Two-dimensional collagen-graphene as colloidal templates for biocompatible inorganic nanomaterial synthesis

Abstract

In this study, natural graphite was first converted to collagen-graphene composites and then used as templates for the synthesis of nanoparticles of silver, iron oxide, and hydroxyapatite. X-ray diffraction did not show any diffraction peaks of graphene in the composites after inorganic nucleation, compared to the naked composite which showed (002) and (004) peaks. Scanning electron micrographs showed lateral gluing/docking of these composites, possibly driven by an electrostatic attraction between the positive layers of one stack and negative layers of another, which became distorted after inorganic nucleation. Docking resulted in single layer-like characteristics in certain places, as seen under transmission electron microscopy, but sp 2 /sp 3 ratios from Raman analysis inferred three-layer composite formation. Strain-induced folding of these layers into uniform clusters at the point of critical nucleation, revealed beautiful microstructures under scanning electron microscopy. Lastly, cell viability studies using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed the highest cell viability for the collagen-graphene-hydroxyapatite composites. In this manner, this study provided – to the field of nanomedicine – a new process for the synthesis of several nanoparticles (with low toxicity) of high interest for numerous medical applications.

Anisotropic architecture and electrical stimulation enhance neuron cell behaviour on a tough graphene embedded PVA: alginate fibrous scaffold

“…The rst peak at 2Q ¼ 19.6 was related to the homogenous mixing of PVA and alginate within the bers and the second was graphene nanosheet's characteristic peak according to other researches. 49,50 According to XRD patterns of pure PVA and alginate, both were semicrystalline with a broad peak at 2Q ¼ 19.3 and 26.6 , respectively. Aer mixing, both peaks disappeared and only one peak at 2Q ¼ 19.6 could be detected which could be due to their homogeneous blending and the interactions between them.…”

The Efficacy of Graphene Foams for Culturing Mesenchymal Stem Cells and Their Differentiation into Dopaminergic Neurons

“…The X-ray diffraction (XRD) peaks of collagen-coated GF confirmed that they existed in separate planes. In addition, they did not interact with each other which is supported by their distinct peak positions without any considerable change that is supported by the above references [ 33 , 35 , 36 ].…”

“…After coating the GF with collagen, D peak appeared near 1350 cm −1 and some other peaks emerged including a minor peak at ~2450 cm −1 ( G ′ band). The defect was increased from 0.02 to 0.7 in collagen-coated GF which is estimated from the intensity ratio of the D band and G band ( D / G ) [ 33 ]. The amide-III peak appeared at 1242 cm −1 which is a characteristic of the collagen ( Figure 3(c) ), though the amide-I and amide-II peaks were absent in the spectra [ 34 ].…”

“…XRD spectra of the collagen-coated GF is shown in Figure 3(d) and was indexed as described. The two diffraction peaks at 2 θ = 26.5° and 2 θ = 55° correspond to the (002) and (004) planes of graphene, respectively, where the intensity of the peak at 2 θ = 26.5° got reduced for the collagen coating [ 33 , 35 ]. The diffraction peaks of collagen appeared to correspond to the crystallographic planes (211) and (222) at about 2 θ = 32° and 2 θ = 45.3° indicating a traditional mineralized collagen [ 36 ].…”

Applications of Polymeric Composites in Bone Tissue Engineering and Jawbone Regeneration

“…Collagen–graphene–HA is another candidate for bone repair and regeneration, and drug delivery. The addition of graphene to the scaffold provided it with the capacity to synthesize and fold at the nanometric level [ 85 ]. Both graphene and its derivatives have denoted positive outcomes in nanomedicine approaches in bone repair, due to their additional mechanical properties and electrical conductivity, besides atomic structure stability.…”