Adsorption of rivanol onto nanocrystalline titania surface

Nanoscale oxide systems become the basis for research in the biotechnology field, medicine and environmental chemistry more frequently. Much attention is focused on titanium dioxide due to its low toxicity, stability of physicochemical parameters and high biocompatibility. It is known that titanium is a fairly inert material and has the ability to bind to bone tissue. It can be used for the manufacture of medical implants, the surface of which in the body is completely covered with a layer of its dioxide. This layer contacts and interacts with biological liquids directly, in which various biologically active substances may be present. In addition, understanding the nature of such interaction is very important issue, because it includes the formation of bonds of different nature between groups of biomolecules and surface functional groups of solids. Also, the issue of creation of potential carriers of biologically active substances that would be safe, biocompatible, stable and effective in the development of new therapeutic drugs is always relevant. Diamino derivatives of acridine are widely used for the treatment of wounds, skin and mucous membranes in various types of infections due to the antimicrobial, antiviral and antibacterial properties. The aim of this work was be to study the adsorption of rivanol, which is one of the diamino derivatives of acridine, on the surface of nanocrystalline titanium dioxide and elucidate qualitative characteristics of such interaction. The dependence of the stability constant of the surface complex TiO2-rivanol from the value of the ionic strength of the solution confirming the electrostatic nature of the interaction in the studied system was shoun based on the experimental dependences of rivanol adsorption on pH and ionic strength of the solution established by GRFIT program using Stern complexation models. According to the thermodynamic characteristics calculated on the basis of the effect of rivanol adsorption on its initial concentration in solution, the adsorption process is spontaneous for the studied system, has a favorable character on the surface of this sorbent and is carried out by the ion-exchange mechanism. The formation of a stable surface complex in the studied system indicates the prospects for using nanocrystalline titanium dioxide as a material for the creation of new therapeutic agents, where it can serve as a carrier of biologically active substances.