ABSTRACT
Stainless steel 316 L material is commonly used for the production of coronary and peripheral vessel stents. Effective biofunctionalization is a key to improving the performance and safety of the stents after implantation. This paper reports the method for the immobilization of recombinant antibody fragments (scFv) on stainless steel 316 L to facilitate human endothelial progenitor cell (EPC) growth and thus improve cell viability of the implanted stents for cardiovascular applications. The modification of stent surface was conducted in three steps. First the stent surface was coated with titania based coating to increase the density of hydroxyl groups for successful silanization. Then silanization with 3 aminopropyltriethoxysilane (APTS) was performed to provide the surface with amine groups which presence was verified using FTIR, XPS, and fluorescence microscopy. The maximum density of amine groups (4.8*10(-5) mol/cm(2)) on the surface was reached after reaction taking place in ethanol for 1 h at 60 °C and 0.04M APTS. On such prepared surface the glycosylated scFv were subsequently successfully immobilized. The influence of oxidation of scFv glycan moieties and the temperature on scFv coating were investigated. The fluorescence and confocal microscopy study indicated that the densest and most uniformly coated surface with scFv was obtained at 37 °C after oxidation of glycan chain. The results demonstrate that the scFv cannot be efficiently immobilized without prior aminosilanization of the surface. The effect of the chemical modification on the cell viability of EPC line 55.1 (HucPEC-55.1) was performed indicating that the modifications to the 316 L stainless steel are non-toxic to EPCs.
Subject(s)
Antibodies, Immobilized/chemistry , Coated Materials, Biocompatible/chemistry , Propylamines/chemistry , Silanes/chemistry , Single-Chain Antibodies/chemistry , Stainless Steel/chemistry , Stents , Cell Adhesion , Cell Line , Cell Proliferation , Endothelial Progenitor Cells/cytology , Humans , Materials Testing , Recombinant Proteins/chemistry , Surface PropertiesABSTRACT
Silica powders consisting of small spherical particles (50-200 nm) have been obtained by the sol-gel method. A suspension of such particles in the Krebs-Hanseleit solution has been introduced into the coronary circulation of a beating perfused rat heart. The influence of the suspension on the heart muscle and the coronary vessels in the rat body has been histopathologically examined. The particles have not left the lumen of the vessels and have not caused any side effects. These observations suggest the possibility of using such silica particles as a carrier for selected drugs.
