Morphopathological Effect of Ferrihydrite Nanoparticles in an Experimental Model of Toxic Hemolytic Anemia.

We studied the effect of biogenic ferrihydrite nanoparticles synthesized as a result of the culturing of Klebsiella oxytoca on Wistar rats with experimental toxic hemolytic anemia. The pathology was simulated by single intraperitoneal injection of phenylhydrazine hydrochloride. On day 4, the functional parameters of erythrocytes in rats corresponded to the state of toxic hemolytic anemia. It is shown that ferrihydrite nanoparticles suspension has chronic toxicity and causes morphological changes in organs (mainly in the spleen), which are characterized by accumulation of nanoparticles. Administration of phenylhydrazine induced systemic vascular damage and the formation of extramedullary hematopoietic foci, which indicated a compensatory activation in hematopoiesis in the liver and spleen. Injection of nanoparticles reduced discirculatory and necrotic changes in the kidneys.

Efficiency of Ampicillin-Associated Biogenic Ferrihydrite Nanoparticles in Combination with a Magnetic Field for Local Treatment of Burns.

We studied the effectiveness of using magnetic ferrihydrite nanoparticles of bacterial origin carrying ampicillin for local treatment of burn wounds in rats using a magnetic field. It was found that the use of these nanoparticles in combination with a magnetic field accelerated wound healing and reduced the titer of microorganisms in comparison with the corresponding parameters in the untreated animals and animals treated with nanoparticles or ampicillin alone.

Distribution of Ferrihydrite Nanoparticles in the Body and Possibility of Controlling Them in an Isolated Organ by a Permanent Magnetic Field.

We studied the distribution of ferrihydrite nanoparticles isolated from bacteria Klebsiella oxytoca in the whole body in vivo and in a cultured isolated organ (liver). The possibility of controlling these nanoparticles in the body using a magnetic field was assessed. One hour after intravenous injection of ferrihydrite nanoparticles to mice, their accumulation was observed in the liver, lungs, and kidneys. Experiment with cultured isolated rat liver showed that these nanoparticles can be controlled by a magnetic field and the influence of magnetic nanoparticles on the liver over 1 h does not lead to destruction of liver cells associated with the release of the marker enzyme AST. These results show the possibility of using magnetic nanoparticles as a system for controlled drug delivery in the body.

Elimination of iron-containing magnetic nanoparticles from the site of injection in mice: a magnetic-resonance imaging study.

Suspension of magnetic nanoparticles (0.7 g/liter) obtained from Klebsiella oxytoca culture was injected intraperitoneally (1 ml), intramuscularly (in the hip; 100 µl), and subcutaneously (200 µl) or administered orally instead of drinking water for 2 days. The presence of magnetic nanoparticles was evaluated detected by MRI in 15 min and 2 h after injections and in 1 and 2 days after the beginning of oral consumption of the suspension. Magnetic nanoparticles were eliminated from the site of intramuscular and intraperitoneal injections and after oral consumption. The period of elimination after intramuscular and intraperitoneal injections did not exceed 2 h, while after oral consumption it corresponded to the time of gastrointestinal tract contents evacuation.

A method for introduction of magnetic nanoparticles into tissues by means of magnetic field gradient: an experimental study.

Targeted effects of magnetic nanoparticles were studied. Solution with iron-containing nanosubstance was applied to resected nasal bone and cartilage tissues. Magnetic field was generated by a Polus-101 device for low-frequency magnetotherapy, which provided permanent work of one inductor (10.14+/-19.56 mT). The results indicate that magnetic nanoparticles placed into magnetic field gradient penetrate into the thickness of the cartilage and bone tissues.

[Experience with the use of magnetic nanoparticles in medicine and prospects for their application in otorhinolaringology].

The literature review of the methods for application of magnetic nanoparticles in different fields of medicine is presented. The paper summarizes the 40 year-long experience of Russian and foreign scientists with the use of magnetic suspensions, liquids, and particles with magnetic carriers from 10 to 1000 nm in diameter. Results of recent studies are presented, prospects for the development and application of nanomedical techniques in otorhinolaringology are discussed.

[Bacterial leaching of manganese ores].

Leaching of various types of ores, containing 12-30% manganese, by the thiobacterium Acidithiobacillus ferrooxidans was studied. Leaching of reduced ores (manganocalcite and manganiferous limestone) was mediated mainly by degradation of manganiferous minerals (by sulfuric acid produced in the course of bacterial oxidation of pyrite or sulfur). Bacterial treatment of the ores for 144 and 192 h allowed solubilization of 96-98% of manganese. Inoculation of bacteria into pulp with pyrite increased the rate of leaching of oxide ore (psilomelane) by 37%, and the degree of its extraction within 180 h increased from 80 to 97%.

[Characteristics of bacterioplankton in the Loess-containing Lake Khanka]. / Issledovanie kharakteristik bakterioplankton ozera Khanka v sviazi s lessovost'iu vodoema.

Some characteristics of bacterioplankton--generation time, daily (P) and specific (P/B) bacterioplankton production, and bacterial metabolic coefficient K2--in the loess-containing Lake Khanka were determined using five modifications of the bacterial-count procedure with the fluorescent dyes fluorescamin and erythrosin. Experiments showed that the organomineral complex (OMC) in this lake is broken down by chemoorganoheterotrophic bacteria. The increase in the loess content of the lake water intensified bacterial growth and the cycles of potassium, silicon, and other biogenic elements. The addition of starch to a loess suspension activated the breakdown of OMC due to the adsorption of starch on the OMC/water interface and stimulation of the metabolism of attached bacteria.

[Protist plankton from the Khanka lake]. / Protistoplankton ozera Khanka.

We present data on studies of protists in Lake Khanka in late August-early September. A total of 99 species of protists have been found, of them 14 phytoflagellates, 14 zooflagellates, five sarcodins, two heliozoans, 62 infusoria, and two suctorians. Small infusoria from the class of Kinetophragminophora, order Oligotrichida, as well as suborder Tetrahymenina were most numerous. The density of many protist species in Lake Khanka exceeds markedly that in several other high-productivity water reservoirs. Most of the protists belong to bacteriovores (bacteriophages). Many of the found species have high density. This is evidence of the production of bacterial plankton in the lake. In view of very high water turbidity in the lake, we assume that the total production of phytoplankton is not that high. In this connection, an abundance of protists (protist plankton) indicates is an indication for the existence of an additional source of organic matter in Lake Khanka.