Properties of Langmuir and immobilized layers of betulin diphosphate on aqueous solutions of zinc sulfate and on the surface of zinc oxide nanoparticles

This work examines the specific features of interaction of betulin diphosphate (BDP), exhibiting antitumor and wound-healing properties, with zinc cations during its immobilization on ZnO nanoparticles. The properties of Langmuir and transferred BDP monolayers from an aqueous subphase of zinc sulfate onto the surface of a solid substrate (CaF 2 , quartz) by the Langmuir—Schaefer method are investigated using IR and UV spectroscopy. It is shown that there is a twofold increase of the molecular area in the immobilized layers, while the compressibility modulus decreases by a factor of 1.5. Zinc oxide nanoparticles with immobilized BDP 10–20 nm in size (surface concentration of BDP is 100 mg g −1 ) retain the original hexagonal wurtzite structure. The efficiency of betulin diphosphate immobilized on the surface of zinc oxide nanoparticles is demonstrated in in vivo experiments for burn wounds in rats.