Layer-Number Dependent Antibacterial and Osteogenic Behaviors of Graphene Oxide Electrophoretic Deposited on Titanium

Abstract

Graphene oxide has attracted widespread attention in the biomedical fields due to its excellent biocompatibility. Herein we investigated the layer-number dependent antibacterial and osteogenic behaviors of graphene oxide in biointerfaces. Graphene oxide with different layer numbers was deposited on the titanium surfaces by cathodal electrophoretic deposition with varied deposition voltages. The initial cell adhesion and spreading, cell proliferation, and osteogenic differentiation were observed from all the samples using rat bone mesenchymal stem cells. Both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used to investigate the antibacterial effect of the modified titanium surfaces. Cocultures of human gingival fibroblasts (HGF) cells with Escherichia coli and Staphylococcus aureus were conducted to simulate the conditions of the clinical practice. The results show that the titanium surfaces with graphene oxide exhibited excellent antibacterial and osteogenic effects. Increasing the layer-number of graphene oxide resulted in the augment of reactive oxygen species levels and the wrinkling, which led to the antibacterial and osteogenic effects, respectively. Compared to pure titanium surface in the cells-bacteria coculture process, the modified titanium surfaces with graphene oxide exhibited higher surface coverage percentage of cells.

In vitro effect of graphene structures as an osteoinductive factor in bone tissue engineering: A systematic review

“…Similarly, graphene coating on the Ti alloy scaffolds also enhanced cell proliferation due to promoted adsorption of the growth factor of the seeding cells; 28 however, in some studies different observations were reported. In a study by Qiu et al, 47 increased layers of graphene coated on Ti showed less cell proliferation, and cells grown on Ti exhibited the greatest proliferation among all GO modified groups after 4 days. Indeed, increasing layer-number of GO resulted in decreased cell proliferation.…”

“…The metal or metalloid category consists of silicon (Si), 65 zinc oxide (ZnO), 89 28 and nitinol (NiTi). 57 Polymers include poly(L-lactide) (PLLA), 46 poly(dopamine) (PDA), 68 poly(ɛ-caprolactone) (PCL), 14,36,203 poly(ethylenimine) (PEI), 37, 82 poly(lacticcoglycolic acid) (PLGA)-tussah, 61 silk fibroin (SF), 43 polyethylene terephthalate-based artificial ligament group (PET-ALs), 78 47,65,89 and inductively coupled plasma-optical emission spectroscopy (ICP-OES) 49,71 were employed to measure the release rate of ions, and inductively coupled plasma-mass spectroscopy (ICP-MS) 64 was utilized to assess the Ca/P ratio. Additional assays and measures used for sample characterization include thermal gravimetric analysis (TGA), 37,71,82,84,87 energy dispersive X-ray spectroscopy (EDX), 33 75 swelling study, 75 weight loss measurement, 60 diametral tensile strength (DTS), 60 nanoindentation measurements, 67, 76 photoluminescence (PL) spectra, 94 elemental analysis experiment, 25 magnetometry, 25 selected-area electron diffraction (SAED), 57, 91 wettability evaluation, 89 roughness evaluation 14,28,89 and PL spectrum.…”

“…Graphene has unique physiochemical features, especially its potential for osteogenic induction of stem cells, that make it a promising material for promoting surface modification and bioactive character of metal-based composites. 48 Several studies 13,26,28,45,47,50,65,69,71,76,86,89,92 raised a debate regarding the influential role of metals combined with graphene on cell proliferation and viability.…”

“…Cell adhesion and spread within the scaffold are usually the first steps following seeding of cells onto the biomaterials, and therefore, have a significant effect on modulating the forthcoming cell responses, including cell proliferation and differentiation. 47 In most reviewed studies, presence of graphene and its derivatives resulted in accelerated cell adhesion and spreading, 19,21,52 yet, there are few studies showing no difference between cell density on GO-coated substrates and noncoated substrate . 62,79 Besides, in a study by Kanayama et al, 70 GO and RGO films were found to show less DNA content compared to controls.…”

Antibacterial Activity against Staphylococcus Aureus of Titanium Surfaces Coated with Graphene Nanoplatelets to Prevent Peri-Implant Diseases. An In-Vitro Pilot Study

“…This makes difficult to compare current results with those reported in previous papers, although some generalizations can be made. The GNP production process represents a viable solution for large-scale development of anti-biofilm devices, being low-cost, highly scalable, non-toxic, and non-oxidizing [36,37], when compared to a dry transfer technique based on a hot-pressing method [20], chemical vapour deposition coupled with a wet technique transfer (using polymethyl methacrylate or PMMA) [43], electroplating and ultraviolet reduction methods [44], evaporation-assisted electrostatic assembly processes and a mussel-inspired one-pot assembly process [45], and cathodal electrophoretic deposition [46]. Furthermore, differences in antibacterial properties might depend on the specimens (Ti-disks with commercially available sand-blasted and acid-etched surfaces) and microbial species (S. aureus) used in the present study, which were different from commercial pure Ti-plates or solid titanium and microbial species, such as Streptococcus mutans, Enterococcus faecalis, Porphyromanas gengivalis, and Escherichia coli, which have been used in other studies.…”