RU2460553C1 - Method of treating infected wounds in experiment - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely experimental medicine, surgery and aims at treating purulent wound in experiment. A method involves a pre-toilet, application of a dressing containing an iron nanoparticle suspension in the concentration of 0.1 mg/ml and a copper nanoparticle suspension in the concentration of 0.001 mg/ml in 0.9% normal saline prepared by plasma flow of temperature 5000-6000 K. Copper nanoparticle dispersion makes 30 nm, while iron nanoparticle dispersion is 70 nm.

EFFECT: along with simplified and cheaper treatment of purulent wounds, eliminated toxic action of the nanoparticles the method reduces time of elimination of contaminating agent substantially, provides wound sterility, faster wound regeneration and complete repair.

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Description

The invention relates to medicine and biology and is intended for the treatment of purulent wounds in an experiment.

A known method of treating nonhealing wounds in an experiment, comprising a combination of ozone and EHF-therapy, in which daily until complete healing, gaseous ozone is applied to the wound surface with a concentration of 5 mg / l at the outlet of the apparatus and a gas flow rate of 1 l / min for 30 min and locally irradiated with millimeter waves of the EHF range with a white noise spectrum in the frequency range 53.57-78.33 GHz for 20 min (RF patent No. 2349326, IPC A61K 33/00, A61N 5/02. Publ. March 20, 2009).

The disadvantages of this method include a narrow spectrum of effects of ozone and EHF-therapy, mainly on gram-positive microorganisms (staphylococcus, streptococcus); instability of ozone molecules, especially in the presence of a large number of organic components of necrotic wound detritus, toxicity of ozone when it enters the respiratory tract; the possibility of treating only superficial wounds, because deep wounds and fistulous passages cannot be treated in this way.

There is also a method of treating infected wounds in animals, including cleansing the skin from contamination, drying it and applying an alcohol solution of BF-8 glue to the skin, in which bromacide is added to the solution in a ratio of 100: 1, mixed, applied with a thin layer to form a film 2 thick -5 mm, and when the wound is completely healed, the film is removed (RF patent No. 2383333, IPC A61K 31/00. Publish. March 10, 2010).

However, this method is intended for the treatment of only small linear cuts, not complicated by a purulent-inflammatory process. Used drugs are toxic and not effective enough. In addition, in this method it is impossible to control the course of the wound process under the film, the development of maceration and anaerobic infection under the gas and waterproof film is not ruled out.

Closest to the proposed in its technical essence is a method of treating wounds with a wound dressing based on woven and non-woven materials of natural or synthetic origin, containing metal particles with biological activity in the pathogenic flora. As metal particles, the wound cover contains silver nanoparticles from 80 to 99.7%, iron from 0.1 to 20%, aluminum from 0.1 to 20%, copper from 0.1 to 20%, which are applied in a vacuum chamber with using magnetron sputtering. After the preliminary toilet of the wound (treatment with furatsilinom 1: 5000; 3% solution of hydrogen peroxide, chlorhexidine bigluconate), a bandage of the proposed material is applied to the surface of the wound or trophic ulcer. With a deep postoperative wound or in the presence of a fistula, a turunda is formed from a napkin, with which drainage is carried out. Dressings are changed daily, and in the postoperative period, in the presence of a blind suture, after 1-2 days (RF patent No. 2314834, IPC A61L 15/18, A61L 15/44, A61P 17/02, A61F 13/00. Publish. 20.01. 2008).

But this method is complicated and expensive due to the use of magnetron sputtering in a vacuum chamber when applying nanoparticles. In addition, it can have a general toxic effect due to high concentrations of iron and copper nanoparticles.

The problem to which the claimed invention is directed, is to simplify and reduce the cost of the treatment of purulent wounds, to eliminate the toxic effects of nanoparticles.

The technical result consists in increasing the effectiveness of the treatment of purulent wounds in the experiment.

The problem is solved in that in a method for treating infected wounds in an experiment, including a preliminary wound toilet, applying a dressing containing iron and copper nanoparticles, and changing dressings daily, a dressing is applied to the wound containing 0.9% sodium chloride in an isotonic solution (NaCl) suspension of iron nanoparticles at a concentration of 0.1 mg / ml and copper nanoparticles at a concentration of 0.001 mg / ml obtained by exposure to a plasma stream with a temperature of 5000-6000 K. The dispersion of copper nanoparticles is 30 nm, and the nanoparticles are jelly and - 70 nm.

Obtaining nanoparticles when exposed to a plasma stream simplifies and reduces the cost of the treatment of purulent wounds. And the selected concentration and dispersion of nanoparticles excludes their toxic effects.

The method is as follows.

First get a model of purulent wounds as follows. After pretreatment of the skin under aseptic conditions, under anesthesia, on the shaved area of the skin in the interscapular region of the rats, the skin with subcutaneous tissue is excised in the form of a square 2 × 2 cm (400 mm ² ) along the contour. The edges and bottom of the wound are crushed by Kocher clamp. A gauze swab is added to the wound with a suspension of the daily culture of a polyantibiotic-resistant clinical strain of Staphylococcus aureus at a dose of 2 billion microbial bodies in 1 ml of physiological solution. The wound in animals of the control and experimental groups is covered with a gauze dressing moistened with an isotonic solution, sealed with a plaster to prevent drying of the wound. In animals in the interscapular region, an abscess forms with all the characteristic signs of purulent inflammation: there is swelling and flushing of the skin in the area of the wound, swelling, pus is released in some animals. In order to prevent wound contraction, as well as for standardized treatment conditions, a metal frame corresponding to the size of the wound is hemmed to the edges of the wound.

Treatment begins with extraction of the infected gauze wipe, evacuation of pus, removal of necrotic tissue and washing the wound with a suspension of copper and iron nanoparticles in an isotonic solution. Sterile wipes moistened with a suspension of nanoparticles in concentrations are placed on the wound surface daily, for 14 days: iron - 0.1 mg / ml, copper - 0.001 mg / ml in an isotonic NaCl solution.

For a comprehensive assessment of the course of the wound healing process, methods of planimetric and bacteriological research of wounds were used, which were carried out on the 3rd, 5th, 7th, 10th and 14th days.

The following parameters of the course of the wound process were taken into account: the presence and nature of the inflammatory reaction, the condition of the edges and bottom of the wound, the timing of cleansing the wound from necrotic tissues and the appearance of granulations, the nature of granulation tissue, the timing of the onset of wound epithelization. To study the rate of wound healing by secondary intention, we used the planimetric method of L.N. Popova, based on recording the rate of reduction of the wound surface over time. The percentage reduction in wound area per day was determined by the formula

,

,

where: S is the area of the wound in the previous measurement;

S _n is the area of the wound in the subsequent measurement;

t is the number of days between the previous and subsequent measurements.

Table 1 shows the change in the area of the purulent wound in experimental animals under the influence of a suspension of iron nanoparticles, copper nanoparticles, a suspension of iron and copper nanoparticles compared with the control group of animals.

The table shows that a more rapid decrease in the area of the wound, as well as complete healing of the wound, is observed by the 10th day after treatment with a mixture of suspended nanoparticles of iron and copper compared to the control group and groups in which iron and copper nanoparticles were used in isolation.

Table 1 The area of the wound in experimental animals infected with Staphylococcus aureus during treatment, mm ² (M ± m) Day Groups of animals 1st (control) group, n = 10 2nd (experimental) group, n = 10 3rd (experimental) group, n = 10 4th (experimental) group, n = 10 The use of isotonic solution The use of iron nanoparticles (0.1 mg / ml) The use of copper nanoparticles (0.001 mg / ml) The combined use of iron nanoparticles (0.1 mg / ml) and copper (0.001 mg / ml) 1st 400.9 ± 8.3 401.1 ± 6.8 ^* 400.1 ± 5.7 ^* 402.5 ± 6.2 ^* 3rd 427.1 ± 2.8 382.9 ± 9.1 ^* 355.2 ± 2.5 ^* 333.0 ± 14.8 ^* 5th 384.4 ± 8.1 327.4 ± 2.4 ^* 296.7 ± 6.3 ^* 119.2 ± 4.7 ^** 7th 336.7 ± 5.8 289.5 ± 4.7 ^* 245.9 ± 13.5 ^* 53.4 ± 9.1 ^*** 10th 307.2 ± 8.4 263.7 ± 5.1 ^* 217.5 ± 10.4 ^* Complete healing 14th 290.8 ± 7.9 209.3 ± 3.8 ^* 198.0 ± 4.1 ^* Complete healing Note: ^* - p <0.05; ^** - p <0.01; ^*** - p <0.001 - reliability in relation to the control group.

The inventors also conducted a bacteriological study of purulent wounds, including the study of the qualitative composition of microbial pathogens and a quantitative study of wound microflora in dynamics on the 1st, 3rd, 5th, 7th and 14th days of treatment.

When bacteriological examination of the wound on the 1st day after the formation of the model received a culture of Staphylococcus aureus, the other flora was not sown. With the isolated use of copper, Staphylococcus aureus culture was seeded until the 5th day, with the isolated use of iron nanoparticles - until the 10th day. In the control group (without treatment) received a culture of Staphylococcus aureus until the 14th day of observation. When using a suspension containing copper and iron nanoparticles, starting from the 3rd day, there was no microbial growth when plating the wounds that were separated from the wounds.

Table 2 shows the rate of destruction of the pathogen of the purulent process in the wound under the influence of a suspension of iron nanoparticles, a suspension of copper nanoparticles, and also a suspension of a mixture of iron and copper nanoparticles in comparison with the control group treated with dressings with isotonic solution.

table 2 The results of bacteriological studies of experimental wounds in dynamics Day Groups of animals 1st (control) group, n = 10 2nd (experimental) group, n = 10 3rd (experimental) group, n = 10 4th (experimental) group, n = 10 The use of isotonic solution The use of iron nanoparticles (0.1 mg / ml) The use of copper nanoparticles (0.001 mg / ml) The use of iron nanoparticles (0.1 mg / ml) and copper (0.001 mg / ml) 1st Vseyan St. aureus Vseyan St. aureus Vseyan St. aureus Vseyan St. aureus 3rd Vseyan St. aureus Vseyan St. aureus Vseyan St. aureus No growth 5th Vseyan St. aureus Vseyan St. aureus Vseyan St. aureus No growth 7th Vseyan St. aureus Vseyan St. aureus No growth No growth 10th Vseyan St. aureus Vseyan St. aureus No growth No growth 14th Vseyan St. aureus No growth No growth No growth

Thus, the use of a suspension of iron nanoparticles (0.1 mg / ml) in combination with copper nanoparticles (0.001 mg / ml) ensures the destruction of the pathogen contaminating wound in a short time and quick healing of the wound compared to the control group and groups in which they were isolated nanoparticles of iron and copper.

According to two parameters: the rate of decrease in the area of the wound and the rate of elimination of the contaminating pathogen from the wound, it can be concluded that the use of a mixture of iron and copper nanoparticles in the indicated concentrations is effective for treating purulent wounds caused by polyantibiotic-resistant Staphylococcus aureus strains.

Thus, in addition to simplifying and reducing the cost of the treatment of purulent wounds, eliminating the toxic effects of nanoparticles, the claimed method significantly reduces the elimination time of the contaminating pathogen, ensures sterility of the wound, increases the rate of regeneration and complete healing of wounds.

The obtained results allow us to recommend the claimed method of treatment of infected wounds for use in clinical practice.

Claims (1)

A method of treating infected wounds in an experiment, including pre-wound dressing, dressing containing iron and copper nanoparticles, and daily dressing changing, characterized in that a dressing is applied to the wound containing a suspension of iron nanoparticles in an isotonic 0.9% sodium chloride solution at a concentration of 0.1 mg / ml and copper nanoparticles at a concentration of 0.001 mg / ml obtained by exposure to a plasma stream with a temperature of 5000-6000K, while the dispersion of copper nanoparticles is 30 nm, and iron nanoparticles is 70 nm.