Artikel
Cellular compatibility and osteogenic potential of chemically modified graphene coated chitosan scaffolds in vitro
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Veröffentlicht: | 23. Oktober 2017 |
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Gliederung
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Objectives: Bone substitute materials build by chitosan display the advantages of interconnected-porous structures, good biocompatibility, biodegradation, and antibacterial activity whereas their mechanical properties are improvable. Recently it was reported that coating with graphene oxide (GO) and reduced graphene oxide (rGO) substantially increased the mechanical properties of chitosan scaffolds [1]. Here we asked whether such coating affects the viability of osteoblasts and its osteogenic potential.
Methods: Chitosan scaffolds were prepared by dissolving chitosan powder (1%, Fluka Chemicals, Germany, 85% deacetylated) in 2% acetic acid, neutralized to pH 9.0 with 10% NaOH, washed with dionized water and dried. For GO coating chitosan scaffolds were incubated 48 h in a GO dispersion that was produced according to the Hummers method [2]. GO was further processed by treatment with 150°C in Ar atmosphere for 12 h to reduce GO into rGO. Scaffolds had a size of approximately 1 cm in diameter and 2 mm thickness. They were placed into 24 well plates, incubated for 24 h with 0.5 M NaOH followed by 24 h incubation in cell culture medium containing 10% fetal bovine serum. Afterwards murine osteoblasts of the cell line MC3T3-E1 (DSMZ, Braunschweig) were seeded and lactate dehydrogenase (LDH) test for cell viability, alkaline phosphatase (ALP) assay for osteogenic potential and immunofluorescence were performed. Kruskal-Wallis and Mann-Whitney Tests were used for statistical analysis (SPSS V23, Institute Inc, Chicago, USA).
Results and Conclusion: MC3T3 cells growing on chitosan, GO and rGO scaffolds showed after 3 and 7 days (d) of incubation no significant differences in viability while compared to pure cell culture plastic the toxicity was significantly increased (p = 0.006). The ALP activity was up-regulated at GO and rGO coated scaffolds after 3 and 7 d in cell culture (p = 0.001) compared to pure chitosan and cell culture plastic, respectively. No differences were determined between GO and rGO scaffolds.
The results demonstrated an increase in osteogenic potential and a good biocompatibility of both, GO and rGO chitosan scaffolds. Therefore, the chosen graphene derivatives are proved to be suitable coatings for designing mechanically enhanced and biocompatible chitosan scaffolds.