Graphene Oxide and Reduced Graphene Oxide Nanoflakes Coated with Glycol Chitosan, Propylene Glycol Alginate, and Polydopamine: Characterization and Cytotoxicity in Human Chondrocytes

Abstract

Recently, graphene and its derivatives have been extensively investigated for their interesting properties in many biomedical fields, including tissue engineering and regenerative medicine. Nonetheless, graphene oxide (GO) and reduced GO (rGO) are still under investigation for improving their dispersibility in aqueous solutions and their safety in different cell types. This work explores the interaction of GO and rGO with different polymeric dispersants, such as glycol chitosan (GC), propylene glycol alginate (PGA), and polydopamine (PDA), and their effects on human chondrocytes. GO was synthesized using Hummer’s method, followed by a sonication-assisted liquid-phase exfoliation (LPE) process, drying, and thermal reduction to obtain rGO. The flakes of GO and rGO exhibited an average lateral size of 8.8 ± 4.6 and 18.3 ± 8.5 µm, respectively. Their dispersibility and colloidal stability were investigated in the presence of the polymeric surfactants, resulting in an improvement in the suspension stability in terms of average size and polydispersity index over 1 h, in particular for PDA. Furthermore, cytotoxic effects induced by coated and uncoated GO and rGO on human chondrocytes at different concentrations (12.5, 25, 50 and 100 µg/mL) were assessed through LDH assay. Results showed a concentration-dependent response, and the presence of PGA contributed to statistically decreasing the difference in the LDH activity with respect to the control. These results open the way to a potentially safer use of these nanomaterials in the fields of cartilage tissue engineering and regenerative medicine.

Recent advances and challenges in graphene‐based nanocomposite scaffolds for tissue engineering application

“…Graphene‐based nanomaterials coated with biocompatible polymers such as chitosan and dextran have lower hemolytic activity than unreformed graphene. A recent study also showed that the dispersion of GO (100 μg/ml) and rGO (100 μg/ml) in polymeric surfactants, including glycol chitosan (GC), propylene glycol alginate (PGA), and polydopamine (PDA), improved the stability of the suspensions 52 . It showed that cytotoxic effects induced by coated materials, especially those coated with PGA, on human chondrocytes are lower than those of the control.…”

“…A recent study also showed that the dispersion of GO (100 μg/ml) and rGO (100 μg/ml) in polymeric surfactants, including glycol chitosan (GC), propylene glycol alginate (PGA), and polydopamine (PDA), improved the stability of the suspensions. 52 It showed that cytotoxic effects induced by coated materials, especially those coated with PGA, on human chondrocytes are lower than those of the control. Most studies showed that the toxicity of graphene and GO is associated with its interaction with the cell membrane, which physically harms the lipid membrane.…”

Piezoelectric nanocomposite bioink and ultrasound stimulation modulate early skeletal myogenesis

“…No insights are reported in the state of the art so far regarding the use of PGA for BTNP coating. In the literature, PGA has been proposed for stabilizing graphene oxide nanoflakes, 55 demonstrating high biocompatibility and the ability to keep these nanomaterials well dispersed in aqueous media. However, the dimensions of these flakes (lateral dimension: ∼10 µm, thickness: ∼1.5 nm) were not comparable with the ones of BTNPs used in this study.…”

Characterization and In Vitro Studies of Low Reflective Magnetite (Fe3O4) Thin Film on Stainless Steel 420A Developed by Chemical Method

“…A repeated sterilization test was performed as per ISO 17665-1 standard for assessing the effect of sterilization temperature on the adhesion property of the black oxide coating [29]. In the conventional method, the temperature of the steam varies from 121-134 • C for a period of 15−21 min to ensure adequate sterilization.…”