Nanostructured calcium phosphate coatings on magnesium alloys: characterization and cytocompatibility with mesenchymal stem cells
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This article reports the deposition and characterization of nanostructured calcium phosphate (nCaP) on magnesium–yttrium alloy substrates and their cytocompatibility with bone marrow derived mesenchymal stem cells (BMSCs). The nCaP coatings were deposited on magnesium and magnesium–yttrium alloy substrates using proprietary transonic particle acceleration process for the dual purposes of modulating substrate degradation and BMSC adhesion. Surface morphology and feature size were analyzed using scanning electron microscopy and quantitative image analysis tools. Surface elemental compositions and phases were analyzed using energy dispersive X-ray spectroscopy and X-ray diffraction, respectively. The deposited nCaP coatings showed a homogeneous particulate surface with the dominant feature size of 200–500 nm in the long axis and 100–300 nm in the short axis, and a Ca/P atomic ratio of 1.5–1.6. Hydroxyapatite was the major phase identified in the nCaP coatings. The modulatory effects of nCaP coatings on the sample degradation and BMSC behaviors were dependent on the substrate composition and surface conditions. The direct culture of BMSCs in vitro indicated that multiple factors, including surface composition and topography, and the degradation-induced changes in media composition, influenced cell adhesion directly on the sample surface, and indirect adhesion surrounding the sample in the same culture. The alkaline pH, the indicator of Mg degradation, played a role in BMSC adhesion and morphology, but not the sole factor. Additional studies are necessary to elucidate BMSC responses to each contributing factor.
KeywordsMass Gain Scanning Electron Micrographs Image Standard Cell Culture Condition Dicalcium Phosphate Dihydrate Initial Seeding Density
The authors would like to thank the NSF BRIGE award (CBET 1125801), NIH/NIDCR SBIR award (6 R43 DE023287-02), and the University of California Regents Faculty Fellowship (H.L.) for financial support. We would also like to thank Dr. Krassimir Bozhilov at the Central Facility for Advanced Microscopy and Microanalysis (CFAMM) for the SEM training at the University of California, Riverside.
- 2.Reifenrath J, Bormann D, Meyer-Lindenberg A. Magnesium alloys as promising degradable implant materials in orthopedic research. In: Czerwinski F, editor. Magnesium alloys—corrosion and surface treatments. Rijeka: Intech; 2011. p. 94–108.Google Scholar
- 35.Webster TJ, Ahn ES. Nanostructured biomaterials for tissue engineering bone. Tissue engineering II: basics of tissue engineering and tissue applications. Berlin: Springer; 2007. p. 275–308.Google Scholar
- 40.Little MA, Kalkhoran NM, Aslani A, Tobin EJ, Burns JE. Process for depositing calcium phosphate therapeutic coatings with different release rates and a prosthesis coated via the process. Google Patents. 2011.Google Scholar
- 48.Lock J, Liu H. Nanomaterials enhance osteogenic differentiation of human mesenchymal stem cells similar to a short peptide of BMP-7. Int J Nanomedicine. 2011;6:2769–77.Google Scholar
- 51.Jager M, Zilkens C, Zanger K, Krauspe R. Significance of nano- and microtopography for cell-surface interactions in orthopaedic implants. J Biomed Biotechnol. 2007;8:69036.Google Scholar
- 54.Gayathri BPK. Macrophage and osteoblast response to micro and nano hydroxyapatite—a review. Nano Vis. 2011;1:1–53.Google Scholar