The principal possibility for preparing tritiated hyaluronic acid by the thermal activation method is demonstrated. The influence exerted by the conditions of preparing substances and the conduction of the isotope exchange reaction on the specific activity of the labeled product and the uniformity of tritium distribution among the molecules with different molecular weights is determined. It is shown that under mild experimental conditions and double dialysis purification of the samples (before and after the introduction of tritium), tritium-labeled hyaluronic acid with a specific activity of 26–52 GBq/g can be obtained without significant changes in the molecular weight distribution.

Nanodiamond-chitosan composites of definite composition were prepared to modify heart valve biological prostheses materials. The final material is characterized by higher failure stress and Young modules. Moreover, primary modification of nanodiamonds with chitosan provides an additional strength to collagen-based final material.

Adsorption of alkyltrimethylammonium bromides (DTAB, TTAB and CTAB) on detonation nanodiamonds was studied. Nanodiamonds of positive and negative zeta potentials in aqueous suspensions were used. The amount of the compound on nanodiamond surface was determined using tritium labeled surfactants. Our results suggested the same mechanism of the adsorption complex formation for nanodiamonds of total positive and negative charge.

Chitosan adsorption complexes were obtained with nanodiamonds possess negative as well as positive zeta-potential in the aqueous suspensions. The application of tritium labeled chitosan allowed the determination of its surface concentration on the nanomaterial and the construction of the adsorption isotherm in the chitosan concentration range from 0.02 to 1 mg/ml. Premodification of nanodiamonds with cationic surfactant suggests mainly electrostatic interactions between chitosan and the surface.

The adsorption of amikacin on the surface of detonation nanodiamonds was revealed as proceeding via the Coulomb or donor–acceptor interactions depending on the functional composition of the nanodiamond surface. In the case of nanodiamonds with carboxyl groups on their surface, the complexes were formed through the Coulomb interactions, while the donor–acceptor mechanism was realized in the presence of nitrate ions on the surface.