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Bone Promoting Coatings

 

Combined Effect of Topography and Strontium on Mineralization

It has been established that the osteogenic expression and mineralization of bone-forming cells at surfaces of artificial materials depends on a number of cues including elastic modulus [1], chemistry [2], pattern shape [3] as well as topography at the nanometer [4, 5] and micrometer scale [6]. At iNANO, we have developed a topographical screening assay, which has already been able to provide further insight into the interaction between surface topographies and osteogenic differentiation [6, 7]. Furthermore, soluble factors may influence the differentiation as well. It has been shown both in vitro (data not published) and in vivo [8, 9] that Strontium (Sr) may guide mineralization. In this bachelor-project we will use a newly developed topographical array in combination with varying soluble SrCl2 to examine any synergistic effects between the topography and Sr as a soluble factor. The project will involve PVD deposition of Titanium, characterization by Scanning Electron Microscopy (SEM), chemical analysis by X-ray photoelectron spectroscopy (XPS) as well as analysis of osteogenic differentiation of human dental pulp stem cells (hDPSCs) by alizarin red staining. The ultimate goal is a better understanding of the bone ingrowth to orthopaedic implants.

 

1. Engler, A.J., et al., Matrix Elasticity Directs Stem Cell Lineage Specification. Cell, 2006. 126(4): p. 677-689.

2. Anderson, D.G., S. Levenberg, and R. Langer, Nanoliter-scale synthesis of arrayed biomaterials and application to human embryonic stem cells. Nature Biotechnology, 2004. 22: p. 863.

3. Kilian, K.A., et al., Geometric cues for directing the differentiation of mesenchymal stem cells. Proceedings of the National Academy of Sciences, 2010. 107(11): p. 4872-4877.

4. Park, J., et al., Nanosize and Vitality:  TiO2 Nanotube Diameter Directs Cell Fate. Nano Letters, 2007. 7(6): p. 1686-1691.

5. Dalby, M.J., N. Gadegaard, and R.O.C. Oreffo, Harnessing nanotopography and integrin-matrix interactions to influence stem cell fate. Nat Mater, 2014. 13(6): p. 558-569.

6. Kolind, K., et al., Control of proliferation and osteogenic differentiation of human dental-pulp-derived stem cells by distinct surface structures. Acta Biomaterialia, 2014. 10(2): p. 641-650.

7. Lovmand, J., et al., The use of combinatorial topographical libraries for the screening of enhanced osteogenic expression and mineralization. Biomaterials, 2009. 30(11): p. 2015-2022.

8. Andersen, O.Z., et al., Accelerated bone ingrowth by local delivery of strontium from surface functionalized titanium implants. Biomaterials, 2013. 34(24): p. 5883-5890.

9. Offermanns, V., et al., Enhanced osseointegration of endosseous implants by predictable sustained release properties of strontium. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2015. 103(5): p. 1099-1106.

If you’re interested in hearing more about this project, SPOMAN or want to hear about the possibilities for starting a collaboration, please contact us at stinek@inano.au.dk.