SURFACE CHARACTERIZATION OF BIOMEDICAL MATERIALS BY MEASUREMENT OF ELECTROOSMOSIS

This paper reviews recent studies by the authors on the surface charac terization of biomedically significant materials through electroosmosi s determination. The surfaces studied include transparent and nontrans parent materials such as quartz, ceramics, paper, and cast polymer cap illaries, slides, and particles, in both native and surface modified f orm. The method is nondestructive, relatively fast, mechanistically si mple, automatable to varying degrees, and can be used to analyze sampl es under physiologically compatible conditions. New experimental and m athematical modeling approaches allow estimates to be obtained with re gard to the surface density and pK of various chemical groups, as well as the thickness of polymer or other surface coatings. Surface modifi cations which may be characterized include, covalent alteration via ra diofrequency plasma discharge or organosilane grafting, noncovalent al teration via polymer adsorption, and covalent grafting of neutral poly mers, such as poly(ethylene glycol) or dextran. Results complement tho se from other surface analysis techniques, and correlate with physiolo gically significant phenomena such as protein adsorption. (C) 1998 Pub lished by Elsevier Science Ltd. All rights reserved.