Nanofiber structure with immobilized organic substance and the method of its preparation

Abstract

The invention concerns a nanofiber structure with immobilized organic agens that consists of silica nanofibers whose surface was modified with aminoaikyialkoxysilane and of subsequently immobilized organic agens. The invention also concerns a method of preparation of the nanofiber structure with immobilized organic agens, while silica nanofibers are prepared by electrostatic spinning from the initial sol synthesized by a sol-gel method from tetraalkoxysilane, heat-treated and their the surface modified by a solution of aminoaikyialkoxysilane and organic agens is then immobilized on the modified surface of the nanofibers.

1 . A nanofibrous structure with immobilized organic substance composed of pure silica nanofibres made by electrostatic spinning, the nanofibers have controlled dissolution in body fluids or in bioreactor and have surface modified by aminoalkylalkoxysilane with subsequently immobilized organic agent substances. 
     
     
         2 . The method of production of nanofibrous structure with immobilized organic substance, wherein, from the initial sol synthesized by the sol-gel method from tetraalkoxysilane by means of electrostatic spinning the pure silica nanofibres are created, which are subsequently heat treated for controlled dissolution in body fluids or in bioreactor and then surface of nanofibres is modified by means of solution of aminoalkylalkoxysilane, after which to such modified surface of nanofibres the organic substances are immobilized. 
     
     
         3 . The method according to the  claim 2 , wherein the initial sol is prepared by the sol-gel method form solution of tetraalkoxysilane in alcohol with addition of water upon an acid catalysis by controlled hydrolysis and polycondensation and by thickening through distilling-off the solvent to a viscosity necessary for electrostatic spinning. 
     
     
         4 . The method according to the  claim 3 , wherein the alcohol is ethanol or isopropylalcohol, an acid catalysis of hydrolysis and polycondensation of tetraalkoxysilane is ensured by addition of inorganic or organic acid, the initial molecular ratio of water to tetraalkoxysilane k=[H 2 O]/[tetraalkoxysilane] is within values k=1.6 to 3, molecular ratio of an acid to tetraalkoxysilane m=[HA]/[tetraalkoxysilane] is within values m=0.001 to 1 and the sol before spinning is thickened by evaporation of the solvent to the content of SiO 2  in the sol to be within values 28 to 44% by weight. 
     
     
         5 . The method according to the  claim 4 , wherein the tetraalkoxysilane is tetraethoxysilane and the acid is hydrochloric acid or nitric acid. 
     
     
         6 . The method according to the  claim 2 , wherein through the electrostatic spinning purely silica nanofibres having mean diameter 100 to 1000 nm are prepared, which are then heat treated within temperature 30 to 900° C. for a period of 10 minutes to 10 hours. 
     
     
         7 . The method according to the  claim 6 , wherein the pure silica nanofibres are heat treated at a temperature within 150° C. to 250° C. for a period 1 to 3 hours. 
     
     
         8 . The method according to the  claim 2 , wherein the solution of aminoalkylalkoxysilane is in water, alcohol or other organic solvent and it has concentration of 0.1 to 10% by weight. 
     
     
         9 . The method according to the  claim 8 , wherein the aminoalkylalkoxysilane is 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane. 
     
     
         10 . The method according to the  claim 2 , wherein the organic agent substance is immobilized to the modified surface of nanofibres in the liquid environment in a period of 30 seconds to 48 hours. 
     
     
         11 . The method according to the  claim 10 , wherein the liquid environment is water, aqueous solution of biochemical buffer, ethanol, isopropylalcohol or acetone and immobilization time varies from 3 minutes to 24 hours.