Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 4 uppsatser.

This thesis examines how the rheological properties change depending on the composition of hyaluronan, HA and sodium hydroxide, NaOH. This was performed to see if there was any relationship between the rheological properties of a sample depending on different compositions of HA and NaOH. Moreover, the fluidity of the samples was studied by investigating . Five concentrations of HA (11, 18, 20, 25, 33 wt%) were investigated with six concentrations of NaOH (0, 1, 2, 4, 6, 8 wt%). Rheology was used to determine rheological properties of the composition and the rheometric data was obtained from three different measurements: time sweep, frequency sweep and amplitude sweep. G', G'' andwere investigated but no clear correlation was found. However, some patterns were detected for frequency sweep and amplitude sweep. The graphs generally followed the same shape and the compositions with 11% HA generally had the lowest G' and G'' values. Additionally, the majority of the samples, that could be measured, could be defined as fluids, due to  being higher than 1.

Ácido Hialurônico (HA) é um componente da matriz extracelular, responsável pela hidratação e manutenção do equilíbrio osmótico tecidual. Concentrações de HA estão elevadas em vários tipos de cânceres, incluindo próstata. Hialuronidases (HAases), são uma família de enzimas relacionadas com a propagação de infecções bacterianas, toxinas de venenos e progressão tumoral. A quebra do HA em pequenos fragmentos (3-25 dissacarídeos) promovidos pela ação das HAases tipo Hyal1, Hyal2 e Hyal3, está relacionada à promoção do câncer através da indução da angiogênese e estímulo a proliferação através de ativação da via tirosina quinase. Algumas isoformas de HAases, descritas como produto de splicing alternativo, possuem atividade enzimática diversificada. A heterogeneidade de expressão das HAases foi identificada em alguns tipos de câncer e pode ser correlacionada com o comportamento diferenciado dos tumores. Para este trabalho estudamos amostras de 55 pacientes submetidos a prostatectomia radical por carcinoma de próstata (CP) . A média de idade foi 66 anos e o tempo médio de seguimento 73,7 meses. Os pacientes foram divididos em dois grupos para análise dos resultados: 1- Escore de Gleason (EG) >=7 (30) e EG <=6 (25). 2- Comportamento tumoral (recidiva-19, e não recidiva-36), considerando o nível sérico de Antígeno Específico da Próstata (PSA) 0,2 ng/mL. O grupo controle foi representado por 11 pacientes com hiperplasia prostática benigna, submetidos à ressecção retropúbica. As HYAL foram identificadas por PCR, com uso de primers específicos para as variantes 1, 2, 3, 4 e 5 e wt da HYAL1, wt da HYAL2, e wt e variantes 1, 2 e 3 da HYAL3. As HYAL mais freqüentemente expressas pelo CP foram HYAL2-wt (65,4%), HYAL1-v1 (63,3%) e HYAL3-wt (47,2%). Em tecidos prostáticos benignos, a HYAL3-v1 foi expressa em 90,9% dos casos, estando presente em 36% dos tumores com EG baixo, e não expressa em tumores com EG alto (p=<0,001). Nos tumores sem recidiva HYAL1-v3 foi expressa em 30,5% dos casos versus 5,2% em casos que recorreram (p=0,041). HYAL3 v2, foi expressa por 33,3% dos tumores que não recorreram e não expressa em tumores que recorreram (p=0,002). Concluímos que a expressão de HYAL1-v3, HYAL3-v1 e HYAL3-v2 está relacionada a tumores mais diferenciados e com menores taxas de recidiva, podendo ser utilizadas como marcadores na prática clínica identificando candidatos a terapias mais conservadoras. / Hyaluronic acid (HA) is a component of the extracellular matrix that hydrates and maintains the osmotic balance of tissues. HA concentration is elevated in several cancers including prostate. Hyaluronidases (HAases) are a family of enzymes related to the spread of bacterial infections, toxins of venoms and probably cancer progression. Small fragments of HA are generated by HAase Hyal1, Hyal2 and Hyal3, stimulating endothelial proliferation and activating mitogen-activated protein kinase pathway. Several isoforms of HAases have been described as a product of alternative splicing, and are responsible for differences in the enzyme activity. The heterogeneity of HAses expression has been identified in tumors and could be related to the differences in their biological behavior. Fifty-five patients submitted to radical prostatectomy for prostate cancer (PC) were the subject of this study. The mean age was 66 years old and the mean follow-up was 73,7 months. Patients were divided into two groups for the analyses: 1- High Gleason score (GE) >=7 (30) and low Gleason score <=6 (25). 2- Tumor behavior; recurrence - 19 and nonrecurrence - 36. Biochemical recurrence was considered when PSA was higher than 0.2 ng/mL. The control was represented by 11 patients submitted to retropubic prostate resection for benign prostatic hyperplasia. The alternative splicing forms of HYAL were identified by PCR, and the primer sequences identified variants 1, 2, 3, 4, 5 e wt of HYAL1, wt of HYAL2, wt and variants 1, 2 and 3 of HYAL3. The HYAL more frequently expressed by PC was HYAL2-wt (65.4%), HYAL1-v1 (63.3%) and HYAL3-wt (47.2%). In benign prostate tissue the main expressed HAase was HYAL3-v1 in 90.9%, being present in 36% of low Gleason score tumors and not expressed by tumors with high Gleason score (p=<0.001). For tumors that not recurred there was expression of HYAL1-v3 in 30.5% of the cases vs. 5.2% in cases that recurred (p=0.041). The same difference was noted regarding the expression of HYAL3-v2, that was expressed by 33.3% of tumors that not recurred and not expressed by tumors that recurred (p=0.002). We conclude that there is a profile of HAase related to low Gleason score and non-recurrent PC that is characterized by expression of HYAL1-v3, HYAL3-v1 and HYAL3-v2 that could be used in clinical practice to choose a better treatment.

The chondroitin sulphate proteoglycan (CSPG) versican forms complexes with hyaluronan (HA), which are essential in a range of functions including cellular proliferation and migration. Four isoforms of versican result from alternative splicing. Furthermore, biological roles have been identified for the proteolytic cleavage product of versican which contains the N-terminal G1 hyaluronan binding domain. All of these versican forms have different tightly regulated tissue expression profiles. Consequently, impaired regulation is associated with a number of disease pathologies. For example the largest variants (V0/V1) have been shown to be negative indicators of disease outcome in a number of malignant cancers and are a marker of disease progression in atherosclerosis. Interestingly, the smaller versican isoform V3 which lacks CS chains has been demonstrated to have the potential to reverse disease associated phenotypes. The motivation for carrying out the work in this thesis was to try and gain a better understanding of how versican functions on a molecular scale. In this regard, the first aim was to investigate the structure of the hyaluronan binding region of versican using a construct called VG1. The structure of VG1 was analysed in the presence and absence of hyaluronan oligomers. This revealed an insight into the multi-modular structure of the versican hyaluronan binding region and demonstrated that on binding to HA, VG1 under goes a conformational change. Furthermore, the interaction between VG1 and longer lengths of hyaluronan (pHA) was investigated. This demonstrated that when VG1 binds to pHA it is does so with positive cooperativity, packing very close to neighbouring VG1 molecules along a chain of HA. One consequence of this interaction was to reorganise pHA into a helical conformation, an organisation that was confirmed by a number of solution phase techniques. The effect of this reorganisation of pHA by VG1 on HA/CD44 interactions was also assessed. Previously the interaction between CD44 (a cell surface hyaluronan receptor) and long chains of HA (>30 kDa) was shown to be irreversible; however we demonstrate that VG1 can reverse this. Furthermore, a TSG-6 enhanced CD44/interaction was also completely reversed by the addition of VG1. This provides an indication that a functional hierarchy of hyaluronan binding proteins may exist which could have important implications in understanding the function of hyaluronan complexes. Currently, we do not know whether intact versican molecules could interact with HA in the same way as VG1. However, preliminary data suggests that the CS-containing variants (i.e. V0, V1 and V2) would not, whereas V3 and versican fragments could. This work provides an exciting mechanistic insight into the function of versican variants and their breakdown products.

Se pretende obtener un material semibiodegradable basado en ácido hialurónico químicamente enlazado a cadenas de polímeros acrílicos. Los hidrogeles de ácido hialurónico presentan en general buenas características para su utilización en regeneración del sistema nervioso central: es biodegradable, es un componente importante del tejido neural, sus propiedades mecánicas son semejantes a las del tejido cerebral, promueve la formación de nuevos capilares (angiogénesis), y limita la inflamación. Con este nuevo material se pretende mejorar el excesivo grado de hinchado en medio fisiológico, su rápida degradación, mejorar la adhesión celular, además la matriz permanente de las cadenas acrílicas pueden actuar como un soporte permanente durante el proceso regenerativo sin que se produzca una pérdida brusca de propiedades mecánicas y estructurales. El trabajo consiste en caracterizar este nuevo material así como los productos intermedios necesarios para su obtención final, comparándolo con las propiedades de un hidrogel de ácido hialurónico sin incorporar cadenas acrílicas. Los estudios celulares se llevaran a cabo in vitro, como fase preliminar para futuros implantes en el cortex cerebral, estudiando la capacidad de diferenciación de precursores neurales y de generación de nuevos capilares con el fenotipo típico de la barrera hematoencefálica, mediante el estudio de cocultivos de precursores neurales y células endoteliales. / Perez Garnes, M. (2015). Structures based on semi-degradable biomaterials for neural regeneration in the central nervous system [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48799 / TESIS

This Master‘s thesis is focused on the preparation of hydrogels based on a hydrophobic derivative of hyaluronic acid palmitoyl hyaluronan in presence of biosurfactant decyl glucoside’s micelles and micelles of surfactant triton X-100. For followed characterization were chosen rheological tests and infrared spectrometry. There was observed influence of preparation method, type and concentration of surfactant and presence of micelles on final features of the hydrogel. Moreover, an experimental test of swelling was performed with interesting results for future research.

The dissertation thesis deals with study of advanced steady-state and time-resolved fluorescence techniques, which can be used for study of micellar systems properties. Selected fluorescence techniques were used for characterization of Septonex and CTAB cationic micellar systems and theirs interactions with hyaluronan. Fluorescent probe pyrene was used for determination of critical micelle concentration (CMC) and micellar aggregation number of these surfactants. The changes of fluorescence behaviour of fluorescein and prodan were studied in wide concentration range of Septonex. Next chapter of thesis deals with study of Förster resonance energy transfer between perylene and fluorescein in Septonex and CTAB micellar solutions and the effect of hyaluronan addition to these systems. Also steady-state and time-resolved fluorescence anisotropy studies were used for research of the effect of hyaluronan addition to micellar solutions. The last chapter of this thesis is focused on photophysical behaviour of Prodan in different solutions (water, Septonex solutions below CMC, hyaluronan solution, Septonex micellar solution and Septonex micellar solution with hyaluronan), which was discussed on the basis of time-resolved emission spectra.

Boli pripravené kryty rán na bázi prírodných látok polyvinyl alcohol/ hyaluronan/ strieborné nanočastice (PVA/ HA/ Ag-NPs). Hyaluronan bol použitý ako redukčné a stabilizačné činidlo pre syntézu nanočastíc striebra. Pri príprave Ag-NPs boli testované viaceré parametre ako koncentrácia dusičnanu strieborného ako zdroja Ag-NPs (0,01; 0,1;0,5;1 M), koncentrácia kyseliny hyalurónovej (1,2 %) a jej rozdielna molekulová hmotnosť. Kryty rán z nanovlákien boli pripravené pomocou techniky electro-spinning z roztokov líšiacich sa pomerom PVA a HA/Ag-NPs (100; 90/10; 80/20; 60/40; 50/50). Vlastnosti nanokompozitu HA/Ag-NPs boli hodnotené pomocou TEM, reológie, DLS, XRD, UV/Vis spektroskopie a kryty rán boli charakterizované pomocou SEM, TGA, FTIR a ťahovej skúšky.

Magnesium and its alloys are interesting materials due to their many physical properties. They have considerable potential, especially in medical applications, where they can serve as a material for the production of orthopedic and cardiovascular implants. The disadvantage of these materials is their sensitivity to corrosion. As a result, it is necessary to know the corrosive properties of magnesium and its alloys in contact with substances that occur in the human body. Hyaluronan is a polysaccharide that is naturally present in the human body and can interact with implants. This master's thesis deals with the influence of low molecular weight (80–130 kDa) and high molecular weight (1 500–1 750 kDa) hyaluronan on the corrosion properties of magnesium alloy AZ31 in the environment of two simulated physiological solutions (0,9 % NaCl and synovial fluid). Potentiodynamic polarization (PD) and electrical impedance spectroscopy (EIS) were used for electrochemical tests. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) to reveal the chemical composition of the corrosion products and the surface morphology after corrosion.

Předmětem této práce bylo popsat agregační vlastnosti kyseliny hyaluronové (HA) a jejích hydrofobně modifikovaných derivátů. Za tímto účelem byly připraveny vodné roztoky kyseliny a dvou derivátů, lišící se stupněm substituce a druhem anorganické soli jako prostředím. Koncentrační řady čisté kyseliny hyaluronové a jejích derivátů byly studovány dvěma metodami, tensiometricky a spektrometricky. Povrchové vlastnosti roztoků byly měřeny s použitím kroužku Du Noüy. Zkoumáno bylo také solubilizační chování ve vodě a v chloridu sodném pomocí dvou sond: Coomassie brilantní modři a sudanu III. Amfifilní deriváty hyaluronanu mohou skutečně tvořit hydrofobní agregáty v roztoku a adsorbovat se na rozhraní vzduch–voda. Tato vlastnost je důležitá v souvislosti s transportními systémy léčiv, protože právě hydrofobní domény agregátů hyaluronanu mohou být použity jako nosiče hydrofobních léčiv. Byly zjištěny kritické agregační koncentrace roztoků derivátů hyaluronanu (tensiometricky a spektrometricky), které odpovídají právě těm koncentracím, při kterých vznikají hydrofobní domény.