Use of a fluorescence method for probing protein adsorption to the surface of intraocular lenses

Abstract

~u~onAdsorption of proteins is the primary reaction of blood and other biological fluids brought into contact with medical materials or devices. This explains the considerable interest in mechanisms of biological compatibility of foreign surfaces at the 9 stage of protein adsorption and in the search for adsorption criteria of biocompatibility of medical materials or devices /n vitro [2]. The interaction of proteins with various surfaces of medical devices (films, plates, tubes, etc.) is presently extensively studied by various physical and chemical methods (radionuclides, infrared spectroscopy, fluorescence spectroscopy, ellipsometry, atomic force microscopy, etc.). However, biocompatibility of a given device depends not only on chemical structure of its materials, but also on its design and manufacturing technology. In addition, functional conditions (duration of exposure to biological tissues, place of location, composition of surrounding medium, etc.) also affect the biocompatibility of the device [3].The type of protein adsorption plays a very important role in biocompatibility and functional properties of intraocular lenses (IOL) made of polymethylmetacrylate (PMMA), polyorganosiloxanes (silicon), and polyhydroxyethylmetacrylate (p-HEMA) [5]. In contrast to blood, intraocular fluid is virtually free of ceils. Therefore, proteins (albumin, a-globulin, E-globulin, and 7-globulin) are major components of the biological medium that determine a patient's reaction to implanted IOL. In addition to the amount of adsorbed protein, the possibility of conformational changes of proteins (including immunoglobulins C1 and (23) should also be taken into consideration. This is of particular importance because immunoglobulins C1 and C3 are responsible for activation of the complement system by the classical and alternative mechanisms, respectively [2, 51. Interaction between implant and protein components of intraocular fluid has a substantial effect on the exudative reaction of the eye during the early postoperative period, the intensity of cellular and pigment deposition on the IOL surface, and the state of corneal endothelial cells during the remote postoperative period.It was shown in [1, 4] that the fluorescence method of total internal reflection (FTIR) can be used for studying the kinetics of adsorption of blood plasma proteins (albumin, 7-globulin, fibrinogen) from solution to the surface of polymer and quartz films.The goal of this work was to use the FFIR method for studying adsorption and desorption of proteins at the IOL surface. Materials and MethodsFour types of IOL manufactured at the Scientific Experimental Works Eye Microsurgery, Ltd. were used: -serially produced IOL made of PMMA; -laboratory prototype IOL samples made of silicon composite material SIEL-Med with additionally treated surface; -laboratory prototype hydrogel IOL samples made of p-HEM.A;

Albumin adsorption onto surfaces of urine collection and analysis containers

“…Investigators have used both chemical and physical methods including radioisotopes [2], atomic force microscopy [3], fluorescence and infrared spectroscopy [4], and ellipsometry [5] to study the interactions of proteins with surfaces. Many have studied albumin adsorption in search of promising materials for use in implantable medical devices, but the albumin concentrations used in these studies approached the concentrations in human serum or plasma, which are considerably greater than those in urine.…”