La peau est un organe à l'architecture complexe qui assure plusieurs rôles essentiels dont celui de barrière contre les agressions extérieures. De plus, il est capable de se régénérer grâce un processus hautement régulé: la cicatrisation. Des biomatériaux, synthétisés à partir de macromolécules d'origine naturelle et/ou synthétique, ont été développés pour servir de pansements, de support de culture cutanée ou de substitut cutané.L'originalité de notre étude a été de mimer, non pas la matrice extracellulaire dermique, mais le réseau de fibrine, temporaire, qui apparait lors de la cicatrisation. Au cours de travaux précédents, il a été démontré qu'il était possible de renforcer mécaniquement un réseau de fibrine, à concentration physiologique, en l'associant, dans une architecture de réseaux interpénétrés de polymères (RIP), avec un réseau de polyoxyde d'éthylène (POE). Durant mes travaux, la non toxicité de ces matériaux envers des cellules modèles a été démontrée. Puis, la composition du matériau a été optimisée pour augmenter son module de stockage jusqu'à un facteur 100 par rapport à celui du gel de fibrine. Ensuite, grâce à la synthèse d'alcool polyvinylique méthacrylate (PVAm) pour le remplacement du POE, un matériau présentant mêmes qualités, mais plus facilement stockable à l'état déshydraté et complètement réhydratable, a pu être obtenu. Nous nous sommes ensuite attachés à rendre ce nouveau matériau biodégradable. L'introduction de sérum albumine bovine méthacrylate (BSAm) copolymérisée avec le PVAm (co-réseau) dans une architecture RIP avec un réseau de fibrine a permis de synthétiser un matériau hydride présentant l'ensemble des propriétés précédemment décrites et dégradable par des enzymes. Ce matériau a été testé en contact avec des populations cellulaires fibroblastiques. Il a pu être démontré, qu'en plus d'être non cytotoxique, ce matériau pouvait être totalement colonisé par ces cellules. Pour finir, l'encapsulation de cellules à l'intérieur de cette matrice et leur prolifération ont pu être observées. En conclusion, les matériaux synthétisés lors de ces travaux, c'est-à-dire des RIPs associant un réseau de fibrine à la concentration physiologique et un réseau de polymère synthétique, possèdent les propriétés nécessaires pour être utilisés en tant que pansements et supports de culture pour la régénération cutanée. De plus, la possibilité d'encapsuler des fibroblastes dans le RIP à base de coréseaux de PVAm et BSAm en fait un substitut cutané potentiel.Mots clefs : hydrogel, réseaux interpénétrés de polymères, fibrine, POE, PVA, BSA, encapsulation cellulaire, fibroblaste, médecine régénérative, peau.

Les maladies ostéoarticulaires représentent environ 10% de l’ensemble des pathologies identifiées en France chaque année. Ces maladies inflammatoires et dégénératives des articulations sont pour la plupart consécutives au vieillissement ou à un traumatisme et évoluent vers l’usure des cartilages, d’où un handicap sévère. Comme aucun traitement ne permet la réparation totale du tissu cartilagineux, la recherche médicale développe des techniques d’ingénierie tissulaire. Ces techniques utilisent des substrats polymériques et des cellules souches qui sont « contraints » de se développer pour former du tissu cartilagineux. Cependant, ces techniques ne peuvent pas encore être utilisées à l’échelle d’une articulation complète car il n’est pas possible de reproduire ex vivo à grande échelle la structure et les propriétés mécaniques et physicochimiques du cartilage articulaire. Dans ce contexte, les travaux de cette thèse ont permis de développer des matériaux polymères capables d’être implantés à l’échelle macroscopique dans les articulations pathologiques afin de combler l’usure des cartilages. Pour se faire, de nouveaux biomatériaux - hydrogels p(HEMA) - ont été obtenus en contrôlant le caractère hydrophile des hydrogels p(HEMA) au cours de leur synthèse chimique en présence de différents co-monomères (acide acrylique, acrylamide, acrylate d'éthylène et acrylate de butyle). Partant de là, les propriétés physicochimiques, mécaniques et tribologiques de ces nouveaux hydrogels ont été optimisées afin d’obtenir des propriétés similaires à celles du cartilage articulaire sain. Ensuite, la libération contrôlée de médicaments par ces hydrogels a été étudiée afin de minimiser les risques inflammatoires lors de leur utilisation en ingénierie tissulaire du cartilage articulaire. / Osteoarticular diseases re present approximately 10% of all diseases identified in France each year. These inflammatory and degenerative joint disease are mostly consecutive with age or injuries and the wear progress of cartilage, resulting in severe disability. Because no treatment will total repair the cartilage tissue, medical research is developing techniques based on tissue engineering. These techniques use polymer substrates and stem cells that are "forced" to develop into cartilage tissue. However, these techniques cannot be used across a run articulation because Il is not possible-to replicate ex vivo a large-scale structure and the physicochemical and mechanical properties of articular cartilage. In this context, the purpose of this thesis is to develop polymer materials that can be implanted at the macroscopic level in the joints disease that will fill the wear of the cartilage. To do so, new biomaterials - hydrogels p (HEMA)- were obtained by controlling the hydrophilic nature of hydrogels p (HEMA) during their chemical synthesis in the presence of various co-monomers (acrylic acid, acrylamide, acrylate ethylene and butyl acrylate). From there, physicochemical, mechanical and tribological properties of these novel hydrogels have been optimized to obtain similar properties to those of healthy articular cartilage. Then, the controlled release of drugs from these hydrogels was studied to minimize inflammatory when used in tissue engineering of articular cartilage.

Made available in DSpace on 2016-06-02T18:55:28Z (GMT). No. of bitstreams: 1 6339.pdf: 1320900 bytes, checksum: ceafdc5598f1fbb6c687c57d58657bc1 (MD5) Previous issue date: 2014-08-07 / Universidade Federal de Sao Carlos / The seasonal semideciduous forests from southeastern Brazil have high plant species richness, but have been strongly affected by human interferences, which let them very degraded: nowadays they are represented by small isolated fragments, immersed in a landscape dominated by agriculture and large urban centers. In this sense, the ecology of restoration arises in order to facilitate, accelerate and direct the processes of secondary succession to manage such areas, considering the knowledge about theoretical concepts that aim to review the effectiveness of natural ecosystem management techniques and practices. In such a perspective, we aimed in this experiment to test the following question: During de production of seedlings of the native forest tree species, Ceiba speciosa (Malvaceae) and Handroanthus heptaphyllus (Bignoniaceae), different dilutions of hydrogel associated to irrigation with reused water, could improve their development? To answer this question, we selected three treatments (1g, 4g and 8g of hydrogel), beyond the witness (no hydrogel). The seedlings of both species were irrigated during one month with water reused and water supply. After this period, we estimated the growth of seedlings: roots, height and diameter. We used ANOVA (p = 0.001), and Tukey s test to verify significative differences between the mean of the treatments. We found significative differences in both height and diameter growth from 4g of hydrogel as to C. speciosa as H. heptaphyllus. In relation to the growth of root system of both tree species, the mean of superficial root area differed significantly from 4g of hydrogel when compared to the witness, confirming our initial assumption that the roots would grow in a lower proportion of area because they are in their hydric comfort zone. With such results added to theoretical knowledge in the ecology of restoration, the association of hydrogels with reused water comes to stand up for the sustainable use of water in the irrigation of native seedlings. / Apesar das florestas estacionais semideciduais do interior do estado de São Paulo possuir elevada riqueza de espécies, as interferências humanas deixaram esses ecossistemas degradados e representados por pequenos fragmentos isolados, imersos numa paisagem dominada pela agricultura e centros urbanos. Diante essa problemática, a restauração ecológica surge com o objetivo de facilitar, acelerar e direcionar os processos sucessionais naturais a fim de manejar essas áreas, considerando os novos teóricos da ecologia de comunidades vegetais tropicais, que pretendem revisitar a eficácia de técnicas de manejo em restauração ecológica. Nesta perspectiva, surge como objetivo desse trabalho, testar a pergunta científica: O uso de polímeros hidrogéis em diferentes concentrações na produção de mudas nativas de Ceiba speciosa (Malvaceae) e de Handroanthus heptaphyllus (Bignoniaceae), associados à irrigação com água de reúso tratada, interfere significativamente no crescimento de seu sistema radicular, sua altura e diâmetro, e aumenta a longevidade das mudas? Para responder a essa pergunta, utilizou-se mudas das duas espécies nativas, em três tratamentos (1g, 4g e 8g de hidrogel), além da uma testemunha, contendo apenas o solo. As mudas foram irrigadas por um mês com água de abastecimento e água de reúso tratada; depois de cessadas as irrigações, foram avaliadas os estimadores citados. Foram realizadas análises de variância (p = 0,001), seguidas do teste de Tukey para verificar diferenças significativas entre as médias dos tratamentos. Verificaram-se diferenças significativas no crescimento em altura e diâmetro a partir do uso de 4g de hidrogel, tanto para C. speciosa quanto para H. heptaphyllus. Em relação ao sistema radicular, as médias de área superficial diferiram-se estatisticamente a partir de 4g de hidrogel quando comparadas às testemunhas, tanto para C. speciosa quanto para H. heptaphyllus, confirmando a expectativa inicial de que com hidrogel, as raízes cresceriam em menor proporção em área porque estariam na zona de conforto hídrico. Com esses resultados aliados aos conhecimentos teóricos da ecologia da restauração, a associação de polímeros hidrogéis com água de reúso vem defender a racionalização do uso da água na irrigação de mudas de espécies nativas, reaproveitando águas de reúso que seriam descartadas em águas superficiais.

Submitted by Fabiana Gonçalves Pinto (benf@ndc.uff.br) on 2015-12-07T14:06:03Z No. of bitstreams: 1 Luciana Miranda Rodrigues.pdf: 2906831 bytes, checksum: c63fff07e6a85a3c8689b9aadbab96a2 (MD5) / Made available in DSpace on 2015-12-07T14:06:03Z (GMT). No. of bitstreams: 1 Luciana Miranda Rodrigues.pdf: 2906831 bytes, checksum: c63fff07e6a85a3c8689b9aadbab96a2 (MD5) Previous issue date: 2010 / Mestrado Acadêmico em Ciências do Cuidado em Saúde / Este estudo teve como objetivos avaliar a efetividade do hidrogel 2% em pacientes com úlceras de perna; estimar o custo médio do uso do hidrogel 2% num período de 90 dias e comparar o custo do uso do hidrogel 2% em pacientes com úlceras de perna com hidrogéis industrializados disponíveis no mercado nacional. Trata-se de um estudo de intervenção terapêutica, prospectivo, do tipo ensaio clínico não controlado sobre a avaliação do uso do hidrogel 2% produzido na farmácia universitária para o tratamento de feridas em pacientes com úlceras de perna. A amostra constou de 20 voluntários, de ambos os sexos, para 90 dias de tratamento com o hidrogel a 2%, totalizando 250 consultas durante o período de fevereiro a outubro de 2010. Este estudo foi encaminhado ao Comitê de Ética em Pesquisa do Hospital Universitário Antônio Pedro sob o parecer CAAE n0 0154.0.258.000-08 e os termos de consentimento livre e esclarecido e de fotografia encontram-se de acordo com as Resoluções n0 196/96 e 251/97 do Conselho Nacional de Saúde. Do grupo amostral, pôde-se identificar que 62,5% dos voluntários eram predominantemente do sexo feminino. A idade média variou de 60,5 anos ± 11,4 e que 52,25% residiam no município de Niterói. Em relação à análise da evolução clínica das úlceras de perna, pôde-se observar que surgiram dois grupos distintos com relação ao tamanho da área da lesão, sendo estas classificadas no estudo como, área 1 – para lesões com tamanho acima de 100 cm 2 e área 2 – para lesões com tamanho abaixo de 100 cm 2. O tecido de maior prevalência na avaliação inicial foi o tecido de esfacelo que apresentou uma média de 3,75 ± 1,2 de presença no leito da lesão dos voluntários do estudo. Destaca-se ainda, que após 90 dias de tratamento com o hidrogel a 2%, foram observadas alterações teciduais importantes para a cicatrização e/ou redução da área lesional (p=0,0416). A presença do tecido de granulação passa a prevalecer com uma média de 3,12 ± 1,0 e 25% dos voluntários obtiveram cicatrização total (100% de tecido de epitelização). Em relação à análise dos custos do tratamento com o hidrogel a 2% destacou-se inicialmente que o tratamento das úlceras pertencentes à área 1 foi maior que a das úlceras da área 2, sendo esta variação de R$114,40 a R$393,23 (M= R$227,55 e Dp=72). Ao comparar o tratamento das úlceras de perna com hidrogel 2% 100 gramas com outros hidrogéis disponíveis no mercado nos valores proporcionais a 100 gramas observou-se uma diferença significativa (p= 0,0003) para os valores referentes às áreas 1 e 2 em todas as perspectivas estudadas. Os valores variaram de acordo com o tamanho das áreas da lesão. A área 1 teve uma variação de preço de R$ 112,85 a R$ 912,11 nas três esferas estudas e a área 2 variou de R$ 70,75 a R$ 558,88 nas três perspectivas do estudo. Ao analisar os custos e a efetividade do uso dessa terapêutica, verificou-se que o hidrogel a 2% apresenta uma efetividade significante assim como os seus custos, não sendo justificável a sua não utilização nos serviços de saúde. O hidrogel a 2% manipulado magistralmente numa farmácia universitária representa uma alternativa para essa situação, uma vez que promove melhora das taxas de cicatrização, com diminuição do tempo de tratamento dessas úlceras, além de ser um tratamento de baixo custo, se comparado a outros hidrogéis industrializados disponíveis no mercado nacional, trazendo menores gastos para os serviços de saúde e órgãos de financiamento. / This study aimed to evaluate the effectiveness of hydrogel 2% in patients with leg ulcers, estimate the average cost of using the hydrogel 2% within 90 days and compare the cost of the use of hydrogel 2% with others hydrogels industrialized. This is a study of therapeutic intervention, prospective clinical trial, uncontrolled on evaluating use of hydrogel 2% produced in the pharmacy college in the treatment of wounds in patients with leg ulcers. The sample consisted of 20 volunteers of both sexes, during 90 days of treatment with the hydrogel to 2% to 250 consultations during the period from February to October 2010. This study was submitted to Committee on Research Ethics at University Hospital on advice CAAE number 0154.0.258.000-08 and terms of consent and photography are in accordance with Resolutions 196/96 and 251/97 of the National Health Council. Of this sample group, could be identified that 62.5% of the volunteers were predominantly female. The mean age ranged from 11.4 ± 60.5 years and 52.25% lived in Niterói. On the analysis of clinical outcome of leg ulcers, it was observed that emerged two distinct groups with respect to the size of the lesion area, which are classified in this study: area1 - for lesions with a size greater than 100 cm2 and area 2 - for lesions with size below 100 cm2. About these group it was noted that the tissue with the highest prevalence at baseline was the desvitalization tissue that showed presence an average 3.75 ± 1.2 of the wound bed. After 90 days by treatment with hydrogel 2%, it has obtained tissue with an important changes to healing and / or reduction area lesion (p = 0.0416). The granulation tissue presence begins to prevail with an average 3.12 ± 1.0 and 25% these volunteers had total healing (100% epithelization tissue). On the costs analysis with hydrogel 2% treatment it has initially the ulcers belonging area 1 was higher than the second area of ulcers, and this variation was the R$ 114.40 to R$ 393, 23 (mean = R$ 227.55 and dv = 72). When comparing the treatment of leg ulcers with hydrogel 2% 100 grams with other commercially available hydrogels in proportionate amounts to 100 grams there was a significant difference (p = 0.0003) for the values related to areas 1 and 2 in all perspectives studied. The values ranged with the size of the lesion areas. The area 1 had a variation in price from R$ 112.85 to R$ 912.11 and the area 2 ranged from R$ 70.75 to R$ 558.88 on the three perspectives of the study. Analyzed the costs and effectiveness using this therapy, it was found that hydrogel 2% shows a significant efficacy as well as their costs are not justified in not using health services. The hydrogel 2% manipulated in a pharmacy college represents an alternative to this situation, since it promotes improved healing rates, decreased treatment time of these ulcers, as well as being a low-cost treatment, as compared to other hydrogels industrialized in the national sale, bringing lower costs to health services.

This PhD project investigated the ramifications of air-cured and nitrogen-cured manufacturing processes during silicone hydrogel contact lens manufacture in terms of lens surface characterisation and clinical performance. A one-hour contralateral clinical study was conducted for ten subjects to compare the clinical performance of the two study lenses. The main clinical findings were reduced levels of subjective performance, reduced surface wettability and increased deposition. Contact angle analysis showed the air-cured lenses had consistently higher advancing and receding contact angle measurements, in comparison with the nitrogen-cured lens. Chemical analysis of the study lens surfaces in the dehydrated state, by x-ray photoelectron spectroscopy (XPS) and time-of-flight mass spectrometry (ToF-SIMS), showed no difference due to surface segregation of the silicone components. Analysis of frozen lenses limited surface segregation and showed a higher concentration of silicone polymer components and lower concentration of hydrophilic polymer components at the surface of the air-cured lens, in comparison with the nitrogen-cured lens. Scanning electron microscope (SEM) imaging showed the nitrogen-cured lens to have a surface typical of a hydrogel material, whereas the air-cured lens had regions of apparent phase separation. In addition, atomic force microscopy (AFM) showed the air-cured lens to have a rougher surface associated with greater adherence of contaminants (often observed in materials with reduced polymer cross-linking). In conclusion, clinical assessment of the study lenses confirmed the inferior performance of the air-cured lens. Surface analysis suggested that the non-wetting regions on the air-cured lenses were associated with elevated level of silicone components, reduced polymer cross-linking and polymer phase separation.

Articular cartilage injuries occur frequently in the knee joint. Several methods have been implemented clinically, to treat osteochondral defects but none have been able to produce a long term, durable solution. Photopolymerizable cartilage tissue engineering approaches appear promising; however, fundamentally, forming a stable interface between the tissue engineered cartilage and native tissue, mainly subchondral bone and native cartilage, remains a major challenge. The overall objective of this research is to find a solution for the current problem of dislodgment of tissue engineered cartilage at the defect site for the treatment of degraded cartilage that has been caused due to knee injuries or because of mild to moderate level of osteoarthritis. For this, an in-vitro model was created to analyze the integration of tissue engineered cartilage with the bone, healthy and diseased cartilage over time. We investigated the utility of hydroxyapatite (HA) nanoparticles to promote controlled bone-growth across the bone-cartilage interface in an in vitro engineered tissue model system using bone marrow derived stem cells. We also investigated the application of HA nanoparticles to promote enhance integration between tissue engineered cartilage and native cartilage both in healthy and diseased states. Samples incorporated with HA demonstrated significantly higher interfacial shear strength (at the junction between engineered cartilage and engineered bone and also with diseased cartilage) compared to the constructs without HA (p < 0.05), after 28 days of culture. These findings indicate that the incorporation of HA nanoparticles permits more stable anchorage of the injectable hydrogel-based engineered cartilage construct via augmented integration between bone and cartilage.

Chapter 1. Supramolecular Gels and their Applications Supramolecular gels are viscoelastic materials composed of a solid like three dimensional fibrillary network that is embedded in a liquid. Supramolecular gels are derived from low molecular weight compounds (typically MW < 3000). In the 1990s, the investigations on gels were mainly focused on designing new gelator molecules. However, during the last decade, research focus shifted towards designing functional gels and their applications. As a result of extensive work in this area, gels have been found to have varied applications in the templated synthesis of inorganic nanomaterials, hybrid materials, light harvesting systems, as responsive system and sensors, and also in drug delivery, tissue engineering etc. This chapter gives an introduction to supramolecular hydrogels/organogels and relevant bile acid chemistry touching upon the gelation properties of the bile acid derivatives. Diverse applications of the supramolecular gels are also illustrated with several examples. Scheme 1. Various applications of functional supramolecular gels Chapter 2. Bile Acid derived novel Hydrogelators Part 1. Hydrogelation of Bile acid protected Amino acids and Hybrid Materials Hydrogels from low molecular weight molecules have significant importance in biomedical applications. In this chapter, we report injectable hydrogel formation from bile acid conjugates of various amino acids. Hydrogel formation was found to be dependent on multiple factors such as bile acid backbone structure, linkage between the bile acid and the amino acid, pH etc. Single crystal structures of lithocholyl phenylalanine, lithocholyl-glycine, lithocholyl-L valine and lithocholyl-L alanine were also determined. Finally, the hydrogel frameworks were utilized to produce hybrid materials with Gold and ZnO nanoparticles. Scheme 2. (a) Crystal structure of LC-LF-OH gelator molecule, (b) photograph of gel, (c) SEM and (d) AFM image of LC-LF-OH xerogel Part 2. Hydrogelation of bile acid-dipeptide conjugates and in situ synthesis of silver and gold nanoparticles in the hydrogel matrix Fabricating supramolecular hydrogels with embedded metal nanostructures are important for the design of novel hybrid nanocomposite materials for diverse applications such as bio sensing and chemo sensing platforms, catalytic and antibacterial functional materials etc. Supramolecular self-assembly of bile acid-dipeptide conjugates have led to the formation of new supramolecular hydrogels. Gelation of these molecules depends strongly on the hydrophobic character of the bile acids. Ag+ and Au3+ salts were incorporated in the hydrogels, and photo reduction and chemical reduction led to the in situ generation of Ag and Au NPs in these supramolecular hydrogels without the addition of any external stabilizing agent. The color, size and shape of silver nanoparticles formed by photo reduction depended on the amino acid residue on the side chain. Furthermore, the hydrogel-Ag nanocomposite was tested for its antimicrobial activity. Scheme 3. Bile acid based dipeptide hydrogelators and soft hybrid materials Chapter 3. Sonogels of bile salts of In(III): use in the formation of self-templated indium sulfide nanostructures In this chapter, facile hydrogel formation by Indium(III) cholate and deoxy cholate are reported. When In(III) solution was added to aqueous solutions of sodium cholate and sodium deoxy cholate and sonicated, the mixtures formed gels. The gels thus obtained were translucent/turbid and thermos irreversible. Rheological measurements showed that all of them could be classified as viscoelastic soft solids. Scanning electron microscopy and atomic force microscopy showed typical entangled three dimensional fibrous networks. The In-Ch hydrogel were further used to prepare nanostructured In2S3 in which the cholate units possibly acted as a surfactant to confine the growth of the Nano flakes. Scheme 4. In-Ch hydrogel (Photograph and SEM image of In-Ch gel) Chapter 4. Palladium-Hydrogel Nanocomposite for C-C Coupling Reactions Supported metallic nanoparticles are important composite materials owing to their enormous potential for applications in various fields. This chapter describes the in situ formation of palladium nanoparticles in a calcium-cholate (Ca-Ch) hydrogel by reduction with sodium cyan borohydride. The hydrogel matrix appeared to assist the controlled growth as well as stabilization of palladium nanoparticles. The palladium nanoparticle/Ca-Ch hydrogel hybrid was characterized by scanning and transmission electron microscopy, atomic force microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Furthermore, PdNP/Ca-Ch hybrid xerogel was shown to act as an active catalyst for Suzuki reaction under aqueous aerobic conditions, up to 4 cycles. This PdNP/Ca-Ch xerogel retained its catalytic activities on storage for several months. Scheme 5. Palladium-hydrogel nanocomposite for C-C coupling reactions in water Chapter 5. Sensitization of Terbium/Europium in self-assembled cholate hydrogel: An approach towards the detection of amine vapours "Luminescent" lanthanides have intrinsic low molar absorptivity, although this problem can be addressed by complexing the lanthanide ion with suitable chelating ligands which improve the luminescence properties drastically. However the design of such systems often involves careful planning and laborious synthetic steps. It is therefore desirable to have a simpler way to sensitize lanthanides with high efficiency. It was observed in our group that trivalent lanthanides formed hydrogels on the addition of sodium cholate. This chapter describes the discovery of the several biphenyl derivatives (such as 4-biphenylcarbaxaldehyde, 4-acetylbiphenyl) for sensitization of Tb(III) and Eu(III) in lanthanide hydrogels. Sensitization of Tb(III) and Eu(III) were observed by doping was characterized by scanning and transmission electron microscopy, atomic force microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Furthermore, PdNP/Ca-Ch hybrid xerogel was shown to act as an active catalyst for Suzuki reaction under aqueous aerobic conditions, up to 4 cycles. This PdNP/Ca-Ch xerogel retained its catalytic activities on storage for several months. Scheme 6. Schematic representation of the sensitization process (the arrangement of themolecules in the gel fiber is arbitrary)(For figures pl refer the abstract pdf file)

No description available.

This work deals with the current topic of carrier systems. Since the biggest problem is the passage of hydrophobic drugs through the bloodstream, or through universal body barriers (eg blood-brain), it is necessary to chemically modify these carriers in order to be able to administer hydrophobic substances effectively. Based on a literature search, several systems are designed and subsequently studied, in which there is a presumption of possible use for carrier systems and at the same time they have biosurfactants incorporated in them due to their ability to solubilize hydrophobic molecules. The theoretical part of this work will describe the individual biosurfactants, the process of their production, their physicochemical properties, and the possibility of their use in carrier systems. At the same time, the individual carrier systems, the procedure of their preparation, the possibilities of their use are described, and their advantages and disadvantages are also compared. In the practical part, the screening of both individual substances and their mutual interactions, as well as methods used to study the emerging structures is then performed. The study of molecular interactions is primarily performed using the technique of dynamic light scattering. The next part describes the optimization of hydrogel formation with incorporated biosurfactants in their structure and then the formed gels are subjected to rheological and solubilization tests. The study of the internal structure of these gels is performed using a scanning electron microscope.

This diploma thesis is focused on the study of bioactive wound dressings. During the thesis, hydrogel, lyophilized and nanofiber wound dressings were prepared. Hydrogel and lyophilized wound dressings were prepared on basis of two polysaccharides – alginate and chitosan. Nanofiber wound dressings were prepared by spinning polyhydroxybutyrate. All prepared wound dressings were enriched with bioactive substances, which represented analgesics (ibuprofen), antibiotics (ampicillin) and enzymes (collagenase). Into hydrogel and lyophilized wound dressings were all the mentioned active substances incorporated, whereas nanofiber wound dressings were only with ibuprofen and ampicillin prepared. The theoretical part deals with the anatomy and function of human skin. There was explained the process of wound healing and also there were introduced available modern wound dressings. The next chapter of the theoretical part deals with materials for preparing wound dressings (alginate, chitosan, polyhydroxybutyrate) and with active substances, which were used during the experimental part of this thesis. In the theoretical part, the methods of preparation of nanofiber wound dressings and also the methods of cytotoxicity testing used in this work were presented. The first part of the experimental part of this thesis was focused on preparing already mentioned wound dressings. Then, their morphological changes over time and also the gradual release of incorporated active substances into the model environment were monitored. The gradual release of ampicillin was monitored not only spectrophotometrically, but also by ultra-high-performance chromatography. In wound dressings, in which collagenase was incorporated, was also the final proteolytic activity of this enzyme monitored. The effect of the active substances was observed on three selected microorganisms: Escherichia coli, Staphylococcus epidermidis and Candida glabrata. The cytotoxic effect of the active substances on the human keratinocyte cell line was monitored by MTT test and LDH test. A test for monitoring the rate of wound healing – a scratch test – was also performed.