Bioactive Three-Dimensional Graphene Oxide Foam/Polydimethylsiloxane/Zinc Silicate Scaffolds with Enhanced Osteoinductivity for Bone Regeneration

Abstract

Nanocomposite scaffold materials have shown great prospect in promoting bone integration and bone regeneration. A three-dimensional graphene oxide foam/polydimethylsiloxane/zinc silicate (GF/PDMS/ZS) scaffold for bone tissue engineering was synthesized via dip coating and hydrothermal synthesis processes, resulting in the interconnected macroporous structure. The scaffold was characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) analysis. The result showed that scaffolds exhibiting a porous characteristic had organic–inorganic components similar to natural bone tissue. Moreover, the scaffolds possessed suitable pore size, high porosity, and good mechanical properties. In vitro experiments with mouse bone marrow mesenchymal stem cells (mBMSCs) revealed that the composite scaffold not only has great biocompatibility but also has the ability to induce mBMSC proliferation and preferential osteogentic differentiation. Thereafter, the expression of critical genes, ALP, RUNX2, VEGFA, and OPN, was activated. In vivo analysis of critical bone defect in rabbits demonstrated superior bone formation in defect sites in the GF/PDMS/ZS scaffold group at 12 weeks of post implantation without no significant inflammatory response. All the results validated that the GF/PDMS/ZS scaffold is a promising alternative for applications in bone regeneration.

The effect of curvature on chondrocytes migration and bone mesenchymal stem cells differentiation

“…PDMS has poor wettability and biocompatibility, which makes it difficult for chondrocytes and hydrophilic proteins to adhere to the surface. Therefore, prior to studying the effects of curvature and micro‐nano patterns with different perimeter curvatures on cell migration and differentiation, the surface of PDMS was required to be modified to improve its surface wettability 40,41 . Simple and convenient oxygen plasma is one of the commonly used modification methods 42,43 .…”

Scaffold-based developmental tissue engineering strategies for ectodermal organ regeneration

“…In most works, the mechanical properties are only tested after tissue/organ regeneration and compared to those of native mature tissues to demonstrate functionality has been achieved [ 100 ]. In classical TE approaches, scaffolds are mainly designed to target the properties of the mature tissue to be regenerated [ [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] ]. For developmental TE approaches, it is more likely that the properties of the scaffold should mimic those of the metastable environment where the native developmental process occurs and that the mechanical properties of the construct dynamically change following the developmental regeneration process [ 20 ].…”

“…In addition to incorporating fundamental features such as biocompatibility and biodegradability, classical TE scaffolds are designed to mimic the microarchitecture and mechanical properties of the mature tissue to be regenerated [ 9 , 10 ]. For instance, different scaffold designs include relatively stiff scaffolds with tuned porous structure for bone [ 11 , 12 ] and gradient porosity for osteochondral regeneration [ 13 , 14 ], scaffolds with preferential orientation for the regeneration of anisotropic tissues [ 15 , 16 ], or scaffolds with relatively soft mechanical properties and big pores for adipose tissue regeneration [ 17 , 18 ]. Classical TE strategies mainly aim at cell growth in a 3D structure and differentiation into the desired phenotype to form the mature tissue, pursued by guiding cell fate by modulating the scaffolds properties (e.g.…”

Two-Dimensional Nanomaterials beyond Graphene for Biomedical Applications

“…Moreover, the SA–CS–Col–GO scaffold gained more stability in water compared to non-GO filled samples and the swelling ratio was significantly decreased in water (pH 7) and PBS (pH 7.4) due to increased crosslinking in the presence of GO [ 121 ]. Another study by Li and co-workers was conducted by preparing a three-dimensional GO foam/polydimethylsiloxane/zinc silicate (GF/PDMS/ZS) composite scaffold through dip coating and hydrothermal synthesis method, to make a macroporous platform for bone-tissue engineering [ 122 ]. The mechanical strength of the composite was enforced by incorporating PDMS to GF because the compressive modulus increased.…”

“…In vitro studies using laser confocal images of cells cocultured with GF/PDMS/ZS scaffold after 7 days revealed more mouse bone marrow mesenchymal stem cells (mBMSCs) grew than on GF, GF/PDMS scaffolds and expression of alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX-2) gens as markers of osteogenic differentiation were enhanced. For in vivo analysis, rabbits’ bone defects were treated with the GF/PDMS/ZS and revealed comparable bone formation after 12 weeks of implantation with no inflammatory reaction [ 122 ]. Incorporation of a graphene-silver-polycationic peptide (GAP) nanocomposite into chitosan (Cs) in the form of sponge can also provide a scaffold for wound healing [ 123 ].…”