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1.
Int J Mol Sci ; 23(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36555859

RESUMO

Living organisms do not disregard the laws of thermodynamics and must therefore consume energy for their survival. In this way, cellular energy exchanges, which aim above all at the production of ATP, a fundamental molecule used by the cell for its metabolisms, favor the formation of waste products that, if not properly disposed of, can contribute to cellular aging and damage. Numerous genes have been linked to aging, with some favoring it (gerontogenes) and others blocking it (longevity pathways). Animal model studies have shown that calorie restriction (CR) may promote longevity pathways, but given the difficult application of CR in humans, research is investigating the use of CR-mimetic substances capable of producing the same effect. These include some phytonutrients such as oleuropein, hydroxytyrosol, epigallo-catechin-gallate, fisetin, quercetin, and curcumin and minerals such as magnesium and selenium. Some of them also have senolytic effects, which promote the apoptosis of defective cells that accumulate over the years (senescent cells) and disrupt normal metabolism. In this article, we review the properties of these natural elements that can promote a longer and healthier life.


Assuntos
Produtos Biológicos , Senoterapia , Humanos , Animais , Produtos Biológicos/farmacologia , Envelhecimento , Senescência Celular , Quercetina/farmacologia
2.
Biotechnol Bioeng ; 117(3): 789-797, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31736057

RESUMO

Cell-based in vitro biological models traditionally use monolayer cell cultures grown over plastic surfaces bathing in static media. Higher fidelity to a natural biological tissue is expected to result from growing the cells in a three-dimensional (3D) matrix. However, due to the decreased rate of diffusion inherent to increased distances within a tridimensional space, proper fluidic conditions are needed in this setting to better approximate a physiological environment. To this aim, we here propose a prototypal dynamic cell culture platform for the automatic medium replacement, via periodic perfusion flow, in a human umbilical vein endothelial cell (HUVECs) culture seeded in a Geltrex™ matrix. A state-of-the-art angiogenesis assay performed in these dynamic conditions showed sizable effects with respect to conventional static control cultures, with significantly enhanced pro-(dual antiplatelet therapy [DAPT]) and anti-(EDTA) angiogenic compound activity. In particular, dynamic culture conditions (a) enhance the 3D-organization of HUVECs into microtubule structure; (b) accelerate and improve endothelial tube formation by HUVECs in the presence of DAPT; (c) are able to completely revert the blocking effects of EDTA. These evidence emphasize the need of setting proper fluidic conditions for a better approximation of a physiological environment as an appropriate evolution of current cell culture paradigms.


Assuntos
Reatores Biológicos , Técnicas de Cultura de Células/métodos , Células Endoteliais da Veia Umbilical Humana/citologia , Neovascularização Fisiológica/fisiologia , Células Cultivadas , Análise de Elementos Finitos , Humanos
3.
Int J Mol Sci ; 21(7)2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32235449

RESUMO

In this study, we explore the behaviour of intracellular magnesium during bone phenotype modulation in a 3D cell model built to mimic osteogenesis. In addition, we measured the amount of magnesium in the mineral depositions generated during osteogenic induction. A two-fold increase of intracellular magnesium content was found, both at three and seven days from the induction of differentiation. By X-ray microscopy, we characterized the morphology and chemical composition of the mineral depositions secreted by 3D cultured differentiated cells finding a marked co-localization of Mg with P at seven days of differentiation. This is the first experimental evidence on the presence of Mg in the mineral depositions generated during biomineralization, suggesting that Mg incorporation occurs during the bone forming process. In conclusion, this study on the one hand attests to an evident involvement of Mg in the process of cell differentiation, and, on the other hand, indicates that its multifaceted role needs further investigation.


Assuntos
Magnésio/análise , Osteogênese , Fósforo/análise , Técnicas de Cultura de Células/métodos , Diferenciação Celular , Linhagem Celular Tumoral , Humanos , Magnésio/metabolismo , Fósforo/metabolismo
4.
Biotechnol Bioeng ; 116(7): 1777-1794, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30905072

RESUMO

Poly-lactic-co-glycolic acid (PLGA) microcarriers (0.8 ± 0.2 µm) have been fabricated with a load of 20 µg/gPLGA by an emulsion-based-proprietary technology to sustained deliver human bone morphogenetic protein 2 (hBMP2), a growth factor largely used for osteogenic induction. hBMP2 release profile, measured in vitro, showed a moderate "burst" release of 20% of the load in first 3 days, followed by a sustained release of 3% of the load along the following 21 days. PLGA microbeads loaded with fluorescent marker (8 mg/gPLGA ) and hydroxyapatite (30 mg/gPLGA ) were also fabricated and successfully dispersed within three-dimensional (3D) alginate scaffold (Ca-alginate 2% wt/wt) in a range between 50 and 200 mg/cm3 ; the presence of microcarriers within the scaffold induced a variation of its stiffness between 0.03 and 0.06 MPa; whereas the scaffold surface area was monitored always in the range of 190-200 m2 /g. Uniform microcarriers dispersion was obtained up to 200 mg/cm3 ; higher loading values in the 3D scaffold produced large aggregates. The release data and the surface area were, then, used to simulate by finite element modeling the hBMP2 mass transfer within the 3D hydrogel bioengineered with stem cells, in dynamic and static cultivations. The simulation was developed with COMSOL Multiphysics® giving a good representation of hBMP2 mass balances along microbeads (bulk eroded) and on cell surface (cell binding). hBMP2 degradation rate was also taken into account in the simulations. hBMP2 concentration of 20 ng/cm3 was set as a target because it has been described as the minimum effective value for stem cells stimulation versus the osteogenic phenotype. The sensitivity analysis suggested the best microbeads/cells ratio in the 3D microenvironment, along 21 days of cultivations in both static and dynamic cultivation (perfusion) conditions. The simulated formulation was so assembled experimentally using human mesenchymal stem cells and an improved scaffold stiffness up to 0.09 MPa (n = 3; p ≤ 0.01) was monitored after 21 days of cultivation; moreover a uniform extracellular matrix deposition within the 3D system was detected by Von Kossa staining, especially in dynamic conditions. The results indicated that the described tool can be useful for the design of 3D bioengineered microarchitecture by quantitative understanding.


Assuntos
Proteína Morfogenética Óssea 2 , Portadores de Fármacos , Células-Tronco Mesenquimais/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Nicho de Células-Tronco/efeitos dos fármacos , Proteína Morfogenética Óssea 2/química , Proteína Morfogenética Óssea 2/farmacocinética , Proteína Morfogenética Óssea 2/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Humanos , Hidrogéis/química , Hidrogéis/farmacocinética , Hidrogéis/farmacologia , Células-Tronco Mesenquimais/citologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Engenharia Tecidual
5.
Nano Lett ; 18(9): 5827-5838, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30088941

RESUMO

Graphene-based materials are the focus of intense research efforts to devise novel theranostic strategies for targeting the central nervous system. In this work, we have investigated the consequences of long-term exposure of primary rat astrocytes to pristine graphene (GR) and graphene oxide (GO) flakes. We demonstrate that GR/GO interfere with a variety of intracellular processes as a result of their internalization through the endolysosomal pathway. Graphene-exposed astrocytes acquire a more differentiated morphological phenotype associated with extensive cytoskeletal rearrangements. Profound functional alterations are induced by GO internalization, including the upregulation of inward-rectifying K+ channels and of Na+-dependent glutamate uptake, which are linked to the astrocyte capacity to control the extracellular homeostasis. Interestingly, GO-pretreated astrocytes promote the functional maturation of cocultured primary neurons by inducing an increase in intrinsic excitability and in the density of GABAergic synapses. The results indicate that graphene nanomaterials profoundly affect astrocyte physiology in vitro with consequences for neuronal network activity. This work supports the view that GO-based materials could be of great interest to address pathologies of the central nervous system associated with astrocyte dysfunctions.


Assuntos
Astrócitos/citologia , Grafite/metabolismo , Neurônios/citologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Comunicação Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Células Cultivadas , Ácido Glutâmico/metabolismo , Grafite/química , Homeostase/efeitos dos fármacos , Nanoestruturas/química , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Canais de Potássio/metabolismo , Ratos , Sinapses/metabolismo
6.
Int J Mol Sci ; 20(21)2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31671788

RESUMO

Mesenchymal stem cells (MSC) have piqued worldwide interest for their extensive potential to treat a large array of clinical indications, their unique and controversial immunogenic and immune modulatory properties allowing ample discussions and debates for their possible applications. Emerging data demonstrating that the interaction of biomaterials and physical cues with MSC can guide their differentiation into specific cell lineages also provide new interesting insights for further MSC manipulation in different clinical applications. Moreover, recent discoveries of some regulatory molecules and signaling pathways in MSC niche that may regulate cell fate to distinct lineage herald breakthroughs in regenerative medicine. Although the advancement and success in the MSC field had led to an enormous increase in the amount of ongoing clinical trials, we still lack defined clinical therapeutic protocols. This review will explore the exciting opportunities offered by human and animal MSC, describing relevant biological properties of these cells in the light of the novel emerging evidence mentioned above while addressing the limitations and challenges MSC are still facing.


Assuntos
Regeneração Óssea/fisiologia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/fisiologia , Pesquisa Translacional Biomédica/métodos , Animais , Comunicação Autócrina , Materiais Biocompatíveis , Doenças Ósseas/terapia , Diferenciação Celular , Linhagem da Célula , Plasticidade Celular , Humanos , Comunicação Parácrina , Medicina Regenerativa , Transdução de Sinais , Alicerces Teciduais
7.
J Theor Biol ; 395: 153-160, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-26874228

RESUMO

The small number of molecules, unevenly distributed within an isogenic cell population, makes gene expression a noisy process, and strategies have evolved to deal with this variability in protein concentration and to limit its impact on cellular behaviors. As translational efficiency has a major impact on biological noise, a possible strategy to control noise is to regulate gene expression processes at the post-transcriptional level. In this study, fluctuations in the concentration of a green fluorescent protein were compared, at the single cell level, upon transformation of an isogenic bacterial cell population with synthetic gene circuits implementing either a transcriptional or a post-transcriptional control of gene expression. Experimental measurements showed that protein variability is lower under post-transcriptional control, when the same average protein concentrations are compared. This effect is well reproduced by stochastic simulations, supporting the hypothesis that noise reduction is due to the control mechanism acting on the efficiency of translation. Similar strategies are likely to play a role in noise reduction in natural systems and to be useful for controlling noise in synthetic biology applications.


Assuntos
Proteínas de Escherichia coli/biossíntese , Escherichia coli/metabolismo , Redes Reguladoras de Genes/fisiologia , Modelos Biológicos , Biossíntese de Proteínas/fisiologia , Transcrição Gênica/fisiologia , Escherichia coli/genética , Razão Sinal-Ruído
8.
J Biomed Sci ; 21: 100, 2014 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-25358954

RESUMO

Hyaluronan (HA) is abundantly expressed in several human tissues and a variety of roles for HA has been highlighted. Particularly relevant for tissue repair, HA is actively produced during tissue injury, as widely evidenced in wound healing investigations. In the heart HA is involved in physiological functions, such as cardiac development during embryogenesis, and in pathological conditions including atherosclerosis and myocardial infarction. Moreover, owing to its relevant biological properties, HA has been widely used as a biomaterial for heart regeneration after a myocardial infarction. Indeed, HA and its derivatives are biodegradable and biocompatible, promote faster healing of injured tissues, and support cells in relevant processes including survival, proliferation, and differentiation. Injectable HA-based therapies for cardiovascular disease are gaining growing attention because of the benefits obtained in preclinical models of myocardial infarction. HA-based hydrogels, especially as a vehicle for stem cells, have been demonstrated to improve the process of cardiac repair by stimulating angiogenesis, reducing inflammation, and supporting local and grafted cells in their reparative functions. Solid-state HA-based scaffolds have been also investigated to produce constructs hosting mesenchymal stem cells or endothelial progenitor cells to be transplanted onto the infarcted surface of the heart. Finally, applying an ex-vivo mechanical stretching, stem cells grown in HA-based 3D scaffolds can further increase extracellular matrix production and proneness to differentiate into muscle phenotypes, thus suggesting a potential strategy to create a suitable engineered myocardial tissue for cardiac regeneration.


Assuntos
Materiais Biocompatíveis/uso terapêutico , Coração/fisiologia , Ácido Hialurônico/uso terapêutico , Infarto do Miocárdio/terapia , Regeneração , Indutores da Angiogênese/metabolismo , Indutores da Angiogênese/farmacologia , Indutores da Angiogênese/uso terapêutico , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/farmacologia , Humanos , Ácido Hialurônico/metabolismo , Ácido Hialurônico/farmacologia , Células-Tronco Mesenquimais/metabolismo , Cicatrização
9.
Amino Acids ; 46(3): 595-603, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23836422

RESUMO

Natural polyamines are involved in many molecular processes, including maintenance of DNA structure and RNA processing and translation. Our aim here is to present an overview of the literature concerning the significance of polyamines in the modulation of chromatin arrangement and the transcriptional regulation of gene expression. The pleiotropic picture emerging from the published data highlights that these polycations take part in apparently diverging effects, possibly depending on the heterogeneous experimental settings described, and on a methodological approach aimed at the evaluation of the global levels of the histone chemical modifications. Since the relevant changes observed appear to be rather local and gene specific, investigating histone modifications at the level of specific gene promoters of interest is thus to be recommended for future studies. Furthermore, decoding the multiple regulatory mechanisms by which polyamines exert their influence on chromatin-modifier enzymes will reasonably require focus on selected individual polyamine-regulated genes. The evaluation of the many known chromatin-remodeling enzymes for their individual susceptibility to polyamines or polyamine derivatives will also be helpful: determining how they discriminate between the different enzyme isoforms is expected to be a fruitful line of research for drug discovery, e.g., in cancer prevention and therapy. Indeed, polyamine derivatives acting as epigenetic modulators appear to be molecules with great potential as antitumor drugs. All these novel polyamine-based pharmacologically active molecules are thus promising tools, both as a stand-alone strategy and in combination with other anticancer compounds.


Assuntos
Antineoplásicos/metabolismo , Cromatina/metabolismo , Neoplasias/metabolismo , Poliaminas/metabolismo , Animais , Antineoplásicos/farmacologia , Cromatina/genética , Humanos , Neoplasias/prevenção & controle , Neoplasias/terapia , Poliaminas/farmacologia
10.
Heliyon ; 10(9): e29395, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38699000

RESUMO

Computational simulations are becoming increasingly relevant in biomedical research, providing strategies to reproduce experimental results, improve the resolution of in-vitro experiments, and predict the system's behavior in untested conditions. Their use to determine the features associated with an extensive response to treatment and optimize treatment schedules has, however received little attention. To bridge this gap, we propose a deep learning framework capable of reliably classifying simulated time series data and identifying class-defining features. This information will be shown to be useful for the determination of which changes in treatment schedule elicit a more extensive cellular response. This analysis pipeline will be initially tested on a synthetic dataset created ad-hoc to identify its accuracy in identifying the most relevant portion of the signals. Successively this method will be applied to simulations describing the behaviors of populations of cancer cells treated with either one or two drugs in different concentrations. The proposed method will be shown to be effective in identifying which changes in the treatment protocol lead to a more extensive response to treatment. While lacking direct experimental validation, this result holds great potential for the integration of in-silico and in-vitro analyses and the effective optimization of experimental conditions in complex experimental setups.

11.
J Biomed Sci ; 20: 63, 2013 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-23985033

RESUMO

The efficiency of regenerative medicine can be ameliorated by improving the biological performances of stem cells before their transplantation. Several ex-vivo protocols of non-damaging cell hypoxia have been demonstrated to significantly increase survival, proliferation and post-engraftment differentiation potential of stem cells. The best results for priming cultured stem cells against a following, otherwise lethal, ischemic stress have been obtained with brief intermittent episodes of hypoxia, or anoxia, and reoxygenation in accordance with the extraordinary protection afforded by the conventional maneuver of ischemic preconditioning in severely ischemic organs. These protocols of hypoxic preconditioning can be rather easily reproduced in a laboratory; however, more suitable pharmacological interventions inducing stem cell responses similar to those activated in hypoxia are considered among the most promising solutions for future applications in cell therapy. Here we want to offer an up-to-date review of the molecular mechanisms translating hypoxia into beneficial events for regenerative medicine. To this aim the involvement of epigenetic modifications, microRNAs, and oxidative stress, mainly activated by hypoxia inducible factors, will be discussed. Stem cell adaptation to their natural hypoxic microenvironments (niche) in healthy and neoplastic tissues will be also considered.


Assuntos
Células-Tronco Adultas/metabolismo , Diferenciação Celular , Medicina Regenerativa/métodos , Adulto , Células-Tronco Adultas/citologia , Hipóxia Celular , Sobrevivência Celular , Humanos , Precondicionamento Isquêmico Miocárdico
12.
Materials (Basel) ; 16(17)2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37687590

RESUMO

Tissue-engineered bone tissue grafts are a promising alternative to the more conventional use of natural donor bone grafts. However, choosing an appropriate biomaterial/scaffold to sustain cell survival, proliferation, and differentiation in a 3D environment remains one of the most critical issues in this domain. Recently, chitosan/gelatin/genipin (CGG) hybrid scaffolds have been proven as a more suitable environment to induce osteogenic commitment in undifferentiated cells when doped with graphene oxide (GO). Some concern is, however, raised towards the use of graphene and graphene-related material in medical applications. The purpose of this work was thus to check if the osteogenic potential of CGG scaffolds without added GO could be increased by improving the medium diffusion in a 3D culture of differentiating cells. To this aim, the level of extracellular matrix (ECM) mineralization was evaluated in human bone-marrow-derived stem cell (hBMSC)-seeded 3D CGG scaffolds upon culture under a perfusion flow in a dedicated custom-made bioreactor system. One week after initiating dynamic culture, histological/histochemical evaluations of CGG scaffolds were carried out to analyze the early osteogenic commitment of the culture. The analyses show the enhanced ECM mineralization of the 3D perfused culture compared to the static counterpart. The results of this investigation reveal a new perspective on more efficient clinical applications of CGG scaffolds without added GO.

13.
AoB Plants ; 15(2): plac067, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36751365

RESUMO

Nuptial and extranuptial nectaries are involved in interactions with different animal functional groups. Nectar traits involved in pollination mutualisms are well known. However, we know little about those traits involved in other mutualisms, such as ant-plant interactions, especially when both types of nectaries are in the same plant organ, the flower. Here we investigated if when two types of nectaries are exploited by distinct functional groups of floral visitors, even being within the same plant organ, the nectar secreted presents distinct features that fit animal requirements. We compared nectar secretion dynamics, floral visitors and nectar chemical composition of both nuptial and extranuptial nectaries in natural populations of the liana Amphilophium mansoanum (Bignoniaceae). For that we characterized nectar sugar, amino acid and specialized metabolite composition by high-performance liquid chromatography. Nuptial nectaries were visited by three medium- and large-sized bee species and extranuptial nectaries were visited mainly by ants, but also by cockroaches, wasps and flies. Nuptial and extranuptial nectar differed regarding volume, concentration, milligrams of sugars per flower and secretion dynamics. Nuptial nectar was sucrose-dominated, with high amounts of γ-aminobutyric acid and ß-aminobutyric acid and with theophylline-like alkaloid, which were all exclusive of nuptial nectar. Whereas extranuptial nectar was hexose-rich, had a richer and less variable amino acid chemical profile, with high amounts of serine and alanine amino acids and with higher amounts of the specialized metabolite tyramine. The nectar traits from nuptial and extranuptial nectaries differ in energy amount and nutritional value, as well as in neuroactive specialized metabolites. These differences seem to match floral visitors' requirements, since they exclusively consume one of the two nectar types and may be exerting selective pressures on the composition of the respective resources of interest.

14.
Amino Acids ; 42(2-3): 507-518, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21814794

RESUMO

Ornithine decarboxylase (ODC), the first enzyme of polyamine metabolism, is rapidly upregulated in response to agents that induce a pathological cardiac hypertrophy. Transgenic mice overexpressing ODC in the heart (MHC-ODC mice) experience a much more dramatic left ventricular hypertrophy in response to ß-adrenergic stimulation with isoproterenol (ISO) compared to wild-type (WT) controls. ISO also induced arginase activity in transgenic hearts but not in controls. The current work studies the cooperation between the cardiac polyamines and L-arginine (L-Arg) availability in MHC-ODC mice. Although ISO-induced hypertrophy is well-compensated, MHC-ODC mice administered L-Arg along with ISO showed a rapid onset of systolic dysfunction and died within 48 h. Myocytes isolated from MHC-ODC mice administered L-Arg/ISO exhibited reduced contractility and altered calcium transients, suggesting an alteration in [Ca(2+)] homeostasis, and abbreviated action potential duration, which may contribute to arrhythmogenesis. The already elevated levels of spermidine and spermine were not further altered in MHC-ODC hearts by L-Arg/ISO treatment, suggesting alternative L-Arg utilization pathways lead to dysregulation of intracellular calcium. MHC-ODC mice administered an arginase inhibitor (Nor-NOHA) along with ISO died almost as rapidly as L-Arg/ISO-treated mice, while the iNOS inhibitor S-methyl-isothiourea (SMT) was strongly protective against L-Arg/ISO. These results point to the induction of arginase as a protective response to ß-adrenergic stimulation in the setting of high polyamines. Further, NO generated by exogenously supplied L-Arg may contribute to the lethal consequences of L-Arg/ISO treatment. Since considerable variations in human cardiac polyamine and L-Arg content are likely, it is possible that alterations in these factors may influence myocyte contractility.


Assuntos
Cardiomegalia/fisiopatologia , Ventrículos do Coração/fisiopatologia , Ornitina Descarboxilase/metabolismo , Sístole , Potenciais de Ação , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/enzimologia , Cromatografia Líquida de Alta Pressão , Ventrículos do Coração/enzimologia , Isoproterenol/farmacologia , Camundongos , Camundongos Transgênicos
15.
PeerJ ; 10: e13338, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35582620

RESUMO

3D cell cultures are becoming the new standard for cell-based in vitro research, due to their higher transferrability toward in vivo biology. The lack of established techniques for the non-destructive quantification of relevant variables, however, constitutes a major barrier to the adoption of these technologies, as it increases the resources needed for the experimentation and reduces its accuracy. In this review, we aim at addressing this limitation by providing an overview of different non-destructive approaches for the evaluation of biological features commonly quantified in a number of studies and applications. In this regard, we will cover cell viability, gene expression, population distribution, cell morphology and interactions between the cells and the environment. This analysis is expected to promote the use of the showcased technologies, together with the further development of these and other monitoring methods for 3D cell cultures. Overall, an extensive technology shift is required, in order for monolayer cultures to be superseded, but the potential benefit derived from an increased accuracy of in vitro studies, justifies the effort and the investment.


Assuntos
Técnicas de Cultura de Células em Três Dimensões , Sobrevivência Celular
16.
Materials (Basel) ; 15(7)2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35407727

RESUMO

3D printing has opened exciting new opportunities for the in vitro fabrication of biocompatible hybrid pseudo-tissues. Technologies based on additive manufacturing herald a near future when patients will receive therapies delivering functional tissue substitutes for the repair of their musculoskeletal tissue defects. In particular, bone tissue engineering (BTE) might extensively benefit from such an approach. However, designing an optimal 3D scaffold with adequate stiffness and biodegradability properties also guaranteeing the correct cell adhesion, proliferation, and differentiation, is still a challenge. The aim of this work was the rewiring of a commercial fuse deposition modeling (FDM) 3D printer into a 3D bioplotter, aiming at obtaining scaffold fiber thickness and porosity control during its manufacturing. Although it is well-established that FDM is a fast and low-price technology, the high temperatures required for printing lead to limitations in the biomaterials that can be used. In our hands, modifying the printing head of the FDM device with a custom-made holder has allowed to print hydrogels commonly used for embedding living cells. The results highlight a good resolution, reproducibility and repeatability of alginate/gelatin scaffolds obtained via our custom 3D bioplotter prototype, showing a viable strategy to equip a small-medium laboratory with an instrument for manufacturing good-quality 3D scaffolds for cell culture and tissue engineering applications.

17.
Front Bioeng Biotechnol ; 10: 1075715, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36704300

RESUMO

In this work, a 3D environment obtained using fibrin scaffold and two cell populations, such as bone marrow-derived mesenchymal stem cells (BM-MSCs), and primary skeletal muscle cells (SkMs), was assembled. Peripheral blood mononuclear cells (PBMCs) fraction obtained after blood filtration with HemaTrate® filter was then added to the 3D culture system to explore their influence on myogenesis. The best cell ratio into a 3D fibrin hydrogel was 1:1 (BM-MSCs plus SkMs:PBMCs) when cultured in a perfusion bioreactor; indeed, excellent viability and myogenic event induction were observed. Myogenic genes were significantly overexpressed when cultured with PBMCs, such as MyoD1 of 118-fold at day 14 and Desmin 6-fold at day 21. Desmin and Myosin Heavy Chain were also detected at protein level by immunostaining along the culture. Moreover, the presence of PBMCs in 3D culture induced a significant downregulation of pro-inflammatory cytokine gene expression, such as IL6. This smart biomimetic environment can be an excellent tool for investigation of cellular crosstalk and PBMC influence on myogenic processes.

18.
Plants (Basel) ; 10(3)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803275

RESUMO

The Mediterranean basin hosts a high diversity of plants and bees, and it is considered one of the world's biodiversity hotspots. Insect pollination, i.e., pollen transfer from male reproductive structures to conspecific female ones, was classically thought to be a mutualistic relationship that links these two groups of organisms, giving rise to an admirable and complex network of interactions. Although nectar is often involved in mediating these interactions, relatively little is known about modifications in its chemical traits during the evolution of plants. Here, we examine how the current sucrose-dominated floral nectar of most Mediterranean plants could have arisen in the course of evolution of angiosperms. The transition from hexose-rich to sucrose-rich nectar secretion was probably triggered by increasing temperature and aridity during the Cretaceous period, when most angiosperms were radiating. This transition may have opened new ecological niches for new groups of insects that were co-diversifying with angiosperms and for specific nectar-dwelling yeasts that originated later (i.e., Metschnikowiaceae). Our hypothesis embeds recent discoveries in nectar biology, such as the involvement of nectar microbiota and nectar secondary metabolites in shaping interactions with pollinators, and it suggests a complex, multifaceted ecological and evolutionary scenario that we are just beginning to discover.

19.
Adv Med Sci ; 66(1): 98-104, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33461101

RESUMO

PURPOSE: The aim of this study was to evaluate the effects exerted over chondrogenic commitment of human adipose-derived mesenchymal stem cells (ADSCs) by a very low oxygen tension (<1% pO2). MATERIALS/METHODS: Cell morphology, mRNA levels of chondrocyte-specific marker genes and the involvement of p38 MAPK signalling were monitored in human ADSCs under a very low oxygen tension. RESULTS: Cell morphology was significantly changed after two days of hypoxic preconditioning when they featured as elongated spindle-shaped cells. SRY-box containing gene 9, aggrecan and collagen type II mRNA levels were enhanced under severe hypoxic culture conditions. Moreover, the inhibition of p38 MAPK resulted in a substantial reduction in transcription of the above-mentioned specific genes, proving the pivotal role of this pathway in the transcriptional regulation of chondrogenesis. CONCLUSIONS: Here, we propose a protocol showing the early commitment of stem cells towards the chondrogenic phenotype in only 2 days of culture via a very low hypoxic environment, in the absence of growth factors added in the culture medium.


Assuntos
Condrócitos/citologia , Condrogênese , Regulação da Expressão Gênica/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Oxigênio/farmacologia , Adulto , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Feminino , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo
20.
Physiol Meas ; 42(6)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34190050

RESUMO

Objective. 3D cell cultures are becoming a fundamental resource forin-vitrostudies, as they mimic more closelyin-vivobehavior. The analysis of these constructs, however, generally rely on destructive techniques, that prevent the monitoring over time of the same construct, thus increasing the results variability and the resources needed for each experiment.Approach. In this work, we focus on mineralization, a crucial process during maturation of artificial bone models, and propose electrical impedance tomography (EIT) as an alternative non-destructive approach. In particular, we discuss the development of an integrated hardware/software system capable of acquiring experimental data from 3D scaffolds and reconstructing the corresponding conductivity maps. We also show how the same software can test how the measurement is affected by biological features such as scaffold shrinking during the culture.Main results. An initial validation, comprising the acquisition of both a non-conductive phantom and alginate/gelatin scaffolds with known calcium content will be presented, together with thein-silicostudy of a cell-induced mineralization process. This analysis will allow for an initial verification of the systems functionality while limiting the effects of biological variability due to cell number and activity.Significance. Our results show the potential of EIT for the non-destructive quantification of matrix mineralization in 3D scaffolds, and open to the possible long term monitoring of this fundamental hallmark of osteogenic differentiation in hybrid tissue engineered constructs.


Assuntos
Osteogênese , Alicerces Teciduais , Biopolímeros , Impedância Elétrica , Tomografia Computadorizada por Raios X
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