title: Effects of hierarchical micro/nano-topographies on the morphology, proliferation and differentiation of osteoblast-like cells.
abstract: Coating the surfaces of titanium-based implants with appropriate hierarchical micro/nano-topographies resembling the structure of natural bone significantly enhances their biological performance. However, the relationship between nanostructures surfaces and their effects on modulating cellular response is not clearly understood. Moreover, it is not clear whether the surface chemistry or topography is the main factor on modulating cellular behavior, because the commonly used surface modification techniques for titanium-based implants simultaneously modify surface topography and chemistry. The aim of this study is to investigate osteoblast-like cell adhesion, proliferation and differentiation on hierarchical micro/nano-topographies with similar surface chemistry but different nano-scale features. Micro-arc oxidation and post hydrothermal treatment were employed to fabricate micro/nano-topographies on titanium. According to the morphological features, they were classified as microcrater (micro-topography), nanoplate (hierarchical topography with nanoplates) and nanoleaf (hierarchical topography with nanoleaves). The response of osteoblast like cells (SaOS-2) was studied on each surface after sputtering with a thin layer of gold (Au) to minimize the influence of surface chemistry. The morphological evaluation after histochemical staining revealed that the adherent cells were polygonal-shaped on microcrater surface, roundish on nanoplate surface and elongated on nanoleaf surface. Additionally, compared to microcrater surface, nanoplate surface slowed down cell proliferation and exhibited no enhancement on cell differentiation. However, nanoleaf surface supported cell proliferation and promoted cell differentiation. The results indicate that tuning morphological features of nanostructures on micro-topography can serve as a promising strategy to specifically modulate cellular response, such as cell morphology, proliferation, differentiation and mineralization.
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Qianli
authors.initials: Q
authors.lastname: Huang
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; Department of Ceramics, Inorganic Chemical Industries Division, National Research Centre, Dokki, 12622 Cairo, Egypt.
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Elkhooly
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
authors.forename: Xujie
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Ranran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Shen
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. Electronic address: biomater@mail.tsinghua.edu.cn.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Feng
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000502:physiology*; D006801:Humans; D049329:Nanostructures / Q000737:chemistry; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D014025:Titanium
keywords: Cellular response; Metallic implant; Micro/nano-topography; SaOS-2 cells