Heparin conjugated silica nanoparticle synthesis

We report on a facile method towards a synthesis of novel hybrid heparin silica nanoparticles involving a modification of the Stober method. Tetrapropyl orthosilicate (TPOS) was used instead of the traditional TEOS or TMOS: by this way we could overcome the solubility problems of heparin in ethanol and exploit the good solubility of heparin in proper isopropanol-water mixtures. Aminopropyl triethoxysilane (APTS) was also used to have a good link of heparin to silica particles. SEM. DLS, FTIR and NMR proved that we did find conditions in which heparin conjugated silica particles were produced. Thermogravimetry allowed to evaluate the heparin/silica weight ratio to be 0.61. The efficiency of heparin binding to the particles was appreciated to be 35 wt.%. (C) 2012 Elsevier B.V. All rights reserved.