An effective method for quantitative evaluation of proteins adsorbed on biomaterial surfaces

Abstract

An effective method for the quantitative evaluation of proteins adsorbed on biomaterial surfaces has been developed. First, the kinetic behavior of a range of human fibrinogen (Fib) adsorbed onto polystyrene (PS) films was investigated by using a reflectometry interference spectroscopy setup. The specific molecular number of adsorbed proteins, N(p,) was then defined. According to the definition, the numbers of Fib molecules adsorbed on PS films were calculated. An atomic force microscope (AFM) was used to scan the lateral distribution of the Fib molecules adsorbed on the PS films. From the AFM images, the practical specific molecular numbers were obtained by direct counting of the molecules. In order that the adsorbed number of Fib molecules on a unit area of the PS films could be counted easily, the solution concentration of proteins was reduced to 5 ag/mL (10(-18)g/mL). There was good consistency between the numbers calculated with the formula defined by us and the numbers counted from AFM images. Therefore, the results of the present study prove the validity of our definition of the specific molecular number of adsorbed proteins and the effectiveness of the reflectometry interference spectroscopy-based method for quantitative evaluation of adsorptive proteins.

Interaction of Human Plasma Fibrinogen with Commercially Pure Titanium as Studied with Atomic Force Microscopy and X-ray Photoelectron Spectroscopy

“…A cascade of events occurs on the surface of a biomaterial when it is implanted in the human body. Proteins adsorb within seconds onto it, followed by cells interacting with the earlier adsorbed proteins rather than with the surface of the implant itself. − The adsorption of proteins in this early stage influences strongly the biocompatibility of a material. , …”

Real-time label-free detection of complement activation products in human serum by white light reflectance spectroscopy

“…In RIfS, detection involves monitoring the changes in the reflectance pattern of a white light beam on a thin transparent film that occur as a result of changes in optical thickness caused by interfacial molecular reactions (Hänel and Gauglitz, 2002; Lü et al, 2003; Spaeth et al, 1997). Recently, we described a methodology for monitoring biomolecular interactions that is based on white light reflectance spectroscopy (Zavali et al, 2006).…”