compared with the non-coated scaffold. Tissue ingrowth rate was 39% in RGO-coated scaffolds, as compared to 20% in the GO-coated scaffold and 16% in the non-coated scaffold. CONCLUSION: In summary, these results suggest that GO and RGO coatings provide different biological properties to collagen scaffolds, and that RGO-coated scaffolds are more bioactive than GO-coated scaffolds

Preliminary In Vitro Evaluation of Chitosan–Graphene Oxide Scaffolds on Osteoblastic Adhesion, Proliferation, and Early Differentiation

“…Most of the findings have been ascribed to the various planar oxygen-containing functional groups like hydroxyl, carboxyl, and epoxide which have allowed various π–π stacking interactions, electrostatic and hydrogen bonds for the concentration of osteogenic inducers [ 39 ] and growth factors [ 40 ]. Besides, the osteoinducer used in this study, l -ascorbic acid, was also suggested to adsorb onto GO and subsequently binds calcium ions which mediated increase in ALP activity and mineralization in mouse osteoblasts [ 41 ].…”

Graphene-based materials for tissue engineering

“…In one study, ascorbic acid reduced rGO was tested versus the hydrazine method and it was evident that the ascorbic acid reduction method was more biocompatible than the hydrazine reduction methods[64]. For example, cells cultured on the collagen scaffold coated with rGO reduced by ascorbic acid possessed high cell viability and nontoxicity properties [65]. This indicates that ascorbic acid is a suitable reducing agent for rGO for biomedical applications.…”

Synthetic Biodegradable Aliphatic Polyester Nanocomposites Reinforced with Nanohydroxyapatite and/or Graphene Oxide for Bone Tissue Engineering Applications

“…Till to present, there exists no reports in the literature on the biological effects and cytotoxicity induced by the GO nanofillers of aliphatic polyester scaffolds. Recently, Kanayama et al coated collagen scaffolds with GO and rGO, and then subcutaneously implanted into male Wistar rats [284]. From the histological examination of rat tissues, they reported that inflammatory cells such as neutrophils and lymphocytes were rarely seen.…”