title: Biocompatibility of atomic layer-deposited alumina thin films.
abstract: Presented in this paper is a study of the biocompatibility of an atomic layer-deposited (ALD) alumina (Al2O3) thin film and an ALD hydrophobic coating on standard glass cover slips. The pure ALD alumina coating exhibited a water contact angle of 55 degrees +/- 5 degrees attributed, in part, to a high concentration of -OH groups on the surface. In contrast, the hydrophobic coating (tridecafluoro-1,1,2,2-tetrahydro-octyl-methyl-bis(dimethylamino)silane) had a water contact angle of 108 degrees +/- 2 degrees. Observations using differential interference contrast microscopy on human coronary artery smooth muscle cells showed normal cell proliferation on both the ALD alumina and hydrophobic coatings when compared to cells grown on control substrates. These observations suggested good biocompatibility over a period of 7 days in vitro. Using a colorimetric assay technique to assess cell viability, the cellular response between the three substrates can be differentiated to show that the ALD alumina coating is more biocompatible and that the hydrophobic coating is less biocompatible when compared to the control. These results suggest that patterning a substrate with hydrophilic and hydrophobic groups can control cell growth. This patterning can further enhance the known advantages of ALD alumina, such as conformality and excellent dielectric properties for bio-micro electro mechanical systems (Bio-MEMS) in sensors, actuators, and microfluidics devices.
authors: National Institute of Standards and Technology, Materials Reliability Division (853), 325 Broadway, Boulder, Colorado 80305-3328, USA. dfinch@mse.vt.edu
authors: Dudley S
authors: DS
authors: Finch
authors: Tammy
authors: T
authors: Oreskovic
authors: Krishna
authors: K
authors: Ramadurai
authors: Cari F
authors: CF
authors: Herrmann
authors: Steven M
authors: SM
authors: George
authors: Roop L
authors: RL
authors: Mahajan
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D002448:Cell Adhesion; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D005898:Glass / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D008857:Microscopy, Interference; D032389:Myocytes, Smooth Muscle / Q000166:cytology
chemical_list: D020099:Coated Materials, Biocompatible; D000537:Aluminum Oxide