35 research outputs found

    Melanoma in the Eyes of Mechanobiology

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    Skin is the largest organ of the human body with several important functions that can be impaired by injury, genetic or chronic diseases. Among all skin diseases, melanoma is one of the most severe, which can lead to death, due to metastization. Mechanotransduction has a crucial role for motility, invasion, adhesion and metastization processes, since it deals with the response of cells to physical forces. Signaling pathways are important to understand how physical cues produced or mediated by the Extracellular Matrix (ECM), affect healthy and tumor cells. During these processes, several molecules in the nucleus and cytoplasm are activated. Melanocytes, keratinocytes, fibroblasts and the ECM, play a crucial role in melanoma formation. This manuscript will address the synergy among melanocytes, keratinocytes, fibroblasts cells and the ECM considering their mechanical contribution and relevance in this disease. Mechanical properties of melanoma cells can also be influenced by pigmentation, which can be associated with changes in stiffness. Mechanical changes can be related with the adhesion, migration, or invasiveness potential of melanoma cells promoting a high metastization capacity of this cancer. Mechanosensing, mechanotransduction, and mechanoresponse will be highlighted with respect to the motility, invasion, adhesion and metastization in melanoma cancer.The authors acknowledge to Ana Silva ([email protected]) for expert assistance with graphical design, and to Portuguese funds – FCT UID/BIM/04293/2019

    Mechanobiology of Colorectal Cancer

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    In this review, the mechanobiology of colorectal cancer (CRC) are discussed. Mecha-notransduction of CRC is addressed considering the relationship of several biophysical cues and biochemical pathways. Mechanobiology is focused on considering how it may influence epithelial cells in terms of motility, morphometric changes, intravasation, circulation, extravasation, and metastization in CRC development. The roles of the tumor microenvironment, ECM, and stroma are also discussed, taking into account the influence of alterations and surface modifications on mechanical properties and their impact on epithelial cells and CRC progression. The role of cancer-associated fibroblasts and the impact of flow shear stress is addressed in terms of how it affects CRC metastization. Finally, some insights concerning how the knowledge of biophysical mechanisms may contribute to the development of new therapeutic strategies and targeting molecules and how mechanical changes of the microenvironment play a role in CRC disease are presented.The authors are grateful to Ana Silva ([email protected]) for expert assistance with graphical design and to Portuguese Fundação para a Ciência e a Tecnologia (FCT) for funds in the framework of the project Instituto de Investigação e Inovação em Saúde (i3S), ref. ID/BIM/04293/2020

    Engineering modular half-antibody conjugated nanoparticles for targeting CD44v6-expressing cancer cells

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    Gastric cancer (GC) remains a major cause of death worldwide mainly because of the late detection in advanced stage. Recently, we proposed CD44v6 as a relevant marker for early detection of GC, opening new avenues for GC-targeted theranostics. Here, we designed a modular nanoscale system that selectively targets CD44v6-expressing GC cells by the site-oriented conjugation of a new-engineered CD44v6 half-antibody fragment to maleimide-modified polystyrene nanoparticles (PNPs) via an efficient bioorthogonal thiol-Michael addition click chemistry. PNPs with optimal particle size (200 nm) for crossing a developed biomimetic CD44v6-associated GC stromal model were further modified with a heterobifunctional maleimide crosslinker and click conjugated to the novel CD44v6 half-antibody fragment, obtained by chemical reduction of full antibody, without affecting its bioactivity. Collectively, our results confirmed the specific targeting ability of CD44v6-PNPs to CD44v6-expressing cells (1.65-fold higher than controls), highlighting the potential of CD44v6 half-antibody conjugated nanoparticles as promising and clinically relevant tools for the early diagnosis and therapy of GC. Additionally, the rational design of our nanoscale system may be explored for the development of several other nanotechnology-based disease-targeted approaches.This work was supported by Norte Portugal Regional Operational Programme (NORTE2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (ERDF) projects Norte-01-0145-FEDER-000012 and NORTE-07-0124-FEDER-000029, through COMPETE 2020-Operational Programme for Competitiveness and Internationalization (POCI) Portugal 2020 and Portuguese Foundation for Science and Technology (FCT) in the framework of the projects POCI-01-0145-FEDER-007274, POCI-01-0145-FEDER-016390, and PTDC/CTMNAN/120958/2010, B.N.L. doctoral grant (SFRH/BD/87400/2012) and postdoctoral grant (PTDC/MEC-GIN/29232/2017). R.F.P. was supported by Institute of Network Bioengineering for Healthy Aging (0245_IBEROS_1_E)

    A Fast Alternative to Soft Lithography for the Fabrication of Organ-on-a-Chip Elastomeric-Based Devices and Microactuators

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    Organ-on-a-chip technology promises to revolutionize how pre-clinical human trials are conducted. Engineering an in vitro environment that mimics the functionality and architecture of human physiology is essential toward building better platforms for drug development and personalized medicine. However, the complex nature of these devices requires specialized, time consuming, and expensive fabrication methodologies. Alternatives that reduce design-to-prototype time are needed, in order to fulfill the potential of these devices. Here, a streamlined approach is proposed for the fabrication of organ-on-a-chip devices with incorporated microactuators, by using an adaptation of xurography. This method can generate multilayered, membrane-integrated biochips in a matter of hours, using low-cost benchtop equipment. These devices are capable of withstanding considerable pressure without delamination. Furthermore, this method is suitable for the integration of flexible membranes, required for organ-on-a-chip applications, such as mechanical actuation or the establishment of biological barrier function. The devices are compatible with cell culture applications and present no cytotoxic effects or observable alterations on cellular homeostasis. This fabrication method can rapidly generate organ-on-a-chip prototypes for a fraction of cost and time, in comparison to conventional soft lithography, constituting an interesting alternative to the current fabrication methods.C.O. and P.L.G. contributed equally to this work as co‐senior authors. This work was supported by Fundação para a Ciência e Tecnologia (FCT) and Doctoral Programme on Cellular and Molecular Biotechnology Applied to Health Sciences (BiotechHealth Programme; ref. PD/00016/2012), by Programa Operacional Potencial Humano (POPH), and SkinChip project (PTDC/BBB‐BIO/1889/2014). The work has been also financed by: 1) Fundo Europeu de Desenvolvimento (FEDER) Regional funds through the COMPETE 2020 – Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT/Ministério da Ciência, Tecnologia e Inovação in the framework of the projects “Institute for Research and Innovation in Health Sciences” (POCI‐01‐0145‐FEDER‐007274), 3DChroMe (PTDC/BTM‐TEC/30164/2017); Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) for projects NORTE‐01‐0145‐FEDER‐000029 and DOCnet (NORTE‐01‐0145‐FEDER‐000003). D.A.F. acknowledges FCT for his support through a FCT/BiotechHealth PhD Programme grant, ref. PD/BD/105976/2014. J.P.C. acknowledges funding from the European Structural and Investment funds through the Compete Programme (Grant #: LISBOA‐01‐0145‐FEDER‐016405) and from National funds through FCT (SAICTPAC/0019/2015) via the research project POINT4PAC, and FCT funding through INESC MN (Unidade ID 5367). The authors would also like to thank: Jorge Ferreira (Chromosome Instability Group, i3S/IBMC) for granting access to the plasma cleaner equipment and for the insightful scientific support; i3S Scientific Platform (Biointerfaces and Nanotechnology core facility, i3S/INEB), member of the national infrastructure PPBI – Portuguese Platform of Bioimaging (PPBI‐POCI‐01‐0145‐FEDER‐022122), in particular Maria Lázaro for support and access to the SP5 confocal microscope; Aureliana Sousa (Biofabrication Group at i3S/INEB) for scientific support and discussion; Dina Leitão (Centro Hospitalar e Universitário São João) for providing access to the normal gastric mucosa specimens; Celso Reis for kindly providing the antibody against Mucin‐1. C.O. and P.L.G. contributed equally to this work as co-senior authors. This work was supported by Funda??o para a Ci?ncia e Tecnologia (FCT) and Doctoral Programme on Cellular and Molecular Biotechnology Applied to?Health Sciences (BiotechHealth Programme; ref.?PD/00016/2012),?by Programa Operacional Potencial Humano (POPH), and SkinChip project (PTDC/BBB-BIO/1889/2014). The work has been also financed by: 1) Fundo Europeu de Desenvolvimento (FEDER) Regional funds through the COMPETE 2020 ? Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT/Minist?rio da Ci?ncia, Tecnologia e Inova??o in the framework of the projects ?Institute for Research and Innovation in Health Sciences? (POCI-01-0145-FEDER-007274), 3DChroMe (PTDC/BTM-TEC/30164/2017); Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) for projects NORTE-01-0145-FEDER-000029 and DOCnet (NORTE-01-0145-FEDER-000003). D.A.F. acknowledges FCT for his support through a FCT/BiotechHealth PhD Programme grant, ref. PD/BD/105976/2014. J.P.C. acknowledges funding from the European Structural and Investment funds through the Compete Programme (Grant #: LISBOA-01-0145-FEDER-016405) and from National funds through FCT (SAICTPAC/0019/2015) via the research project POINT4PAC, and FCT funding through INESC MN (Unidade ID 5367). The authors would also like to thank: Jorge Ferreira (Chromosome Instability Group, i3S/IBMC) for granting access to the plasma cleaner equipment and for the insightful scientific support; i3S Scientific Platform (Biointerfaces and Nanotechnology core facility, i3S/INEB), member of the national infrastructure PPBI ? Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122), in particular Maria L?zaro for support and access to the SP5 confocal microscope; Aureliana Sousa (Biofabrication Group at i3S/INEB) for scientific support and discussion; Dina Leit?o (Centro Hospitalar e Universit?rio S?o Jo?o) for providing access to the normal gastric mucosa specimens; Celso Reis for kindly providing the antibody against Mucin-1

    Strategies to obtain designer polymers based on cyanobacterial extracellular polymeric substances (EPS)

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    Biopolymers derived from polysaccharides are a sustainable and environmentally friendly alternative to the synthetic counterparts available in the market. Due to their distinctive properties, the cyanobacterial extracellular polymeric substances (EPS), mainly composed of heteropolysaccharides, emerge as a valid alternative to address several biotechnological and biomedical challenges. Nevertheless, biotechnological/biomedical applications based on cyanobacterial EPS have only recently started to emerge. For the successful exploitation of cyanobacterial EPS, it is important to strategically design the polymers, either by genetic engineering of the producing strains or by chemical modification of the polymers. This requires a better understanding of the EPS biosynthetic pathways and their relationship with central metabolism, as well as to exploit the available polymer functionalization chemistries. Considering all this, we provide an overview of the characteristics and biological activities of cyanobacterial EPS, discuss the challenges and opportunities to improve the amount and/or characteristics of the polymers, and report the most relevant advances on the use of cyanobacterial EPS as scaffolds, coatings, and vehicles for drug delivery.This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project POCI-01-0145-FEDER-028779, contract DL57/2016/CP1327/CT0007 and fellowship SFRH/BD/119920/2016

    ECM-enriched alginate hydrogels for bioartificial pancreas: an ideal niche to improve insulin secretion and diabetic glucose profile

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    Introduction: The success of a bioartificial pancreas crucially depends on ameliorating encapsulated beta cells survival and function. By mimicking the cellular in vivo niche, the aim of this study was to develop a novel model for beta cells encapsulation capable of establishing an appropriate microenvironment that supports interactions between cells and extracellular matrix (ECM) components. Methods: ECM components (Arg-Gly-Asp, abbreviated as RGD) were chemically incorporated in alginate hydrogels (alginate-RGD). After encapsulation, INS-1E beta cells outcome was analyzed in vitro and after their implantation in an animal model of diabetes. Results: Our alginate-RGD model demonstrated to be a good in vitro niche for supporting beta cells viability, proliferation, and activity, namely by improving the key feature of insulin secretion. RGD peptides promoted cell–matrix interactions, enhanced endogenous ECM components expression, and favored the assembly of individual cells into multicellular spheroids, an essential configuration for proper beta cell functioning. In vivo, our pivotal model for diabetes treatment exhibited an improved glycemic profile of type 2 diabetic rats, where insulin secreted from encapsulated cells was more efficiently used. Conclusions: We were able to successfully introduce a novel valuable function in an old ally in biomedical applications, the alginate. The proposed alginate-RGD model stands out as a promising approach to improve beta cells survival and function, increasing the success of this therapeutic strategy, which might greatly improve the quality of life of an increasing number of diabetic patients worldwide.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by FCT/MEC through National Funds and co-financed by FEDER through the PT2020 Partnership Agreement under the 4293 Unit I&D, FCT Strategic Project PEst-C/SAU/UI3282/2011-2013 and UID/NEU/04539/2013, FCT in the framework of project UID/BIM/04293/2013, FCT in the framework of project IF/00939/2013/CP1179/CT0001, FCT for Joana Crisóstomo (grant number SFRH/BD/72964/2010), FCT for Sílvia J Bidarra (grant number SFRH/BPD/80571/2011), and FCT and POPH/ESF (EC) for Cristina C Barrias research position FCT Investigator (IF2013)

    A Randomized Placebo-Controlled Trial of Intermittent Preventive Treatment in Pregnant Women in the Context of Insecticide Treated Nets Delivered through the Antenatal Clinic

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    Background:Current recommendations to prevent malaria in African pregnant women rely on insecticide treated nets(ITNs) and intermittent preventive treatment (IPTp). However, there is no information on the safety and efficacy of theircombined use.Methods:1030 pregnant Mozambican women of all gravidities received a long-lasting ITN during antenatal clinic (ANC)visits and, irrespective of HIV status, were enrolled in a randomised, double blind, placebo-controlled trial, to assess thesafety and efficacy of 2-dose sulphadoxine-pyrimethamine (SP). The main outcome was the reduction in low birth weight.Findings:Two-dose SP was safe and well tolerated, but was not associated with reductions in anaemia prevalence atdelivery (RR, 0.92 [95% CI, 0.79-1.08]), low birth weight (RR, 0.99 [95% CI, 0.70-1.39]), or overall placental infection(p = 0.964). However, the SP group showed a 40% reduction (95% CI, 7.40-61.20]; p = 0.020) in the incidence of clinicalmalaria during pregnancy, and reductions in the prevalence of peripheral parasitaemia (7.10% vs 15.15%) (p,0.001), and ofactively infected placentas (7.04% vs 13.60%) (p = 0.002). There was a reduction in severe anaemia at delivery of borderlinestatistical significance (p = 0.055). These effects were not modified by gravidity or HIV status. Reported ITN's use was morethan 90% in both groups.Conclusions:Two-dose SP was associated with a reduction in some indicators, but these were not translated to significantimprovement in other maternal or birth outcomes. The use of ITNs during pregnancy may reduce the need to administerIPTp. ITNs should be part of the ANC package in sub-Saharan Afric

    Quality of life after carotid endarterectomy

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    <p>Abstract</p> <p>Background</p> <p>Most studies documenting beneficial outcomes after carotid endarterectomy (CE) are limited to mortality and morbidity rates, costs, and length of hospital stay (LOS). Few have examined the dependency of patients and how they perceive their own health changes after surgery. The aim of the present study was to evaluate quality of life and independence in activities of daily living (ADL) and to study its determinants.</p> <p>Methods</p> <p>Sixty-three patients admitted in the Post Anaesthesia Care Unit (PACU) after CE were eligible for this 14-month follow-up study. Patients were contacted 6 months after discharge to complete a Short Form-36 questionnaire (SF-36) and to have their dependency in ADL evaluated.</p> <p>Results</p> <p>Among 59 hospital survivors at 6 months follow-up, 43 completed the questionnaires. Sixty-three percent reported that their general level of health was better on the day they answered the questionnaire than 12 months earlier. Patients had worse SF-36 scores for all domains except bodily pain than a general urban population, and comparison with a group of patients 6 months after surgical ICU discharge showed no differences. Six months after PACU discharge, the Lawton Instrumental Activities of ADL Scale and the Katz Index of ADL demonstrated higher dependency scores (5.9 ± 2.2 versus 4.3 ± 2.4 and 0.3 ± 0.8 versus 0.6 ± 0.9, p < 0.001 and p = 0.047). Sixty-five percent and 33% were dependent in at least one activity in instrumental and personal ADL, respectively. Patients dependent in at least one ADL task had higher Revised Cardiac Risk Index (RCRI) scores (1.0 versus 1.5, p = 0.017). After controlling for multiple comparisons, no significant differences were found.</p> <p>Conclusion</p> <p>Patients undergoing CE have improved self-perception of quality of life despite being more dependent. Almost all their scores are worse than those in an urban population. We could identify no predictors of greater dependency in ADL tasks six months after PACU discharge.</p

    Novel inhibitors of the calcineurin/NFATc hub - alternatives to CsA and FK506?

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    The drugs cyclosporine A (CsA) and tacrolimus (FK506) revolutionized organ transplantation. Both compounds are still widely used in the clinic as well as for basic research, even though they have dramatic side effects and modulate other pathways than calcineurin-NFATc, too. To answer the major open question - whether the adverse side effects are secondary to the actions of the drugs on the calcineurin-NFATc pathway - alternative inhibitors were developed. Ideal inhibitors should discriminate between the inhibition of (i) calcineurin and peptidyl-prolyl cis-trans isomerases (PPIases; the matchmaker proteins of CsA and FK506), (ii) calcineurin and the other Ser/Thr protein phosphatases, and (iii) NFATc and other transcription factors. In this review we summarize the current knowledge about novel inhibitors, synthesized or identified in the last decades, and focus on their mode of action, specificity, and biological effects
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