The invention concerns the area of medicine, namely bandages for treatment of purulent and infected wounds, trophic ulcers and for preventive avoidance of suppurations of infected wounds.

State of the art

Use of proteolytic enzymatic agents for treatment of pyoinflammatory diseases is known in medical practice. However enzymatic agents are too expensive and in short supply and, despite of high medical efficiency, they are not stable in relation to inhibitors contained in wound secretions (products of development of wound process), to changes of pH and temperature. Enzymes are inactivated quickly at entering in a wound and thus a big charge of enzymes is required during treatment.

For decrease in the charge of enzymes at treatment of purulent and infected wounds, therapeutic bandages including wound bandages both with wound-cleaning and antimicrobic action have been created (see, for example, Russian patents No 2142818 and No 2357753).

In the invention under Russian patent No. 2357753 a wound bandage with antimicrobic properties is described; this patent is chosen as the closest prior art of the present declared invention.

According to said invention the wound bandage with antimicrobic properties contains a textile carrier on the basis of dialdehydecellulose, with a proteolytic enzyme and an antimicrobic preparation immobilized on its fibres, after water processing.

A cellulose-containing textile carrier, preferably medical gauze on the basis of cotton cellulose is used for obtaining wound bandages with antimicrobic properties. The named textile carrier is activated, preferably, with use of a solution of sodium periodate. It is kept in said given solution, is washed with water and is dried up so obtaining the dialdehydecellulo se .

As a result of modification of the initial material up to dialdehydecellulose, the molecular structure of fibres of cellulose changes with formation of aldehydic groups capable of reacting with amino groups joined to lateral chains of used enzyme, preferably, of trypsin. The bacteriolytic enzyme - lysozyme is used as an antimicrobic preparation in the wound bandage according to the given invention.

However the known bacteriolytic enzyme has a limited spectrum of antimicrobic action. Lysozyme is effective against gram-positive bacteria and, owing to the specific action, does not exert any influence on gram-negative bacteria and on fungous microorganisms, which can be in soft tissues with a purulent inflammation and in purulent exudates.

As a result medical efficiency of a bandage with the proteolytic enzyme - trypsin, providing cleaning of wounds from purulent- necrotic masses, worsens.

Tests performed on said wound bandages have shown the presence of significant residual microbic semination at its application.

It is known, that in the medical practice significant attention is paid to the antimicrobic preparations containing metals such as Ag, Au, Pt, Pd, Cu, and Zn (see H.E. Morton, Pseudomonas in Disinfection, Sterilization and Preservation, ed. S.S. Block, Lea and Febider, 1977 and N. Grier, Silver and Its Compounds in Disinfection, Sterilization and Preservation, ed. S.S. Block, Lea and Febider, 1977).

In particular, the use of an antiseptic preparation on the basis of natural mineral components which are corresponding to the requirements of ecological compatibility and safety is described in a known technical specification (see Russian patent No. 2361029).

A nanostructured powder of bentonite intercalated by ions of metals Ag ⁺ or/and Cu ²⁺ is used in said patent as an antiseptic preparation for processing of cellulose- containing materials.

The known technical solution is used at manufacturing paper production including for sanitary- and-hygienic purpose and for improvement of antibacterial and antifungal properties.

However, it does not follow from the given technical solution:

- expediency of application of the given antiseptic preparation for dressings, including wound bandages on the basis of dialdehydecellulose with the immobilized proteolytic enzyme;

- expediency of using the given antiseptic preparation in the structure of the named dressings for improvement of their medical properties and decrease in microbic semination of purulent-necrotic wounds. Disclosure of the invention

The technical result of the present invention consists in creation of a wound bandage with antimicrobic properties, on the basis of biological and mineral components, whose synergic interaction improves medical properties of the bandage and its antimicrobic activity in respect to a wide spectrum of gram-positive and gram-negative bacteria and fungous microorganisms, at processing of wounds with the presence of pyoinflammatory processes.

For the solution of the present technical problem a wound bandage with antimicrobic properties is disclosed, containing the textile carrier on the basis of dialdehydecellulose (DAC) with an immobilized proteolytic enzyme and an antimicrobic preparation. According to the invention a nanostructured powder of bentonite intercalated by ions of metals Ag ⁺ or/and Cu ²⁺ or/and Zn ²⁺ is used as an antimicrobic preparation. The wound bandage has the following contents of components, expressed as % by weight (% b.w.):

proteolytic enzyme 0,03-0, 1 nanostructured powder of bentonite intercalated by ions of

Ag ⁺ or/and Cu ²⁺ , or/and Zn 2+

2,0 -10,0

Dialdehydecellulose the rest

According to the invention a mix of powders of bentonite intercalated by ions of Ag ⁺ and ions of Cu ²⁺ has the ratio between the two powders as 0,5 : 1,0 ( weight parts.) :

- a mix of powders of bentonite intercalated by ions of Ag ⁺ and ions of Zn ²⁺ has the ratio between the two powders as 0,5 : 1,0 ( weight parts);

- a mix of powders of bentonite intercalated by ions of Cu ²⁺ and ions of Zn ²⁺ has the ratio between the two powders as 1,0: 1,0 ( weight parts);

- a mix of powders of bentonite intercalated by ions of Ag , ions of Cu ²⁺ and ions of Zn ²⁺ has the ratio among the three powders as 0,5 : 1,0 : 1,0 ( weight parts).

According to the invention trypsin is used as the proteolytic enzyme.

According to the invention dialdehydecellulose, with immobilized trypsin and an antimicrobic preparation, has no more than 10 % moisture.

According to the invention the size of particles of a nanostructured powder of bentonite is no more than 100 nanometers. According to the invention nanostructured powders of bentonite contain 2,0 - 6,0% b.w. of the above named metals intercalated into bentonite.

According to the invention a hydrosol containing 5,0-10,0% b.w. of a nanostructured powder of bentonite, intercalated by ions of the named metals, is used for immobilization of an antimicrobic preparation on dialdehydecellulose.

At realization of the present invention, medical properties of the wound bandages and its antimicrobic activity improve in respect to a wide spectrum of gram-positive, gram- negative bacteria and fungous microorganisms.

The technical result achievable with the invention is explained as follows:

- by the use of biological and mineral components, whose synergic interaction promotes achievement of the specified result at creation of a wound bandage with antimicrobic properties;

- by the use of dialdehydecellulose for manufacturing the wound bandage. The molecular structure of fibres of dialdehydecellulose provides both chemical immobilization of functional groups of the proteolytic enzyme and effective sorption interaction with an antibacterial preparation on the basis of a nanostructured powder of bentonite intercalated by ions of the mentioned metals;

- by the use of an antibacterial preparation as a nanostructured powder of bentonite intercalated by ions of metals Ag ⁺ , Cu ²⁺ , Zn ²⁺ , providing a big contact area to the bacterial environment and effective prolonging influence on pathogenic microflora in respect to a wide spectrum of gram-positive, gram-negative and fungous microorganisms;

- by the use of the mineral antibacterial preparation containing ions of metals Ag ⁺ , Cu ²⁺ , Zn ²⁺ , participating in reactions of ionic replacement and not having negative action (allergic, edematous) on processed zones of tissues of an alive organism;

- by the use of an antibacterial preparation as a nanostructured powder of bentonite intercalated by ions of Zn ²⁺ , possessing both antimicrobic, antifungal properties and regenerating wound healing effects (peculiar to metal Zn). The named properties of zinc are widely used in medical practice for manufacturing antiseptic, regenerating and wound healing means in case of dermatitis and pyoinflammatory diseases of the skin;

- by the technical solution of the wound bandage (dressing) by means of components biologically compatible with tissues of live organisms. At realization of the declared invention antimicrobic properties of bandages improve due to immobilization on the wound bandage of an antimicrobic preparation on the basis of a mix of nanostructured powders of bentonite intercalated by ions of the named metals. The given effects are explained by a wide spectrum of biocidal properties of the specified metals which, as known, possess bioactive, antibacterial, fungicidal (antifungal) properties. What defines their use for products of sanitary- and-hygienic and medical purposes, intended for contact with integuments.

The use of an antimicrobic preparation as hydrosol containing the above mentioned nanostructured powders of bentonite for immobilization on the wound bandage, improves the process of distribution of the given preparation on the wound bandage and decreases costs for its application.

Analysis of the available art did not reveal technical solutions with the set of characteristics corresponding to the present declared invention and able to realize the above described result for antimicrobic and antifungal influence on wound zones under treatment with characteristics of a pyoinflammatory process and with purulent exudation.

The analysis of available art testifies about conformity of the declared technical solution to criteria of "novelty" and "degree of inventiveness".

The declared technical solution can be industrially realized for manufacture of wound bandages with antimicrobic properties for processing of wound, burn and ulcer zones of integuments.

For realization of the invention medical and labware and commodity products are used, including therapeutic material which is manufactured with the technical process described in the Russian patent No. 2142818.

According to the present technical solution a cellulose-containing textile carrier, preferably medical gauze on the basis of cotton cellulose, was used for obtaining dialdehydecellulo se .

The mentioned textile carrier was activated by a solution of sodium periodate. The proteolytic enzyme trypsin was immobilized on fibres of dialdehydecellulose after water processing. Trypsin, in a phosphatic buffer solution at pH 5.5, was used for water processing of dialdehydecellulose.

For realization of the declared invention the following products were used: 6,0 g of periodic acid in 3,3 1 of distilled water; 1,0 g of caustic soda in 3,3 1 of distilled water for obtaining a solution of sodium periodate with pH 5,0. 1 kg of medical gauze was processed with this solution. As a result the textile carrier on the basis of dialdehydecellulose was obtained.

The proteolytic enzyme-trypsin was immobilized on obtained dialdehydecellulose. 3,3 1 of distilled water were used for preparation of a solution of trypsin in a phosphatic buffer solution with pH 5,5.

0,01 ; 0,007 % and 0,03 % solutions of trypsin have been obtained with which the activated textile materials were processed. Therapeutic materials (wound bandages) with a content of the proteolytic enzyme of: 0,02; 0,03 and 0,09% b.w. on the weight of dialdehydecellulose have been obtained.

Samples of bandages in the size of 10 x 10 cm and each with the weight of 1,9 g have been prepared from the obtained therapeutic materials.

The quantitative contents of the proteolytic enzyme in the wound bandage specified in the invention is the optimum, as proved by clinical tests of these therapeutic materials. Decrease in its amount reduces therapeutic efficiency of the wound bandage in processes of cleaning of wounds from purulent and necrotic masses while its increase extends costs for manufacturing of a bandage.

Trypsin covalent bound with the reactive groups of dialdehydecellulose possesses necrolytic action, accelerates cleaning of wounds from purulent and necrotic masses and has effective anti-inflammatory and anti-edematous action. What accelerates granulation and healing of wounds.

Enzymes related to trypsin, for example chymotrypsin, also possessing proteolytic activity, can be used for the wound bandages according to the invention.

Antiseptic preparations possessing antimicrobic and antifungal properties (see, for example, Russian patents No. 2361029 and No. 2330673) were also used for manufacturing the wound bandages according to the present invention.

The disclosed preparation has been obtained as follows:

1 ^st step. Preparation of semi-finished powders of bentonite preliminarly enriched with cations of sodium Na ⁺ .

Bentonite (montmorillonite) in Na-form, in amount of 5 g, was coated with 5% water solution of NaCl, with retention interval in this solution. Then bentonite was enriched with ions of sodium with subsequent repeated washings for removal of anions of chlorine, filtration and drying.

2 ^nd step. Obtaining of nano structured powders of bentonite intercalated by ions of metals: Ag ⁺ , Zn ²⁺ , Cu ²⁺ .

Nanostructured bentonite powders (nanoparticles of bentonite) intercalated by ions of the specified metals and not containing salts of sodium are obtained from semifinished products of bentonite made in the 1 ^st step, according to the following examples.

Example 1.

A semifinished product cleaned from acid anions was dried up and modified with 10-20% water solution of silver nitrate (at red illumination). 15 % water solution of silver nitrate (AgN0 ₃ ) was preferably used. The obtained modified semifinished product was repeatedly washed out for removal of salts of sodium and was filtered and dried.

The amount of water solutions for processing of 5 g of a semifinished product (1 ^st step) was the following: bentonite : water solution, as 1:20 (weight parts). After drying the product was grinded up for obtaining a dispersed powder of bentonite.

As a result a bentonite powder intercalated by ions of Ag ⁺ and not containing salts of sodium was obtained. Useful yield of the product was 4,8 g.

Example 2.

The same materials and methods as in the Example 1 were used, but 15% water solution of copper sulfate (CuS04) was used to modify bentonite enriched with ions of Na ⁺ .

A bentonite powder intercalated by ions of Cu ²⁺ and not containing salts of sodium was obtained. Useful yield of the product was 4,8 g.

Example 3.

The same materials and methods as in the Example 1 were used, but a 15% water solution of inorganic salts of Zn, preferably zinc chloride (ZnCl ₂ ), was used to modify the bentonite enriched with ions of Na ⁺ . It is possible to use in alternative zinc sulfate (ZnS0 ₄ ).

A bentonite powder intercalated by ions of Zn ²⁺ , and not containing salts of sodium, was obtained. Useful yield of the product was 4,8 g.

Deionized water is used for realization of steps 1 and 2 (mentioned above). The process of grinding of the products obtained by Examples 1-3, up to the size of particles of a powder of bentonite as above specified for the invention, was carried out in all examples as follows:

- after intercalation (modification) by ions of the specified metals and cleaning from salts of sodium and drying, the obtained products are intensively mixed in a plenty of water, are allowed to settle during some time and are decanted into supernatant liquid.

The deposit is slurred, settled and decanted again after addition of water. This process is carried out repeatedly. A nano structured product is isolated from decanted liquid with a filtration; then it is dried and grinded in planetary mills. A plenty of deionized water is spent in such a way to obtain powders of nanostructured bentonite. The process is rather long.

For decreasing the work the named products of Examples 1-3 were poured into deionized water at the ratio (weight parts): product (Examples 1-3) : solvent, as 1: 10, and nanostructuring (superdispersion) was implemented till a size of the particles of no more than 100 nm, with use of an ultrasonic dispersant accelerating process of nanostructuring of bentonite powders. The process was carried out with use of the dispersant Bandelin Sonoplus HD2070 at the power 40 Wt, within 5-10 minutes.

Obtained colloidal systems were deposited on a sublayer and, after evaporation of water, measurements of the sizes of particles of the nanostructured powder of bentonite were carried out by methods of microscopy. Tests have shown that nanostructured powders of bentonite have the following sizes of particles: 20-30 nm - 30 % of the amount of the powder; 100 nm - the rest.

Nanostructured powders of bentonite (Examples 1-3) were tested for determination of the percentage of the contents of silver, copper, zinc with a method of titrimetric analysis.

The titrimetric analysis for determination of amount of metals in powders of bentonite was carried out with use of the indicators fixing a point of equivalence of titration.

It has been established, as a result of the tests carried out, that powders of bentonite, intercalated by ions of the named metals, could contain from 2,0 up to 8,0% b.w. of silver or copper, or zinc, depending on the amount of activating and modifying (intercalating) reagents. The specified % b.w. content of metals in an intercalated (modified) bentonite powder are the optimum. Increase of the percentage of the contents of metals leads to increase in costs of used reagents for obtaining nano structured bentonite powders. Decrease in the percentage of the contents of the named metals in bentonite powders, decreases their antimicrobic and fungicidal activity.

According to the results of the titrimetric analyses, the quantitative content of metals (Ag, Cu, Zn) in nano structured bentonite powders (in products of Examples 1-3) is of about 2,0 - 6,0% b.w..

Antiseptic preparations as nano structured powders of bentonite intercalated by ions of metals Ag ⁺ , Cu ²⁺ , Zn ²⁺ were deposited on wound bandages containing the proteolytic enzyme - trypsin immobilized on dialdehydecellulose.

Deposition of antimicrobic preparations was carried out by processing of bandages in 5-10 % hydrosols on the basis of nanostructured powders of bentonite.

The content of a powder of bentonite in hydrosol specified as percentage b.w. in the invention is the optimum. Decrease in the amount of bentonite powder in water system leads to deterioration of its sorption ability on fibres of dialdehydecellulose. What worsens antimicrobic properties of the wound bandage. Increase in the amount of a bentonite powder in water system, increases costs for manufacturing wound bandages.

6,0 % hydrosols containing a nanostructured powder of bentonite and deionized water were prepared for realization of the invention.

Materials obtained after processing with hydrosol were dried up to initial moisture of no more than 10% b.w..

The moisture of the obtained wound bandage specified in the invention is optimum in conditions of its storage. At decrease in moisture of the bandage its operational characteristics worsen, while increase in initial moisture of the obtained wound bandage requires a special packing that increases costs.

Wound bandages with antimicrobic properties have been obtained according to the described process, with the following contents of components in % b.w.: Example 4.

Proteolytic enzyme - trypsin 0,02 Nano structured powder of bentonite intercalated by ions of

Ag ⁺ (Example 1) 3,0

Dialdehydecellulose the rest Example 5.

Proteolytic enzyme - trypsin 0,03 Nano structured powder of bentonite intercalated by ions of

Ag ⁺ and Zn ²⁺ (Examples 1 and 3) at the ratio 0,5: 1,0 (weight parts) 3,0

Dialdehydecellulose the rest Example 6.

Proteolytic enzyme - trypsin 0,02

Nano structured powder of bentonite intercalated by ions of

Ag ⁺ , Zn ²⁺ and Cu ²⁺ (Examples 1, 2 and 3) at the ratio 0,5: 1,0 : 1,0

(weight parts) 3,0

Dialdehydecellulose the rest

Example 7.

Proteolytic enzyme - trypsin 0,03 Nano structured powder of bentonite intercalated by ions of

Zn ²⁺ and Cu ²⁺ (Examples 2 and 3) at the ratio 1,0 : 1,0 (weight parts) 3,0

Dialdehydecellulose the rest Example 8.

Proteolytic enzyme - trypsin 0,09 Nano structured powder of bentonite intercalated by ions of

Cu ²⁺ (Example 2) 5, 0

Dialdehydecellulose the rest Wound bandages with antimicrobic properties, having immobilized on dialdehydecellulose the proteolytic enzyme - trypsin and an antimicrobic preparation on the basis of nanostructured powders of bentonite, as specified under the invention, correspond to contents of components as specified. A content of components in the wound bandage, as declared in the invention, is the optimum for its therapeutic action in processing wounds with characteristics of pyoinflammatory process.

Decrease in the % of the contents of the specified antimicrobic preparation, immobilized on dialdehydecellulose in the wound bandage, reduces antimicrobic influence of ions of metal on pathogenic microflora.

Increase in the % of the contents of the antimicrobic preparation in the wound bandage increases costs for its manufacturing.

Test samples were prepared from the wound bandages obtained in the Examples 4- 8. They were estimated on their action for terms of cleaning of purulent- necrotic wounds and on their action on clinical strains.

Wound bandages prepared according to the following examples were used as control samples for comparation of the obtained results:

Example 9.

A wound bandage prepared according to the Russian Patent No. 2142818 and containing the following components in % b.w.:

Proteolytic enzyme - trypsin 0,03 Dialdehydecellulose the rest

Example 10.

A wound bandage prepared according to the Russian Patent No. 2142818, with the immobilized bacteriolytic enzyme-lysozyme (Russian Patent No. 2357753) containing the following components in % b.w.:

Proteolytic enzyme - trypsin 0,03 Bacteriolytic enzyme - lysozyme 0,055 Dialdehydecellulose the rest

Example 11.

A wound bandage with antimicrobic properties containing the following components in % b.w.:

Proteolytic enzyme - trypsin 0, 03

Bacteriolytic enzyme - lysozyme 3,0 Dialdehydecellulose the rest Estimation of terms for cleaning of purulent-necrotic wounds, was carried out in accordance with the following technique:

A full-layered piece of a tissue between shoulder bones, in the area of 400 mm , was excised under a ether narcosis from white rats of average weight 173,0 g. A Teflon ring was sewed in the formed defect. 1 ml of the microbic suspension containing golden staph was put on the surface of the wound. The surface of the Teflon ring was covered with the punched polyethylene cover. In 2 days it was established the following: edges of the wound were hyperaemic; there is a fibrinogenous film and yellowish exudates on the wound.

Wounds were covered with fragments of bandages prepared (two-layer) according to Examples 4-8 with the size 2x2 cm.

Functional properties of wound bandages were estimated in terms of cleaning of purulent-necrotic wounds, accompanied by reduction of edema and hyperemia of soft tissues.

Results of tests are collected in Table 1: «Terms of cleaning of purulent-necrotic wounds at treatment with wound bandages».

Estimation of tested samples on antimicrobic properties was carried out in respect to various clinical strains: gram-positive (Staphylococcus Aureus, Staphylococcus Epidermidis) and gram-negative (Pseudomonas Aeruginosa, Enterobacter Spp., Proteus vulgaris) bacteria.

The following means were used for tests:

- sterilized distilled water;

- membrane filters;

- Petri dishes (D up to 120 mm) with dry environments: soy agar (Soyabean Casein Digest Medium) for calculation of the common number of microorganisms; Chapman Stone Medium for isolation and calculation of staphylococcus; ECO Medium for isolation and calculation of colon bacillus and other coliform microorganisms.

Tests were carried out during 2 - 5 days at a temperature of cultivation 35°C - 37°C. A sharp growth of various microorganisms and funguses at the specified parameters of incubation took place . At tests each controlled sample of bandage was soaked in the tank with the sterilized distilled water and then was closed with a cover. The samples were kept over 24 hours at usual conditions at room temperature.

Washouts obtained after retention interval of samples was filtered through membrane filters with subsequent placement (with the working surface upwards) on the surface of a restored nutrient medium in Petri dishes. The size of the zones of growth inhibition of microorganisms (mm) was determined in each test.

The results of the tests are collected in Table 2: «Action of bandages on clinical strains».

The data submitted in Tables 1 and 2 testify and prove expediency of the composite structure of the wound bandage with antimicrobic properties according to the present invention.

The carried out research testify the following:

- high antimicrobic properties of the wound bandage under the invention in respect to a wide spectrum of gram-positive and gram-negative bacteria, for processing and treatment of wounds with characteristics of pyoinflammatory processes of various etiology;

- high efficiency of the wound bandage at primary closing wounds with high microbic semination;

- efficiency of using of biological and mineral components in a composite structure of the wound bandage according to the invention, whose synergic interaction improves medical properties of a dressing.

The wound bandage described in the invention is simple and convenient in application. It can stay on a wound within 2 days without loss of functional properties and possesses prolonged antimicrobic and proteolytic action.

Range of application of the wound bandage is the first aid to the wounded man and to the victim and also in medicine, hygiene and cosmetics. Table 1

Terms of cleaning of purulent-necrotic wounds at treatment with wound

bandages

f Nbmer ou

t _t ess

Table 2

Action of bandages on clinical strains

Micro

organisms Average size of zones of growth inhibition of microorganisms (mm)

Sample Sample Sample Sample Sample Sample Sample 4 6 7 8 9 10 11

Staphylococcus 22 18 19 16 12 5 7 9 Aureus

Staphylococcus 20 18 20 16 13 5 7 10 Epidermidis

Pseudomonas 15 17 19 17 15 0 1 3 Aeruginosa

Enterobacter 15 16 20 19 16 0 1 2 Spp.

Proteus vulgaris 15 17 19 18 17 0 0 0