In this work, the synthesis of biopolymer-based hydrogel networks with defined architecture is presented. In order to obtain materials with defined properties, the chemoselective copper-catalyzed azide-alkyne cycloaddition (or Click Chemistry) was used for the synthesis of gelatin-based hydrogels. Alkyne-functionalized gelatin was reacted with four different diazide crosslinkers above its sol-gel transition to suppress the formation of triple helices. By variation of the crosslinking density and the crosslinker flexibility, the swelling (Q: 150-470 vol.-%;) and the Young’s and shear moduli (E: 50 kPa - 635 kPa, G’: 0.1 kPa - 16 kPa) could be tuned in the kPa range. In order to understand the network structure, a method based on the labelling of free functional groups within the hydrogel was developed. Gelatin-based hydrogels were incubated with alkyne-functionalized fluorescein to detect the free azide groups, resulting from the formation of dangling chains. Gelatin hydrogels were also incubated with azido-functionalized fluorescein to check the presence of alkyne groups available for the attachment of bioactive molecules. By using confocal laser scanning microscopy and fluorescence spectroscopy, the amount of crosslinking, grafting and free alkyne groups could be determined. Dangling chains were observed in samples prepared by using an excess of crosslinker and also when using equimolar amounts of alkyne:azide. In the latter case the amount of dangling chains was affected by the crosslinker structure. Specifically, 0.1% of dangling chains were found using 4,4’-diazido-2,2’-stilbene-disulfonic acid as cosslinker, 0.06% with 1,8-diazidooctane, 0.05% with 1,12-diazidododecane and 0.022 % with PEG-diazide. This observation could be explained considering the structure of the crosslinkers. During network formation, the movements of the gelatin chains are restricted due to the formation of covalent netpoints. A further crosslinking will be possible only in the case of crosslinker that are flexible and long enough to reach another chain. The method used to obtain defined gelatin-based hydrogels enabled also the synthesis of hyaluronic acid-based hydrogels with tailorable properties. Alkyne-functionalized hyaluronic acid was crosslinked with three different linkers having two terminal azide functionalities. By variation of the crosslinking density and crosslinker type, hydrogels with elastic moduli in the range of 0.5-3 kPa have been prepared. The variation of the crosslinking density and crosslinker type had furthermore an influence also on the hydrolytic and enzymatic degradation of gelatin-based hydrogels. Hydrogels with a low crosslinker amount experienced a faster decrease in mass loss and elastic modulus compared to hydrogels with higher crosslinker content. Moreover, the structure of the crosslinker had a strong influence on the enzymatic degradation. Hydrogels containing a crosslinker with a rigid structure were much more resistant to enzymatic degradation than hydrogels containing a flexible crosslinker. During hydrolytic degradation, the hydrogel became softer while maintaining the same outer dimensions. These observations are in agreement with a bulk degradation mechanism, while the decrease in size of the hydrogels during enzymatic degradation suggested a surface erosion mechanism. Because of the use of small amount of crosslinker (0.002 mol.% 0.02 mol.%) the networks synthesized can still be defined as biopolymer-based hydrogels. However, they contain a small percentage of synthetic residues. Alternatively, a possible method to obtain biopolymer-based telechelics, which could be used as crosslinkers, was investigated. Gelatin-based fragments with defined molecular weight were obtained by controlled degradation of gelatin with hydroxylamine, due to its specific action on asparaginyl-glycine bonds. The reaction of gelatin with hydroxylamine resulted in fragments with molecular weights of 15, 25, 37, and 50 kDa (determined by SDS-PAGE) independently of the reaction time and conditions. Each of these fragments could be potentially used for the synthesis of hydrogels in which all components are biopolymer-based materials. / In dieser Arbeit wird die Synthese Biopolymer-basierter Hydrogelnetzwerke mit definierter Architektur beschrieben. Um Materialien mit definierten und einstellbaren Eigenschaften zu erhalten, wurde die chemoselektive Kupferkatalysierte Azid-Alkin-Cycloadditionsreaktion (auch als Click-Chemie bezeichnet) für die Synthese Gelatine-basierter Netzwerke eingesetzt. Alkin-funktionalisierte Gelatine wurde mit vier verschiedenen Diazid-Quervernetzern oberhalb der Gel-Sol-Übergangstemperatur umgesetzt, um die Formierung tripelhelikaler Bereiche durch Gelatineketten zu unterdrücken. Durch Variation der Menge an Quervernetzer (und damit der Netzdichte) sowie der Länge und Flexibilität der Quervernetzer konnten u.a. die Quellung (Q: 150-470 vol.-%) sowie der Young’s - und Schermodul im kPa Bereich eingestellt werden (E: 50 kPa - 635 kPa, G’: 0.1 kPa - 16 kPa). Um die Netzwerkarchitektur zu verstehen, wurde eine Methode basierend auf dem Labeln unreagierter Azid- und Alkingruppen im Hydrogel entwickelt. Die Gelatine-basierten Hydrogele wurden mit Alkin-funktionalisiertem Fluorescein umgesetzt, um freie Azidgruppen zu detektieren, die bei einem Grafting entstehen. Darüber hinaus wurden die Hydrogele mit Azid-funktionalisiertem Fluorescein reagiert, um die Menge an freien Alkingruppen zu bestimmen, die zudem potentiell für die Anbindung bioaktiver Moleküle geeignet sind. Quervernetzung, Grafting, und die Anzahl freier Alkingruppen konnten dann mit Hilfe der konfokalen Laser Scanning Mikroskopie und der Fluoreszenzmikroskopie qualitativ und quantitativ nachgewiesen werden. Gegraftete Ketten wurden in Systemen nachgewiesen, die mit einem Überschuss an Quervernetzer hergestellt wurden, entstanden aber auch beim Einsatz äquimolarer Mengen Alkin- und Azidgruppen. Im letzteren Fall wurde in Abhängigkeit von der Struktur des Diazids unterschiedliche Anteile gegrafteter Ketten festgestellt. 0.1 mol-% von gegrafteten Ketten wurden für 4,4’-Diazido-2,2’-stilbendisulfonsäure gefunden, 0.06 mol-% für 1,8-Diazidooktan, 0.05 mol% für 1,12-diazidododecan und 0.022 mol-% für PEG-Diazid. Diese Beobachtung kann durch die unterschiedliche Flexibilität der Vernetzer erklärt werden. Während der Netzwerkbildung werden die Bewegungen der Gelatineketten eingeschränkt, so dass kovalente Netzpunkte nur erhalten werden können, wenn der Vernetzer lang und flexibel genug ist, um eine andere Alkingruppe zu erreichen. Die Strategie zur Synthese von Biopolymer-basierten Hydrogelen mit einstellbaren Eigenschaften wurde von Gelatine- auf Hyaluronsäure-basierte Gele übertragen. Alkin-funktionalisierte Hyaluronäure wurde mit drei verschiedenen Diaziden quervernetzt, wobei Menge, Länge, und Flexibilität des Quervernetzers variiert wurden. In dieser Weise wurden sehr weiche Hydrogele mit E-Moduli im Bereich von 0.5-3 kPa hergestellt. Die Variation der Vernetzungsdichte und des Vernetzertyps beeinflusste weiterhin den hydrolytischen und enzymatischen Abbau der Hydrogele. Hydrogele mit einem geringerem Anteil an Quervernetzer wurden schneller abgebaut als solche mit einem höheren Quervernetzeranteil. Darüber hinaus konnte gezeigt werden, dass Hydrogele mit Quervernetzern mit einer rigiden Struktur deutlich langsamer degradierten als Hydrogele mit flexibleren Quervernetzern. Während des hydrolytischen Abbau wurden die Materialien weicher, behielten aber ihre Form bei, was mit einem Bulk-Abbau-Modell übereinstimmt. Während des enzymatischen Abbaus hingegen änderten sich die Materialeigenschaften kaum, jedoch wurden die Proben kleiner. Diese Beobachtung stimmt mit einem Oberflächenabbaumechanismus überein. Da in allen vorgestellten Systemen nur eine kleine Menge synthetischer Vernetzer eingesetzt wurde (0.002 – 0.02 mol%), können die Materialien noch als Biopolymer-basierte Materialien klassifiziert werden. Jedoch enthalten die Materialien synthetische Abschnitte. In Zukunft könnte es interessant sein, einen Zugang zu Materialien zu haben, die ausschließlich aus Biopolymeren aufgebaut sind. Daher wurde der Zugang zu Biopolymer basierten Telechelen untersucht, die potentiell als Vernetzer dienen können. Dazu wurden durch die kontrollierte Spaltung von Gelatine mit Hydroxylamin Gelatinefragmente mit definiertem Molekulargewicht hergestellt. Hydroxalamin reagiert unter Spaltung mit der Amidbindung zwischen Asparagin und Glycin, wobei Aspartylhydroxamate und Aminoendgruppen entstehen. Die Reaktion von Gelatine mit Hydroxylamin ergab Fragmente mit Molekulargewichten von 15, 25, 37, und 50 kDa (bestimmt mit SDS-PAGE), und die Formierung dieser Fragmente war unabhängig von den weiteren Reaktionsbedingungen und der Reaktionszeit. Jedes dieser Fragmente kann potentiell für die Synthese von Hydrogelen eingesetzt werden, die ausschließlich aus Biopolymeren bestehen.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Thesis (Ph. D.)--Virginia Commonwealth University, 2006. / Prepared for: School of Medicine. Bibliography: leaves 142-154. Also available online.

O excesso de tecido cicatricial (quelóides e cicatrizes hipertróficas) é um defeito do processo de cicatrização das feridas, caracterizado por um aumento na produção da matriz extracelular. Neste estudo, fibroblastos dérmicos humanos tratados com 50 <font face=\"symbol\">mM verapamil apresentaram discreta modificação na distribuição dos microfilamentos e alteraram sua morfologia de fusiformes para estrelados/arredondados. Estes efeitos poderiam estar associados a baixos níveis de cálcio citosólico. Esta hipótese foi confirmada através marcação de fibroblastos tratados com calcium green. Observamos também, que o verapamil inibiu a proliferação celular em 64,4%, aumentou a secreção de MMP1 e diminuiu o colágeno sintetizado pelos fibroblastos, sem aparentes efeitos citotóxicos. O metabolismo celular do cálcio está aparentemente relacionado a produção da matriz extracelular e portanto as patologias hipertróficas da cicatrização (quelóides e cicatrizes hipertróficas) podem responder ao tratamento com bloqueadores do canal de cálcio (verapamil). / Excessive scar tissue (keloids and hypertrophic scars) is a defective wound healing process characterized by overproduction of extracellular matrix. In the present study human dermal fibroblasts treated with 50 <font face=\"symbol\">mM verapamil changed their normal spindle-shaped morphology to stellate/rounded and showed discrete reorganization of microfilaments We hypothesized that these effects would be associated to lower levels of cytosolic Ca2+. Indeed, short time loading with calcium green confirmed that verapamil-treated fibroblasts exhibited lower intracellular calcium levels. We also observed that verapamil decrease cellular proliferation by 64.4%, increase the secretion of MMP1 and decrease synthesis of collagen in cultured fibroblasts. This alterations induced by verapamil are not associated with cytotoxic effects. The cellular calcium metabolism appears to regulate extracellular matrix production and so those hypertrophic disorders of wound healing (keloids and hypertrophic scars) may respond to therapy with calcium antagonist drugs (verapamil).

O estudo de macrointeraçães na matriz extracelular (ECM) foi abordado em três modelos; a interação colágeno/colagenase, a interação colágeno/fibronectina e finalmente, a evolução da família enzimática das metaloproteinases de matriz (MMP). As MMP se caracterizam por sua notável especificidade contra componentes da ECM. As colagenases intersticiais, os membros mais estudados, clivam os colágenos intersticiais em um único ponto da molécula produzindo dois fragmentos característicos. Usando a hipótese da hidropaticidade complementar, a qual estipula que peptídeos codificados por sequências nucleotídicas complementares podem interagir entre si, foi possível caracterizar a sequência SQNPVQP em colagenase de fibroblasto ou SSNPIQP em colagenase de neutrófilo como importantes na interação das respectivas enzimas com o colágeno nativo. O fato da fibronectina, outro componente da ECM, ligar-se no mesmo domínio do colágeno clivado pelas colagenases possibilitou a utilização da mesma abordagem acima (hidropaticidade complementar) no estudo da interação colágeno/fibronectina. Sendo assim, foi possível caracterizar a sequência TNEGVMY da fibronectina como importante na interação com o colágeno. Adjacente a este sítio na fibronectina, existe uma sequência (AAHEEIC) que é homóloga ao sítio de ligação ao zinco presente nas MMP. Isto originou a possibilidade de que zinco pudesse modular a interação colágeno/fibronectina. De fato, zinco aumentou especificamente a ligação entre colágeno e fibronectina. Finalmente, abordou-se alguns aspectos filogenéticos da família das MMP. Foi caracterizada uma relação filogenética entre o núcleo enzimático das MMP e o domínio correspondente tanto na protease de Serratia como na protease B de Erwinia chrysanthemi, membros da mesma família de metaloproteinases bacterianas. Sendo assim, a atividade catalítica das MMP pode ter sido herdada das metaloproteinases bacterianas, enquanto a especificidade ao substrato talvez se constitua em uma aquisição das MMP eucarióticas. / The study of extracellular matrix (ECM) macrointeractions was approached in three models: the collagen/collagenase interaction, the collagen/fibronectin interaction and the molecular evolution of the matrix metalloproteinase (MMP) family of enzymes. MMP is characterized by its remarkable specificity against ECM components. Interstitial collagenases, the best studied members, attack interstitial collagens at a unique site producing two fragments. Using the complementary hydropathy hypothesis that states that peptides encoded by complementary nucleotide sequence can interact one to another, it was possible to characterize the sequence SQNPVQP (in fibroblast collagenase) or SSNPIQP (in neutrophil collagenase) as important in the interaction of the respective enzymes with collagen. The fact that fibronectin, another ECM component, binds at the same domain on collagen that is cleaved by collagenases arose the possibility of using the same approach (complementary hydropathy) in the study of collagen/fibronectin interaction. It was possible to characterize the fibronectin sequence TNEGVMY as important in the interaction with collagen. Adjacent to this site, there is a sequence (AAHEEIC) that shows an homology to the zinc-binding site present in several MMP. Therefore, zinc could be a modulator the collagen/fibronectin interaction. Finnaly, some phylogenetic aspects of the MMP family were studied. It was characterized a phylogenetic relationship between the catalytic core of MMP and the corresponding domain in Serratia protease and protease B from E. chrysanthemi, members of the same family of bacterial metalloproteinases. The catalytic activity of MMP can have evolved from the bacterial metaloproteinases whereas the substrate specificity is an acquisition of eukaryotic MMP

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No description available.

One of the principal impediments to the broad success of conventional chemotherapy is poor delivery to and transport within the tumor microenvironment (TME), caused by irregular and leaky vasculature, the lack of functional lymphatics, and underscored by the overproduction of extracellular matrix (ECM) proteins such as collagen. Coupled with limited specificity, the high chemotherapeutic doses needed to effectively treat tumors often lead to unacceptable levels of damage to healthy tissues. Bacteria-based cancer therapy (BBCT) is an innovative alternative. Attenuated strains of species such as Salmonella Typhimurium have been shown to preferentially replicate in the TME, competing for cellular resources and imparting intrinsic and immune-mediated cytotoxic effects on cancer cells. Nevertheless, the immense successes observed in in vitro and immunocompromised murine models have not translated to the clinic, attributable to the lack of sufficient tumor colonization. Synthetic biology today enables the precision engineering of microbes with traits for improved survival, penetration, and replication in the TME, rationally optimizable through computational modeling. In this dissertation, we explore several facets of rationally engineering of bacteria toward augmenting bacterial penetration and retention in the TME. Namely, we (1) develop a novel assay to interrogate the neutrophil migratory response to pathogens and characterize the effects of modifying the molecular structure of the outer membrane (OM) of S. Typhimurium, (2) develop a mathematical model of bacterial intratumoral transport and growth and explore the effects of nutrient availability and the tumor ECM on colonization, (3) engineer bacteria that constitutively secrete collagenase and show significantly augmented transport in collagen hydrogels and collagen-rich tumor spheroids, and (4) develop computational models to explore control schemes for the programmed behavior of bacteria-based biohybrid systems, which will leverage the engineered bacteria to deliver therapeutics to the TME. Our work serves as the foundation for the logical and efficient design of the next generation of BBCTs. / Doctor of Philosophy / Cancer is one of the deadliest diseases facing our world today not because of a lack of effective medications in most cases, but because of our inability to target the diseased sites with those treatments. Many tumors lie in deep and sensitive regions that render them untouchable by direct physical means. Poor vascularization leads to only small fractions of toxic, systemically injected drugs being deposited in tumors. State-of-the-art treatments such as so-called "nano-medicines" that can target features of the diseased tissues and immunotherapies that train the immune system to attack tumor cells have made tremendous strides, but for many types of cancer, the underlying challenge of reaching cells far from blood vessels and targeting immunologically cold tumors remains. Bacteria-based cancer therapy (BBCT) presents an exciting opportunity to address these challenges. Based on microorganisms that can self-propel, proliferate, and display a preference for diseased tissues, their potential not only to carry chemotherapeutic payloads but also to elicit directly toxic or immunotherapeutic effects on cancer cells is clear from experimental work. Nevertheless, the same delivery and transport barriers facing other treatments, as well as immune-mediated clearance, have limited BBCTs' clinical success. Advances in synthetic biology and computational modeling today make the precision engineering of BBCT for traits that favor targeted cancer therapy a reality. The central hypothesis of this dissertation is that endowing tumor-targeting bacteria with a tissue-degrading enzyme has the potential to enhance tumor penetration and colonization. This dissertation work has led to development of computational and experimental frameworks for the design, testing, and optimization of BBCTs through direct quantitative assessment of the immune response, simulations to both optimize nutrient consumption for optimal growth and for programming genetic control strategies, and characterization of transport in tissue. Our work serves as a foundation for engineering "intelligent" BBCT.

Desde o início da espécie humana, houve quem procurasse auxiliar o corpo na tentativa natural de restaurar suas partes injuriadas. Um dos grandes desafios atuais é a substituição de tecidos do organismo, inclusive em áreas de lesão cutânea. Um biomaterial pode ser utilizado para melhorar, aumentar ou substituir, parcial ou inteiramente tecidos ou órgãos. A membrana de celulose bacteriana (CB) possui moldabilidade, boas propriedades mecânicas, permeabilidade seletiva, permitindo a passagem de vapor d\'água, mas impedindo a passagem de microrganismos. O colágeno (COL) vem sendo amplamente usado como material na fabricação de biomateriais. Neste trabalho obteve-se membrana e hidrogel de CB-COL, caracterizados de diferentes maneiras. Foram realizados, estudos in vivo, análises macroscópica e histológica de coberturas de CB-COL, comparando com os controles (coágulo e a pomada de colagenase), após a aplicação sobre as feridas confeccionadas no dorso de ratos. Os animais foram sacrificados depois de 3, 7, 15 e 30 dias, e os dorsos processados segundo rotina histológica para coloração em HE. As caracterizações realizadas neste trabalho (microscopia eletrônica de varredura (MEV), análise termogravimétrica (TG), espectroscopia no infravermelho com transformada de Fourier (FT-IR) e difratometria de raios-X (DRX)) confirmaram a incorporação do COL às matrizes de CB. A avaliação macroscópica somente demonstrou diferença estatisticamente significante da reparação tecidual entre os tratamentos aos sete dias de pós-operatório, sendo que o hidrogel apresentou uma tendência para uma reparação mais rápida. Os resultados da avaliação histológica demonstraram diferença estatisticamente significante para reação inflamatória tecidual entre os tratamentos em todos os períodos estudados. Na avaliação da qualidade, quantidade e orientação das fibras colágenas, somente o período de três dias que não apresentou diferença estatisticamente significante entre os tratamentos. Conclui-se com esses resultados que as duas coberturas são biocompatíveis. / Since the beginning of the human race, there was those who sought to assist the body in a natural attempt to restore yours injured parts. One of the main current challenges is the replacement of body tissues, including areas of skin lesion. A biomaterial can be used to improve, enhance or replace, partially or fully tissues or organs. The membrane of bacterial cellulose (BC) has moldability, good mechanical properties, selective permeability, allowing the passage of water vapor but preventing the passage of microorganisms. The collagen (COL) has been widely used as material in the manufacture of biomaterials. In this study was obtained hydrogel and membrane BC-COL, characterized in different ways. Were realized in vivo studies, macroscopic and histological analyzes from dressings of BC-COL, comparing with controls (clot and collagenase ointment), after applying in wounds on the backs of rats. The animals were sacrificed after 3, 7, 15 and 30 days, and the scars were processed according to histological routine to HE staining. The characterizations performed in this study (scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared spectroscopy with Fourier transform (FT-IR) and X-ray diffraction (XRD)) confirmed the incorporation of the COL to matrices BC. The macroscopic evaluation only demonstrated statistically significant difference of tissue repair between treatments at seven days postoperative, and the hydrogel showed a trend for a faster repair. The results of the histological evaluation showed statistically significant difference in inflammatory tissue reaction between treatments in all periods studied. In quality evaluation, quantity and orientation of collagen fibers, only three days period didnt show statistically significant difference between treatments. We conclude from these results that the two dressings are biocompatible.

La cellule principale de l’os sous-chondral est l’ostéoblaste qui joue un rôle central dans la production qualitative et quantitative de la matrice ostéoïde. Plusieurs études montrent que le collagène de type I et la phosphatase alcaline sont des marqueurs précoces de la différenciation des ostéoblastes tandis que l’ostéocalcine (OCN) et la minéralisation sont des marqueurs des stades tardifs de cette différenciation. L’os sous-chondral est le site actif de nombreux changements morphologiques qui peuvent être différents au cours de l’arthrose (OA) mais qui sont partie prenante du processus pathologique. Ces changements consistent en une formation de la matrice osseuse importante associée une inhibition de la minéralisation. Ces phénomènes peuvent être reliés aux changements phénotypiques des ostéoblastes. La galectine-3 (gal-3) est un facteur inflammatoire qui a été détecté dans le tissu synovial et dans le liquide synovial lors d’inflammation d’OA. Des études antérieures ont montré que la gal-3 participait à la destruction du cartilage et inhibait fortement la production d’OCN par les ostéoblastes OA. Ces faits ont permis de suggérer que la gal-3 pouvait participer soit à l’initiation soit à la progression de l’arthrose. Peu d’études ont globalement été réalisées sur le rôle de la galectine-3 dans l’arthrose et encore moins sur le rôle de gal-3 sur les altérations de l’os sous-chondral.Dans ce contexte, ce travail de thèse a consisté à caractériser les ostéoblastes arthrosiques, puis investigué la modulation du phénotype des ostéoblastes arthrosiques par gal-3 en et enfin identifier les mécanismes cellulaires impliqués. D’une part, nous avons identifié deux populations ostéoblastes OA grâce à l’expression d’OCN. Dans les conditions basales, ces deux populations expriment de façon différentielle le TGF-ß1, Wnt5b et DKK2, ce qui suggère une différenciation et un phénotype hétérogènes des ostéoblastes chez les patients OA. D’autre part, nous confirmons le rôle délétère de la gal-3 dans l’articulation lors d’inflammation puisqu’elle stimule la production de collagénase 1 impliquée dans la dégradation osseuse. De plus, elle accentue la perturbation phénotypique des ostéoblastes qui produisent plus de leptine lors d’épisodes hypoxiques. Bien que plusieurs ligands membranaires puissent médier les effets de gal-3, 4F2hc semble jouer un rôle récurrent / Osteoblasts are the main cells in subchondral bone (SCB), which are responsible for the bone matrix production. Their differentiation can be evaluated by type I collagen and alkaline phosphatase in the early stage and by osteocalcin (OCN) and mineralization in the late stage. Alterations of SCB are essential episodes of osteoarthritis (OA) and are represented by a significant bone formation accompanied with abnormal hypomineralization. These changes in SCB are related to phenotypic modifications of osteoblasts. Galectin-3 (Gal-3) is an inflammatory factor markedly detected in the synovial tissue and synovial fluid during OA inflammation. Previous studies have demonstrated that gal-3 was deleterious for cartilage and inhibited the production of OCN in OA osteoblasts. These findings suggest that gal-3 can participate in either the initiation or progression of osteoarthritis. So far, a few studies have been conducted to explore the role of Gal-3 in OA and particularly related to SCB. In this context, the thesis has consisted to characterize OA osteoblasts, to investigate the modulation of the OA osteoblast phenotype by gal-3 and finally to identify the involved cellular mechanisms. We have identified two populations of OA osteoblasts according to the OCN expression. Under basal conditions, these two populations express TGF-ß1, Wnt5b and DKK2 differentially, suggesting various differentiation and heterogeneous phenotype of osteoblasts in OA patients. Moreover, we confirmed the deleterious role of gal-3 in the joint during inflammation since it stimulates the production of collagenase 1 involved in bone degradation. In addition, it emphasizes the disruption of phenotypic osteoblasts by producing more leptin during hypoxic episodes. Although several membrane ligands can mediate the effects of gal-3, 4F2hc seems to play a prominent role