Oxygen Plasma Technology-Assisted Preparation of Three-Dimensional Reduced Graphene Oxide/Polypyrrole/Strontium Composite Scaffold for Repair of Bone Defects Caused by Osteoporosis.

Xiaoxue Mai,Fuxiang Song,Zebiao Kang,Na Wang,Xiaoli Qin,Weibo Xie

doi:10.3390/molecules26154451

Xiaoxue Mai, Fuxiang Song + Show 4 more

Open Access

https://doi.org/10.3390/molecules26154451

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Abstract

Repairs of bone defects caused by osteoporosis have always relied on bone tissue engineering. However, the preparation of composite tissue engineering scaffolds with a three-dimensional (3D) macroporous structure poses huge challenges in achieving osteoconduction and osteoinduction for repairing bone defects caused by osteoporosis. In the current study, a three-dimensional macroporous (150–300 μm) reduced graphene oxide/polypyrrole composite scaffold modified by strontium (Sr) (3D rGO/PPY/Sr) was successfully prepared using the oxygen plasma technology-assisted method, which is simple, safe, and inexpensive. The findings of the MTT assay and AO/EB fluorescence double staining showed that 3D rGO/PPY/Sr has a good biocompatibility and effectively promoted MC3T3-E1 cell proliferation. Furthermore, the ALP assay and alizarin red staining showed that 3D rGO/PPY/Sr increased the expression levels of ALP activity and the formation of calcified nodules. The desirable biocompatibility, osteoconduction, and osteoinduction abilities, assure that the 3D macroporous rGO/PPY/Sr composite scaffold offers promising potential for use in the repair of bone defects caused by osteoporosis in bone tissue engineering.

Highlights

Previous studies have reported a gradual increase in the incidence of bone defects caused by osteoporosis due to the aging of the population
The Energy Dispersive X-ray spectrometer (EDX) findings showed that, besides the main C, N, and O elements of the 3D rGO/PPY modified by the Sr scaffold itself, the increased Sr element was uniformly deposited on the skeleton surface of the scaffold (Figure 1e–h)
The findings of the current study indicated that the 3D rGO/PPY/Sr scaffold was loaded with a compression strain up to 90% (Figure 7a); the strain vs. stress curve presented a non-linear elastic deforming mechanism during compression

Summary

Introduction

Previous studies have reported a gradual increase in the incidence of bone defects caused by osteoporosis due to the aging of the population. Previous studies have reported that about 50% of people aged 65 suffer from osteoporotic fractures [2]. Current efforts for the improvement of bone defect repairs for osteoporotic fractures entail the improvement of physical and chemical properties as well as the physiological activity of implant materials to improve osteogenic activity or inhibit osteoclast activity in situ. Yang et al [5] demonstrated improved osteogenesis in osteoporotic rats upon the implantation of strontium-containing calcium sulfate hemihydrate. These repair materials lacked the morphology of a natural bone macroporous structure and sufficient biological activity. Scaffolds with three-dimensional (3-D) porous networks provide effective matrix conditions for bone tissue engineering [6]

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Conclusion