Abstract
Proteins are known to readily adsorb to glass surfaces, although the nature of this interaction is not fully understood. The adsorption of human serum albumin (HSA) to a series of soda lime silicate (SLS) glass microspheres of varied composition was investigated using sodiumdodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), a sensitive protein characterization technique commonly employed by molecular biologists. The HSA adsorption capacity increased as CaO was substituted for Na2O into SLS glass microspheres containing 70 and 80 mol% SiO2. This increase was attributed to an electrostatic attraction between the negatively charged HSA protein and positive charges introduced into the glass surface. An abrupt decrease in HSA adsorption capacity was observed for SLS glass microspheres containing 60 mol% silica, possibly due to an alternate conformation of adsorbed HSA.
