143 research outputs found

    Functional cell microcarriers: a new platform for cell separation and expansion

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    Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013)The success of many stem cell applications in the biomedical field is highly dependent on the development of separation techniques for isolation and purification of cells with a very high yield and purity. Despite all the achievements made in the field over the past several years, new systems for effective cell separation are still needed. Previous work from our group demonstrated that functional chitosan films grafted with antibodies promote selective cell adhesion. 1 Herein we developed chitosan microparticles able to capture a specific cell types based in the concept of antibody coating for cell sorting. Our goal was to create new biomaterial surfaces capable of recruit a specific cell population within a mixture, reducing cell manipulation and time-consuming allowing at the same time cell expansion. Such system acts as a microcarrier for cell expansion of a specific cell target. Microcarrier culture system offers the advantage of providing a larger surface area for the growth of anchorage-dependent cells in a suspension culture system. Chitosan was chosen due to the excellent biocompatibility, gel forming properties, chemistry surface and low cell adhesion. This allows the modification with specific biochemical cues, for a controllable cell attachment. Here we develop functional biotinylated microparticles, such system allows tailoring microparticles to a variety of functional biomolecules. Here we tested the immobilization of antibodies to target specific cell types, CD31 for endothelial cells and CD90 for adipose stem cells. Primarily designed for an application in tissue engineering, two main challenges are accomplished with the herein presented microparticles: separation and scale-up expansion of specific cell type. The herein developed polymeric microparticles can also be used for directly deliver cells in vivo to repair and regenerate tissues

    Functional chitosan microcarriers for selective cell attachment and expansion

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    The success of many stem cell applications in the biomedical field is highly dependent on the development of reliable techniques either for isolation or selection of specific cell populations with a very high yield and purity.1 In this work we propose the use of chitosan microparticles (μPs) to capture a specific cell type based in the concept of antibody-antigen binding. Our goal was to create new biomaterials capable of selecting within a heterotypic cell suspension, a specific sub-population, and supporting subsequent cell expansion. Such system simultaneously allows the selection and acts as a microcarrier for a specific target, thus reducing cell manipulation and time-consumption

    The effect of chitosan on the in vitro biological performance of chitosan-poly(butylene succinate) blends

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    Chitosan blends with synthetic biodegradable polymers have been proposed for various biomedical applications due to their versatile mechanical properties and easier processing. However, details regarding the main surface characteristics that may benefit from the blending of these two types of materials are still missing. Hence, this work aims at investigating the surface properties of chitosan-based blends, illustrating the way these properties determine the material-proteins interactions and ultimately the behavior of osteoblast-like cells. The surface characteristics of modified and nonmodified blends were assessed using complimentary techniques such as optical microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), contact angle measurements and surface energy calculations. The adsorption of human serum albumin (HSA) and human plasma fibronectin (HFN) onto the different surfaces was quantified by association of an indirect method with a colorimetric assay. It was found that the presence of chitosan on the surface promoted the adsorption of proteins. Moreover, a preferential adsorption of albumin over fibronectin was registered. The in vitro biological performance of the studied materials was further investigated by a direct contact assay with an osteoblastic-like cell line (SaOs-2). A synergistic effect of the two components of the blend was observed. While the synthetic polyester promoted the adhesion of SaOs-2, the presence of chitosan significantly enhanced the osteoblastic activity of these cells. This work further confirmed the interest in designing polymeric blends with natural polymers as a successful strategy to enhance the biological performance of a biomaterial

    Scaffolding strategies for tissue engineering and regenerative medicine applications

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    During the past two decades, tissue engineering and the regenerative medicine field have invested in the regeneration and reconstruction of pathologically altered tissues, such as cartilage, bone, skin, heart valves, nerves and tendons, and many others. The 3D structured scaffolds and hydrogels alone or combined with bioactive molecules or genes and cells are able to guide the development of functional engineered tissues, and provide mechanical support during in vivo implantation. Naturally derived and synthetic polymers, bioresorbable inorganic materials, and respective hybrids, and decellularized tissue have been considered as scaffolding biomaterials, owing to their boosted structural, mechanical, and biological properties. A diversity of biomaterials, current treatment strategies, and emergent technologies used for 3D scaffolds and hydrogel processing, and the tissue-specific considerations for scaffolding for Tissue engineering (TE) purposes are herein highlighted and discussed in depth. The newest procedures focusing on the 3D behavior and multi-cellular interactions of native tissues for further use for in vitro model processing are also outlined. Completed and ongoing preclinical research trials for TE applications using scaffolds and hydrogels, challenges, and future prospects of research in the regenerative medicine field are also presented.This research was funded by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) (NORTE-01-0145-FEDER-000023) and by the Portuguese Foundation for Science and Technology ((M-ERA-NET/0022/2016), Transitional Rule DL 57/2016 (CTTI-57/18-I3BS(5)), and (IF/01285/2015))

    Gold nanoparticles functionalised with stable, fast water exchanging Gd3+ chelates as high relaxivity contrast agents for MRI

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    Gold nanoparticles functionalized with Gd3+ chelates displaying fast water exchange, superb pH stability and inertness towards transmetalation with Zn2+ have been prepared and characterized as a new high relaxivity (29 mM-1s-1, 30 MHz, 25 ºC) Contrast Agent potentially safe for in vivo MRI applications. The Lipari-Szabo treatment for internal rotation was used to evaluate the effect of linker flexibility on the relaxivity of the gold nanoparticles. The relaxivity is limited by chelate flexibility. The effect of fast water exchange on the relaxivity of gold nanoparticles functionalized with Gd3+ chelates is also addressed in this communication.Fundação para a Ciência e TecnologiaProjecto PTDC/QUI/70063/2006PhD grant SFRH/BD/63994/2008 to Miguel FerreiraRede Nacional de RMN REDE/1517/RMN/2005 for the acquisition of the Varian VNMRS 600 NMR spectrometer in Coimbra and the Bruker Avance-3 400 Plus in BragaB. Mousavi and L. Helm acknowledge financial support by the Swiss National Science Foundation.COST D38 Actio

    An intracellular metabolic signature as a potential donor-independent marker of the osteogenic differentiation of adipose tissue mesenchymal stem cells

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    This paper describes an untargeted NMR metabolomics study to identify potential intracellular donor-dependent and donor-independent metabolic markers of proliferation and osteogenic differentiation of human adipose mesenchymal stem cells (hAMSCs). The hAMSCs of two donors with distinct proliferating/osteogenic characteristics were fully characterized regarding their polar endometabolome during proliferation and osteogenesis. An 18-metabolites signature (including changes in alanine, aspartate, proline, tyrosine, ATP, and ADP, among others) was suggested to be potentially descriptive of cell proliferation, independently of the donor. In addition, a set of 11 metabolites was proposed to compose a possible donor-independent signature of osteogenesis, mostly involving changes in taurine, glutathione, methylguanidine, adenosine, inosine, uridine, and creatine/phosphocreatine, choline/phosphocholine and ethanolamine/phosphocholine ratios. The proposed signatures were validated for a third donor, although they require further validation in a larger donor cohort. We believe that this proof of concept paves the way to exploit metabolic markers to monitor (and potentially predict) cell proliferation and the osteogenic ability of different donors.publishe

    Cancer Theranostic Dyes

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    Funding Information: This work was financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., within the scope of the projects of the Ministry of Science Technology and Higher Education: UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB and, in part, by the Jeanne and J.-Louis Lévesque foundation, Montreal, QC, Canada (J.E.v.L.). J.E.v.L. is a member of the Research Center of the CHUS (CRCHUS), Sherbrooke, QC, Canada, supported by the Fonds de la Recherche du Québec—Santé. C.R.R., A.L. and R.V. were funded by FCT/MCTES, grant numbers SFRH/BPD/124612/2016, SFRH/BD/12161/2022, and SFRH/BD/09845/2022, respectively. Publisher Copyright: © 2023 by the authors.Estradiol-BODIPY linked via an 8-carbon spacer chain and 19-nortestosterone- and testosterone-BODIPY linked via an ethynyl spacer group were evaluated for cell uptake in the breast cancer cell lines MCF-7 and MDA-MB-231 and prostate cancer cell lines PC-3 and LNCaP, as well as in normal dermal fibroblasts, using fluorescence microscopy. The highest level of internalization was observed with 11β-OMe-estradiol-BODIPY 2 and 7α-Me-19-nortestosterone-BODIPY 4 towards cells expressing their specific receptors. Blocking experiments showed changes in non-specific cell uptake in the cancer and normal cells, which likely reflect differences in the lipophilicity of the conjugates. The internalization of the conjugates was shown to be an energy-dependent process that is likely mediated by clathrin- and caveolae-endocytosis. Studies using 2D co-cultures of cancer cells and normal fibroblasts showed that the conjugates are more selective towards cancer cells. Cell viability assays showed that the conjugates are non-toxic for cancer and/or normal cells. Visible light irradiation of cells incubated with estradiol-BODIPYs 1 and 2 and 7α-Me-19-nortestosterone-BODIPY 4 induced cell death, suggesting their potential for use as PDT agents.publishersversionpublishe

    Multifunctional materials for bone cancer treatment

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    The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen-hydroxyapatite composites used for skin and bone cancer treatments. The multi-functionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies

    Metabolomic applications in stem cell research: a review

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    This review describes the use of metabolomics to study stem cell (SC) characteristics and function, excluding SCs in cancer research, suited to a fully dedicated text. The interest in employing metabolomics in SC research has consistently grown and emphasis is, here, given to developments reported in the past five years. This text informs on the existing methodologies and their complementarity regarding the information provided, comprising untargeted/targeted approaches, which couple mass spectrometry or nuclear magnetic resonance spectroscopy with multivariate analysis (and, in some cases, pathway analysis and integration with other omics), and more specific analytical approaches, namely isotope tracing to highlight particular metabolic pathways, or in tandem microscopic strategies to pinpoint characteristics within a single cell. The bulk of this review covers the existing applications in various aspects of mesenchymal SC behavior, followed by pluripotent and neural SCs, with a few reports addressing other SC types. Some of the central ideas investigated comprise the metabolic/biological impacts of different tissue/donor sources and differentiation conditions, including the importance of considering 3D culture environments, mechanical cues and/or media enrichment to guide differentiation into specific lineages. Metabolomic analysis has considered cell endometabolomes and exometabolomes (fingerprinting and footprinting, respectively), having measured both lipid species and polar metabolites involved in a variety of metabolic pathways. This review clearly demonstrates the current enticing promise of metabolomics in significantly contributing towards a deeper knowledge on SC behavior, and the discovery of new biomarkers of SC function with potential translation to in vivo clinical practice.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for co-funding the BIOIMPLANT project (PTDC/BTM-ORG/28835/2017) through the COMPETE2020 program and European Union fund FEDER (POCI-01–0145- FEDER-028835). CSHJ and KR are grateful to the same project for funding their contracts with the University of Aveiro. DSB acknowl- edges the Sociedade Portuguesa de Química and FCT for her PhD grant SFRH/BD/150655/2020. AMG acknowledges the CICECO-Aveiro Institute of Materials project, with references UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Part- nership Agreement. The NMR spectrometer used in this work is part of the National NMR Network (PTNMR) and, partially supported by Infrastructure Project Nº 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC).publishe

    An integrated in vitro approach unveils the biocompetence and glutathiolomic profile of a human hepatocyte-like cell 3d model

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    Funding: This work was supported by FCT (Portugal) through the research grant PTDC/MED-TOX/29183/2017. Acknowledgments: The authors thank ECBio S.A. for providing the hnMSCs and F.A. Beland (NCTR, Jefferson, AR, USA) for the kind donation of nevirapine. FCT (UID/DTP/04138/2019, UID/QUI/00100/2019, RECI/QEQ-MED/0330/2012, SFRH/BD/144130/2019 to J.S.R., SFRH/BD/110945/2015 to P.F.P. and CEECIND/02001/2017 to A.M.M.A) are also acknowledged.The need for competent in vitro liver models for toxicological assessment persists. The differentiation of stem cells into hepatocyte-like cells (HLC) has been adopted due to its human origin and availability. Our aim was to study the usefulness of an in vitro 3D model of mesenchymal stem cell-derived HLCs. 3D spheroids (3D-HLC) or monolayer (2D-HLC) cultures of HLCs were treated with the hepatotoxic drug nevirapine (NVP) for 3 and 10 days followed by analyses of Phase I and II metabolites, biotransformation enzymes and drug transporters involved in NVP disposition. To ascertain the toxic effects of NVP and its major metabolites, the changes in the glutathione net flux were also investigated. Phase I enzymes were induced in both systems yielding all known correspondent NVP metabolites. However, 3D-HLCs showed higher biocompetence in producing Phase II NVP metabolites and upregulating Phase II enzymes and MRP7. Accordingly, NVP-exposure led to decreased glutathione availability and alterations in the intracellular dynamics disfavoring free reduced glutathione and glutathionylated protein pools. Overall, these results demonstrate the adequacy of the 3D-HLC model for studying the bioactivation/metabolism of NVP representing a further step to unveil toxicity mechanisms associated with glutathione net flux changes.publishersversionpublishe
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