PS are made of PM and are finished products for intended use. presented on It includes such PS groups as bandages, bags, napkins, plasters, tampons, aerosols (spray foams and spray films), wound coverings.
Bandages are a kind of dressings made from cotton-viscose gauze in the form of rolls of certain sizes; belong to the traditional, widely used PS. Types of bandages are presented on
Non-sterile gauze bandages are produced in sizes 10 m x 16 cm, 10x10, 5x10, 5x5, 5x7, 7x10, 7x14, 7x7 cm both in secondary and in individual packaging.
Sterile gauze bandages are produced in sizes 5x10, 5x7, 7x14 cm in individual packaging.
PS classification depending on the form
PS classification depending on the form
Types of medical bandages
Types of medical bandages
Plaster bandages contain gypsum, which, after getting wet, is applied to the injured parts of the body in order to fix them; used mostly in traumatology. Available in sizes 3x10, 3x15, 3x20 in individual packaging. In recent years, such bandages have been produced with PVA plasticizer to improve consumer properties.
Elastic bandage is made of harsh cotton yarn, which is based on woven rubber threads, which sharply increase the elasticity of the bandage. Elastic bandages are not sterilized, they are used for non-rigid tightening of soft tissues.
Bandage tubular is a seamless tube of hydrophilic material; its elasticity is provided by the knitted type of weaving. Available in several diameters for use on various areas of the upper and lower extremities.
A special type of tubular bandage is mesh bandage - a mesh tube of various diameters, which is rolled up in the form of a roll. A piece of the required length is cut off from it in order to fix the surgical dressing on the wound.
The hydrophilic bandage has the ability to absorb water; available in two versions: sterile and non-sterile (width 4-20 cm).
Starched bandage is made from starched gauze or organza. It is used as a reinforcing material over hydrophilic bandages (it can “dry up” directly on the wound, damage the skin at the fold).
The zinc-containing adhesive bandage is a conventional bandage, on which a thin layer of paste containing glycerin, gelatin, sodium chloride, zinc oxide is applied, i.e. this type of bandage refers to therapeutic PS. When dried, such a bandage “sits down” and the bandage becomes very tight, so it is used where it is necessary to avoid tissue swelling, for example, in case of skin inflammatory diseases.
In the group of napkins, dressing napkins proper (for example, gauze napkins) and medical napkins (for example, Koletex napkins) are distinguished,
Gauze napkins are two-layer cuts of gauze sized 16x14 cm, 45x29 cm, etc. Sterile wipes are available in packs of 5, 10, 40 pcs., non-sterile - 100 pcs.
Medical wipes are a composite dosage form, which is either a medical biopolymer on a substrate (most often tissue), in which a medicinal substance is immobilized, or a tissue base impregnated with a medicinal substance.
Napkins "Coletex" - composite PS, which is a layer of special textile material as a carrier of a biopolymer with a therapeutic effect, with a drug immobilized in it. They contain hemostatic, anti-inflammatory, wound healing and analgesic substances (furagin, chlorhexidine, propolis, sodium alginate, urea, metronidazole) in various combinations. They are intended for use as a therapeutic and prophylactic agent for the primary closure of injured tissues, sutured wounds, for the closure of infected and granulating wounds, trophic ulcers, burns, bedsores. Packed in primary packaging in the form of a sterile (inside) paper bag and secondary packaging - cardboard boxes. Can also be used in oncology
as a local application radiosensitizing agent for radiation therapy and post-radiation lesions.
Dressing bags are a ready-made dressing for applying to a wound in order to protect it from contamination, infections and blood loss. The composition of individual dressing packages includes a sterile hydrophilic bandage (7 cm x 5 m), a cotton pad (13.5x11 cm), which can be sewn to the beginning of the bandage, and a pin to secure the ends of the bandage. Cotton-gauze pads are impregnated with a solution of sublimate. There are two types of packages: small and large, in which there is one or two pads (one is sewn to the beginning of the bandage, the second is free). Individual dressing bags are made in such a way that sterility is not violated during constant wear. If, nevertheless, the protective shell is broken, then the core of the bag remains sterile.
At present, dressing pads are made that adhere weakly to the wound (they dry little to exuding wounds).
Dressing swabs are a small piece of cotton wool or dressing cloth used to close a wound or ulcer or to stop bleeding (during surgery to remove blood from dissected vessels).
Plasters used as PS, taking into account the purpose of the application, refer to fixing and covering plasters. They may contain a medicinal substance (cover patches), may not contain it (fixing patches).
Fixing plasters are used in surgery and traumatology for fixing dressings; cover patches - in dermatology for the treatment of a number of diseases or mechanical damage to the epidermis.
Usually dressing patches are combined under the conditional name "adhesive plaster". In appearance, they are divided into tape and strips. As a rule, adhesive plasters have a sticky (adhesive) layer on one side; in the case of cover adhesive plasters, a gauze pad impregnated with drugs (for example, a bactericidal plaster) is attached to the sticky side.
Adhesive plasters are produced: Leukoplast, Siofaplast, Tricoplast, Santavik, etc. In addition, perforated paper-based plasters are produced under the trade names Leukopor, Betabant, etc.
Firm "Veropharm" (Russia) produces a series of plasters "Uniplast", including: Fixing adhesive adhesive medical tape, dimensions 500x10 cm, 500x1.25 cm, 500x2.5 cm, 500x0.5 cm; release
etsya in rolls with a protective coating, and a smaller size - on coils; the base of the tape is elastic viscose fabric, non-woven adhesive fabric.
Dressing strips "Uniplast Plus" provide reliable fixation of the dressing, protect the wound from microbes, do not cause allergic reactions and skin irritation. They have a flesh color, do not leave marks on the skin and clothes.
Patches are made in different sizes and configurations, including rectangular or round shapes on a fixing adhesive tape with or without perforation. In packs of 8, 10, 20 pcs. one standard size and in the form of sets of 10, 16, 24, 30 pcs. products of various shapes and sizes.
Variety of dressing strips:
Waterproof;
Hypoallergenic;
Elastic (convenient for use on the joints).
The Band-Aid series of antimicrobial patches is manufactured by Johnson & Johnson. It is made of non-woven material, does not stick to the wound, contains benzalkonium chloride antiseptic, transparent. The adhesive coating fixes the patch on the skin, does not cause irritation. Sizes 7x2 cm, 4x1 cm, 4x4 cm, packs of 24 different sizes.
Types: antiseptic waterproof, antiseptic tissue - suitable for protecting wounds on the folds.
Medicinal sponges are a dosage or non-dosed dosage form, which is a porous mass of various sizes and shapes, containing medicinal and excipients (mainly polymeric materials). Sponges have the form of plates of different sizes (50x50, 100x100, 90x90, 240x140 mm, etc.). Currently, sponges are obtained mainly from the skin or tendons of cattle, seaweed; released in sterile packaging.
The nomenclature of medicinal sponges is presented on
Types of medicinal sponges
The hemostatic sponge is made from human blood plasma with the addition of calcium chloride and aminocaproic acid; is a dry, porous substance of white color with a yellowish tint. It is applied topically, and gradually dissolves in the wound. Contains thrombin, fibrin, aminocaproic acid, hemostatic; issued in vials. The hemostatic sponge can also be made with collagen.
Absorbable gelatin sponge is a hardened sterile foam, soluble in water; undergoes resorption in body tissues. Designed to stop bleeding during surgery. A variety of gelatin sponge is a gelatin-starch sponge, which serves the same purpose.
The collagen sponge is a sterile porous plate obtained from collagen; has resorptive, hemostatic and weak adhesive properties, due to which it is widely used for wound dressings. Collagen sponges are often combined with various natural polymers and medicinal substances (for example, chitosan, pectin, antibiotics, etc.), which can significantly improve their consumer properties.
Algipor is a sponge made from a polymeric substance (alginate), which is extracted from seaweed. A sterile sponge is applied to the wound and absorbs the wound discharge. Over time, this coating will dissolve. The sponge itself contains medicinal substances that actively promote healing. It is used to treat trophic ulcers, bedsores; due to complete resorption, it can be used in operations on internal organs.
Algimaf is a modification of algipore, contains a different set of antiseptic substances, promotes accelerated wound healing.
In recent decades, such a segment of the PS market as wound coatings has been developing very dynamically. This is due, on the one hand, to the demand for new types of PS in medicine, on the other hand, to scientific and technological achievements.
Wound dressings are intended mainly for the treatment of chronic wounds. Their composition and types depend on the type of wound and the stage of the treatment process (the main stages of treatment: cleaning, removal of organic matter, granulation, vascularization, epithelialization). They produce alginate, sponge, hydrogel and hydrocolloid coatings, from which dressings are made, designed to absorb wound exudate and control the condition
wound hydration. Vapor-permeable films and membranes are also used as wound coverings.
Perforated absorbent film covers solve the problem of drying mesh dressings for wounds with light to moderate exudate.
The Austrian company "NYCOMED" produces an absorbent wound dressing "Tachocomb", designed for hemostasis and tissue bonding, especially during surgical interventions on the parenchyma of various organs (liver, spleen, etc.), in gynecology, urology, vascular surgery, traumatology, etc. .d. Tachocomb is a collagen plate coated with a special fibrin glue that contains fibrinogen, thrombin, riboflavin, etc. The Tachocomb plate applied to the wound is absorbed in the human body within 3-6 weeks. The coating is produced in hermetic packaging and applied under strict sterility conditions. Plate dimensions 9.5x4.8x0.5 cm; 1 PC. in a package, in a pack of 5 or 10 pcs.
Wound films are usually sterile perforated sheets of different colors (yellow, dark blue, colorless, etc.) depending on the antiseptics they contain. The range of wound films is presented on
Nomenclature of wound films
Polyvinyl alcohol aseptic film "Aseplen" is intended for the treatment of infected wounds, burns of I-II degrees, for temporary closure of transplanted skin autografts and donor sites. The films are produced in three modifications: with dioxidine (Aseplen-D), with iodine (Aseplen-I), with catapol (Aseplen-K). They are hydrophilic, easily modeled on the wound, due to perforated holes they do not interfere with the outflow of wound discharge, provide a prolonged antimicrobial effect, are easily removed from the wound surface, create a tender scab and favorable conditions for regenerative processes in the wound,
prevent the development of infectious complications. The transparency of the film provides visual control over the condition of the wound.
Perforated polyvinyl alcohol film "Viniplen" is intended for the treatment of donor site wounds in dermatomal skin grafting. It can also be used for temporary closing of flat wounds of other etiologies, in cosmetology, etc. The film is non-toxic, reduces the time of wound treatment, avoids treatment with tanning disinfectant solutions, does not injure the wound and has good draining properties.
Film with vaseline "Vasoderm-S" is made on the basis of cotton fabric and special production and impregnated with a neutral ointment containing anhydrous wax, liquid vaseline, fish oil, Peruvian balsam. It is used for the treatment of fresh and weeping wounds, burns, nail exfoliation, ulceration, phimosis operations, skin grafts in plastic surgery and various skin lesions. Advantages: does not stick to the wound, absorbs secreted, improves granulation and epigelization, prevents secondary infection, has an antiseptic effect.
Biological wound dressing "Biokol-1" is a transparent, elastic, porous film that reliably self-fixes on the wound, stimulates regeneration, which leads to accelerated wound healing. It has an absolute atraumaticity, has an analgesic effect. It is used to treat burns, trophic ulcers, protect donor sites and autografts.
The above films are produced in Russia.
Dressings are fabric applied to a wound or part of the body to protect against external influences and speed up healing.
Aseptic dressings are made of sterile dressing material (one or two cotton-gauze pads, gauze bandage and fixative) and are intended to protect against microbial contamination and other contamination of wound surfaces.
Elafom synthetic dressings are intended for the treatment of various wounds, including burns. Are issued in single packings, sterile. The use of these dressings can halve the number and duration of dressings.
Foreign manufacturers produce a variety of dressings as a type of wound dressing that absorbs exudates and has a therapeutic effect due to the content of various medicinal
substances (absorbent deodorizing, primary viscose, povidone-iodine, etc.).
In Russia, in recent years, new PS with immobilized enzymes have been developed, for example, Dalceks-trypsin, Lax-trinsin, Dalceks-Collitin. They are a cellulose or polycaproamide carrier with immobilized proteolytic enzymes, trypsin or with lysocine, collitin. They are used in surgery for the treatment of purulent-necrotic wounds at the stage of hydration, as well as bedsores, ulcers of various etiologies, and burns.
Study of the performance properties of polymeric dressings
O. A. Legonkova1, V. G. Vasiliev2, L.Yu. Asanova1
1FGBU "Institute of Surgery named after A.I. A.V. Vishnevsky" of the Ministry of Health of Russia; Russia, 117997, Moscow, st. Bolshaya Serpukhovskaya, 27; 2FGBU “Institute of Organoelement Compounds named after A.I. A.N. Nesmeyanov" RAS; Russia, 119991, Moscow, st. Vavilova, 28
Contacts: Olga Aleksandrovna Legonkova [email protected]
Currently, there are a large number of modern dressings in the form of sponges and films made on the basis of various polymers. In practical work, it is important for doctors to know the optimal specific values of the key performance characteristics of dressings, which determine comfort and ease of use. As the main operational characteristics, we have chosen: sorption capacity, which determines the amount of liquid absorbed by a unit mass of material; modulus of elasticity, which is an indicator of the elasticity of the material; surface and apparent density of the material; as well as investigated the relationship between these performance characteristics.
We have suggested differentiating materials according to specific swelling values, as manufacturers categorize wound dressings with different amounts of exudate without specifying exact values. We also studied the physical and mechanical properties of multilayer dressings, paying attention to the parameters that determine the elasticity of the material.
Therefore, the purpose of this work as a whole is to conduct comparative tests of the operational properties of dressings of domestic and foreign manufacturers in order to assess the sorption and physico-mechanical properties.
Key words: dressings, deformation-strength characteristics, operational properties, polyurethane, cellulose, sorption capacity
DOI: 10.17650/2408-9613-2015-2-2-32-39
Investigation of polymeric wound dressings" operational properties
O.A. Legon"kova1, V.G. Vasil"ev2, L. Yu. Asanova1
IA.V. Vishnevsky Institute of Surgery, Ministry of Health of Russia; 27 Bolshaya Serpukhovskaya St., Moscow, 117997, Russia
2A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences; 28 Vavilova St., Moscow, 119991, Russia
Nowadays there are a lot of contemporary wound dressings in theforms like foams and films made on the basis of different polymers. It "s necessary to know optimal particular numeric values of wound dressings" key operational properties, which determine comfort and easy to use.
As the basic operational characteristics we have chosen for investigation such parameters as: swelling behavior, which indicates the amount of liquid, swollen by the unit weight of the material; elastic modulus as a measure of material "s elasticity; surface and apparent density of the material; relations among these characteristics.
We "ve offered to differentiate materials in accordance with particular values of swelling behavior, because manufactures range wound dressings for wounds with different amount of secreted exudate without specifying exact values.
Also physical and mechanical properties of multilayer wound dressings were investigated, paying attention to the elasticity of the material. So, the target of the investigation as a whole was thecomparison of wound dressings" operational properties from different manufactures to investigate swelling behavior, physical and mechanical properties.
Key words: wound dressing, deformation and strength characteristics, operational properties, polyurethane, cellulose, swelling behavior
Introduction
Evaluation of the effectiveness of modern dressings is one of the activities of the department of dressings, sutures and polymeric materials in surgery of the Testing Center of the Federal State Budgetary Institution “Institute of Surgery named after A.I. A.V. Vishnevsky" of the Ministry of Health of Russia. To date, for the management of the wound process, there is a sufficient
a range of dressings, such as hydrocolloid dressings, foams, films, differing in physical structure, chemical composition, methods of preparation and intended for wounds with different amounts of exudate.
The performance characteristics of synthetic and natural dressings are determined by the functional activity of the polymer base,
WOUNDS AND WOUND INFECTIONS THE PROF. B.M. KOSTYUCHENOK JOURNAL
Rice. 1. Samples under study
the correct choice of the drug and the method of its immobilization in the polymer matrix. At the same time, the properties of the polymer matrix should not reduce the bioavailability of drugs, sorption and desorption properties, and mechanical characteristics, i.e., the operational properties of the medical device as a whole.
The purpose of this work is to study the performance properties of some dressings in the form of sponges and films available on the Russian market and selected randomly. The products of the following companies were studied: Urgo (Urgoclean, Urgostart), Starmedix (foam dressing, silver foam dressing, oxidized carboxymethylcellulose, oxidized regenerated cellulose, alginate dressing, silver alginate dressing), Cellonex, Bay-medix, Advancis medical (Advazorb, Advazorb Border, Eclypse ), Smith&Nephew (Allevyn Life), Cureamedical (Curea P1, Curea P1 drain, Curea P2), Vancive (Bene-hold), NPP Nanosintez LLC (Hyamatrix), AS-pharma OJSC (Biodespol-1), LLC "SPC Amphion" (Vini-krol-M), OJSC Luzhsky plant "Belkozin" (hemostatic collagen sponge, Meturakol). Products are differentiated by manufacturers according to their purpose for wounds with different amounts of exudate: high-, medium-, low-exuding (Fig. 1).
Materials and methods
In the study, 20 types of samples of dressings indicated above were used. For statistical evaluation of the experimental results, a series of 10 or more tests was performed on each sample.
Since there are currently no target regulatory documents for modern dressings in the form of sponges and films, the selected samples were examined according to the regulatory documents used in the registration procedure for medical devices: GOST 29104.1-91, GOST 9412-93, GOST 3913-72, GOST 409-77, GOST 15873-70, GOST
24616-81, GOST 26605-93, GOST 29088-91, GOST 2908991, GOST 2439-93, GOST 14236-81.
Performance was evaluated by:
♦ swelling coefficient (g/g; at t = 25 °C), which was calculated by the formula:
Q = (Mw - Ms) / Ms, where Mw and Ms are the masses of the wet and dry samples, respectively;
♦ swelling rate constant (min-1), which is the tangent of the slope of the straight line in coordinates: 1^m/ - Q) = K(0,
where Q is the amount of liquid absorbed by 1 g of the swelling substance during the time ^ Qm is the maximum amount of absorbed liquid (limiting swelling);
♦ surface density (rpov), mass in grams per 1 m2 of material (g/m2);
♦ apparent density value (for porous sponges) (rkazh), mass in grams per 1 m3 of material (g/m3);
♦ modulus of elasticity, stress and relative strain in tension (MPa) - the tangent of the slope of the dependence stress/relative strain in tension, characterizes the elasticity of the material (Erast);
♦ modulus of elasticity and stress in compression - the tangent of the slope of the dependence stress/relative strain in tension, characterizes the elasticity of the material (Ecompress).
The deviations of the obtained values in the determination of sorption and physico-mechanical properties do not exceed 10% of the average value. Compression was carried out at 10% at a clamping speed of 30 mm/min. In tensile testing of specimens, the clamping speed was 50 mm/min.
Brief information on the initial characteristics is presented in Table. one.
Table 1. Test objects differentiated by the manufacturer according to their purpose
Starmedix Foam Dressing* Pp = 605.1 ± 46.5 g/m2; RKaj = 1492.6 ± 119.2 g/m3 Polyurethane, sodium polyacrylate
Starmedix Silver Foam Dressing Pp = 293.1 ± 0.2 g/m2; Rkazh = 1068.7 ± 77.6 g/m3 Polyurethane + silver
Cellonex Ppov = 314.6 ± 10.6 g/m2; Pp°w = 700.8 ± 72.3 g/m3 Regenerated cellulose and cotton fiber
Continuation of the table. 1 End of the table. one
Brand name, density Dressing base
Baymedix Ppov = 417.8 ± 14.2 g/m2; RKaj = 1753.4 ± 36.3 g/m3 Polyurethane
Vinicrol-M Rpov = 669.1 ± 77.4 g/m2; Pp°l = 1115.1 ± 129.0 g/m3 Polyvinyl alcohol
Eclypse 1-Ppov = 85.1 ± 4.1 g/m2; 2 - Рsov = 56.8 ± 3.8 g/m2; 3 - Рsov = 206.9 ± 22.5 g/m2; 4 - Рpow = 86.5 ± 11.9 g/m2 Cellulose-based multi-layer coating
Allevyn life 3 - Ppov = 737.3 ± 107.5 g/m2; Papp = 3686.4 ± 537.4 g/m3; 4 - Rpov = 484.1 ± 14.9 g/m2; Ppow = 1613.6 ± 49.4 g/m3 Breathable film / Protective layer / Super absorbent layer / Porous sponge / Silicone layer
Curea P1/Curea P1 drain Pp = 481.2 ± 26.6 g/m2 Epoxy resin, cellulose
Collagen hemostatic sponge Belkozin Рcase = 1264 ± 65 g/m3 Collagen
Meturacol Rkazh = 1137.1 ± 180.7 g/m3 Collagen
Urgostart Рsov = 645.3 ± 41.4 g/m2; Pcase = 1411.4 ± 7.8 g/m3 Polyurethane with silicone contact layer
Advazorb Ppov = 624.9 ± 36.7 g/m2; P^w = 1315.1 ± 60.5 g/m3 Polyurethane
Advazorb Border Pp = 799.3 ± 39.5 g/m2; Pcase = 3996.7 ± 197.3 g/m3 Polyurethane with silicone contact layer
Starmedix Alginate Dressing Pp = 152.4 ± 6.3 g/m2 Calcium alginate
Starmedix Silver Alginate Dressing Rp = 150.25 ± 10.9 g/m2 Calcium alginate + silver
Curea P2 Psov = 473 ± 50.9 g/m2 Epoxy resin, cellulose
Urgoclean Pp = 373.0 ± 15.2 g/m2 Ammonium polyacrylate with acrylic core
Starmedix Oxidized Carboxymethyl Cellulose Pp = 102.2 ± 15.5 g/m2 Oxidized Carboxymethyl Cellulose
Starmedix Oxidized Regenerated Cellulose Pp = 232.6 ± 25.5 g/m2 Oxidized Regenerated Cellulose
Benehold (for weakly and moderately exuding wounds) Рpov = 172.8 ± 5.1 g/m2 Polyurethane with acrylic contact layer
Brand name, density Dressing base
Biodespol-1 (for the treatment of II-111A degree burns) 1 - Рsov = 62.5 ± 2.7 g/m22 2 - Рsov = 124.5 ± 3.4 g/m2 Copolymer of lactide with glycolide
Nuasha ^1x (for the restoration of skin defects) Ps = 62.4 ± 1.9 g/m2 Hyaluronic acid
*Apparent density values are given for porous samples only.
Results and discussion
The results of the study of the sorption properties of the samples are given in table. 2 and in fig. 2-5.
Table 2. Values of the degree and rate constants of swelling of the studied samples of medical devices
Grade Equilibrium values of swelling degree, g/g Swelling rate constant, min-1
Dressings for highly exuding wounds
Starmedix Foam Dressing 13.7 ± 0.3 0.083
Starmedix Silver Foam Dressing 15.1 ± 0.5 0.073
Cellonex 16.1 ± 1.2 0.052
Baymedix 17.4 ± 0.6 0.068
Vinicrol-M 16.9 ± 0.6 0.065
Allevyn Life 16.1 ± 0.8 0.081
Curea P1/Curea P1 drain 41.8 ± 2.6 0.1
Eclypse 53.7 ± 4.1 0.047
Hemostatic collagen sponge Belkozin 52.3 ± 1.4 0.087
Meturacol 8.2 ± 0.2 0.085
Dressings for moderately exuding wounds
Urgostart 11.2 ± 0.4 0.067
Advazorb 14.5 ± 0.6 0.08
Advazorb Border 4.4 ± 0.4 0.063
Curea P2 38.8 ± 2.6 0.076
Starmedix Alginate Dressing 10.7 ± 0.6 0.17
Starmedix Silver Alginate Dressing 13.2 ± 1.4 0.11
The end of the table. 2
Grade Equilibrium values of swelling degree, g/g Swelling rate constant, min-1
Urgoclean 8.5 ± 0.2 0.054
Dressings for low-exuding wounds
Starmedix Oxidized Regenerated Cellulose 5.6 ± 0.7 0.051
Starmedix Oxidized Carboxymethyl Cellulose 11.0 ± 0.6 0.13
Benehold 6.2 ± 0.6 0.028
Hyamatrix 7.2 ± 1.2 0.051
Biodespol-1 3.9 ± 0.3 0.062
Starmedix Foam Dressing Starmedix Silver Foam Dressing
Cellonex Baymedix Vinicrol-M Allevyn Life
5 6 Time, h
■ Curea P1 Eclypse
Rice. 2. Curves of swelling of dressings for highly exuding wounds
Swelling rates for most dressings for highly exuding wounds range from 13.7 ± 0.3 to 17.4 ± 0.6 g/g or above 40 g/g (note that these samples are based on natural polymers) . Even if a swelling-limiting layer, such as epoxy resin or silicone, is present, the values for the degree of swelling are high.
In dressings for moderately exuding wounds, the values of the degrees of swelling are in the range
4 5 6 7 Time, h
Urgostart Advazorb ■ Advazorb Border Starmedix Alginate Dressing
Starmedix Silver Alginate Dressing Urgoclean
012345678 Time, h
Rice. 3. Swelling curves of dressings for moderately exuding wounds
□ 1 2 3 4 5 b? E
Rice. 4. Curves of swelling of dressings for low-exuding wounds
Biodespol-1
2 3 Time, h
Rice. 5. Film swelling curves
vale from 8.5 ± 0.2 to 14.5 ± 0.6 g/g. In the case of the Advazorb Border sample (Q = 4.4 ± 0.4 g/g), the silicone contact layer reduces the absorption capacity, which puts the sample in the group of sponges for low-exuding wounds and films.
Samples of Fe1urFe, Cugea P1, and Cugea P2 stand out (equilibrium values of the degrees of swelling: 53.7 ± 4.1; 41.8 ± 2.6 and 38.8 ± 2.6 g/g, respectively) made of cellulose.
In the group of dressings for low-exuding wounds, the values of the degree of swelling are in the range from 5.6 ± 0.7 to 11.0 ± 0.6 g/g.
In the group of films, the values of the degree of swelling range from 3.9 ± 0.3 to 7.2 ± 1.2 g/g.
Thus, the ranges of swelling degrees of sponge dressings for high and medium exuding wounds overlap. It can be assumed that the values of the degree of swelling of dressings for highly exuding wounds should start from the value of 14 g/g, for medium exuding - to be in the range from 8 to 14 g/g, for low exuding - below 8 g/g.
Therefore, the division recommended by the manufacturer is very conditional. For example, a sample of the brand UCLOCLEAN is recommended by the manufacturer for highly exuding wounds, while its degree of swelling is 8.5 ± 0.2 g/g.
From the values of the swelling degree kinetics obtained experimentally, the swelling rate constants were calculated. For dressings in the form of sponges for highly exuding wounds, the values of the constants are in the range from 0.047 to 0.1 min 0.028 to 0.062 min-1. However, it is interesting to note that sponges based on polyurethane from different manufacturers have approximately the same swelling rates, in the range from 0.06 to 0.08 min-1.
Rice. Fig. 6. Distribution histogram of the equilibrium values of the degrees of sponge swelling with increasing apparent density
Despite the fact that the swelling rates of the sponges vary significantly, in general, all samples reach equilibrium swelling in 0.5-1.5 h. The films behave somewhat differently: equilibrium swelling is observed after 4 h. In this work, we did not study the processes of drug migration from various polymer matrices under conditions of a completed sorption process, when the diffusion rate of the latter is significantly hindered.
It should be noted that no relationship between the apparent density and the equilibrium values of the degrees of swelling was found (Fig. 6).
The next stage of the work was the study of the physical and mechanical properties of dressings in the dry and swollen state of sponges and films under various deformation conditions (tension and compression) in order to investigate changes in the properties of materials. The data are given in table. 3-5.
Table 3. Changes in the physical and mechanical properties of sponges during tensile testing
Starmedix Foam Dressing
Starmedix Silver Foam Dressing
0.1 ± 0.01 0.29 ± 0.02
0.26 ± 0.04 0.35 ± 0.034 1.0 ± 0.1 0.8 ± 0.05
Dry samples
swollen samples
78.7 ± 10.4 393.9 ± 19.1
433.8 ± 75.0 37.7 ± 7.5 47.7 ± 6.8 32.5 ± 3.5
Yarast MPa
0.1 ± 0.01 0.34 ± 0.04
0.15 ± 0.08 2.3 ± 0.3 6.1 ± 0.9 5.3 ± 0.5
0.024 ± 0.003 2.3 ± 0.2
0.14 ± 0.03 154.0 ± 1.2
The sample is destroyed 0.12 ± 0.026 238.9 ± 42.7
0.095 ± 0.012 0.057 ± 0.0057
120.7 ± 12.9 Forms a gel Forms a gel Forms a gel
0.02 ± 0.007 0.08 ± 0.01
0.096 ± 0.021 0.04 ± 0.002 0.06 ± 0.005
0Dast, MPa
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Table 4. Physical and chemical properties of sponges under compression
Grade "compressed* Mpa Ezhat MPa
Cellonex 0.03 ± 0.002 0.13 ± 0.04
Starmedix Foam Dressing 0.003 ± 0.0002 0.02 ± 0.004
Baymedix 0.005 ± 0.0004 0.05 ± 0.006
Urgostart 0.002 ± 0.0008 0.013 ± 0.0001
Starmedix Silver Foam Dressing 0.005 ± 0.001 0.038 ± 0.006
Vinicrol-M 0.1 ± 0.07 0.8 ± 0.009
Advazorb 0.002 ± 0.0002 0.01 ± 0.002
As a criterion for the atraumaticity of dressings, the modulus of elasticity (E, MPa) was used as a measure of the elasticity of the material, which is a key parameter that determines its comfort for the patient during operation.
From a series of experiments on changing the physical and mechanical properties, it can be seen that the swollen sponges lose their strength properties, and the studied films practically do not change their performance in the wet state. The best mechanical properties in this study are polyurethane films with an acrylic contact layer Bene-hold.
The compressive elastic moduli compared with the tensile elastic moduli for samples of polyurethane sponges without a top film coating (Baymedix, Starmedix Silver Foam Dressing) decrease by 2.2 times. For samples with a film coating, the difference was: Starmedix Foam Dressing - 10 times, Urgostart - 26 times, Advazorb - 15 times. This increase is precisely explained by the effect of the film coating on the strength of the samples.
Despite the fact that the elastic modulus of the sponges decreases with increasing degree of swelling (Fig. 7), which is associated with the plasticizing effect of sorbi-
Rice. Fig. 7. Dependence of the tensile modulus of samples in the swollen state on the degree of swelling (on the example of polyurethane sponges)
Rice. Fig. 8. Dependence of the ratio of elastic moduli in the dry and swollen state of the samples on the magnitude of the degree of swelling (on the example of polyurethane sponges)
liquids, the ratio of the elastic moduli in the dry and swollen state remains practically unchanged (Fig. 8).
In the case of monolayer materials, the lower the modulus of elasticity, the softer and more elastic is
Table 5. Changes in the physicochemical properties of films under tension
Grade Dry samples Swollen samples
Vcr> MPa £, % MPa VcT MPa £, % EpacT MPa
Hyamartix 10.1 ± 2.3 3.3 ± 1.6 335.0 ± 106.2 0.9 ± 0.2 6.3 ± 3.1 1.9 ± 0.8
Biodespol-1 (1) 62.8 ± 6.4 4.5 ± 0.5 2666.7 ± 400 22.8 ± 9.5 6.4 ± 2.3 400.6 ± 53.7
Biodespol-1 (2) 27.0 ± 3.7 4.1 ± 0.3 855.6 ± 361.0 Sample slides
Benehold 11.0 ± 1.5 1056.7 ± 55.0 3.4 ± 0.1 5.6 ± 2.1 932.9 ± 266.2 3.3 ± 0.6
WOUNDS AND WOUND INFECTIONS THE PROF. B.M. KOSTYUCHENOK JOURNAL
0,4 0,35 0,3 0,25 0,2 0,15 0,1 0,05 0
293,1 417,8 605,1 624,9 645,3
medix Silver Foam essing X mk<и Е medix Foam essing ■Q О N a го (Л o
Rpow, g/m2
Rice. Fig. 9. Histogram of the distribution of tensile moduli depending on the surface density on the example of polyurethane sponges (the last three samples are coated in the form of a film)
0,06 0,05 0,04 0,03 0,02 0,01 0
Rice. Fig. 10. Histogram of the distribution of moduli of elasticity in compression depending on the surface density on the example of polyurethane sponges (the last three samples are coated in the form of a film)
the material itself. In the case of multilayer materials (in our version, for sponges), during tensile tests, the modulus of elasticity is determined by the most elastic layer of the multilayer structure of sponges (additional silicone and / or polyurethane film layer), during compression tests, by the porous component of the multilayer material, which was confirmed as a result of the tests (Fig. 9, 10).
Conclusion
The work studied the performance properties (water absorption (swelling) and mechanical properties)
stva) dressings made of individual and multilayer materials produced by several manufacturers and intended for wounds with varying degrees of exudation. It should be noted that the division by the manufacturer of dressings according to the use for wounds with different amounts of exudate is very conditional. As a result of the study, it was calculated that the degree of swelling of dressings for highly exuding wounds should start from 14 g/g, for medium exuding wounds it should be in the range from 8 to 14 g/g, for low exuding wounds it should be less than 8 g/g.
The degree and rate constant of swelling weakly depend on the purpose of the dressings, but are determined by the type of material.
The degree of swelling does not depend on the surface and apparent density, in contrast to the mechanical characteristics.
The most resistant to breaking loads are samples of sponges and films made of polyurethane (in the swollen and dry state), as well as multi-layer dressings (with a silicone layer and/or film-like top coating). The mechanical properties of coatings depend on the surface and apparent densities of porous coatings.
The elastic modulus and deformation-strength characteristics of multilayer materials depend on the load application mode (tension or compression). The mechanical properties of combined (multilayer) materials are determined by the polymer coating in tension; in compression, the properties of the porous sponge will be decisive.
The value of the modulus of elasticity serves as an additional criterion for technical tests for the registration of dressings, which determines the performance of materials under various types of load application.
Due to the fact that there are currently no target standards for modern dressings in the form of sponges and films, the need for their development becomes obvious and relevant. In the meantime, unfortunately, one has to rely on the experience of clinical practice or contact accredited laboratories to study the performance properties of dressings purchased at a specific medical institution.
WOUNDS AND WOUND INFECTIONS THE PROF. B.M. KOSTYUCHENOK JOURNAL
1. GOST 29104.1-91. Technical fabrics. Methods for determining linear dimensions, linear and surface densities. .
2. GOST 9412-93. Medical gauze. General specifications. .
3. GOST 3913-72. Textile materials. Fabrics and handicrafts. Methods for determining discontinuous characteristics in tension. .
4. GOST 409-77. Cellular plastics
and rubber sponges. Method for determining the apparent density. .
5. GOST 15873-70. Plastics are cellular elastic. Tensile test method
LITERATURE
nie. .
6. GOST 24616-81. Elastic cellular plastics and foam rubbers. Method for determining hardness. .
7. GOST 26605-93. Polymer elastic cellular materials. Determination of stress-strain dependence in compression and compression stress. .
8. GOST 29088-91. Materials polymeric cellular elastic. Determination of conditional strength and relative elongation at break. .
9. GOST 29089-91. Materials polymeric cellular elastic. The definition of the
precise compression deformation. .
10. GOST 2439-93. Materials polymeric cellular elastic. Determination of indentation hardness. .
11. GOST 14236-81. Films are polymeric. Tensile test method. .
12. Tsyurupa N.N. Workshop on colloid chemistry. M., 1963. S. 139-40. )
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