N.B. Leonidov

Detonation diamond—A perspective carrier for drug delivery systems

Analysis of published and author’s own experimental data provides convincing evidence for the theoretical possibility to create drug delivery systems on the basis of detonation nanodiamonds and for the promise such systems hold for commercialization and practical application.

An approach to unification of the physicochemical properties of commercial detonation nanodiamonds

In recent years, detonation nanodiamond is regarded as a promising material for biomedical applications. However, a significant problem that stops of intensive development of this area is a absence of commercial NDs standardization. This article presents the results of the study of physicochemical properties of several industrial nanodiamonds available in the international market. The differences of physicochemical characteristics of nanodiamonds produced, selected and purified in various ways are shown. A method is developed for industrial processing of nanodiamonds, that represents high-temperature hydrogenation of diamond surface and allows to unify their properties. It is shown that after these processing nanodiamonds have the same surface chemistry and can form stable hydrosols. The proposed method of industrial nanodiamonds unification can become a universal method of its standardization.

Immobilization of inorganic pyrophosphatase on nanodiamond particles retaining its high enzymatic activity

Nanodiamond (ND) particles are popular platforms for the immobilization of molecular species. In the present research, enzyme Escherichia coli inorganic pyrophosphatase (PPase) was immobilized on detonation ND through covalent or noncovalent bonding and its enzymatic activity was characterized. Factors affecting adsorption of PPase such as ND size and surface chemistry were studied. The obtained material is a submicron size association of ND particles and protein molecules in approximately equal amounts. Both covalently and noncovalently immobilized PPase retains a significant enzymatic activity (up to 95% of its soluble form) as well as thermostability. The obtained hybrid material has a very high enzyme loading capacity (∼1 mg mg(-1)) and may be considered as a promising delivery system of biologically active proteinaceous substances, particularly in the treatment of diseases such as calcium pyrophosphate crystal deposition disease and related pathologies. They can also be used as recoverable heterogeneous catalysts in the traditional uses of PPase.

Obtaining Tritium-Labeled Amikacin and Its Adsorption Immobilization on Functionalized Nanodiamonds

The effect of the chemical nature of the surface of detonation nanodiamond on the adsorption of an antibiotic is revealed with the help of tritium-labeled amikacin. It is found that nanodiamonds with a carboxylated surface (Ssp = 283 ± 5 m2/g) chemisorbed twice as much amikacin as nanodiamonds with a hydrogenated surface (Ssp = 289 ± 5 m2/g): 48 and 22 mg/g, respectively. Maintaining nanodiamonds with immobilized amikacin in the form of hydrosol for 1 month results in a release of up to 9.6 and 6.4 mg/g of the antibiotic, respectively. The results demonstrate the possibility of creating an amikacin delivery system based on nanodiamonds.