1. Response of Dental Pulp and Osteoblast Cells to Substrate Morphology for Applications in Dental Reconstruction G. Chen1 , M. Kennedy1 , D. Dean2 1 School of Materials Science and Engineering, Clemson University 2 Department of BioEngineering, Clemson University 2/8/2011
5. They are very similar in differentiation and protein expression.Optical image of human osteoblast cells (Saos-2 ) Image is from ATCC. http://www.atcc.org/Attachments/1995.jpg
6. Previous Studies on Cell Response to Micropatterns [1]Walboomers, X.F., Ginsel, L.A., Jansen, J.A. Early spreading events of fibroblasts on micro grooved substrates. J. Biomed. Mater. Res. 2000, 51, 529. [2]M. Winkelmanna, J. Goldb, R. Hauertc, B. Kasemob, N.D. Spencera, D.M. Brunetted, M. Textor . Chemically patterned, metal oxide based surfaces produced by photolithographic techniques for studying protein– and cell–surface interactions I: Micro fabrication and surface characterization. Biomaterials 24, 2003, 1133–1145. [3]Matthew J. Dalby, Mathis O. Riehle, Stephen J. Yarwood, Chris D.W. Wilkinson, Adam S.G. Curtisa. Nucleus alignment and cell signaling in fibroblasts: response to a micro-grooved topography. Experimental Cell Research, 2003, 284. [4]Schmidt JA, von Recum AF. Texturing of polymer surfaces at the cellular level. Biomaterials 1991; 12: 385-9.
7. Previous Studies on Cell Response to Chemistry [1]M. Andreiotelli, et al., "Are ceramic implants a viable alternative to titanium implants? A systematic literature review," 2009, pp. 32-47. [2]I. Abrahamsson and G. Cardaropoli, "Peri-implant hard and soft tissue integration to dental implants made of titanium and gold," Clinical Oral Implants Research, vol. 18, pp. 269-274, Jun 2007. [3]J. C. Setcos, et al., "The safety of nickel containing dental alloys," Dental Materials, vol. 22, pp. 1163-1168, Dec 2006. [4}A. C. L. Faria, et al., "In vitro cytotoxicity of dental alloys and cpTi obtained by casting," Journal of Biomedical Materials Research Part B-Applied Biomaterials, vol. 85B, pp. 504-508, May 2008. [5] H. X. Cheng, et al., "Effects of Surface Palladium/Ferrum Film on the Biocompatibility of 316L Stainless Steel," Rare Metal Materials and Engineering, vol. 37, pp. 2037-2040, Nov 2008. [6]K. Anselme and M. Bigerelle, "Effect of a gold-palladium coating on the long-term adhesion of human osteoblasts on biocompatible metallic materials," 2006, pp. 6325-6330. [7]A. Celebic, et al., “Ion release from gold/platinum dental alloy: could release of other elements be accountable in the contact allergy attributed to the gold?,” Journal of Materials Science-Materials in Medicine, vol. 17, pp. 301-305, Apr 2006.
9. Experimental Overview: Design Micropatterns Masks Culture Osteoblasts and Dental Pulp Cells Create Micropatterns and Characterize them with profilometer, AFM, EDAX Deposit Osteoblasts Deposit Dental Pulp Cells and track cell response.
10. Masks Design The masks were design by ICWIN program. Four masks were designed with feature size of 5 um, 10 um, 25 um and 50 um. Ordered from University of Minnesota.
11. Fabrication of Micropatterns and plating cells (a) 3 inch (100) silicon wafer (e) Applying amino group on top (b) Wafer with sputtered Au film (f)Culture osteoblast and dental pulp cells (c)Etch surface by photolithography Silicon wafer Gold film Amino group Cell (d) Sputter a 2nd layer of Au
12. Substrate matrix : Hexagon : Dot : Line : Hole Feature size: Diameter and width
13. AFM Image of Patterns Hole, 25 um Hexagon, 50 um Dot, 5 um Line, 10 um
14. Results: Film Thickness Parameters: RF power: 260 V Argon: 0.150 mmp Pressure: 1 *10-6torr Sputtering system in Kennedy’s lab
17. T.Y. Zhang, ect. Measurements of residual stresses in thin films deposited on silicon wafers by indentation fracture. Acta material, 1999, Vol. 47., No. 14, pp. 3869-3878.
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19. Actual Feature Size Green area Deflection (real size/target size)> 5%. Others are <5 %. Made the patterns we aimed for.
20. Surface roughness Roughness of Au Film increases with film thickness.
21. Surface Roughness vs. Scan Area film thickness/nm Matches results seen from other groups.
22. AFM Image of surface roughness 528 nm thick film. Height range: 50 nm 960 nm thick film. Height range: 50 nm Surface became rougher
23. Characterization of Au Grain Size Grain size was calculated by line- cross section method. (ASTM, E112 – 96 (Reapproved 2004)). 5 pictures for each sample were chosen. Grain Size increases with film thickness.
24. Surface change after applying amino group Purpose: Amino group lies between cells and patterns. Will it change morphology of patterns?
25. Characterization of Surface Morphology before and after applying amino group Holes, 25 um before applying amino group after applying amino group Surface morphology didn’t change much with amino group application.
26. Characterization of Surface Morphology before and after applying amino group Hexagon, 50 um before applying amino group after applying amino group Surface morphology didn’t change much with amino group application.
27. Cell culture Process Media: consists of MEM alpha (dipeptide L-Alanyl-L-Glutamine), pen/strep (Penicillin- Streptomycin), and FBS (Fetal bovine serum). DPBS: Dulbecco's Phosphate Buffered Saline
28. Initial Results of Plating Cells 100 um 100 um Fluorescence image of osteoblast vicilin and nuclei Fluorescence image of osteoblast vicilin Fluorescence image of osteoblast nuclei Au films with micropatterns are non- cytotoxic.
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Hinweis der Redaktion
Change the back ground to simple.Add two images on the first slide…. Patterns and cell.
Add applications for objective. That is why it is important. Details on slides about overviewDelete some results, like chemistry, roughness and cell alignment, proliferation and whole discussion part
Orange boxes are this presentation’s topic
Schematically show the process and give objective of this study. Title is not proper. Preparing sample?
Show the film thicknesses, feature size and shapes.
Picture of sputtering system, process parameters onto slide…..
Finish defining constants and symbols used in equations.Get rid of mean and standard deviation. Just say that you measured six times.
Look up papers on film thickness and stress… should we be seeing this?Overall, there’s no common agreement on trend between film thickness and residual stress.In Brennan’s study, film thickness ranges from 0.79 um to 2.54 um. The results show that residual stress decreases with increasing film thickness. However, the differences are not distinguished [1]In another study, where the thickness was range from 36.5 nm to 84.5 nm, it is really hard to tell the trend in stress changing with film thickness. [2] Possible mechanism:roughness and tensile stress; rougher surfaces generate higher tensile stress due to the propensity for in-plane contact between neighboring grain surfaces. Doljack and Hoffman considered the stress developed when newly deposited grains are attracted to one another during deposition, causing grain coalescence or “zipping” of the grain boundaries. I haven't written them in the article as more tests are needed to investigate exact mechanism behind the results.[1] S. Brennan, ect. X-ray measurements of the depth dependence of stress in gold films. Physica B. 2000, pp. 125-129.[2] GregerThornell, ect. Residual stress in sputtered gold films on quarts measured by the cantilever beam deflection technique. IEEE transactions on ultrasonics, perroelectrus, and frequency control, 1999, Vol. 46, No.4
Put instrument that you used to determine the film roughness. Also how you did the measurements.
Fix scans
InsertaFM slide… how it works and how you will use it (tapping and contact mode)
