2,618 research outputs found
Scaffolds derived from decellularized tumor matrix of colorectal cancer patients as a 3D model for the study of the liver metastatic microenvironment
No full textopenIl cancro del colon-retto (CRC) è il terzo tumore più diffuso al mondo ed il fegato è il più comune sito di metastasi; risulta, quindi, urgente la necessità di sviluppare nuovi modelli di coltura tissutale per studiare le metastasi epatiche del tumore (CRLM). La decellularizzazione fornisce un nuovo approccio per lo studio della matrice extracellulare (ECM) dei tessuti tumorali, poiché permette di mantenere le proprietà strutturali e biologiche del tessuto di partenza. Nel presente studio è stato realizzato un modello 3D di CRC/CRLM derivato da ECM colorettale ed epatica decellularizzata e poi ripopolata con cellule della linea HT-29. Le cellule hanno dimostrato una migliore capacità di proliferazione/migrazione quando coltivate su scaffold derivati da tessuti tumorali piuttosto che dai tessuti sani dello stesso paziente, regolando il profilo di espressione genica/proteica per realizzare una transizione epitelio-mesenchimale. Infine, le cellule HT-29 coltivate in microambienti 3D tumorali risultavano meno responsive al trattamento con agenti chemioterapici in confronto con sistemi di coltura 2D. In conclusione, il modello 3D di ECM decellularizzata di CRC/CRLM sembra mimare in modo migliore il microambiente metastatico rispetto alle condizioni di coltura 2D convenzionali, rappresentando un approccio promettente per lo studio di CRLM e la valutazione di agenti chemioterapici
Pre-nucleation clusters in liquid benzoic acid
No full textCarboxylic acids play a pivotal role in crystal engineering, owing to their ability to form hydrogen-bonded cyclic dimers, which route the crystallization process. Benzoic acid (BZA) is the prototype of aromatic carboxylic acids. Recent results from our group point out that several intermolecular recognition modes are present in the liquid phase, where the cyclic dimers that are found also in the P21/c crystal – the only known to date – are overcome by trimeric structures with almost trigonal symmetry, and coexist with greater and more complex HB clusters. Thus, a question arises – when and why does the structure of the liquid change, so that nucleation of BZA dimers can occur? To gain insights on the problem, we investigate liquid benzoic acid as a function of T by means of molecular dynamics with the free MiCMoS platform. We propose novel structure-free energy-based criteria to highlight relevant supramolecular clusters that show a detectable cohesion and, for this reason, have lifetimes significantly longer than thermal fluctuations. Our tool allows to single out nanoscale inhomogeneities that impact on the average structure of the liquid, in what is the nano-equivalent of bulk de-mixing within a binary system. We find clusters up to 17 molecules large that persist by more than 100 ps in undercooled BZA, and display an inner structure that is somewhat intermediate between the liquid and the crystal. Thus, they might lie on the path to the ripening of critical clusters or semi-liquid crystal embryos. Large aggregates still lack a definite inner symmetry and are highly dynamic and fluxional, as we expect. We hypothesise that, on longer time scales, persistent nanoscale inhomogeneities could set up a favourable environment that enhances the probability of nucleation, in agreement with non-classical theories
Changes in tension regulates proliferation and migration of fibroblasts by remodeling expression of ECM proteins
No full textWound healing is a complicated but highly organized process in which cell migration and proliferation are actively involved. However, the process by which mechanical stretch regulates the proliferation and migration of human skin fibroblasts (HFs) and keratinocytes is poorly understood. Using a house built mechanical stretch device, we examined the HFs extracellular matrix (ECM) components changes under non-stretch, static stretch or cyclic stretch conditions. We further investigated the changes in ECM component protein expression levels in keratinocytes and analyzed the effects of individual ECM component on keratinocyte proliferation and migration. Particularly, the roles of calcium/calmodulin-dependent serine protein kinase (CASK) in the HF proliferation under cyclic stretch were investigated. Cyclic stretch suppressed HF proliferation compared with HFs without stretch or with static stretch. Cyclic stretch also led to a significant reduction in the levels of collagen I and a marked increase of fibronectin in HFs ECM. By contrast, collagen I levels increased and fibronectin levels decreased in response to non-stretch and static stretch conditions. After cyclic stretch, the proliferation of keratinocytes was inhibited by the cyclic stretch-induced ECM in HFs. The inoculation of keratinocytes with single ECM component suggested that collagen I was more capable of inducing cell proliferation than fibronectin, while it had less impact on cell migration compared with fibronectin. Furthermore, cyclic stretch induced by proliferation inhibition was associated with altered integrin 1-CASK signal pathway. The present results demonstrated the existence of HF-ECM-keratinocyte cross-talk' in cutaneous tissues. Thus, the integrin 1-CASK signal pathway in HFs may be involved in the outside-in signal transduction of extracellular stretch and the altered ECM component expression
Enhancing therapeutic efficacy through degradation of endogenous extracellular matrix in primary breast tumor spheroids
No full textSolid tumors have a complex extracellular matrix (ECM) that significantly affects tumor behavior and response to therapy. Understanding the ECM's role is crucial for advancing cancer research and treatment. This study established an in vitro model using primary cells isolated from a rat breast tumor to generate three-dimensional spheroids. Monolayer cells and spheroid cultures exhibited different protein expression patterns, with primary tumor spheroids presenting an increased level of ECM-related proteins and a more complex extracellular environment. Furthermore, spheroids produce endogenous collagen type I matrix, which is the main component of the tumoral ECM. This matrix is arranged predominantly around the 3D structure, mimicking the conditions of solid tumors. Treatments with recombinant collagenases class II (acting on the linear collagen region) and class I (acting on the 3D-helix region) completely degrade collagen within the spheroid structure. Collagenase pretreatment enhances the accessibility of the anticancer drug doxorubicin to penetrate the core of spheroids and sensitize them to doxorubicin-induced cytotoxicity. Our findings highlight the importance of overcoming drug resistance in breast cancer by targeting the ECM and proposing a novel strategy for improving therapeutic outcomes in solid tumors. By employing a three-dimensional spheroid model, with an endogenous ECM, we can offer more relevant insights into tumor biology and treatment responses
Subcritical clusters of liquid benzoic acid: insights from molecular dynamics simulations
No full textNucleation is a crucial process in material science and pharmaceutical chemistry, yet it remains poorly understood and presents numerous unanswered questions. How does a crystal nucleus form? Does it emerge from a completely disordered liquid phase through the continuous addition of building units, as suggested by Classical Nucleation Theory? And is the structure of the nucleus identical to that of the resulting crystal? Recent studies, suggest that for benzoic acid, nucleation may occur via a non-classical pathway. This is due to the formation of stable aggregates in the liquid phase, which persist for several picoseconds but do not share the same structure as the final crystal. However, a precise and unique definition of these so-called subcritical clusters is elusive, due to their dynamic nature. In this work, we perform molecular dynamics simulations on liquid benzoic acid employing the free MiCMoS platform, and propose a definition of subcritical clusters based on three criteria: molecular connectivity, time persistence, and energetic stability. Finally, we describe the structural and dynamic characteristics of subcritical clusters comparing them with the crystallographic structure. Subcritical clusters must be aggregates of bonded molecules: two molecules are considered bonded if their interaction energy is more negative than a specified energy threshold. Additionally, these aggregates must be persistent, meaning that their lifetime must exceed that of thermal fluctuations. Furthermore, they must be energetically "stable": we introduce the concept of excess energy as a stability condition, defined as the difference between the cohesive energy of the aggregate and the interaction energy between the aggregate and the surrounding molecules. Only aggregates meeting all these criteria are considered subcritical clusters: they must exhibit interaction energies more negative than an arbitrary “binding” threshold, lifetimes longer than thermal fluctuations, and a negative average excess energy. Interestingly, while the P21/c crystal structure of benzoic acid consists of cyclic dimers, the subcritical clusters are composed of folded H-bonded catemers with a globular shape. Longer simulations and a systematic study of their temporal evolution could potentially reveal the growth of these subcritical clusters and their eventual rearrangement into a crystal nucleus
The Multifaced Role of Collagen in Cancer Development and Progression
No full textCollagen is a crucial protein in the extracellular matrix (ECM) essential for preserving tissue architecture and supporting crucial cellular functions like proliferation and differentiation. There are twenty-eight identified types of collagen, which are further divided into different subgroups. This protein plays a critical role in regulating tissue homeostasis. However, in solid tumors, the balance can be disrupted, due to an abundance of collagen in the tumor microenvironment, which significantly affects tumor growth, cell invasion, and metastasis. It is important to investigate the specific types of collagens in cancer ECM and their distinct roles in tumor progression to comprehend their unique contribution to tumor behavior. The diverse pathophysiological functions of different collagen types in cancers illustrate collagen's dual roles, offering potential therapeutic options and serving as prognostic markers
Transizione verso lo smart working in ECM S.p.a.
No full textIl presente elaborato illustra i risultati ottenuti dal lavoro svolto nel corso del tirocinio in area HR e comunicazione presso la sede pistoiese di ECM S.p.a., Progress Rail, a Caterpillar Company.
L’obiettivo è l’individuazione di un piano operativo che consenta la gestione della transizione verso lo smart working all’interno delle imprese. Lo studio è partito dalla necessità per le organizzazioni, a valle dello sconvolgimento relativo alla pandemia Covid-19, di rivedere le modalità di lavoro in presenza. A seguito di una prima fase di raccolta ed analisi dei dati, ci si è concentrati nella definizione di un piano operativo che consenta di fornire un efficace supporto nell’adozione dello smart working dal punto di vista organizzativo, strategico e tecnologico.
Il progetto si inserisce nel più ampio contesto di valutazione dell’impatto sulle aziende della transizione verso nuovi modelli di lavoro: dalla riduzione dei costi attraverso una riorganizzazione del layout, al miglioramento del processo di comunicazione interna, al guadagno in termini di attrattività di nuove risorse.
This paper illustrates the results obtained from the work carried out during the internship in HR and Communication area at ECM S.p.a., Progress Rail, a Caterpillar Company, in Pistoia. The operational methodology identified aims to facilitate the transition towards remote working within companies. The study started from the need for organizations to review the methods of working in presence after the Covid-19 pandemic. Following an initial phase of data collection and analysis, we focused on the definition with a replicable methodology of an operational plan that would allow to provide effective support in the adoption of remote work, from an organizational, strategical, and technological point of view.
The project is part of the broader context of assessing the impact on companies of the transition to new working models: from reducing costs through a reorganisation of the layout, to improving the internal communication process, to gaining the attractiveness of new resources
A Study on the Acceptance of ECM Systems
No full textThe present paper summarizes selected results of the first au-thor‟s Master‟s thesis for the student track at the 10th Interna-tional Conference on Wirtschaftsinformatik in Zurich, Switzer-land. The thesis was co-supervised by the second and the third author. Building upon the technology acceptance model (TAM), the assignment was to investigate factors impacting on end users‟ acceptance of enterprise content management (ECM) systems. The study suggests twenty-two factors at the enterprise, process, technology, and content level that can influence ECM success. The results are grounded in both a systematic review of the lite-rature on ECM, including related fields such as document man-agement and records management, and an analysis of qualitative data collected from five ECM-adopting organizations. It is hoped that the findings will inform future Information Systems (IS) research on ECM acceptance. Practitioners can use the results in the process of planning and conducting their own ECM projects
EphrinB2/EphB4 signaling regulates angiogenesis of dental pulp stem cells and endothelial cells
No full textEstablishment of an instantaneous and adequate blood supply is critically important for dental pulp regeneration. However, the pulp cavity is enclosed by a rigid mineralized tissue shell and allows a single blood supply via a constricted apical opening, causing frequent ischemic necrosis. To overcome this challenge, stem cells with angiogenic potential, or in combination with endothelial cells (ECs), have been used to engineer pulp substitute in vitro, in order to accelerate in vivo vascular anastomosis upon transplantation.
Dental pulp stem cells (DPSCs) and stem cells from exfoliated deciduous teeth (SHED) are promising cell sources for vascular tissue engineering. Previous evidence suggests that DPSCs and SHED could differentiate into functional endothelial-like cells under defined stimuli, but the efficiency is low. One reason may be the lack of in vivo microenvironment, such as the extracellular matrix (ECM) that provides various signaling molecules guiding cell differentiation. Therefore, in the 1st study, human umbilical vein endothelial cells (HUVECs) was decellularized and the ECM was extracted for endothelial induction. The results, for the first time, showed that the decellularized ECM significantly promoted adhesion, proliferation, as well as endothelial differentiation of SHED in vitro.
The ligand EphrinB2 with its tyrosine kinase receptor EphB4 is one of the most essential ligand-receptor systems implicated in vascular development and remodeling. The 2nd and 3rd studies focus on investigating the synergistic effect of DPSCs and HUVECs in inducing angiogenesis and the specific role of EphrinB2/EphB4 signaling in regulating their interaction. To closely mimic in vivo angiogenic process, two three-dimensional (3-D) angiogenesis model–a fibrin gel microbead model and a Matrigel-dependent model were used for coculture of DPSCs and HUVECs. The results showed that the in vitro and in vivo vascular formation by HUVECs was greatly enhanced by coculture with DPSCs, which however was significantly suppressed by pharmacological inhibitors of EphB4. Knockdown of EphrinB2 and EphB4 expression in DPSCs reduced their tube forming capacity and delayed the coassembly of DPSCs with HUVECs into reticular structures. The EphrinB2/EphB4 signaling regulated angiogenesis in a phosphotyrosine-dependent manner and the Src family kinases are indispensably required for EphrinB2 reverse signaling-mediated angiogenesis. More importantly, the EphrinB2/EphB4 signaling showed a crosstalk with VEGF signaling. Stimulation of DPSCs with EphrinB2-Fc and EphB4-Fc enhanced the production of VEGF, and thus facilitating the vessel formation of HUVECs.
In summary, the ECM derived from HUVECs could promote endothelial differentiation of SHED in vitro; and EphrinB2/EphB4 signaling may contribute to the in vitro and in vivo angiogenic functions of DPSCs and HUVECs. The current findings advance our understanding of the synergy function of DPSCs and ECs in enhancing angiogenesis as well as the underlying mechanisms. This present study has significant implications for developing strategies for promoting vascular tissue engineering in regenerative endodontics.published_or_final_versionDentistryDoctoralDoctor of Philosoph
ECM formation and degradation during fibrosis, repair, and regeneration
No full text\ua9 The Author(s) 2025.Imperfect attempts at organ repair after repeated injury result in aberrant formation of extracellular matrix (ECM) and loss of tissue structure. This abnormal ECM goes from being a consequence of cellular dysregulation to become the backbone of a persistently fibrotic cell niche that compromises organic function and ultimately drives systemic disease. Here, we review our current understanding of the structure of the ECM, the mechanisms behind organ-specific fibrosis, resolution, healing and regeneration, as well as the development of anti-fibrotic strategies. We also discuss the design of biomarkers to investigate fibrosis pathophysiology, track fibrosis progression, systemic damage, and fibrosis resolution
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