Collagen Functionalized With Graphene Oxide Enhanced Biomimetic Mineralization and in Situ Bone Defect Repair

Abstract

Biomimetic mineralization using simulated body fluid (SBF) can form a bonelike apatite (Ap) on the natural polymers and enhance osteoconductivity and biocompatibility, and reduce immunological rejection. Nevertheless, the coating efficiency of the bonelike apatite layer on natural polymers still needs to be improved. Graphene oxide (GO) is rich in functional groups, such as carbonyls (−COOH) and hydroxyls (−OH), which can provide more active sites for biomimetic mineralization and improve the proliferation of the rat bone marrow stromal cells (r-BMSCs). In this study, we introduced 0%, 0.05%, 0.1%, and 0.2% w/v concentrations of GO into collagen (Col) scaffolds and immersed the fabricated scaffolds into SBF for 1, 7, and 14 days. In vitro environment scanning electron microscopy (ESEM), energy-dispersive spectrometry (EDS), thermogravimetric analysis (TGA), micro-CT, calcium quantitative analysis, and cellular analysis were used to evaluate the formation of bonelike apatite on the scaffolds. In vivo implantation of the scaffolds into the rat cranial defect was used to analyze the bone regeneration ability. The resulting GO−Col−Ap scaffolds exhibited a porous and interconnected structure coated with a homogeneous distribution of bonelike apatite on their surfaces. The Ca/P ratio of 0.1% GO−Col−Ap group was equal to that of natural bone tissue on the basis of EDS analysis. More apatites were observed in the 0.1% GO−Col−Ap group through TGA analysis, micro-CT evaluation, and calcium quantitative analysis. Furthermore, the 0.1% GO−Col−Ap group showed significantly higher r-BMSCs adhesion and proliferation in vitro and more than 2-fold higher bone formation than the Col−Ap group in vivo. Our study provides a new approach of introducing graphene oxide into bone tissue engineering scaffolds to enhance biomimetic mineralization.

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

“…It has been shown that the incorporation of GO and GQD into aliphatic polyesters can also induce the deposition of apatite crystals on their surfaces [76,228]. The oxygenated groups of GO such as carboxyl (−COOH) and hydroxyl (−OH) provide active sites for biomineralization [228,252]. For instance, a thick layer of calcium phosphate mineral can be deposited on electrospun PCL/0.3 wt% GO mat surface by immersion in 10 SBF solution at room temperature for 20 h [228].…”

Cytotoxicity and Immune Dysfunction of Dendritic Cells Caused by Graphene Oxide

“…In addition, Zhang et al proposed a GO-based fluorescent nanosensor that can be used to quickly detect telomerase content in cells and image telomerase (Zhang et al, 2018). Zhou et al studied a new method of introducing GO into bone tissue to enhance biomineralization, and they found that when the GO concentration was 0.1% w/v and immersed in simulated body fluids for 7 days, GO-collagen-apatite 3D scaffold showed good therapeutic effect in repairing skull defects in rats (Zhou et al, 2018).…”

Graphene-modified CePO4 nanorods effectively treat breast cancer-induced bone metastases and regulate macrophage polarization to improve osteo-inductive ability

“…Notably, graphene oxide (GO) with excellent light-absorbing property and photothermal conversion efficiency has been widely used for PTT application [20,25]. Moreover, the carbonyl, epoxy and hydroxyl groups in the GO can serve as bioactive sites for cell proliferation and bone mineralization via activating MAPK signaling pathway [26][27][28]. It is reasonably inferred that the GO-modified scaffolds are fit for PTT against tumors and subsequent bone defect healing.…”