Development of Graphene-Reinforced Bone Cements and Characteristics of Graphene-Based Platform with Electromagnetic Field

Abstract

Tissue engineering is the study to reconstruct tissue and organs of living things by applying material science engineering and biological principles. It has been reported that according to the change of size, shape, and conformation of nanostructure, cellular adhesion, proliferation, and differentiation can be modulated. In other words, regulation of nanostructure can engineer cellular fate. Another method to control cellular function is using nanomaterials. The nanomaterials can derive synergic effects if the nanomaterials have additional functionality. Nowadays, graphene is getting spotlight. The graphene, recently discovered in 2004, also have high thermal and electrical conductivity, large specific surface area, and good mechanical properties. Further, it can be functionalized, indicating graphene can be used as diverse forms. Due to those unique characteristics, the graphene have been frequently used in biosensors, drug delivery, and gene delivery but it is recently focused in tissue engineering field. The graphene, which can flow electric current, serve as electrical stimulator, too. Moreover, it can emit microelectric current when it is exposed to magnetic or electromagnetic field. The general goal of this doctoral thesis is to fabricate graphene-based platforms, investigate the interaction of nanostructure and graphene-based nanomaterials, in case of structural, morphological, chemical characteristics, and assess synergic effects by on cell adhesion, cell proliferation, differentiation, and tissue regeneration. Biostimulation-inducing systems on graphene will be also composed and it will be applied on graphene-based nanostructural platforms. Its synergic effects will be thoroughly investigated. First, we combined reduced graphene oxide (RGO) and EMF on osteogenesis and neurogenesis of MSCs. Combination of RGO and PEMFs synergically increased ECM formation, membrane protein, metabolisme, etc. It is expected that the combination of RGO and PEMFs will be an efficient platform for stem cell and tissue engineering. Second, graphene was incorporated into bone cements to reinforce mechanical properties. Owing to the ability that graphene can induce osteogenic differentiation of stem cells, the graphene-incorporated nanocomposite bone cement enhanced osteogenic differentiation. Moreover, the graphene-incorporated nanocomposite bone cement under PEMFs synergically enhanced osteogenic differentiation. Because EMFs can be induced on the implants noninvasively, this system would be applied not only in vivo study but also clinical application, resulting in the innovation of regenerative medicine. It can be applicable in clinical study as well as in vivo study by combining with biodegradable scaffolds. Particularly, EMFs can be exerted on the transplanted scaffolds noninvasively. These systems can be easily applied in clinical study as well as in vivo study. Other stimulation systems, electrical, light, etc., have limitations to be applied in in vivo study. On the other hand, EMFs stimulation is already commercialized in clinical application. Thus, it is expected that EMFs stimulation system would come true in tissue engineering-based therapy. That would become a turning point in tissue engineering and regenerative medicine.