Protein Adsorption to HEMA/EMA Copolymers Studied by Integrated Optical Techniques
✍ Scribed by D.S. Walker; M.D. Garrison; W.M. Reichert
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 547 KB
- Volume
- 157
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
Adsorption of chromophore-labeled bovine serum albumin (BSA) to homopolymers and copolymers of hydroxyethyl methacrylate (HEMA) and ethyl methacrylate (EMA) was measured using integrated optical waveguide attenuated total reflection (IOW-ATR) spectrometry. In IOW-ATR, the intrinsic propagation loss of the waveguide, usually on the order of (1 \mathrm{~dB}) / (\mathrm{cm}), is increased by the adsorption of a chromophoric molecule to the waveguide/solution interface. Measuring the difference in propagation losses before and after protein adsorption allows one to calculate the amount of protein adsorption (e.g., (\mathrm{ng} / \mathrm{cm}^{2}) ) directly from the Beer-Lambert law without calibration. Adsorbed amounts ranged from (35 \pm 2) to (684 \pm 55 \mathrm{ng} / \mathrm{cm}^{2}) for the HEMA and EMA homopolymers, respectively. Radiolabeling experiments of ({ }^{125}) I-BSA adsorption to the HEMA/EMA polymers performed in tandem correlated strongly with the IOWATR results (\left(R^{2}=0.934\right)). Except for the EMA homopolymer, both techniques showed BSA surface densities that increased linearly with decreasing mol% HEMA of the polymer. (1993 Academic Press, Inc.