Prof. Dr. Ivan Martin Department of Biomedical Engineering Profiles & Affiliations OverviewResearch Publications Publications by Type Projects & Collaborations Academic Activities Academic Self-Administration Continuing Education Junior Development, Doctorate and Advanced Studies Academic Reputation & Networking Teaching Bachelor/Master Projects & Collaborations OverviewResearch Publications Publications by Type Projects & Collaborations Academic Activities Academic Self-Administration Continuing Education Junior Development, Doctorate and Advanced Studies Academic Reputation & Networking Teaching Bachelor/Master Profiles & Affiliations Projects & Collaborations 31 foundShow per page10 10 20 50 Engineered Cartilage from Nose for the Treatment of Osteoarthritis Research Project | 4 Project MembersImported from Grants Tool 4665049 Direct 3D Bioprinting strategies to study articular cartilage development and regenerative therapy for osteoarthritis Research Project | 2 Project MembersBy the year 2030, approximately 25% of the adult population is projected to suffer from clinically diagnosed osteoarthritis (OA). At present OA cannot be treated, but only the associated pain is managed by administration of anti-inflammatory drugs. Implantation of tissue engineered cartilage in the affected lesions has been a hotly pursued research area worldwide for last three decades. However, this line of research has not succeeded so far. The most common problem encountered is that the engineered cartilage generated using mesenchymal progenitor cells (MSCs) does not share the molecular properties of native permanent cartilage but, instead, become vascularized, undergoes hypertrophic differentiation and eventually is replaced by bone once implanted in vivo. These latter features characterize both the transient cartilage (i.e.; cartilage formed at the epiphyseal growth plates of long bones) and the articular cartilage in OA joint. The overall objective of this proposal is to engineer a cartilage tissue which will be molecularly indistinguishable from healthy articular cartilage and which remains phenotypically stable also when implanted in a OA environment. We propose a comprehensive plan to achieve this, at the core of which is to engineer developmental processes in order to control fate specification by MSC and developing functional cartilage tissue construct by 3D bioprinting.Working hypothesis. Most of the tissue engineering studies did not take into account: (i) the natural process of permanent cartilage differentiation; (ii) the molecular niche in native permanent cartilage and the changes it undergoes during OA; (iii) the nature of the engineered cartilage; (iii) the effect that the niche, particularly the altered one in OA, has on tissue engineered cartilage. In the current proposal, we will develop a comprehensive strategy for designing a disease modifying therapy of OA, combining our strengths in 3D bioprinting, biomedical engineering, microfluidics and joint cartilage developmental biology. We hypothesize that phenotypical stable cartilage can be engineered by culturing MSC with signalling proteins (i.e.: Wnt ligands) and morphogenetic inhibitors (BMP inhibitors) recently shown (mainly by the applicants) to be key in regulating differentiation of MSC into stable or transient cartilage. Specific aims & experimental design. The first aim is to generate 3D bioprinted permanent cartilage in vitro. For this purpose, we will initially perform a screening of different doses and temporal stages of supplementation of Wnt ligands and BMP inhibitor within a microfluidic platform allowing generating and perfusing 3D MSCs microaggregates. This will allow identify the most promising conditions enabling the differentiation of MSCs into stable cartilage, to be scaled up and applied into the 3D bioprinted constructs. We will then explore use of silk-gelatin bioink tethered pathway-regulatory molecules on differentiation of the encapsulated mesenchymal cells (Aim 1). Once this is achieved, we will work towards two distinct but complementary approaches: (i) We will develop an in vitro model for OA. For this we will activate BMP signalling in the 3D bioprinted permanent cartilage to investigate if it recapitulates changes associated with OA. This will allow us to create a platform for rapid screening of drugs or other bioactive molecules which may be therapeutically relevant (Aim2). We will then develop bioink which will be either sensitive to matrix metalloproteases or mechanical stimulation to release in situ BMP inhibitors to protect the 3D bioprinted permanent cartilage once implanted in an OA joint (induced in mice), environment which would instead promote transient cartilage differentiation (Aim 3).Expected value of the proposed project. Even after 30 years of efforts, fabrication of load bearing and clinically relevant, biochemically equivalent cartilage tissue constructs still remains elusive. We are aware that this is a novel and highly ambitious objective, but collectively we have the necessary expertise and insight to attempt this, which if achieved will surely be a major boost for developing a disease modifying therapy for OA. Engineering of cell-free extracellular matrices enriched with osteoinductive and immunomodulatory factors to enhance bone healing Research Project | 2 Project MembersInfection, trauma or tumors can generate critical bone defects with compromised regeneration capacity, still not resolvable through clinical gold standard solutions. Extracellular matrices (ECMs) have been proposed for the physiological presentation of various cytokines at sites of tissue repair to activate and regulate endogenous cells. ECMs do not need to be derived from native tissues, but can be tissue-engineered and then devitalized. This provides the potential advantages of standardization (e.g., thanks to the use of cell lines) and of customization (e.g., by transducing cells to overexpress defined factors). ECMs could be engineered to deliver not only osteoinductive factors, but also immunomodulatory signals, which are increasingly being recognized as strong regulators in bone regeneration. Working hypothesis. We hypothesize that engineered and devitalized ECMs, specifically enriched in osteoinductive factors (BMP-2), as well as in cytokines polarizing immune response towards a pro-regenerative phenotype (IL4) and resolving acute inflammation (IL1Ra), can enhance bone regeneration. Specific aims. In order to generate the modular bricks for the engineering of ECMs, cell lines expressing different instructive cues (BMP-2, IL4 and IL1Ra) will be derived from an existing death-inducible human mesenchymal cell line (MSOD) (Aim1). ECMs enriched with different combinations and doses of such cues will be engineered, characterized and tested in a standard ectopic implantation model (Aim2). The capacity of these ECMs in modulating human immune cell recruitment and polarization will be investigated in vitro (Aim3). The effect of signals presented by ECMs on bone repair and the possible role of macrophages and T cells will be investigated in a rat critical sized calvarial defect (Aim4).Experimental design. Three cell lines will be generated by lentivirally transducing the MSOD line to express BMP2, IL4 and IL1Ra under the control of inducible promoters, and characterized in vitro for secretion of factors, proliferation, differentiation capacity and death-induction responsiveness (Aim1). Generated cell lines will be cultured on collagen scaffolds within a perfusion bioreactor to engineer ECMs, enriched in the different instructive signals. Obtained ECMs will be assessed for protein content and release, compatibility with inducible apoptosis and osteoinductive potential (Aim2). The immunomodulatory effect of engineered ECMs will be evaluated in an in vitro human setup based on i) chemokine release profiles, ii) recruitment and polarization of macrophages and iii) macrophage-mediated polarization of T cells (Aim3). The capacity of engineered ECMs to enhance bone repair will be studied in critical sized calvarial bone defects in immunocompetent rats, with or without depletion of T cells (Aim4). Expected value of the proposed project. Our studies will lead to the establishment of a strategy to engineer cell-free customizable materials presenting specific signals crucial for tissue regeneration. Moreover, our research will allow gaining new insights on the possibility to enhance bone healing by modulating inflammation and immunity. Such knowledge will be instrumental to improve the design of biomaterials/drugs in the broader field of regenerative immunology. NCCR Molecular Systems Engineering - phase 2 Research Project | 30 Project MembersMolecular Systems Engineering is a National Centre of Competence in Research (NCCR) funded by the Swiss National Science Foundation (SNSF), and headed by the University of Basel and the ETH Zurich. This NCCR combines expertise from chemistry, biology, physics, bioinformatics, and engineering. The overreaching aim is to develop tools and devices to monitor and manipulate off-equilibrium (bio)chemical systems. These may find applications in the synthesis of high added-value products, as innovative diagnostic tools and for the restoration of a desired cellular or organ function. The underestimated role of the human omentum in metastatic spread Research Project | 4 Project MembersHigh-grade serous ovarian (SOC), peritoneal (SPC) and tubal cancers (STC) are diagnosed in 75% of cases at advanced stage disease in women, when 5 year survival is only 20%. All three cancers have the same histological appearance and are diagnosed and treated the same way. However, knowledge is increasing that whilst all three arise via p53 mutations, they origin from different sites and have different genetic drivers. Whilst STC/SOC is defined by having the biggest tumor volume in the tubes/ovaries and only metastatic disease in the omentum, SPC presents with massive omental tumor-load with no invasion into the ovaries or tubes. Until now, there are no published data to support a different origin for SPC because it seems to be specifically located in the omentum. However, unpublished work from us has shown a revolutionary result: on genetic, proteomic and glycomic level, STC/SOC are distinct to SPC and should therefore be diagnosed and especially treated individually. Correct classification of these cancers, identifying the place of origin and their distinct development would change the paradigm that they are all the same disease which is relevant for the treatment regime and possible survival of women.Since SPC develops specifically in the omentum, we aim to (a) reveal the human omental structure in situ and (b) to design, based on the in-situ information, a relevant 3D human model mimicking the development of SPC.Like the omentum, the fallopian tubes and ovaries are covered by mesothelial cells with submesothelial vascular and lymphatic networks where resident macrophages mature; a robust 3D in vivo-like model, which allows the assessment of cancer cell mesothelial clearance and invasion as well as stem cell population studies has not been designed before and is highly innovative. We will use native tissue and for the first-time tissue-engineered omentum including 3D cell printing technology. Molecular analyses will be performed by deconstructing and reconstructing both omental models, systematically exposing the structures to normal tubal epithelial and serous tubal cancer cells. Hereby, we aim to understand the mechanism of invasion and thus develop new therapeutic targets. Together, these results have the potential to invalidate medical textbooks and shift the paradigm of diagnosis and treatment of high grade serous adenocarcinomas of apparently tubal, ovarian and peritoneal origin. NANOTRANSMED: Innovationen in der Nanomedizin - von der Diagnose zur Implantologie Research Project | 4 Project MembersDurch den Rückgriff auf Nanoobjekte soll das Projekt innovative und effektive Lösungen zur Behandlung von Patienten schaffen: - Frühzeitigen Diagnose: Hauptziel ist die Verbesserung der Effizienz von Targeting-Bildgebungssonden, um eine Vielzahl an Krankheiten (Krebs, neurodegenerative Erkrankungen, Entzündungen) frühzeitig zu diagnostizieren. - Individualisierte Behandlung: Entwicklung theranostischer Nanoobjekte, die in der Lage sind, Diagnose und Behandlung auf wirksame Art und Weise zu kombinieren. - Vermeidung von Infektionen: Entwicklung von robusten Antihaftoberflächen, um eine mikrobielle Besiedlung (die in 5% aller Krankenhausbehandlungen auftritt) effektiv zu vermeiden. BIOengineered grafts for Cartilage Healing In Patients (BIO-CHIP) Research Project | 1 Project MembersArticular cartilage injuries are a prime target for regenerative techniques, as spontaneous healing is poor and untreated defects predispose to osteoarthritis. Current strategies, including cell-based treatments, still have major drawbacks and show unsatisfactory long-term results due to inferior quality of repair tissue as compared to native cartilage. This proposal aims at testing new promising therapies for cartilage repair in the knee based on the use of nasal chondrocytes (instead of typically used articular chondrocytes) and on the implantation of a tissue (instead of a cell-based graft). The main objectives are: (1) To compare the clinical efficacy of a tissue therapy (nasal chondrocyte-derived engineered cartilage, NC-TECI) with that of a cell therapy (nasal chondrocyte delivery from a matrix, NC-MACI) for cartilage repair. A multicenter, prospective, phase II trial will be conducted in four clinical centers with enrollment of 108 patients. This trial will be build on a phase I study demonstrating the safety and feasibility of NC-TECI for treatment of traumatic articular cartilage injuries. The phase II study will give an indication about the role of graft maturation on the clinical outcome. The clinical efficacy will be measured through a 10 points increase in the KOOS score (primary outcome) reflecting improvement in patients 'pain and knee function. (2) To extend the range of potential clinical indications of NC-TECI and NC-MACI to so far untreatable ( pre)osteoarthritic lesions. This objective will be achieved through treatment of kissing cartilage lesions in an animal model. The relevance of the BIO-CHIP project with the scope of this call lies within the translation of basic knowledge on regenerative medicine into the clinic. It will increase the attractiveness of Europe as a location to develop new therapeutic options related to tissue therapy and also explore new indications for the management of currently untreatable cartilage lesions. Developmental Engineering of Cartilage from Adult MSCs - Mimicking Differentiation of Limb Mesenchymal Progenitors Research Project | 3 Project MembersVerletzungsbedingte und degenerative skeletale Krankheiten, die derzeit meist chirurgisch behandelt werden, könnten auch mit funktionellen skeletalen Ersatzgeweben behandelt werden. Durch die Nutzung von genetischen Modellen der Maus und den Vergleich des Maustranskriptoms von mesenchymalen Vorläuferzellen der Gliedmassen (LMP) mit Maus- und humanen MSCs, wollen wir (i) die gemeinsame moleculare Signatur zwischen LMP und MSCs identifizieren, (ii) die Marker für die Selektion von MSCs mit robustem chondrogenem Potential definieren, und (iii) eine entwicklungsinspirierte Strategie zur Züchtung von Knorpeltemplates entwickeln. Dadurch wird könnte es möglich sein Subpopulationen mit definierten funktionellen Eigenschaften zu identifizieren und stabile Protokolle für die Gewebezüchtung zu etablieren. A systems medicine approach to hematopoietic stem cell diseases 'StemSysMed' Research Project | 5 Project MembersBlood cancer occurs relatively rarely in humans, despite the fact that hematopoietic stem cells divide frequently, making mutations common. The scientists involved in the StemSysMed MRD Project aim to identify the factors that contribute to an onset of rampant proliferation of mutated blood cells. During blood formation, also called hematopoiesis, blood cells are produced from precursor or stem cells. This process features some of the highest cell formation, division and therefore mutation rates of all the cell types in our bodies. Nonetheless, blood cancer is not the most frequent type of cancer in humans. The reason for this is the presence of a fine-tuned control system. This system prevents excessive cell proliferation on various levels of blood formation, and eliminates the progeny of mutated precursor or stem cells, called malignant clones. Numerous mutations are already known to give rise to blood cancer. However, what is not yet known, is what happens before a clone is able to proliferate sufficiently to cause blood cancer. The StemSysMed MRD Project team aims to collect data and insight pertaining to this early phase, and to model them systematically. The scientists will examine healthy individuals displaying normal or clonal blood production as well as patients suffering from myeloproliferative neoplasms. This disease serves as a model for a neoplastic disease in which blood cells begin to proliferate uncontrollably. Identifying factors that enable clones to proliferate It is already known that frequency and traceability of mutations in hematopoietic cells increase with age. Additionally, infections, inflammations and other stress factors can influence the frequency and number of mutations. The StemSysMed project will examine the influence of these additional factors on the mutation profile, as well as the presence of clones during hematopoiesis. Using a systems biology approach, and taking myeloproliferative neoplasms as an example, the scientists will examine how the disease develops in a mouse model as well as in primary cells of affected patients. The goal is to identify the factors that enable a clone to proliferate to such an extent that disease occurs. Is it possible to explain the development of myeloproliferative neoplasms solely by the occurrence of a crucial cancer-inducing mutation in a precursor or stem cell? Or do oncogenic mutations in fact occur quite frequently, leading to blood cancer only in the presence of additional external factors? The scientists will test these hypotheses using mathematical models. Modulation of pre-vascularization in osteogenic tissue engineered grafts Research Project | 3 Project MembersBackground. Promoting an efficient vascularization of tissue-engineered (TE) osteogenic constructs upon in vivo implantation remains a major challenge towards their clinical application for bone regeneration and repair. Though numerous studies based on pre-vascularization of TE grafts by using vascular cells demonstrated the validity of this approach, they so far failed to define precise parameters, such as the cellular composition (density of endothelial and pericytic cells and of macrophages) and the degree of maturation/ramification of the preformed vascular structures necessary to make such pre-vascular structures fully supportive of vascularization, engraftment and survival of cell inside the implant upon in vivo implantation. This is likely to ultimately regulate tissue formation in vivo. Working hypothesis. The degree of pre-vascularization and the density of macrophages in vitro regulate the vascularization, the engraftment and the bone formation capacity of TE osteogenic grafts in vivo. Specific aims. To address this question, 3 aims are defined: 1) Aim 1 will define if, and how, different in vitro maturation/ramification levels of vascular structures in vitro could affect the density (number of capillaries, branches and total capillary length) of the vascularization in those grafts upon in vivo implantation. 2) Aim 2 will investigate to which extent such different densities of vascularization reached in vivo could in turn affect the engraftment, as judged by cell survival in the graft and performance of the osteogenic grafts in terms of density and volume of bone formation. 3) Finally, aim 3 will examine how macrophages of different phenotypes, included in the grafts or recruited from the host, affect vascularization and bone formation, and how to better harness the power of macrophages to produce enhanced TE bone. Experimental design. The study will use a previously established cell culture and in vivo system using progenitor cells freshly isolated from human adipose tissue, typically referred to as stromal vascular fraction (SVF) cells, demonstrated not to only generate osteogenic grafts but also an intrinsic vasculogenic capacity in vivo. Pre-vascularization density in vitro will be modulated by varying the in vitro culture duration and the effect of this pre-vascularization density on the vascular density, survival of cells inside the implanted grafts and volume of bone formation in vivo. In the same model, the contribution of macrophages of different phenotypes to those processes will be evaluated by depletion of specific populations by using cell sorting or enrichment with peripheral-blood derived macrophages. Expected value of the proposed project. We propose a systematic approach to aim at defining release criteria and quality markers for the use of SVF cells-based grafts as clinical tools, such as i) percentage of specific vascular cells, ii) degrees of vascular cells organization/vascular structure density and iii) percentage and phenotype of macrophages. This is an essential step to initiate preclinical scaled-up models and to pave the way to a pilot clinical trial based on the use of SVF cells-based grafts. 1234 1...4 OverviewResearch Publications Publications by Type Projects & Collaborations Academic Activities Academic Self-Administration Continuing Education Junior Development, Doctorate and Advanced Studies Academic Reputation & Networking Teaching Bachelor/Master
Projects & Collaborations 31 foundShow per page10 10 20 50 Engineered Cartilage from Nose for the Treatment of Osteoarthritis Research Project | 4 Project MembersImported from Grants Tool 4665049 Direct 3D Bioprinting strategies to study articular cartilage development and regenerative therapy for osteoarthritis Research Project | 2 Project MembersBy the year 2030, approximately 25% of the adult population is projected to suffer from clinically diagnosed osteoarthritis (OA). At present OA cannot be treated, but only the associated pain is managed by administration of anti-inflammatory drugs. Implantation of tissue engineered cartilage in the affected lesions has been a hotly pursued research area worldwide for last three decades. However, this line of research has not succeeded so far. The most common problem encountered is that the engineered cartilage generated using mesenchymal progenitor cells (MSCs) does not share the molecular properties of native permanent cartilage but, instead, become vascularized, undergoes hypertrophic differentiation and eventually is replaced by bone once implanted in vivo. These latter features characterize both the transient cartilage (i.e.; cartilage formed at the epiphyseal growth plates of long bones) and the articular cartilage in OA joint. The overall objective of this proposal is to engineer a cartilage tissue which will be molecularly indistinguishable from healthy articular cartilage and which remains phenotypically stable also when implanted in a OA environment. We propose a comprehensive plan to achieve this, at the core of which is to engineer developmental processes in order to control fate specification by MSC and developing functional cartilage tissue construct by 3D bioprinting.Working hypothesis. Most of the tissue engineering studies did not take into account: (i) the natural process of permanent cartilage differentiation; (ii) the molecular niche in native permanent cartilage and the changes it undergoes during OA; (iii) the nature of the engineered cartilage; (iii) the effect that the niche, particularly the altered one in OA, has on tissue engineered cartilage. In the current proposal, we will develop a comprehensive strategy for designing a disease modifying therapy of OA, combining our strengths in 3D bioprinting, biomedical engineering, microfluidics and joint cartilage developmental biology. We hypothesize that phenotypical stable cartilage can be engineered by culturing MSC with signalling proteins (i.e.: Wnt ligands) and morphogenetic inhibitors (BMP inhibitors) recently shown (mainly by the applicants) to be key in regulating differentiation of MSC into stable or transient cartilage. Specific aims & experimental design. The first aim is to generate 3D bioprinted permanent cartilage in vitro. For this purpose, we will initially perform a screening of different doses and temporal stages of supplementation of Wnt ligands and BMP inhibitor within a microfluidic platform allowing generating and perfusing 3D MSCs microaggregates. This will allow identify the most promising conditions enabling the differentiation of MSCs into stable cartilage, to be scaled up and applied into the 3D bioprinted constructs. We will then explore use of silk-gelatin bioink tethered pathway-regulatory molecules on differentiation of the encapsulated mesenchymal cells (Aim 1). Once this is achieved, we will work towards two distinct but complementary approaches: (i) We will develop an in vitro model for OA. For this we will activate BMP signalling in the 3D bioprinted permanent cartilage to investigate if it recapitulates changes associated with OA. This will allow us to create a platform for rapid screening of drugs or other bioactive molecules which may be therapeutically relevant (Aim2). We will then develop bioink which will be either sensitive to matrix metalloproteases or mechanical stimulation to release in situ BMP inhibitors to protect the 3D bioprinted permanent cartilage once implanted in an OA joint (induced in mice), environment which would instead promote transient cartilage differentiation (Aim 3).Expected value of the proposed project. Even after 30 years of efforts, fabrication of load bearing and clinically relevant, biochemically equivalent cartilage tissue constructs still remains elusive. We are aware that this is a novel and highly ambitious objective, but collectively we have the necessary expertise and insight to attempt this, which if achieved will surely be a major boost for developing a disease modifying therapy for OA. Engineering of cell-free extracellular matrices enriched with osteoinductive and immunomodulatory factors to enhance bone healing Research Project | 2 Project MembersInfection, trauma or tumors can generate critical bone defects with compromised regeneration capacity, still not resolvable through clinical gold standard solutions. Extracellular matrices (ECMs) have been proposed for the physiological presentation of various cytokines at sites of tissue repair to activate and regulate endogenous cells. ECMs do not need to be derived from native tissues, but can be tissue-engineered and then devitalized. This provides the potential advantages of standardization (e.g., thanks to the use of cell lines) and of customization (e.g., by transducing cells to overexpress defined factors). ECMs could be engineered to deliver not only osteoinductive factors, but also immunomodulatory signals, which are increasingly being recognized as strong regulators in bone regeneration. Working hypothesis. We hypothesize that engineered and devitalized ECMs, specifically enriched in osteoinductive factors (BMP-2), as well as in cytokines polarizing immune response towards a pro-regenerative phenotype (IL4) and resolving acute inflammation (IL1Ra), can enhance bone regeneration. Specific aims. In order to generate the modular bricks for the engineering of ECMs, cell lines expressing different instructive cues (BMP-2, IL4 and IL1Ra) will be derived from an existing death-inducible human mesenchymal cell line (MSOD) (Aim1). ECMs enriched with different combinations and doses of such cues will be engineered, characterized and tested in a standard ectopic implantation model (Aim2). The capacity of these ECMs in modulating human immune cell recruitment and polarization will be investigated in vitro (Aim3). The effect of signals presented by ECMs on bone repair and the possible role of macrophages and T cells will be investigated in a rat critical sized calvarial defect (Aim4).Experimental design. Three cell lines will be generated by lentivirally transducing the MSOD line to express BMP2, IL4 and IL1Ra under the control of inducible promoters, and characterized in vitro for secretion of factors, proliferation, differentiation capacity and death-induction responsiveness (Aim1). Generated cell lines will be cultured on collagen scaffolds within a perfusion bioreactor to engineer ECMs, enriched in the different instructive signals. Obtained ECMs will be assessed for protein content and release, compatibility with inducible apoptosis and osteoinductive potential (Aim2). The immunomodulatory effect of engineered ECMs will be evaluated in an in vitro human setup based on i) chemokine release profiles, ii) recruitment and polarization of macrophages and iii) macrophage-mediated polarization of T cells (Aim3). The capacity of engineered ECMs to enhance bone repair will be studied in critical sized calvarial bone defects in immunocompetent rats, with or without depletion of T cells (Aim4). Expected value of the proposed project. Our studies will lead to the establishment of a strategy to engineer cell-free customizable materials presenting specific signals crucial for tissue regeneration. Moreover, our research will allow gaining new insights on the possibility to enhance bone healing by modulating inflammation and immunity. Such knowledge will be instrumental to improve the design of biomaterials/drugs in the broader field of regenerative immunology. NCCR Molecular Systems Engineering - phase 2 Research Project | 30 Project MembersMolecular Systems Engineering is a National Centre of Competence in Research (NCCR) funded by the Swiss National Science Foundation (SNSF), and headed by the University of Basel and the ETH Zurich. This NCCR combines expertise from chemistry, biology, physics, bioinformatics, and engineering. The overreaching aim is to develop tools and devices to monitor and manipulate off-equilibrium (bio)chemical systems. These may find applications in the synthesis of high added-value products, as innovative diagnostic tools and for the restoration of a desired cellular or organ function. The underestimated role of the human omentum in metastatic spread Research Project | 4 Project MembersHigh-grade serous ovarian (SOC), peritoneal (SPC) and tubal cancers (STC) are diagnosed in 75% of cases at advanced stage disease in women, when 5 year survival is only 20%. All three cancers have the same histological appearance and are diagnosed and treated the same way. However, knowledge is increasing that whilst all three arise via p53 mutations, they origin from different sites and have different genetic drivers. Whilst STC/SOC is defined by having the biggest tumor volume in the tubes/ovaries and only metastatic disease in the omentum, SPC presents with massive omental tumor-load with no invasion into the ovaries or tubes. Until now, there are no published data to support a different origin for SPC because it seems to be specifically located in the omentum. However, unpublished work from us has shown a revolutionary result: on genetic, proteomic and glycomic level, STC/SOC are distinct to SPC and should therefore be diagnosed and especially treated individually. Correct classification of these cancers, identifying the place of origin and their distinct development would change the paradigm that they are all the same disease which is relevant for the treatment regime and possible survival of women.Since SPC develops specifically in the omentum, we aim to (a) reveal the human omental structure in situ and (b) to design, based on the in-situ information, a relevant 3D human model mimicking the development of SPC.Like the omentum, the fallopian tubes and ovaries are covered by mesothelial cells with submesothelial vascular and lymphatic networks where resident macrophages mature; a robust 3D in vivo-like model, which allows the assessment of cancer cell mesothelial clearance and invasion as well as stem cell population studies has not been designed before and is highly innovative. We will use native tissue and for the first-time tissue-engineered omentum including 3D cell printing technology. Molecular analyses will be performed by deconstructing and reconstructing both omental models, systematically exposing the structures to normal tubal epithelial and serous tubal cancer cells. Hereby, we aim to understand the mechanism of invasion and thus develop new therapeutic targets. Together, these results have the potential to invalidate medical textbooks and shift the paradigm of diagnosis and treatment of high grade serous adenocarcinomas of apparently tubal, ovarian and peritoneal origin. NANOTRANSMED: Innovationen in der Nanomedizin - von der Diagnose zur Implantologie Research Project | 4 Project MembersDurch den Rückgriff auf Nanoobjekte soll das Projekt innovative und effektive Lösungen zur Behandlung von Patienten schaffen: - Frühzeitigen Diagnose: Hauptziel ist die Verbesserung der Effizienz von Targeting-Bildgebungssonden, um eine Vielzahl an Krankheiten (Krebs, neurodegenerative Erkrankungen, Entzündungen) frühzeitig zu diagnostizieren. - Individualisierte Behandlung: Entwicklung theranostischer Nanoobjekte, die in der Lage sind, Diagnose und Behandlung auf wirksame Art und Weise zu kombinieren. - Vermeidung von Infektionen: Entwicklung von robusten Antihaftoberflächen, um eine mikrobielle Besiedlung (die in 5% aller Krankenhausbehandlungen auftritt) effektiv zu vermeiden. BIOengineered grafts for Cartilage Healing In Patients (BIO-CHIP) Research Project | 1 Project MembersArticular cartilage injuries are a prime target for regenerative techniques, as spontaneous healing is poor and untreated defects predispose to osteoarthritis. Current strategies, including cell-based treatments, still have major drawbacks and show unsatisfactory long-term results due to inferior quality of repair tissue as compared to native cartilage. This proposal aims at testing new promising therapies for cartilage repair in the knee based on the use of nasal chondrocytes (instead of typically used articular chondrocytes) and on the implantation of a tissue (instead of a cell-based graft). The main objectives are: (1) To compare the clinical efficacy of a tissue therapy (nasal chondrocyte-derived engineered cartilage, NC-TECI) with that of a cell therapy (nasal chondrocyte delivery from a matrix, NC-MACI) for cartilage repair. A multicenter, prospective, phase II trial will be conducted in four clinical centers with enrollment of 108 patients. This trial will be build on a phase I study demonstrating the safety and feasibility of NC-TECI for treatment of traumatic articular cartilage injuries. The phase II study will give an indication about the role of graft maturation on the clinical outcome. The clinical efficacy will be measured through a 10 points increase in the KOOS score (primary outcome) reflecting improvement in patients 'pain and knee function. (2) To extend the range of potential clinical indications of NC-TECI and NC-MACI to so far untreatable ( pre)osteoarthritic lesions. This objective will be achieved through treatment of kissing cartilage lesions in an animal model. The relevance of the BIO-CHIP project with the scope of this call lies within the translation of basic knowledge on regenerative medicine into the clinic. It will increase the attractiveness of Europe as a location to develop new therapeutic options related to tissue therapy and also explore new indications for the management of currently untreatable cartilage lesions. Developmental Engineering of Cartilage from Adult MSCs - Mimicking Differentiation of Limb Mesenchymal Progenitors Research Project | 3 Project MembersVerletzungsbedingte und degenerative skeletale Krankheiten, die derzeit meist chirurgisch behandelt werden, könnten auch mit funktionellen skeletalen Ersatzgeweben behandelt werden. Durch die Nutzung von genetischen Modellen der Maus und den Vergleich des Maustranskriptoms von mesenchymalen Vorläuferzellen der Gliedmassen (LMP) mit Maus- und humanen MSCs, wollen wir (i) die gemeinsame moleculare Signatur zwischen LMP und MSCs identifizieren, (ii) die Marker für die Selektion von MSCs mit robustem chondrogenem Potential definieren, und (iii) eine entwicklungsinspirierte Strategie zur Züchtung von Knorpeltemplates entwickeln. Dadurch wird könnte es möglich sein Subpopulationen mit definierten funktionellen Eigenschaften zu identifizieren und stabile Protokolle für die Gewebezüchtung zu etablieren. A systems medicine approach to hematopoietic stem cell diseases 'StemSysMed' Research Project | 5 Project MembersBlood cancer occurs relatively rarely in humans, despite the fact that hematopoietic stem cells divide frequently, making mutations common. The scientists involved in the StemSysMed MRD Project aim to identify the factors that contribute to an onset of rampant proliferation of mutated blood cells. During blood formation, also called hematopoiesis, blood cells are produced from precursor or stem cells. This process features some of the highest cell formation, division and therefore mutation rates of all the cell types in our bodies. Nonetheless, blood cancer is not the most frequent type of cancer in humans. The reason for this is the presence of a fine-tuned control system. This system prevents excessive cell proliferation on various levels of blood formation, and eliminates the progeny of mutated precursor or stem cells, called malignant clones. Numerous mutations are already known to give rise to blood cancer. However, what is not yet known, is what happens before a clone is able to proliferate sufficiently to cause blood cancer. The StemSysMed MRD Project team aims to collect data and insight pertaining to this early phase, and to model them systematically. The scientists will examine healthy individuals displaying normal or clonal blood production as well as patients suffering from myeloproliferative neoplasms. This disease serves as a model for a neoplastic disease in which blood cells begin to proliferate uncontrollably. Identifying factors that enable clones to proliferate It is already known that frequency and traceability of mutations in hematopoietic cells increase with age. Additionally, infections, inflammations and other stress factors can influence the frequency and number of mutations. The StemSysMed project will examine the influence of these additional factors on the mutation profile, as well as the presence of clones during hematopoiesis. Using a systems biology approach, and taking myeloproliferative neoplasms as an example, the scientists will examine how the disease develops in a mouse model as well as in primary cells of affected patients. The goal is to identify the factors that enable a clone to proliferate to such an extent that disease occurs. Is it possible to explain the development of myeloproliferative neoplasms solely by the occurrence of a crucial cancer-inducing mutation in a precursor or stem cell? Or do oncogenic mutations in fact occur quite frequently, leading to blood cancer only in the presence of additional external factors? The scientists will test these hypotheses using mathematical models. Modulation of pre-vascularization in osteogenic tissue engineered grafts Research Project | 3 Project MembersBackground. Promoting an efficient vascularization of tissue-engineered (TE) osteogenic constructs upon in vivo implantation remains a major challenge towards their clinical application for bone regeneration and repair. Though numerous studies based on pre-vascularization of TE grafts by using vascular cells demonstrated the validity of this approach, they so far failed to define precise parameters, such as the cellular composition (density of endothelial and pericytic cells and of macrophages) and the degree of maturation/ramification of the preformed vascular structures necessary to make such pre-vascular structures fully supportive of vascularization, engraftment and survival of cell inside the implant upon in vivo implantation. This is likely to ultimately regulate tissue formation in vivo. Working hypothesis. The degree of pre-vascularization and the density of macrophages in vitro regulate the vascularization, the engraftment and the bone formation capacity of TE osteogenic grafts in vivo. Specific aims. To address this question, 3 aims are defined: 1) Aim 1 will define if, and how, different in vitro maturation/ramification levels of vascular structures in vitro could affect the density (number of capillaries, branches and total capillary length) of the vascularization in those grafts upon in vivo implantation. 2) Aim 2 will investigate to which extent such different densities of vascularization reached in vivo could in turn affect the engraftment, as judged by cell survival in the graft and performance of the osteogenic grafts in terms of density and volume of bone formation. 3) Finally, aim 3 will examine how macrophages of different phenotypes, included in the grafts or recruited from the host, affect vascularization and bone formation, and how to better harness the power of macrophages to produce enhanced TE bone. Experimental design. The study will use a previously established cell culture and in vivo system using progenitor cells freshly isolated from human adipose tissue, typically referred to as stromal vascular fraction (SVF) cells, demonstrated not to only generate osteogenic grafts but also an intrinsic vasculogenic capacity in vivo. Pre-vascularization density in vitro will be modulated by varying the in vitro culture duration and the effect of this pre-vascularization density on the vascular density, survival of cells inside the implanted grafts and volume of bone formation in vivo. In the same model, the contribution of macrophages of different phenotypes to those processes will be evaluated by depletion of specific populations by using cell sorting or enrichment with peripheral-blood derived macrophages. Expected value of the proposed project. We propose a systematic approach to aim at defining release criteria and quality markers for the use of SVF cells-based grafts as clinical tools, such as i) percentage of specific vascular cells, ii) degrees of vascular cells organization/vascular structure density and iii) percentage and phenotype of macrophages. This is an essential step to initiate preclinical scaled-up models and to pave the way to a pilot clinical trial based on the use of SVF cells-based grafts. 1234 1...4
Engineered Cartilage from Nose for the Treatment of Osteoarthritis Research Project | 4 Project MembersImported from Grants Tool 4665049
Direct 3D Bioprinting strategies to study articular cartilage development and regenerative therapy for osteoarthritis Research Project | 2 Project MembersBy the year 2030, approximately 25% of the adult population is projected to suffer from clinically diagnosed osteoarthritis (OA). At present OA cannot be treated, but only the associated pain is managed by administration of anti-inflammatory drugs. Implantation of tissue engineered cartilage in the affected lesions has been a hotly pursued research area worldwide for last three decades. However, this line of research has not succeeded so far. The most common problem encountered is that the engineered cartilage generated using mesenchymal progenitor cells (MSCs) does not share the molecular properties of native permanent cartilage but, instead, become vascularized, undergoes hypertrophic differentiation and eventually is replaced by bone once implanted in vivo. These latter features characterize both the transient cartilage (i.e.; cartilage formed at the epiphyseal growth plates of long bones) and the articular cartilage in OA joint. The overall objective of this proposal is to engineer a cartilage tissue which will be molecularly indistinguishable from healthy articular cartilage and which remains phenotypically stable also when implanted in a OA environment. We propose a comprehensive plan to achieve this, at the core of which is to engineer developmental processes in order to control fate specification by MSC and developing functional cartilage tissue construct by 3D bioprinting.Working hypothesis. Most of the tissue engineering studies did not take into account: (i) the natural process of permanent cartilage differentiation; (ii) the molecular niche in native permanent cartilage and the changes it undergoes during OA; (iii) the nature of the engineered cartilage; (iii) the effect that the niche, particularly the altered one in OA, has on tissue engineered cartilage. In the current proposal, we will develop a comprehensive strategy for designing a disease modifying therapy of OA, combining our strengths in 3D bioprinting, biomedical engineering, microfluidics and joint cartilage developmental biology. We hypothesize that phenotypical stable cartilage can be engineered by culturing MSC with signalling proteins (i.e.: Wnt ligands) and morphogenetic inhibitors (BMP inhibitors) recently shown (mainly by the applicants) to be key in regulating differentiation of MSC into stable or transient cartilage. Specific aims & experimental design. The first aim is to generate 3D bioprinted permanent cartilage in vitro. For this purpose, we will initially perform a screening of different doses and temporal stages of supplementation of Wnt ligands and BMP inhibitor within a microfluidic platform allowing generating and perfusing 3D MSCs microaggregates. This will allow identify the most promising conditions enabling the differentiation of MSCs into stable cartilage, to be scaled up and applied into the 3D bioprinted constructs. We will then explore use of silk-gelatin bioink tethered pathway-regulatory molecules on differentiation of the encapsulated mesenchymal cells (Aim 1). Once this is achieved, we will work towards two distinct but complementary approaches: (i) We will develop an in vitro model for OA. For this we will activate BMP signalling in the 3D bioprinted permanent cartilage to investigate if it recapitulates changes associated with OA. This will allow us to create a platform for rapid screening of drugs or other bioactive molecules which may be therapeutically relevant (Aim2). We will then develop bioink which will be either sensitive to matrix metalloproteases or mechanical stimulation to release in situ BMP inhibitors to protect the 3D bioprinted permanent cartilage once implanted in an OA joint (induced in mice), environment which would instead promote transient cartilage differentiation (Aim 3).Expected value of the proposed project. Even after 30 years of efforts, fabrication of load bearing and clinically relevant, biochemically equivalent cartilage tissue constructs still remains elusive. We are aware that this is a novel and highly ambitious objective, but collectively we have the necessary expertise and insight to attempt this, which if achieved will surely be a major boost for developing a disease modifying therapy for OA.
Engineering of cell-free extracellular matrices enriched with osteoinductive and immunomodulatory factors to enhance bone healing Research Project | 2 Project MembersInfection, trauma or tumors can generate critical bone defects with compromised regeneration capacity, still not resolvable through clinical gold standard solutions. Extracellular matrices (ECMs) have been proposed for the physiological presentation of various cytokines at sites of tissue repair to activate and regulate endogenous cells. ECMs do not need to be derived from native tissues, but can be tissue-engineered and then devitalized. This provides the potential advantages of standardization (e.g., thanks to the use of cell lines) and of customization (e.g., by transducing cells to overexpress defined factors). ECMs could be engineered to deliver not only osteoinductive factors, but also immunomodulatory signals, which are increasingly being recognized as strong regulators in bone regeneration. Working hypothesis. We hypothesize that engineered and devitalized ECMs, specifically enriched in osteoinductive factors (BMP-2), as well as in cytokines polarizing immune response towards a pro-regenerative phenotype (IL4) and resolving acute inflammation (IL1Ra), can enhance bone regeneration. Specific aims. In order to generate the modular bricks for the engineering of ECMs, cell lines expressing different instructive cues (BMP-2, IL4 and IL1Ra) will be derived from an existing death-inducible human mesenchymal cell line (MSOD) (Aim1). ECMs enriched with different combinations and doses of such cues will be engineered, characterized and tested in a standard ectopic implantation model (Aim2). The capacity of these ECMs in modulating human immune cell recruitment and polarization will be investigated in vitro (Aim3). The effect of signals presented by ECMs on bone repair and the possible role of macrophages and T cells will be investigated in a rat critical sized calvarial defect (Aim4).Experimental design. Three cell lines will be generated by lentivirally transducing the MSOD line to express BMP2, IL4 and IL1Ra under the control of inducible promoters, and characterized in vitro for secretion of factors, proliferation, differentiation capacity and death-induction responsiveness (Aim1). Generated cell lines will be cultured on collagen scaffolds within a perfusion bioreactor to engineer ECMs, enriched in the different instructive signals. Obtained ECMs will be assessed for protein content and release, compatibility with inducible apoptosis and osteoinductive potential (Aim2). The immunomodulatory effect of engineered ECMs will be evaluated in an in vitro human setup based on i) chemokine release profiles, ii) recruitment and polarization of macrophages and iii) macrophage-mediated polarization of T cells (Aim3). The capacity of engineered ECMs to enhance bone repair will be studied in critical sized calvarial bone defects in immunocompetent rats, with or without depletion of T cells (Aim4). Expected value of the proposed project. Our studies will lead to the establishment of a strategy to engineer cell-free customizable materials presenting specific signals crucial for tissue regeneration. Moreover, our research will allow gaining new insights on the possibility to enhance bone healing by modulating inflammation and immunity. Such knowledge will be instrumental to improve the design of biomaterials/drugs in the broader field of regenerative immunology.
NCCR Molecular Systems Engineering - phase 2 Research Project | 30 Project MembersMolecular Systems Engineering is a National Centre of Competence in Research (NCCR) funded by the Swiss National Science Foundation (SNSF), and headed by the University of Basel and the ETH Zurich. This NCCR combines expertise from chemistry, biology, physics, bioinformatics, and engineering. The overreaching aim is to develop tools and devices to monitor and manipulate off-equilibrium (bio)chemical systems. These may find applications in the synthesis of high added-value products, as innovative diagnostic tools and for the restoration of a desired cellular or organ function.
The underestimated role of the human omentum in metastatic spread Research Project | 4 Project MembersHigh-grade serous ovarian (SOC), peritoneal (SPC) and tubal cancers (STC) are diagnosed in 75% of cases at advanced stage disease in women, when 5 year survival is only 20%. All three cancers have the same histological appearance and are diagnosed and treated the same way. However, knowledge is increasing that whilst all three arise via p53 mutations, they origin from different sites and have different genetic drivers. Whilst STC/SOC is defined by having the biggest tumor volume in the tubes/ovaries and only metastatic disease in the omentum, SPC presents with massive omental tumor-load with no invasion into the ovaries or tubes. Until now, there are no published data to support a different origin for SPC because it seems to be specifically located in the omentum. However, unpublished work from us has shown a revolutionary result: on genetic, proteomic and glycomic level, STC/SOC are distinct to SPC and should therefore be diagnosed and especially treated individually. Correct classification of these cancers, identifying the place of origin and their distinct development would change the paradigm that they are all the same disease which is relevant for the treatment regime and possible survival of women.Since SPC develops specifically in the omentum, we aim to (a) reveal the human omental structure in situ and (b) to design, based on the in-situ information, a relevant 3D human model mimicking the development of SPC.Like the omentum, the fallopian tubes and ovaries are covered by mesothelial cells with submesothelial vascular and lymphatic networks where resident macrophages mature; a robust 3D in vivo-like model, which allows the assessment of cancer cell mesothelial clearance and invasion as well as stem cell population studies has not been designed before and is highly innovative. We will use native tissue and for the first-time tissue-engineered omentum including 3D cell printing technology. Molecular analyses will be performed by deconstructing and reconstructing both omental models, systematically exposing the structures to normal tubal epithelial and serous tubal cancer cells. Hereby, we aim to understand the mechanism of invasion and thus develop new therapeutic targets. Together, these results have the potential to invalidate medical textbooks and shift the paradigm of diagnosis and treatment of high grade serous adenocarcinomas of apparently tubal, ovarian and peritoneal origin.
NANOTRANSMED: Innovationen in der Nanomedizin - von der Diagnose zur Implantologie Research Project | 4 Project MembersDurch den Rückgriff auf Nanoobjekte soll das Projekt innovative und effektive Lösungen zur Behandlung von Patienten schaffen: - Frühzeitigen Diagnose: Hauptziel ist die Verbesserung der Effizienz von Targeting-Bildgebungssonden, um eine Vielzahl an Krankheiten (Krebs, neurodegenerative Erkrankungen, Entzündungen) frühzeitig zu diagnostizieren. - Individualisierte Behandlung: Entwicklung theranostischer Nanoobjekte, die in der Lage sind, Diagnose und Behandlung auf wirksame Art und Weise zu kombinieren. - Vermeidung von Infektionen: Entwicklung von robusten Antihaftoberflächen, um eine mikrobielle Besiedlung (die in 5% aller Krankenhausbehandlungen auftritt) effektiv zu vermeiden.
BIOengineered grafts for Cartilage Healing In Patients (BIO-CHIP) Research Project | 1 Project MembersArticular cartilage injuries are a prime target for regenerative techniques, as spontaneous healing is poor and untreated defects predispose to osteoarthritis. Current strategies, including cell-based treatments, still have major drawbacks and show unsatisfactory long-term results due to inferior quality of repair tissue as compared to native cartilage. This proposal aims at testing new promising therapies for cartilage repair in the knee based on the use of nasal chondrocytes (instead of typically used articular chondrocytes) and on the implantation of a tissue (instead of a cell-based graft). The main objectives are: (1) To compare the clinical efficacy of a tissue therapy (nasal chondrocyte-derived engineered cartilage, NC-TECI) with that of a cell therapy (nasal chondrocyte delivery from a matrix, NC-MACI) for cartilage repair. A multicenter, prospective, phase II trial will be conducted in four clinical centers with enrollment of 108 patients. This trial will be build on a phase I study demonstrating the safety and feasibility of NC-TECI for treatment of traumatic articular cartilage injuries. The phase II study will give an indication about the role of graft maturation on the clinical outcome. The clinical efficacy will be measured through a 10 points increase in the KOOS score (primary outcome) reflecting improvement in patients 'pain and knee function. (2) To extend the range of potential clinical indications of NC-TECI and NC-MACI to so far untreatable ( pre)osteoarthritic lesions. This objective will be achieved through treatment of kissing cartilage lesions in an animal model. The relevance of the BIO-CHIP project with the scope of this call lies within the translation of basic knowledge on regenerative medicine into the clinic. It will increase the attractiveness of Europe as a location to develop new therapeutic options related to tissue therapy and also explore new indications for the management of currently untreatable cartilage lesions.
Developmental Engineering of Cartilage from Adult MSCs - Mimicking Differentiation of Limb Mesenchymal Progenitors Research Project | 3 Project MembersVerletzungsbedingte und degenerative skeletale Krankheiten, die derzeit meist chirurgisch behandelt werden, könnten auch mit funktionellen skeletalen Ersatzgeweben behandelt werden. Durch die Nutzung von genetischen Modellen der Maus und den Vergleich des Maustranskriptoms von mesenchymalen Vorläuferzellen der Gliedmassen (LMP) mit Maus- und humanen MSCs, wollen wir (i) die gemeinsame moleculare Signatur zwischen LMP und MSCs identifizieren, (ii) die Marker für die Selektion von MSCs mit robustem chondrogenem Potential definieren, und (iii) eine entwicklungsinspirierte Strategie zur Züchtung von Knorpeltemplates entwickeln. Dadurch wird könnte es möglich sein Subpopulationen mit definierten funktionellen Eigenschaften zu identifizieren und stabile Protokolle für die Gewebezüchtung zu etablieren.
A systems medicine approach to hematopoietic stem cell diseases 'StemSysMed' Research Project | 5 Project MembersBlood cancer occurs relatively rarely in humans, despite the fact that hematopoietic stem cells divide frequently, making mutations common. The scientists involved in the StemSysMed MRD Project aim to identify the factors that contribute to an onset of rampant proliferation of mutated blood cells. During blood formation, also called hematopoiesis, blood cells are produced from precursor or stem cells. This process features some of the highest cell formation, division and therefore mutation rates of all the cell types in our bodies. Nonetheless, blood cancer is not the most frequent type of cancer in humans. The reason for this is the presence of a fine-tuned control system. This system prevents excessive cell proliferation on various levels of blood formation, and eliminates the progeny of mutated precursor or stem cells, called malignant clones. Numerous mutations are already known to give rise to blood cancer. However, what is not yet known, is what happens before a clone is able to proliferate sufficiently to cause blood cancer. The StemSysMed MRD Project team aims to collect data and insight pertaining to this early phase, and to model them systematically. The scientists will examine healthy individuals displaying normal or clonal blood production as well as patients suffering from myeloproliferative neoplasms. This disease serves as a model for a neoplastic disease in which blood cells begin to proliferate uncontrollably. Identifying factors that enable clones to proliferate It is already known that frequency and traceability of mutations in hematopoietic cells increase with age. Additionally, infections, inflammations and other stress factors can influence the frequency and number of mutations. The StemSysMed project will examine the influence of these additional factors on the mutation profile, as well as the presence of clones during hematopoiesis. Using a systems biology approach, and taking myeloproliferative neoplasms as an example, the scientists will examine how the disease develops in a mouse model as well as in primary cells of affected patients. The goal is to identify the factors that enable a clone to proliferate to such an extent that disease occurs. Is it possible to explain the development of myeloproliferative neoplasms solely by the occurrence of a crucial cancer-inducing mutation in a precursor or stem cell? Or do oncogenic mutations in fact occur quite frequently, leading to blood cancer only in the presence of additional external factors? The scientists will test these hypotheses using mathematical models.
Modulation of pre-vascularization in osteogenic tissue engineered grafts Research Project | 3 Project MembersBackground. Promoting an efficient vascularization of tissue-engineered (TE) osteogenic constructs upon in vivo implantation remains a major challenge towards their clinical application for bone regeneration and repair. Though numerous studies based on pre-vascularization of TE grafts by using vascular cells demonstrated the validity of this approach, they so far failed to define precise parameters, such as the cellular composition (density of endothelial and pericytic cells and of macrophages) and the degree of maturation/ramification of the preformed vascular structures necessary to make such pre-vascular structures fully supportive of vascularization, engraftment and survival of cell inside the implant upon in vivo implantation. This is likely to ultimately regulate tissue formation in vivo. Working hypothesis. The degree of pre-vascularization and the density of macrophages in vitro regulate the vascularization, the engraftment and the bone formation capacity of TE osteogenic grafts in vivo. Specific aims. To address this question, 3 aims are defined: 1) Aim 1 will define if, and how, different in vitro maturation/ramification levels of vascular structures in vitro could affect the density (number of capillaries, branches and total capillary length) of the vascularization in those grafts upon in vivo implantation. 2) Aim 2 will investigate to which extent such different densities of vascularization reached in vivo could in turn affect the engraftment, as judged by cell survival in the graft and performance of the osteogenic grafts in terms of density and volume of bone formation. 3) Finally, aim 3 will examine how macrophages of different phenotypes, included in the grafts or recruited from the host, affect vascularization and bone formation, and how to better harness the power of macrophages to produce enhanced TE bone. Experimental design. The study will use a previously established cell culture and in vivo system using progenitor cells freshly isolated from human adipose tissue, typically referred to as stromal vascular fraction (SVF) cells, demonstrated not to only generate osteogenic grafts but also an intrinsic vasculogenic capacity in vivo. Pre-vascularization density in vitro will be modulated by varying the in vitro culture duration and the effect of this pre-vascularization density on the vascular density, survival of cells inside the implanted grafts and volume of bone formation in vivo. In the same model, the contribution of macrophages of different phenotypes to those processes will be evaluated by depletion of specific populations by using cell sorting or enrichment with peripheral-blood derived macrophages. Expected value of the proposed project. We propose a systematic approach to aim at defining release criteria and quality markers for the use of SVF cells-based grafts as clinical tools, such as i) percentage of specific vascular cells, ii) degrees of vascular cells organization/vascular structure density and iii) percentage and phenotype of macrophages. This is an essential step to initiate preclinical scaled-up models and to pave the way to a pilot clinical trial based on the use of SVF cells-based grafts.
