Ve specializovaném popáleninovém centru jsou léčeny defekty kožního krytu po popálení, opaření, poleptání, popálení elektrickým proudem, trofické defekty a mechanické traumatické decollement kůže. Podle hloubky postižení klasifikujeme tyto úrazy na I., II. A, II. B a III. stupeň. Ke krytí defektů ran, at už akutních či chronických, je dnes na trhu mnoho různých syntetických (polyuretanové pěny, hydrocelulární materiály, algináty, hydrokoloidy, kryty obsahující sloučeniny stříbra, jodu, chloru, aktivní uhlí, hydrogelové kryty) a biologických krytů (Xe-Derma, Xenoderm). Hydrogely jsou trojrozměrné polymery, které reagují s vodními roztoky, vstřebávají a uchovávají vodu ve svých strukturách. Hydrogelové kryty je možno rozdělit na plošné kryty (Aqua gel), kryty na textilním nosiči (Viacell, Intrasite) a kryty v tubě (Flamigel, Nu-Gel). V této práci jsme se zaměřili na naše zkušenosti s krytem Viacell.

In a specialized burn medical clinic are healed cover skin defects after burns, scalding, electric shock burns, trophic defects and mechanical traumatic skin decollement. According to the depth of affection we classify these injuries of I., II. A, II.B and III. level. To cover the wound defect, whether acute or chronic, there are in these days on the market many different synthetic and biological covers. Hydrogels are three-dimensional polymers, which react with water solutions, absorb and store water in their structures. Hydrogel covers can be divided into surface covers (Aqua gel), covers the textile medium (Viacell, Intrasite) and covers in a tube (Flamigel, Nu-Gel). In this study, we focused on our experience with a cover of Viacell.

• Klíčová slova
• popáleniny,
• MeSH
• hydrogely terapeutické užití   MeSH
• lidé MeSH
• obvazy hydrokoloidní MeSH
• ošetřovatelská péče metody   využití   MeSH
• popálení ošetřování   terapie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH

Pro kinetiku uvolňování prvního řádu je charakteristická lineární závislost rychlosti uvolňování nauvolněném množství léčiva, přičemž trojnásobek absolutní hodnoty exponentu mocninné funkcevyjadřuje reakční fraktální dimenzi DR. Uvolňování skopolaminiumbromidu z hydroxypropylmethylcelulózovéhohydrogelu bylo nejprve vyjádřeno kinetikou prvního řádu s odhadem DR v rozmezí2,98–3,00. Využití mocninné rovnice s exponentem uvolňování n umožňuje předpoklad o mechanizmuuvolňování. V rozmezí n=0,505–0,550 je odhadnuta DR = 2,46–2,94. V této oblasti převládáuvolňování mechanizmem Fickovy difuze. Pro vztah mezi oběma veličinami obecně platí DR=(3/n)– 3, což umožňuje využití poznatků z experimentálního ovlivnění exponentou uvolňování přisledování vztahu mezi reakční fraktální dimenzí a mechanizmem uvolňování skopolaminiumbromiduz hydrogelu. Zvětšení exponentu uvolňování výrazně snižuje odpovídající hodnoty reakčnífraktální dimenze.

First-order release kinetics is characterized by a linear dependence of the release rate on thereleased amount of the active ingredient, the triple of the absolute value of the exponent of theexponential function expressing the reactive fractal dimension DR. Scopolamine bromide releasefrom hydroxypropylmethylcellulose hydrogel was first expressed by first-order kinetics with anestimated DR ranging from 2.98–3.00. The employment of an exponential equation with theexponent of release n renders it possible to make an assumption about the mechanism of release.Within a range of n=0.505–0.550, estimated DR=2.46–2.94. In this region, release by means of themechanism of Fick’s diffusion prevails.DR=(3/n) – 3 generally holds true for the relationship betweenboth variables, which makes it possible to use the knowledge gained in the experimental influencingof the exponent of release in the examination of the relationship between the reactive fractaldimension and the mechanism of release of scopolamine bromide from hydrogel. An increase in theexponent of release markedly decreases the corresponding values of reactive fractal dimension.

• MeSH
• chemické modely MeSH
• farmakokinetika MeSH
• fraktály MeSH
• PEG-DMA hydrogel farmakokinetika   MeSH
• skopolaminové deriváty farmakokinetika   MeSH

PURPOSE OF THE STUDY Articular cartilage defects arise due to injury or osteochondral disease such as osteonecrosis or osteochondritis dissecans. In adult patients cartilage has minimal ability to repair itself and the lesions develop into degenerative arthritis. Overcoming the low regenerative capacity of the cartilage cells and the Hayflick limit poses a challenge for the therapy of osteochondral defects. Composite scaffolds with appropriate biomechanical properties combined with a suitable blend of proliferation and differentiation factors could be a solution. The aim of this in vitro study was to develop a novel functionalised hydrogel with an integrated drug delivery system stimulating articular cartilage regeneration. MATERIAL AND METHODS Injectable collagen/ hyaluronic acid/fibrin composite hydrogel was mixed with nanofibre-based microparticles. These were loaded with ascorbic acid and dexamethasone. In addition, the effect of thrombocyte-rich solution (TRS) was studied. The gels seeded with mesenchymal stem cells (MSCs) were cultivated for 14 days. The viability, proliferation and morphology of the cells were evaluated using molecular and microscopic methods. Scaffold degradation was also assessed. RESULTS The cultivation study showed that MSCs remained viable in all experimental groups, which indicated good biocompatibility of the gel. However, the number of cells in the groups enriched with microparticles was lower than in the other groups. On the other hand, confocal microscopy showed higher cell viability and rounded morphology of the cells, which can be associated with chodrogenic differentiation. The scaffolds containing microparticles showed significantly higher stability during the 14-day experiment. DISCUSSION Our results suggest that the addition of microparticles to the scaffold improved cell differentiation into the chondrogenic lineage, resulting in a lower proliferation rate. Cell viability was better in the groups enriched with microparticles that served as an efficient drug delivery system. In addition, the presence of microparticles slowed down gel degradation which can help achieve sufficient stability of the system for the time frame required for cartilage regeneration. CONCLUSIONS The novel approach described here produced an efficient system where microparticles served as a drug delivery system and stabilised the gel for prolonged periods of time. These characteristics play an important role in the development of scaffolds for cartilage regeneration. In the future the results of these in vitro experiments will be verified in an in vivo study.

• MeSH
• injekce intraartikulární MeSH
• kloubní chrupavka * patologie   účinky léků   MeSH
• lékové transportní systémy * metody   MeSH
• multipotentní kmenové buňky * fyziologie   metabolismus   MeSH
• nanovlákna terapeutické užití   MeSH
• nosiče léků * MeSH
• osteoartróza terapie   MeSH
• PEG-DMA hydrogel terapeutické užití   MeSH
• příprava léků metody   MeSH
• proliferace buněk MeSH
• řízená tkáňová regenerace * metody   MeSH
• techniky in vitro MeSH
• trombocyty fyziologie   metabolismus   MeSH
• Publikační typ
• práce podpořená grantem MeSH

PURPOSE OF THE STUDY: The preclinical study aimed to compare the healing of segmental bone defects treated with biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel with the established autologous spongioplasty. Another aim was to evaluate the hydrogel as a scaffold for osteoinductive growth factor of bone morphogenetic protein-2 (BMP-2) and stem cells. MATERIAL AND METHODS: The study was conducted in an in vivo animal model. A standardized rabbit model of a 15 mm long segmental bone defect of left radius was used. A total of 40 animals were divided into 5 groups of 8 individuals. In the KO- (negative control) group, the created defect was left to heal spontaneously. In the KO+ (positive control) group, the defect was filled with morselized bone autograft prepared from the resected segment. In the study group A, the defect was filled with hydrogel based on hyaluronic acid derivative and tricalcium phosphate. In the study group B, the defect was filled with hydrogel based on hyaluronic acid derivative, tricalcium phosphate and bone marrow aspirate. In the study group C, the defect was filled with hydrogel based on hyaluronic acid derivative, tricalcium phosphate, bone marrow aspirate and BMP-2. Healing was assessed using radiographs at 1, 6, and 12 weeks postoperatively and histology specimens were collected at 16 weeks postoperatively. RESULTS: Altogether 35 rabbits survived (KO- 7, KO+ 7, A 7, B 6, C 8) until the end of the study. As concerns the radiographic assessment, the best results were achieved by the groups KO+ and C, where new bone formation across the entire width of the bone defect was clearly seen at 6 and 12 weeks and the osteotomy line was completely healed too. At 12 weeks, complete bone remodelling was observed in all animals in the group KO+, whereas in the group C, bone remodelling was fully completed in 5 animals and partially completed in 3 animals. In terms of histological assessment, however, the best results were achieved by the group C, where the bone defect was completely remodelled into lamellar bone in 7 specimens, while in 1 specimen it healed with bony callus formation. In the group KO+, the defect was healed in 4 specimens by cartilaginous callus with loci of remodelling into bony callus, in 2 specimens the bony callus was predominant with cartilaginous callus areas, and only one defect was completely remodelled into lamellar bone. DISCUSSION: Compared to autografts that manifest osteogenic, osteoinductive and osteoconductive properties, the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel has osteoconductive properties only. Thus, it was also tested in our study as a scaffold for bone marrow cells and BMP-2 osteoinductive growth factor. Thanks to its semi-liquid properties, the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel is a promising material for use in 3D printing. CONCLUSIONS: The preclinical study in an in vivo animal model confirmed the beneficial effect of the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel on the healing of critical-size segmental bone defects. Better healing of these defects was also confirmed for filling composed of hydrogel and BMP-2 osteoinductive growth factor. The benefit of bone marrow aspirate mixed with hydrogel was not confirmed. KEY WORDS: bone defect, non-union, rabbit, hyaluronic acid, calcium phosphate, stem cells, BMP-2, scaffold, bone healing, spongioplasty.

• MeSH
• fosforečnany vápenaté * farmakologie   MeSH
• hydrogely farmakologie   MeSH
• kostní morfogenetický protein 2 * MeSH
• králíci MeSH
• kyselina hyaluronová * farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• radius chirurgie   zranění   MeSH
• regenerace kostí účinky léků   MeSH
• tkáňové podpůrné struktury * MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

Predmetom tohto príspevku je určiť optimálny polymér pre formuláciu modelového liečiva chlórhexidíniumdichloridu do hydrogélu. Použili sa dva druhy biopolymérov, a to upravené polyméry rastlinného pôvodu zo skupiny derivátov celulózy – metylcelulóza, hydroxyetylcelulóza a hydroxypropylcelulóza – a živočíšneho pôvodu – chitosan o strednej a vysokej molekulovej hmotnosti. Polyméry sa použili v koncentrácii 2,5 % (m/m). Liberácia sa hodnotila percentom uvoľneného liečiva do fyziologického roztoku. Súčasne sa hodnotili aj tokové vlastnosti hydrogélov. Z hľadiska uvoľňovania liečiva z chitosanových hydrogélov sa ako najvhodnejší pre formuláciu hydrogélu ukázal chitosan o strednej molekulovej hmotnosti a z hydrogélov pripravených na báze derivátov celulózy bol to hydroxyetylcelulózový hydrogél.

The aim of this paper was to select the optimal polymer for the formulation of the model drug chlorhexidine dichloride into hydrogel. Two types of biopolymers were used, one of the modified polymers was of herbal origin taken from the group of cellulose derivates – methylcellulose, hydroxyethylcellulose and hydroxypropylcellulose, and the other was of animal origin – chitosan of a medium and a high molecular weight. The polymers were used in a concentration of 2.5% (m/m). Drug liberation was evaluated by the percentage of the drug released into the physiological solution. In addition, the rheological properties of hydrogels were evaluated. Judging the drug release from chitosan hydrogels, the one with the medium molecular weigh was found to be optimal. Contrary to that, from among the hydrogels prepared on the basis of cellulose derivatives, the optimal one was hydroxyethylcellulose hydrogel.

• MeSH
• chlorhexidin normy   terapeutické užití   MeSH
• farmaceutická technologie MeSH
• financování organizované MeSH
• lékové formy MeSH
• nosiče léků farmakokinetika   MeSH
• PEG-DMA hydrogel farmakokinetika   MeSH
• polymery farmakokinetika   MeSH

• MeSH
• hydrogely * terapeutické užití   MeSH
• lidé MeSH
• nádory prostaty radioterapie   MeSH
• radiační ochrana * metody   MeSH
• radioterapie škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH

In order to create a soft tissue surplus, implantable volume expanders are often utilized in dental surgery. Implanted tissue expanders should gradually increase their volume, exerting a constant pressure on the surrounding tissue for weeks. Current tissue expanders are based predominantly on externally inflatable balloons or on osmotically active tissue expanders that use soft hydrogels wrapped in perforated plastic coatings, which limit fluid entry and swelling. We have designed and examined tissue expanders based on the controlled rate expansive hydrogels synthesized from copolymers of selected methacrylates and N-vinylpyrrolidone, cross-linked with a combination of non-degradable (glycol dimethacrylates) and hydrolytically degradable (N,O-dimethacryloylhydroxylamine) cross-linkers. These copolymers have close-to-linear volume expansion rates (up to 6-9 times their original volume) and exert an increasing swelling pressure in vitro. The anesthetic benzocaine has been incorporated into the hydrogels, and kinetic release experiments have shown that most of the drug (90%) was released within 48 h. Our proposed hydrogel expanders are homogeneous and have suitable mechanical properties, thus simplifying the surgical manipulations required. Further studies will be needed to completely evaluate their biocompatibility and tissue response to the implants.

• MeSH
• anestetika aplikace a dávkování   MeSH
• biokompatibilní materiály chemie   MeSH
• hydrogely chemie   MeSH
• hydroxylaminy chemie   MeSH
• kinetika MeSH
• lidé MeSH
• methakryláty chemie   MeSH
• polymery chemie   MeSH
• reagencia zkříženě vázaná chemie   MeSH
• stomatologie metody   MeSH
• tkáňové expandéry * MeSH
• tlak MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Retinoblastoma (Rb) is the most common primary malignant intraocular tumor in children which develops from the retinal stem cells. Systemic chemotherapy is the typical therapeutic treatment and though most children survive Rb, they often lose their vision, or the eye needs to be enucleated. Regarding to the pure availability of the target tumor by systemic chemotherapy, the local anticancer drug administration would be advantageous to increase the local drug concentration and minimize adverse side effects of chemotherapy. The present paper describes a new hydrogel implant enabled to deliver therapeutically active doses of low molecular weight hydrophilic antitumor drugs topotecan and vincristine. The hydrogel implant is proposed as bi-layered with an inner hydrophilic layer from 2-hydroxyethyl methacrylate (HEMA) serving as a reservoir of the chemotherapeutic agent and an outer hydrophobic layer from 2-ethoxyethyl methacrylate (EOEMA) acting as a barrier to protect the surrounding vascularized tissue against cytotoxicity of the delivered chemotherapeutics. The experiments with enucleated pig eyes demonstrated the ability of tested drugs to diffuse through sclera and reach the vitreous humor. HEMA-based hydrogels were examined in terms of sorption, release and transport properties, showing the possibility of adjusting the loading capacity and diffusion of the drugs by the degree of crosslinking. The EOEMA-based gels proved to be an inert for drug sorption and diffusion. A chorioallantoic membrane assay demonstrated excellent biocompatibility of unloaded hydrogels, and in vitro experiments confirmed significant cytotoxicity of drug-loaded hydrogels against a Rb cell line; 2 days for those topotecan-loaded and a minimum of 6 days for vincristine-loaded hydrogels. The bi-layered hydrogel implant can be considered promising for local administration of active agents to eye-globe for the treatment of Rb and also other ocular disorders.

• MeSH
• hydrogely chemie   MeSH
• kinetika MeSH
• lidé MeSH
• methakryláty chemie   MeSH
• nádorové buněčné linie MeSH
• nosiče léků chemie   MeSH
• oči účinky léků   metabolismus   MeSH
• prasata MeSH
• protézy a implantáty MeSH
• retinoblastom metabolismus   patologie   MeSH
• stabilita léku MeSH
• topotekan chemie   metabolismus   farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• vinkristin chemie   metabolismus   farmakologie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Príspevok je zameraný na formuláciu hydrogélu na báze syntetického polyméru s obsahom lokálneho anestetika a hromadne vyrábaného lieku vo forme roztoku s antiflogistickým účinkom. Cieľom tejto štúdie bolo pripraviť hydrogél vhodného zloženia s vyhovujúcimi tokovými vlastnosťami a uvoľňovaním liečiva – lidokaín hydrochlorid. Okrem syntetického polyméru, ktorý zabezpečí zotrvanie lieku na postihnutom mieste, má významné postavenie pri formulácii prítomnosť umelého sladidla, ktoré do veľkej miery ako chuťové korigens ovplyvňuje compliance mnohých pacientov kvôli nepríjemnej chuti liečiva. V štúdii sa sledoval vplyv koncentrácie umelého sladidla – xylitolu na liberáciu liečiva z pripravených hydrogélov. Stanovila sa optimálna koncentrácia umelého sladidla tak, aby neovplyvnila kvalitatívne vlastnosti lieku.

The paper examines the formulation of hydrogel on the base of a synthetic polymer containing a local anaesthetic and a mass-produced drug in the form of a solution with an antiphlogistic effect. It aimed to prepare a hydrogel of a suitable composition with suitable flow properties and drug release, the active ingredient being lidocaine hydrochloride. Besides the role of a synthetic polymer which ensures that the active ingredient remains at the affected site, an important role in the formulation is played by the presence of an artificial sweetener, which to a great extent as a taste correcting agent of the unpleasant taste of the active ingredient influences the compliance of many patients. The study examined the effect of concentration of the artificial sweetener xylitol on the liberation of the active ingredient from prepared hydrogels. The optimum concentration of the artificial sweetener was adjusted to a degree which does not affect the qualitative properties of the active ingredient.

• MeSH
• biologická dostupnost MeSH
• lidé MeSH
• lidokain MeSH
• lokální anestezie MeSH
• PEG-DMA hydrogel MeSH
• xylitol MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The principal focus of this work is the in-depth analysis of the biological efficiency of inorganic calcium-filled bacterial cellulose (BC) based hydrogel scaffolds for their future use in bone tissue engineering/bioengineering. Inorganic calcium was filled in the form of calcium phosphate (β-tri calcium phosphate (β-TCP) and hydroxyapatite (HA)) and calcium carbonate (CaCO₃). The additional calcium, CaCO₃ was incorporated following in vitro bio-mineralization. Cell viability study was performed with the extracts of BC based hydrogel scaffolds: BC-PVP, BC-CMC; BC-PVP-β-TCP/HA, BC-CMC-β-TCP/HA and BC-PVP-β-TCP/HA-CaCO₃, BC-CMC-β-TCP/HA-CaCO₃; respectively. The biocompatibility study was performed with two different cell lines, i.e., human fibroblasts, Lep-3 and mouse bone explant cells. Each hydrogel scaffold has facilitated notable growth and proliferation in presence of these two cell types. Nevertheless, the percentage of DNA strand breaks was higher when cells were treated with BC-CMC based scaffolds i.e., BC-CMC-β-TCP/HA and BC-CMC-β-TCP/HA-CaCO₃. On the other hand, the apoptosis of human fibroblasts, Lep-3 was insignificant in BC-PVP-β-TCP/HA. The scanning electron microscopy confirmed the efficient adhesion and growth of Lep-3 cells throughout the surface of BC-PVP and BC-PVP-β-TCP/HA. Hence, among all inorganic calcium filled hydrogel scaffolds, 'BC-PVP-β-TCP/HA' was recommended as an efficient tissue engineering scaffold which could facilitate the musculoskeletal (i.e., bone tissue) engineering/bioengineering.

• MeSH
• celulosa chemie   MeSH
• hydrogely chemie   MeSH
• hydroxyapatit chemie   MeSH
• kosti a kostní tkáň cytologie   MeSH
• lidé MeSH
• myši MeSH
• tkáňové inženýrství metody   MeSH
• tkáňové podpůrné struktury chemie   MeSH
• vápník chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH