TY - JOUR T1 - Inherently fluorescent and porous zirconia colloids: preparation, characterization and drug adsorption studies JF - J. Mater. Chem. B Y1 - 2015 A1 - Naszályi Nagy, Lívia A1 - Mihály, Judith A1 - Polyák, András A1 - Debreczeni, Balázs A1 - Császár, Barbara A1 - Szigyártó, Imola Csilla A1 - András Wacha A1 - Czégény, Zsuzsanna A1 - Jakab, Emma A1 - Klébert, Szilvia A1 - Drotár, Eszter A1 - Dabasi, G A1 - Bóta, Attila A1 - Balogh, Lajos A1 - Kiss, Éva KW - peer-reviewed AB - Porous, fluorescent zirconia particles of nearly 380 nm diameter were prepared without template molecules or labeling dyes. The porous structure is the result of aggregation-induced particle formation. The inherent fluorescence is assigned to coordinatively unsaturated Zr4+ ions at the sol–{}gel derived ZrO2 surface. After physico-chemical characterization of the native zirconia particles carboxyl and/or amine bearing drug molecules (D,L-\ensuremath{\alpha}-difluoromethylornithine –{} DFMO, ursolic acid –{} UA and doxorubicin –{} DOX) were adsorbed onto their surface, and the products were analyzed with Fourier-transform infrared spectroscopy (FTIR), thermogravimetry (TG), small-angle X-ray scattering (SAXS), fluorimetry and zeta potential vs. pH measurements. We have found that DOX complexes coordinatively unsaturated Zr4+ ions without dislocating them, while carboxyl-bearing drugs interact with basic surface Zr–{}OH sites eliminating some of the carbonate species. The adsorption of UA at the zirconia surface shifts considerably the isoelectric point of the surface and thus provides kinetic stability to the particles at physiological pH. An in vivo biodistribution study in two healthy dogs performed by SPECT/CT detection after 99mTc labeling of the nanocarriers has shown the possibility of drug delivery application. VL - 3 ER -