No description available.

Head and neck cancer is a heterogeneous group of tumours, of which certain subgroups such as cancer of the mobile tongue frequently are associated with a relatively poor prognosis due to the high risk of regional failure and mortality rates that haven’t improved in a significant way over the last 3 decades, despite advancements in both diagnostics and treatment. Today we lack means to assess the biological aggressiveness of each individual tumour, which varies largely. Treatment comprises of surgery with additional radiotherapy and medical therapies in more advanced tumours. The focus in this thesis is on molecular biomarker expression in head and neck cancer and especially in association with radiotherapy. Increased knowledge paves the way to a more individualized cancer treatment aiming for better outcome and less overtreatment and sequelae. The aims of this thesis was: To map the effects of radiotherapy in both tumour and adjacent tissue for the possible markers hyaluronan, EGFR and mast cells. To investigate whether the expression of hyaluronan in the epithelium and connective tissue stroma and EGFR in the tumour correlates with the risk for developing cervical metastasis in N0 patients, and to find out whether the 3-year tumour-specific survival rates correlates with the expression of HA in the epithelium and EGFR in the tumour. To establish an animal model for radiation-induced mucositis and to use that model to examine the pattern of invading inflammatory cells. To investigate whether the expression of podoplanin in tongue cancer correlates with the risk for cervical metastasis and to determine whether the total amount of lymph vessels in the diagnostic biopsy has any impact on the clinical outcome. To investigate the differences in the metabolome of tongue cancer cell lines with different radiosensitivity. The most important findings of this thesis were: The expression of EGFR and hyaluronan hade the same pattern of expression in both tumour and adjacent tissues before radiotherapy. The expression of EGFR was increased in the epithelium of the adjacent tissue close to the tumour after radiotherapy. The intensity of the staining of hyaluronan was correlated to the 3-year survival rates in patients with tongue cancer. An experimental model for radiation-induced oral mucositis in rat was established and in this model a temporal pattern of macrophage invasion with two different subtypes of macrophages was found. There were no correlation between the expression of podoplanin in the tumour tissue and the cervical metastasis rate in patients with tongue cancer, but the younger patients were more likely to have a higher expression of podoplanin in their tumour than elder patients. Tongue cancer cell lines with different radiosensitivity respond to irradiation with different patterns of metabolic expressions.

Background: Prostate Cancer (PC) is a common and highly variable disease. Using current diagnostic methods, the prostate specific antigen (PSA) blood test and histological grading of prostate tissue needle biopsies, it is often difficult to evaluate whether the patient has a PC that requires active treatment or not. The absolute majority of all 10,000 cases of PCs diagnosed annually in Sweden have tumours graded as Gleason score (GS) 6-7 and a PSA value in blood below 10. Many of these are harmless and can be left without active treatment and hence spared problematic post-therapy side-effects, others are highly malignant and require early diagnosis and treatment. Better prognostic markers are needed and the aim of this study was to evaluate prognostic markers and to test if these markers could identify patients with indolent tumours. Methods: We have studied tumour material from 419 men consecutively diagnosed with PC at transurethral resection (1975-1990). The majority of these patients (295) had no metastasis at diagnosis and was not given any curative treatment and only hormonal treatment upon symptoms from metastatic progression. Standard histological sections and tissue microarrays (TMA) from these tumours and surrounding normal prostate tissue were stained and evaluated for cell proliferation (Ki67), blood vessels (endoglin and von Willebrand factor, vWf) and the extracellular matrix component hyaluronan (HA). An orthotopic rat PC model was used to explore hyaluronan staining, hyaluronic acid synthase (HAS)-1 mRNA levels and the effect of local HA treatment on tumour growth. Results: Tumour cell proliferation (Ki67) and the density of intra-tumoural endoglin stained blood vessels were independent prognostic markers (i.e. they added prognostic information to the conventional prognostic markers; clinical stage and GS). None of the GS 6 patients with low staining for both Ki67 and endoglin died of PC within 15 years of follow-up. High HA staining in the tumour epithelium and stroma was a negative prognostic marker of cancer specific survival but they were not independent of GS. High HA staining and high vascular density in the stroma of the surrounding morphologically normal prostate were prognostic for short cancer specific survival. Implantation of tumour cells in the normal rat prostate resulted in an increase in HA and HAS-1 mRNA levels in the prostate tissue surrounding prostate tumours. Concurrently intra-prostatic injection of HA also stimulated tumour growth. Conclusions: By evaluating both tumour cell proliferation (Ki67) and vascular density, it is possible to identify patients with very low risk of cancer specific death in the absence of active treatment. Prostate tumours influence the surrounding non-malignant prostate tissue, for example they cause an increased angiogenesis and synthesis of hyaluronan. Such responses can possibly be used to diagnose PC and to evaluate PC aggressiveness.

Hyaline cartilage is a highly specialized tissue, which plays an important role in the articulating joints of an individual. It provides the joints with a nearly frictionless, impact resisting surface to protect the ends of the articulating bones. Articular cartilage has a poor self-repair capacity and, therefore, it rarely heals back to normal after an injury. Overweight, injuries, overloading and genetic factors may initiate a degenerative disease of the joint called osteoarthritis. Osteoarthiritis is a major global public health issue. Currently, the most used treatment for large articular cartilage defects is joint replacement surgery. However, possibilities to replace this highly invasive operation with strategies based on tissue engineering are currently investigated. The idea of the tissue engineering is to optimize the use of the cells, biomaterials and culture conditions to regenerate a new functional tissue for the defect site. The goal of this thesis was to manufacture cartilage tissue in cell culture conditions in vitro. Bovine primary chondrocytes isolated from the femoral condyles were used in all the experiments for neocartilage production. The samples were collected for histology, gene expression level quantifications, and analyses of proteoglycan (PG) content and quality. The histological sections were stained for type II collagen and PGs, the quantitative RT-PCR was used to observe the relative expressions of aggrecan, Sox9, procollagen α2(I) and procollagen α1(II) genes. The PGs were quantified using a spectrophotometric method, and agarose gel electrophoresis was used to separate the PGs according to their size. In the two first studies, we optimized the culture conditions of in vitro scaffold-free culture technique to produce the native-type hyaline cartilage of a good quality. We found out that high glucose concentration and hypertonic medium at 20% oxygen tension promoted the best hyaline-like neocartilage tissue production. Glucosamine sulfate supplementation, low oxygen tension, 5 mM glucose concentration and a transient TGF-β3 supplementation were not beneficial for the neocartilage formation in the scaffold-free cell culture system. In the third study, we used these newly defined, optimized culture conditions to produce the neocartilage tissues in the HyStem™ and the HydroMatrix™ scaffold materials and we compared these tissues to the ones grown as scaffold-free control cultures. We noticed that there was no difference between the controls and the scaffolds, and occasionally the scaffold-free controls had produced better quality cartilage than the ones with the scaffolds. Overall, the neocartilage tissues were of good hyaline-like quality in the third study. Their extracellular matrix contents were close to the native cartilage, although the neotissues lacked the zonal organization typical to the normal articular cartilage. The tissues had the right components, but their ultrastructure differed from the native cartilage. In conclusion, we were able to optimize our in vitro neocartilage culture method further, and discovered a good combination of the culture conditions to produce hyaline-like cartilage of good quality. Surprisingly, the scaffold materials were not beneficial for the cartilage formation. / Lasi- eli hyaliinirusto on pitkälle erikoistunutta kudosta, jolla on erittäin tärkeä rooli yksilön nivelten toiminnassa. Kudos suojaa ruston alapuolista luuta muodostamalla lähes kitkattoman ja joustavan liikkumista helpottavan pinnan. Lasiruston oma uusiutumiskyky on hyvin heikko, ja näin ollen kudos vain harvoin paranee alkuperäisen kaltaiseksi vaurion jälkeen. Ylipaino, vammat, liiallinen kuormitus tai geneettiset tekijät voivat käynnistää rustokudoksen rappeutumisen. Tätä tilaa kutsutaan nivelrikoksi. Nivelrikko on valtava kansanterveydellinen ongelma. Keinonivelleikkaus on nykyisellään ainoa hoitokeino pinta-alaltaan laajojen nivelruston vaurioiden hoitoon. Vaihtoehtoja tämän suuren ja invasiivisen kirurgisen operaation korvaamiseksi tutkitaan kuitenkin koko ajan ympäri maailmaa. Kudosteknologian ajatuksena on optimoida solujen, biomateriaalien ja erilaisten kasvatusolosuhteiden käyttö uuden, alkuperäisen kaltaisen toiminnallisen kudoksen luomiseksi vauriokohtaan. Väitöskirjan kaikissa kolmessa osatutkimuksessa uudisrustokudoksia tuotettiin käyttäen naudan polven rustosta eristettyjä primäärisiä rustosoluja. Näytteet kerättiin histologisia analyysejä, geenin ilmentymistutkimuksia ja proteoglykaanisisällön ja -jakauman (PG) analyyseja varten. Histologisista leikkeistä värjättiin tyypin II kollageeni ja PG:t, ja kvantitatiivista RT-PCR -menetelmää käytettiin aggrekaani-, Sox9-, prokollageeni α2(I)- ja prokollageeni α1(II)-geenien suhteellisten ilmentymistasojen määrittämiseen. Proteoglykaanisisältö analysoitiin käyttäen spektrofotometristä menetelmää, ja PG:t eroteltiin kokonsa perusteella agaroosigeelielektroforeesia käyttäen. Kahdessa ensimmäisessä osatutkimuksessa optimoitiin tukirakenteetta kasvattujen uudisrustojen kasvatusolosuhteita natiivin kaltaisen lasiruston tuottamiseksi. Havaitsimme, että korkea glukoosipitoisuus ja hypertoninen elatusaine yhdistettynä 20 % happiosapaineeseen tuotti parhaimman laatuista uudisrustokudosta tutkituista yhdistelmistä. Glukosamiinisulfaatin lisäys, matala happiosapaine, 5 mM glukoosi konsentraatio tai TGF-β3:n lisääminen alkuvaiheessa eivät edesauttaneet uudisrustokudosten muodostumisessa. Kolmannessa osatutkimuksessa otettiin käyttöön uudet, hyväksi havaitut kasvatusolosuhteet yhdistettynä HyStem™ and HydroMatrix™ -tukimateriaaleihin, ja niitä verrattiin tukirakenteettomaan kasvatusmenetelmään. Tutkimuksessa havaittiin, ettei tukirakenteettoman kontrollin tai tukimateriaalien välillä ollut mitään eroa, ja että kontrollikasvatukset tuottivat ajoittain jopa parempaa rustoa kuin tukimateriaalein kasvatetut. Kaiken kaikkiaan kaikki tuotetut uudiskudokset muistuttivat laadullisesti lasiruston kaltaista kudosta. Molekyylisisältö lähenteli natiivia rustoa, vaikkakin uudiskudoksista puuttui normaalille nivelrustolle tyypillinen vyöhykkeinen järjestäytyminen. Kudoksissa oli parhaimmillaan oikea määrä oikeita komponentteja, mutta ne eivät vain olleet järjestäytyneet oikealla tavalla. Onnistuimme optimoimaan uudisrustokudosten kasvatusmenetelmäämme. Löysimme hyvän kasvatusolosuhteiden yhdistelmän, jonka avulla kykenimme tuottamaan lasiruston kaltaista uudisrustokudosta. Hivenen yllättäenkin, tukimateriaalit eivät olleet avuksi tutkimuksessamme uudisrustokudoksia muodostettaessa.

Le purinorécepteur P2X7 joue un rôle majeur dans les phénomènes de dégénérescences (Alzheimer, DMLA) et mort cellulaires. Récemment des études ont montré que l’activation basale de ce récepteur est indispensable dans le processus de cicatrisation et de prolifération cellulaire. Nous avons essayé de mieux comprendre le paradoxe de cette activation du récepteur P2X7 qui oriente vers la prolifération et même les métastases tumorales, mais aussi vers les mécanismes de dégénérescence cellulaire. L'influence du microenvironnement (Lipides, matrice extracellulaire, oxygène) apparait essentielle pour comprendre ces différents effets. Notre premier objectif a été d’étudier l’impact de la modulation du microenvironnement du récepteur P2X7 par des composants de la matrice extracellulaire. Ainsi, sur un modèle de cicatrisation cutanée, nous avons mis en évidence l’impact de la taille des fragments du hyaluronate de sodium (composant prédominant dans la matrice extracellulaire). Nos résultats ont montré que l’activation du récepteur P2X7 dépend du poids moléculaire du hyaluronate de sodium. Notre deuxième objectif a été de moduler le microenvironnement lipidique du récepteur P2X7. Nous avons sélectionné une huile riche en acides gras insaturés et avons ainsi étudié son effet sur l’activation du récepteur P2X7. Sur nos modèles de cicatrisation, nous avons mis en évidence qu’une modulation du microenvironnement lipidique du récepteur P2X7 influence son activation. D’autre part la modulation du microenvironnement lipidique sur des cellules tumorale de mélanome active les voies de dégénérescence ouvrant la perspective de nouvelles stratégies thérapeutiques. / The purinoceptor P2X7 plays a role in cytotoxic degenerative processus (Alzheimer, AMD) and cell death. Recent studies have shown that basal activation of this receptor is essential in the healing process and cell proliferation. We tried to understand the paradox that activation of P2X7 receptor that directs to the same proliferation and tumor metastasis, but also to the mechanisms of cell degeneration. The influence of the microenvironment (lipids, extracellular matrix, oxygen) appears essential to understand these effects. Our first objective was to study the impact of the modulation of P2X7 receptor microenvironment by extracellular matrix components. On cell monolayer model of wound healing we have highlighted the impact hyaluronan molecular weight (predominant component in the extracellular matrix). Our results showed that activation of P2X7 receptor is dependent on hyaluronan molecular weight. Our second objective was to modulate lipid microenvironment P2X7 receptor. We selected an oil rich in unsaturated fatty acids and thus have studied its effect on the activation of P2X7 receptor. In our models of healing and melanoma cell, we have demonstrated that modulation of lipid microenvironment affects P2X7 activation.

No description available.

This thesis deals with the study of preparation and characterization of hyaluronan-micelle aggregates. The theoretical part deals with drug delivery systems, characterization of used materials and methods especially fluorescence spectroscopy, dynamic light scattering and turbidimetry. Methods of determination of measured data are summarized in the experimental section. The result section is divided into two subsections dedicated to different preparation methods of hyaluronan-surfactant complexes. Induced aggregates of hyaluronan with Septonex are characterized in terms of their origin and stability, and the results are compared with previously studied surfactants CTAB. In the second part are discussed so-called decorated micelles, their formation, properties and stability.

The aim of the doctoral thesis was to study advanced fluorescence techniques and its use in colloids or hyaluronan-surfactant systems and hydrogels based on hyaluronan, respectively. Steady-state and time-resolved fluorescence were used to study excited state proton transfer fluroescen probes in hyaluronan-surfactant systems to asses the influence of hyaluronan hydration to its interactions with oppositely charged surfactants. Firstly, different excited state proton transfer fluorescence probes were discussed to choose the most suitable candidate for next research. The influence of hyaluronan on inner environment of micells was determined based on the sensitivity of excited state proton transfer of chosen fluorescence probe 1-naphtol and, based on above mentioned experiments, the structure of hyaluronan hydration shell was discussed. The next part of doctoral thesis was focused on fluorescence lifetime correlation spectroscopy and on the development of method of nanorheology. Measured correlation functions were transformed to mean square displacement with developed MATLAB script. Firstly, the fluorescence method was compared with well described methods such as videomicrorheology and dynamic light scattering to asses the reliability of fluorescence correlation spectroscopy in microrheology. Secondly, nanorheology method was developed and its use in passive nanorheology of hyaluronan hydrogels was discussed. Based on mentioned experiments, the fluorescence correlation spectroscopy microrheology and nanorheology methods were optimized to use the methods in hydrogel research.

The thesis deals with the study of hydrophobic domains in phase separated hydrogels. Two types of polyelectrolytes (hyaluronan, dextran) and oppositely charged surfactants (carbethopendecinium bromide, sodium dodecylsulphate ) are used. Phase separated hydrogels are formed by electrostatic interactions. The target of the thesis is to study the polarity of environment in phase separated hydrogeles by fluorescence spectroscopy. Fluorescence measurements is performed by using pyrene, Nile red and laurdane as fluorescence probes. All probes are sensitive to the polarity of the environment. The results showed that probes can be expected in the polar environment of hydrogels.

This diploma thesis investigates the suitability of relaxation tests as a part of complex characterization of hydrogel materials using classical rheology methods. With respect to the current research, creep and three interval thixotropy tests were taken into account. For them, general optimization was done aiming to find an ideal parameter settings. The optimization was performed using physically crosslinked agarose (AG) hydrogel and the tuned tests were also applied to two more samples: hyaluronan (HyA) and polyvinyl alcohol (PVAl) gel. These materials were selected due to their mutually different crosslinking principle. The experiments showed, the AG gel proved to have the best ability to recover after deformation of all studied samples. On the other hand, the HyA gel relaxed the worst. Although the final results of both tests were comparable, the regeneration process itself was different. Hence, the complex relaxation characteristics cannot be described using one of the performed tests alone and both the creep and three interval thixotropy tests have great importance in the scope of complex relaxation behaviour. The obtained results may lead to more precise description of deformation and relaxation, which are frequent phenomena occurring during treatment and application of hydrogel materials.