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Use of textile biomaterials for the topic treatment of chronic venous disease - review Received for publication, November 10, 2014 Accepted, December 22, 2014 Daciana Elena Brănișteanu1, Marieta Nichifor2, Carmen Mihaela Dorobăț3, Daniel Constantin Brănișteanu4, Florin Dumitru Petrariu5, Andreea Dana Molodoi6, Doru Cezar Radu7*, Daniel Boda8 Discipline of Dermatology, „Gr. T. Popa” University of Medicine and Pharmacy, Iasi, Romania 2 Department of Bioactive and Biocompatible Polymers, „P. Poni” Institute of Macromolecular Chemistry, Iasi, Romania 3 Discipline of Infectious Diseases, „Gr. T. Popa” University of Medicine and Pharmacy, Iasi, Romania 4 Discipline of Ophthalmology, „Gr. T. Popa” University of Medicine and Pharmacy, Iasi, Romania 5 Discipline of Hygiene-Environmental Health, „Gr. T. Popa” University of Medicine and Pharmacy, Iasi, Romania 6 Department of Dermatology, Municipal Hospital, Roman, Romania 7 Faculty of Textile and Leather Engineering „Gh. Asachi” Technical University, Iasi, Romania 8 Dermatology Research Laboratory, “Carol Davila” University of Medicine and Pharmacy Bucharest, Romania 1 *Corresponding author: Associate Professor Doru Cezar Radu Faculty of Textile and Leather Engineering „Gh. Asachi” Technical University, Iasi Mangeron Bld. 53, Iasi, 700050, Romania Phone – 0232 278628, Fax – 0232 278628 E-mail: [email protected], [email protected] Abstract The topical treatment options for chronic venous disease (CVD) with special emphasis on elastic compression and topical venoactive agents are reviewed and a new, less known, but very interesting topical treatment is presented. Specialists try to replace classical treatments with modern ones, more efficient and which increase the patients’compliance towards them. The controlled release systems of a bioactive principle (PBA) include protecting PBA against degradation or metabolization and prolonging its optimal duration of action (sustained release). New textile biomaterials have been prepared, by chemical or physical application of biopolymers on the textile material, and the load of the biopolymers and biomaterials with rutin, troxerutin and heparin have been tested using physical or chemical methods. The pharmacologically active substance was then gradually released, in a controlled way, at the level of venous endothelium, as a consequence of the prolonged contact of the biomaterial with the skin. The use of textiles as a support for controlled and sustained release of drugs in CVD was rarely mentioned in the speciality literature. This innovating type of textiles is not being commercialized neither at national or international levels. 1 Key words: biomaterial, biopolymer, elastic compression, chronic venous disease, troxerutin 1. Introduction Chronic venous disease (CVD) is defined as a long term decompensation of venous circulation. CVD is a „frontier” disease, in its diagnosis and treatment being involved, besides dermatologists, a range of other specialists: internal medicine physicians, radiologists, vascular surgeons, ophthalmologists, etc. The data in the speciality literature show an increasing high incidence of CVD. At the European level the prevalence of CVD is estimated at 25-50%. [1] In Romania, the data regarding the incidence of this disease was absent until 2004, when the research entitled SEPIA (Epidemiological Study on the Prevalence of chronic venous insufficiency in Romania in Ambulatory) demonstrated, in a rigorous scientific manner, that CVD was a public health problem in Romania as well (32% of the patients enrolled in the study presented symptoms of CVD). [2] The early stage therapeutically action, even from the first CVD stages, may considerably diminish the social and medical impact of the disease and increase the patient’s quality of life. The increase of the people’s quality of life is nowadays a predominant and continuous concern for the international scientific research. [1, 3, 4, 5] The main compressive and topical venoactive therapies for CVD are reviewed in this review. Current therapeutic options target the control of symptoms and skin lesions and also to prevent related complications of CVD. The therapeutic means suggested for CVD are: external elastic compression, the supine, sclerotherapy, flebotonics, surgical, balneary treatment and hygiene. Never the less, the leg ulcer still raises problems from the therapy point of view. [6, 7, 8, 9] Based on the literature data emphasizing the importance of compression therapy and topical vasoactive medication in CVD, a new topical treatment that synergistically combines them has been designed. [2, 3, 6, 7] Another aim of this review is to demonstrate the chemical, biochemical, pharmacological, medical and technological superiority of a new textile biomaterials for the topic treatment of CVD. These biomaterials were made by grafting the polymers on textile supports and including the drugs used in the CVD topic treatment in the obtained grafted structures. 2. Topical venoactive medication in CVD Venoactive drugs are a heterogeneous group of medicinal products of synthetic or plant origin. Their biovariability can be improved by certain chemical steps. Other steps are the result of chemical synthesis. Mode of action: antiedema effect (decrease in capillary permeability, improved lymphatic drainage, reduction of edema due to prolonged standing); increased venous tonus; inhibition of leukocyte adhesion to valve wall, inflammatory mediator release, leukocyte adhesion and prostaglandin synthesis; moderation of inflammatory reactions in venous valves, process that may lead to their dysfunction, reflux, and elevated upstream venous pressure; powerful antioxidant effect (flavonoids); antiaggregant effect, reducing blood viscosity and erythrocyte deformation; effect on venous pain not responding to nonsteroidal anti-inflammatory drugs. [10, 11, 12, 13, 14, 15] 2 The topical venoactive drugs available in our country and most commonly used by the specialists include mucopolysaccharide polysulfuric acid esters 300mg/25.000 IU (Hirudoid® gel or cream), troxerutin (Venoton® or Troxevazin® gel 2%, Venoruton® gel 4%) and heparin 30.000/50.000 IU (Hepathrombin® gel/ointment) or 100.000 IU (Lioton® gel). 3. Compression therapy in CVD External compression (elastic stockings, elastic bandages or edema reducer) is at the moment the most modern method of fighting against venous stasis, being used in approximately 71% of the CVD patients. It is effective in treating phlebohypertony, normal return circulation, reduces edema and determines the healing of skin trophic lesions. [3] The clinical effects of compression therapy depend mainly on two factors: rigidity and surface pressure. Surface pressure is the pressure exerted by a compression device on a specific area of the skin. Rigidity is defined as the elevated surface pressure induced by the increase in circumference of a specific portion of a limb during muscle contraction. [17, 18, 19] Also, to be effective elastic compression should be adapted to the patient (stronger in over weight and obese patients), corresponding to CVD stage, selective (to exert less pressure on painful areas), concentric (with similar pressure exerted over the whole leg). [20, 21] In the treatment of CVD active compression is indicated. It is defined as the force exerted by an elastic bandage actively acting on a segment during rest or physical exercise. Tissues are continuously compressed with a pressure that does not vary during exercise. Depending on the pressure they exert elastic stockings are divided into four classes: class I (light compression) used in: functional CVD, varicose veins, small pregnancyrelated varicose, pressure exerted 18.4-21 mmHg; class II (medium compression) used in: venous ulcer healed, CVD after sclerotherapy or stripping, post-thrombotic syndrome in patients with vesperal edema, pressure exerted 25.8-32.3 mmHg; class III (strong compression exerted on the deep veins) are indicated in: CVD associated with lymphedema in the onset stages of lipodermatosclerosis, posttrombotic syndrome with significant edema and in venous ulcer stage; exerted external pressure 36.5-46.6 mmHg; class IV (extra-strong compression) used in: pelvic limb elephantiasis and advanced stages of lipodermatosclerosis; they exert strong pressure that exceeds 59 mmHg, also acting on the deep veins. [3, 17, 18] Optimal compression is still under discussion. Compression stockings exerting a pressure of 10-20 mmHg limit or prevent edema, while the compressive effect on the deep venous system occurs at a pressure of 40 mmHg. In prescribing compression stockings their length is also considered: short stockings (bass jarret), knee-length, very well tolerated and most commonly used; long stockings (bass cuisse), ½thigh-high or thigh-high; stockings also covering the pelvis (pelvibas); stockings also covering the abdomen (gravibas). [3, 18] According to leg circumference the following compression stockings are available: stockings for thin leg (circumference 25 cm); stockings for medium-thick legs (circumference 38 cm); stockings for thick legs (circumference over 64 cm). [17, 18, 19, 20] 4. Selection and obtaining of biomaterials The procurence of textiles with biomedical activity has had so far 2 obvious directions: transdermal systems used for the topic administration of drugs with systemic activity. In this case, the skin is just a barrier which has to be penetrated by the 3 active principle, in the presence of permeation enhancers, the drug’s activity happening after this one arrives in the blood circulation (transdermal patches such as Nicoderm® and Transderm Nitro®); textiles (clothes) processed by means of adding on their surface multifunctional layers / grafts with the role of barrier against some factors that may affect skin and, implicitly, the human body (fire, temperature differences, UV rays, insects, microbes etc.). [3] Selection and obtaining of biomaterial are the interface for several fields of activity: fine organic synthesis, polymers science, pharmacology, biochemistry, textiles and dermatology. The textile materials had to be functionalized, in order to create on the surface reservoirs, from which enough biomolecule can be released to its action site. [22] Two biomaterials that were called biomaterials I or II, were prepared by chemical or physical treatment of knitted material based on a mixture of polyamide/elastic. Among the topically active drugs in CVD, the rutin, troxerutin and heparin were tested. The textile product was assessed functionally, aesthetically and chemically, from the point of view of the polymers and drugs integrity. [3, 7, 23] Many aspects that may impact on the biomaterials efficiency have been investigated: type of textile, fiber composition, finishing technology, the way of grafting the polymer on the textile support and the way of including the drugs. In particular, we were interested to test diferent venoactive drugs in the same biomaterial to establish the most potent one. The obtained biomaterials have been tested in vitro and in vivo (on laboratory animals) from the point of view of the release speed, biological activity, tolerance and toxicity. Finally, the most performant biomaterial was selected for being tested on patients. [3, 23] 4.1 Oligosaccharides and polysaccharides Oligosaccharides and polysaccharides are often used in making the textiles for the aim mentioned above. Thus, cyclodextrins (CyD), which have a hydrophobic cavity capable of including many hydrophobic substances, were physically or chemically placed on knitted materials or fibers, for including insecticides, flavors and antimicrobial composites. [23, 24] The chitosan (Ch) (the most abundent polysaccharide after cellulose), deriving from chitin, was very often used in making textiles, for its intrinsic antibacterial properties and for improving the quality of textiles coloring. At the same time, microcapsules of chitosan containing flavors and hydrating products were commercialized under the name of Skintex®. [22, 23, 25] These textiles last for only 2-3 washing cycles, after that the active oligo and polysaccharides being removed. [23] Their use for the controlled release of drugs in the dermatological area was not mentioned in the speciality literature. 4.2 Obtaining of type I biomaterials Biomaterials I were obtained by grafting functional compounds with acrylic double bonds on the textile material. For this purpose, new acrylic derivatives were synthesized or comercial monomers were used. All monomers chemical structure was assessed by Nuclear Magnetic Resonance (NMR) and Fourier Transformed Infrared (FTIR) spectroscopy and their purity was confirmed by thin layer chromatography. [23] Acryloyl troxerutin (AT) and Acryloyl β-cyclodextrin (A-CyD) were synthesized by direct esterification of troxerutin or cyclodextrin with acryloyl chloride in dimethylformamide DMF (figure 1, where R-OH is troxerutin or CyD). As a function of molar ratio troxerutin/acryloyl chloride, two derivatives were obtained: AT 1 and A-CyD 1, with 2 acryloyl groups/molecule, or AT 2 and A-CyD 2 with a higher content of the acryloyl groups/molecule. 4 O O TEA R OH + Cl C CH R O CH2 CH C DMF CH2 Fig. 1. Reaction scheme for the synthesis of acryloyl derivatives of troxerutin (AT) or β-cyclodextrin (A-CyD). TEA =triethylamine Glycidyl methacrylate (GMA) is a commercial monomer, with a functional glycidyl group able to chemically bind nucleophilic molecules such as troxerutin. Type I biomaterials were obtained by grafting the acrylic monomers on the polyamidic material, according to the reaction scheme presented in figure 2, followed, when necessary, by complexation (A-CyD) or chemical binding (GMA) of troxerutin. After the impregnation with an initiator solution, the textile fabric was either sprayed on one face or immersed into the monomer solution. Thus, a material with a bioactive layer on one face or on both faces was obtained. [23] Then the material was left for 6 hours in thermostated oven at 60-70˚C. The amount of grafted polymer was determined by the difference of weight between the treated and not treated material, and it was of 4-6 g% for the spraying procedure and 10-25 g% for the immersion procedure, both for AT and A-CyD derivatives, but lower than 2 g% for GMA. O C NH O Initiation (NH4)2S2O8 (CH2)5 CN Grafting Acryloyl - R Polyamide 6 (CH2)5 CH2 CH2 R1O -cyclodextrin OR1 troxerutin O or R1O glycidyl O OR1 CH2 R= C O O OR1 R O O OR1 O 7 O O O O OH O R1= H or C CH CH2 OH OH O OH O O OH CH3 OH OH Fig .2. Grafting of AT on polyamide material (PA) Materials based on CyD monomers were finally immersed in 1% (g/v) drug solution in methanol/water (6/1), for 48 hours. The resulting PA-T biomaterials contained up to 25 g% troxerutin, PA-CyD 0.16-0.46 g troxerutin and 13 g% rutin. The higher rutin retention was due to its higher hydrophobicity. [23, 26, 27] Grafting efficacy of synthesized biomaterials was evaluated by elemental analysis and FTIR reflexion spectroscopy, and surface morphology was highlighted by optical and scanning electronmicroscopy (SEM), as previously reportedby other authors. [3, 27, 28] 4.3 Obtaining of type II biomaterials Biomaterials II were obtained by covering the surface of the textile material with microparticles that can retain the drug through electrostatic interactions or physical adsorption. The microparticles were synthesized from different polysaccharides: 5 Chitosan microparticles containing troxerutin or heparin. Drug loading was realized either after microparticle synthesis (CH-a and CH-b), or by synthesis of microparticles from the pre-formed mixture of chitosan-drug. CH-a and CH-b microparticles contained 16-20g% heparin and 33 g% troxerutin; CH-b1 retained 50 g% heparin and 15 g% troxerutin; Carboxymethyl dextran (CMD) microparticles, which bound about 22 g% troxerutin by chemical attachment; Carboxymethylated pullulan/sulfo-propionat in association with cyclodextrin microparticles retained an unsignificant amount of troxerutin. [23] The microparticles were characterized by elemental analysis, water retention capacity and optical microscopy. Their fixation on the textile material surface was realized with a binder (polyethylenglycol – PEG MW 4000, epoxysiloxane), followed by drying at room temperature. The fixation yield was almost 100% and optical microscopy indicated PEG as the best binder. [3, 23] 4.4 In vitro tests In vitro release tests of troxerutin from the biopolymers or biomaterials were performed by IMC in solution simulating legs sweat content (0.73 meq NaHCO3/l, 2.41 meq KCl/l, 30.60 meq NaCl/l, pH 5.35). The amount of troxerutin released in the medium was quantified by UV analysis. Biomaterials I released troxerutin faster than their precursor biopolymers, with a burst effect in the first 1-2 hours, followed by a slow release, with almost zero release rate. CH-a and CH-b released troxerutin very fast (90% in 20 minutes), while CH-b1 released about 40 – 50% troxerutin within the first 60 minutes, but after that a slower and more constant release was observed (about 0.5%/hour). The release of troxerutin chemically linked on the carboxymethyl dextran microparticles takes place much slower than the release of the drug physically included into the microparticles. Thus, approximately 10 days later, only 10-12% of the troxerutin quantity is released. This release is conditioned by breaking the esteric connections between the polymer network and troxerutin. The relatively slow release of troxerutin may be an advantage in obtaining a system with a prolonged drug release. [23] In order to get information on biomaterials capacity of acting as controlled release systems on the skin, several biomaterials were prepared, containing either troxerutin or fluorescently marked heparin, in order to be tested on lab animals and establish which biomaterial is the most efficient, in terms of the release speed and the drug quantity arriving at the level of the venous endothelium for a longer period of time (sustained continuous release). [12, 23, 26] 4.5 In vivo tests For preparation parts a compression stocking were used, with a surface of approximately 2 28 cm . All materials were treated on one face. The drug release from the biomaterial and its presence in the skin and the legs venous network was tested on laboratory animals: rats/rabbits/guinea pigs. The textile material was placed on their back, after being shaved. The experiments were focused on the release of the active pharmacological principle from the fabric impregnated with biopolymers. Biopsies were taken from the treated skin, fixed with paraformaldehyde, cut at the cryostat and then examined by means of epifluorescence microscopy and confocal laser microscopy. The presence of the fluorescent drug molecules were examined in different skin layers, in dynamics, at 3 and 6 hours. [3, 27, 28] 4.6 Tested biomaterials Two sets of biomaterials included in table 1 and 2 were tested, in order to choose the biomaterial with the most adequate features to the CVD treatment. [3, 23] 6 Table 1. Set I of biomaterials Sample code Characteristics A1 Biomaterial I with physically embedded rutin (PA- CyD) B1 Biomaterial I, with chemically bound trexorutin (PA-T) C1 Biomaterial II (1) with fluorescently marked heparin (CH-a) C2 Biomaterial II (2) with fluorescently marked heparin (CH-b) C3 Biomaterial II (3) with fluorescently marked heparin (CH-b1) Table 2. Set II of biomaterials Sample Type Biopolymer Binding mode Contents code biomaterial troxerutin troxerutin, g% T1 I PA- CyD physical 0.46 T2 I PA-T chemical 25.0 T3 II CH-a physical 33.0 T4 II CH-b physical 15.4 T5 II CH-b1 physical 9.8 T6 II CMD chemical 21.3 For the synthesis of high amounts of biopolymer used for the treatment of compression stockings, acryloyl troxerutin was synthesized, in 5 turns of 20 g of troxerutin initially in the reaction medium, according to the method described for AT-2 (soluble acryloyl troxerutin in a mixture water/ethanol 1/2 and containing several groups of acryloyl). The average efficiency per turn was of 80%. [3, 23, 24] 4.6 Clinical studies on patients The patients in different stages of CVD had been selected, except for the active chronic leg ulcers, because of the difficulty in performing the venous doppler ultrasound in this stage and of elastic contention.[3] Before treatment, the patients were clinically examined from the dermatological point of view (establishing the CVD stage) and the general status (finding associated diseases or diseases which may turn it into more serious the CVD – cardiologic and ophthalmologic examination). The aim of the ophthalmological examination was double: on one hand it was assessed the patient’s peripheral vascular status, which facilitated the general clinical evaluation, and on the other hand it was obvious its evolution during the clinical evaluation, as well as the occurance of the eventual retine side effects to the studied medication. Besides the clinical examination of the back segment, secondary paramenters were also followed: previous segment aspect (lens, cornea), visual acuity (VA), intraocular pressure (IOP) and chromatic feeling. The data obtained represent arguments for the lack of ocular problems during the treatment. Moreover, no obvious disturbances were noticed at the level of the retine’s structure or the back segment components and no problems were found from the point of view of VA, IOP or chromatic feeling. [3, 7] There were added some paraclinical data regarding the functionality and localization of the profound and superficial leg venous system disturbances (biological investigations and leg venous doppler ultrasound). [29] The CVD evolution under the well known treatments have been monitored and recorded for six months. Then, for other six months, the patients undertook a treatment with the new elastic compression stocking releasing in a controlled way the pharmacologically active active substance, used in CVD treatment. At scheduled intervals of time there have been appreciated the tolerance and toxicity of the new treatment. The most efficient drug was recorded or association of drugs embedded in polymers and released in a controlled manner from the fabric. Manometry was used to assess the fabric quality of stocking and its ability to perform optimal elastic contention. The clinical and paraclinical results were 7 evaluated and the statistical analysis was performed. The design of clinical study and its results have already been presented in detail by the autors in previously published articles [3, 7, 23]. 5. Conclusions The synthesis of type I and II biomaterials and there in vitro and in vivo behavior demonstrated the following aspects: type I and II biomaterials preparation included setting the synthesis conditions of the biopolymer and their precursors (3 monomers), as well as establishing the most adequate procedure for polyamide fabric impregnation. In vitro release experiments showed that both biomaterials types (I and II) with chemically bound troxerutin might ensure a sustained drug release. In vivo experiments on animals with biomaterials I and II with physically or chemically linked troxerutin demonstrated that the biomaterial I with chemically linked troxerutin released the drug for a longer period of time (about 10 days) and with a higher concentration than the one obtained for the physically linked troxerutin or for troxerutin administered as ointment; type I biomaterial, with chemically linked troxerutin was the most adequate for obtaining medical stockings, which cumulate the elastic contention effects with the ones of controlled and prolonged transfer of troxerutin. The results of the clinical testing confirmed the viability of this material to be used on local treatment for CVD. The use fulness of compressive therapy and topical phlebotropic medication has been demonstrated long time ago and was confirmed by the current international guidelines on the management of CVD. The aim of this review was to demonstrated the superiority of this therapeutic option combining two of the most modern therapies for CVD: elastic contention and topic treatment (with phlebotonic drugs, capilarotrophic drugs, heparinoids, anti-inflammatory drugs, etc.). Using the controlled and sustained release of the pharmacologically active principles, their efficiency will be optimized and a substantial drug economy will be made, which will be available where and when it is needed. The increase of patient’s compliance with the new therapy will be based on the increased efficiency of the treatment which is easy to be administered. The performance of this treatment, without any risks, in prophylactic scope, to the patients with high risks in developing CVD, will be an efficient method of preventing the disease. 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