Evaluation of the Stability of Nonfouling Ultrathin Poly(ethylene glycol) Films for Silicon-Based Microdevices
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- 作者：Sadhana Sharma ; Robert W. Johnson ; and Tejal A. Desai
- 刊名：Langmuir
- 出版年：2004
- 出版时间：January 20, 2004
- 年：2004
- 卷：20
- 期：2
- 页码：348 - 356
- 全文大小：1257K
- 年卷期：v.20,no.2(January 20, 2004)
- ISSN：1520-5827
文摘
The creation of nonfouling surfaces is one of the major prerequisites for microdevices for biomedical andanalytical applications. Poly(ethylene glycol) (PEG), a water soluble, nontoxic, and nonimmunogenic polymerhas the unique ability of reducing nonspecific protein adsorption and cell adhesion and, therefore, isgenerally coupled with a wide variety of surfaces to improve their biocompatibility. The performance ofthese modified surfaces for long-term biomedical applications largely depends on the stability of these PEGfilms. To this end, we have investigated the stability of covalently coupled ultrathin PEG films on siliconin aqueous in vivo like conditions for a period of 4 weeks. The PEG-modified silicon substrates wereincubated in PBS (37 
C, pH 7.4, 5% CO2) for different periods of time and then characterized using thetechniques of ellipsometry, contact angle measurement, X-ray photoelectron spectroscopy, and atomicforce microscopy. The ability of the PEG-modified surfaces to control protein fouling was examined byprotein adsorption studies using fluorescein isothiocyanate labeled bovine serum albumin and ellipsometry.Furthermore, the ability of these films to control fibroblast adhesion was examined. Studies suggest thatthe PEG-modified surfaces retain their protein and cell repulsive nature even though the PEG film thicknessdecreases for the period of investigation.
C, pH 7.4, 5% CO2) for different periods of time and then characterized using thetechniques of ellipsometry, contact angle measurement, X-ray photoelectron spectroscopy, and atomicforce microscopy. The ability of the PEG-modified surfaces to control protein fouling was examined byprotein adsorption studies using fluorescein isothiocyanate labeled bovine serum albumin and ellipsometry.Furthermore, the ability of these films to control fibroblast adhesion was examined. Studies suggest thatthe PEG-modified surfaces retain their protein and cell repulsive nature even though the PEG film thicknessdecreases for the period of investigation.