Creating cellular and molecular patterns via gravitational force with liquid droplets

Applied Physics Letters

Volumn 93, Issue 17, 2008, Pages

  Cheng, Chao Min ^a   LeDuc, Philip R ^a  

^a CARNEGIE MELLON UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CONCURRENT ENGINEERING; DROP FORMATION; DROPS; GRAVITATION; JOB ANALYSIS; RAPID PROTOTYPING; SILICONES;

COST PRODUCTIONS; GRAVITATIONAL FORCES; LIQUID DROPLETS; MOLECULAR PATTERNS;

SURFACE TOPOGRAPHY;

EID: 55149097492     PISSN: 00036951     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.3006058     Document Type: Article

References (22)

1. R. Langer and J. P. Vacanti, Science 0036-8075 10.1126/science.8493529 260, 920 (1993).
2. D. T. Chiu, N. L. Jeon, S. Huang, R. S. Kane, C. J. Wargo, I. S. Choi, D. E. Ingber, and G. M. Whitesides, Proc. Natl. Acad. Sci. U.S.A. 0027-8424 10.1073/pnas.040562297 97, 2408 (2000).
3. S. W. Rhee, A. M. Taylor, C. H. Tu, D. H. Cribbs, C. W. Cotman, and N. L. Jeon, Lab Chip 1473-0197 10.1039/b403091e 5, 102 (2005).
4. W. Tan and T. A. Desai, Tissue Eng. 1076-3279 10.1089/107632703764664729 9, 255 (2003).
5. C. J. Flaim, S. Chien, and S. N. Bhatia, Nat. Methods 2, 119 (2005). 1548-7091
6. A. Tourovskaia, X. Figueroa-Masot, and A. Folch, Lab Chip 1473-0197 10.1039/b405719h 5, 14 (2005).
7. Y. Xia and G. M. Whitesides, Angew. Chem., Int. Ed. 1433-7851 10.1002/(SICI)1521-3773(19980316)37:5<550::AID-ANIE550>3.3.CO;2-7 37, 550 (1998).
8. R. J. Jackman, J. L. Wilbur, and G. M. Whitesides, Science 0036-8075 10.1126/science.7624795 269, 664 (1995).
9. C. M. Cheng and P. R. LeDuc, J. Am. Chem. Soc. 129, 9546 (2007).
10. C. M. Cheng and P. R. LeDuc, J. Am. Chem. Soc. 128, 12080 (2006).
11. L. J. Guo, Adv. Mater. (Weinheim, Ger.) 0935-9648 10.1002/adma.200600882 19, 495 (2007).
12. R. A. Venkateswar, D. W. Branch, and B. C. Wheeler, Biomed. Microdevices 2, 255 (2000). 1387-2176
13. S. M. Bhangale, V. Tjong, L. Wu, N. Yakovlev, and P. M. Moran, Adv. Mater. (Weinheim, Ger.) 0935-9648 10.1002/adma.200400547 17, 809 (2005).
14. Y. Zhang and C. Wang, Adv. Mater. (Weinheim, Ger.) 19, 913 (2007). 0935-9648
15. E. Ostuni, C. S. Chen, D. E. Ingber, and G. M. Whitesides, Langmuir 17, 2828 (2001). 0743-7463
16. This is a 10× solution that contains 500 mM KCl, 20 mM MgCl2, and 10 mM ATP.
17. Cell Culture. NIH 3T3 fibroblasts were washed once with PBS and then exposed to trypsin-ethylenediamine-tetraacetate for 5 min. After dissociation from the tissue culture plates, the cells were seeded on the pattern that we fabricated through the proposed method. The cells were cultured at 37 ° C under 5% carbon dioxide in Dulbecco's modified Eagle's medium that was supplemented with 10% calf serum, glutamine (0.3 mg/ml), streptomycin (100 μg/ml), penicillin (100 U/ml), and 20 mM N-2-hydroxyethylpiperazine- N′ 2 -ethanesulfonic acid at a pH of 7.4. After seeding, the cells were subsequently incubated for at least 6 h to allow attachment and spreading.
18. J. Kubicek, S. Brelsford, P. Ahluwalia, and P. R. LeDuc, Langmuir 20, 11552 (2004).
19. Due to the limitations of profile measurement systems, such as an atomic force microscope and our relatively large patterns, we analyzed the three-dimensional profile of a single pattern through the software "NIH IMAGEJ," which is in the public domain, from the National Institute of Health (software resource; http://rsbweb.nih.gov/ij/). This method might not provide the exact three-dimensional size of a single pattern but it allows for approximate size comparisons. M. B. Kiran, B. Ramamoorthy, and V. Radhakrishnan, Int. J. Mach. Tools Manuf. 0890-6955 10.1016/S0890-6955(97)00118-1 38, 685 (1998).
20. C. M. Cesa, N. KirchgeΒner, D. Mayer, U. S. Schwarz, B. Hoffmann, and R. Merkel, Rev. Sci. Instrum. 0034-6748 10.1063/1.2712870 78, 034301 (2007).
21. This buffer contains 5 mM tris-HCl (pH 0.8) and 0.2 mM CaCl2.
22. Actin filament preparation. We prepared filamentous actin in an ATP buffer (general actin buffer, from Cytoskeleton; No. BSA01) (Ref.) or PBS solution. This required several steps: (1) combine 1 ml of ATP buffer with 2 μl pure ATP (100 mM), (2) suspend G-actin to obtain a concentration of 0.4 mg/ml for 1 h at 24 °C, and (3) mix and incubate this solution for 1 h at 24 °C while adding 66 μl of ATP polymerization buffer (Ref.). Finally, we stained actin filaments using 6 μM Alexa Fluor 488 phalloidin (from Molecular Probes, No. A12379).