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1.
Artigo em Inglês | MEDLINE | ID: mdl-38745439

RESUMO

OBJECTIVES: to report real-life data on rituximab retention-rate as indicator of safety and efficacy in a multicentric national cohort of systemic sclerosis patients. METHODS: SSc patients treated with rituximab and followed for at least 36 months were included, clinically characterized, and longitudinally monitored. A competing risk analysis with sub-Hazard Ratio(sHR) definition was performed to explore the clinical variables linked to specific cause of rituximab discontinuation. RESULTS: One-hundred-fifty-two SSc-patients (mean age 47.3 ± 12.3 years; females 79.6%; diffuse disease 77.6%; anti-topoisomerase-I positivity 63.2%) were evaluated over a median(IQR) time of 3.3(1.7-5.0) years. The primary indication for rituximab were interstitial lung disease (ILD)(38.8%), worsening skin fibrosis(36.8%), and arthritis(13.8%); 138 patients(90.8%) received more than one rituximab course. The 5-years rituximab retention rate was 59.9%(44.6-64.7%). Clinical response was the most common reason for rituximab discontinuation[5.7(3.7-8.4) per 100 patient-year] and was associated with a shorter disease duration[sHR 0.8(0.7-0.9)], anti-topoisomerase-I negativity[sHR 0.4(0.2-0.9)], previous digital ulcers[sHR 2.6(1.1-6.2] and no history of arthritis[sHR 0.3 (0.1-0.8)]. Treatment failure was the second cause of rituximab discontinuation[3.7(2.2-6.0) per 100 patient-year] and was associated with anti-centromere antibody positivity[sHR 2.8(1.1-7.4)] and anti-topoisomerase-I negativity[sHR 0.2(0.1-0.6)]. Adverse events(AEs) were the less common cause of discontinuation[3.1(1.7-5.2) per 100 patient-year], associated with limited cutaneous subset[sHR 3.4(1.2-9.7)] and previous mycophenolate mofetil treatment[sHR 4.5(1.2-16.3)]. CONCLUSION: rituximab is a safe and effective treatment in SSc: clinical response emerged as the primary reason for rituximab discontinuation, and AEs had a limited impact on treatment persistence. The identification of specific disease features associated with a response to rituximab will be useful in the management of SSc-patients.

2.
Clin Exp Rheumatol ; 40(2): 237-246, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34796850

RESUMO

OBJECTIVES: We performed a retrospective and prospective observational study to investigate whether the T lymphocyte activation antigen dipeptidyl peptidase 4 (DPP4)/CD26 is expressed in the skeletal muscle of patients with idiopathic inflammatory myopathies (IIM) and whether its expression offers clues to understand the events taking place in the tissue. METHODS: CD26 expression in the muscle, evaluated by immunofluorescence, was assessed in 32 patients with IIM and 5 healthy controls and compared among patients with dermatomyositis (DM), immune-mediated necrotising myopathy (IMNM), inclusion body myositis (IBM), and polymyositis (PM). The relationship of CD26 expression and localization with clinical, serological and histological features was determined. RESULTS: CD26 is selectively expressed in the skeletal muscle of patients with IIM. The highest levels of CD26 are found in the skeletal muscle from patients with DM and in particular in those characterized by tissue necrosis and vascular inflammation. CD26 expression is associated with decreased muscle performance and independently predicts the number of treatments before reaching disease stabilization or improvement (odds ratio, OR=1.2, p<0.05). CONCLUSIONS: CD26 is expressed in the IIM skeletal muscle and may represent a target of molecular intervention for patients with treatment-refractory myositis.


Assuntos
Dermatomiosite , Miosite de Corpos de Inclusão , Miosite , Dipeptidil Peptidase 4 , Humanos , Inflamação/patologia , Músculo Esquelético/patologia , Estudos Retrospectivos
3.
Nano Lett ; 20(1): 577-584, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31846332

RESUMO

Local curvatures on the cell membrane serve as signaling hubs that promote curvature-dependent protein interactions and modulate a variety of cellular processes including endocytosis, exocytosis, and the actin cytoskeleton. However, precisely controlling the location and the degree of membrane curvature in live cells has not been possible until recently, where studies show that nanofabricated vertical structures on a substrate can imprint their shapes on the cell membrane to induce well-defined curvatures in adherent cells. Nevertheless, the intrinsic static nature of these engineered nanostructures prevents dynamic modulation of membrane curvatures. In this work, we engineer light-responsive polymer structures whose shape can be dynamically modulated by light and thus change the induced-membrane curvatures on-demand. Specifically, we fabricate three-dimensional azobenzene-based polymer structures that change from a vertical pillar to an elongated vertical bar shape upon green light illumination. We observe that U2OS cells cultured on azopolymer nanostructures rapidly respond to the topographical change of the substrate underneath. The dynamically induced high membrane curvatures at bar ends promote local accumulation of actin fibers and actin nucleator Arp2/3 complex. The ability to dynamically manipulate the membrane curvature and analyze protein response in real-time provides a new way to study curvature-dependent processes in live cells.


Assuntos
Membrana Celular/metabolismo , Proteínas de Membrana/metabolismo , Nanoestruturas/química , Transdução de Sinais , Linhagem Celular Tumoral , Humanos
5.
Nurs Rep ; 14(1): 455-467, 2024 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-38391080

RESUMO

INTRODUCTION: Situations involving increased workloads and stress (i.e., the COVID-19 pandemic) underline the need for healthcare professionals to minimize patient complications. In the field of vascular access, tunneling techniques are a possible solution. This systematic review and meta-analysis aimed to compare the effectiveness of tunneled Peripherally Inserted Central Catheters (tPICCs) to conventional Peripherally Inserted Central Catheters (cPICCs) in terms of bleeding, overall success, procedural time, and late complications. METHODS: Randomized controlled trials without language restrictions were searched using PUBMED®, EMBASE®, EBSCO®, CINAHL®, and the Cochrane Controlled Clinical Trials Register from August 2022 to August 2023. Five relevant papers (1238 patients) were included. RESULTS: There were no significant differences in overall success and nerve or artery injuries between the two groups (p = 0.62 and p = 0.62, respectively), although cPICCs caused slightly less bleeding (0.23 mL) and had shorter procedural times (2.95 min). On the other hand, tPICCs had a significantly reduced risk of overall complications (p < 0.001; RR0.41 [0.31-0.54] CI 95%), catheter-related thrombosis (p < 0.001; RR0.35 [0.20-0.59] IC 95%), infection-triggering catheter removal (p < 0.001; RR0.33 [0.18-0.61] IC 95%), wound oozing (p < 0.001; RR0.49 [0.37-0.64] IC 95%), and dislodgement (p < 0.001; RR0.4 [0.31-0.54] CI 95%). CONCLUSIONS: The tunneling technique for brachial access appears to be safe concerning intra-procedural bleeding, overall success, and procedural time, and it is effective in reducing the risk of late complications associated with catheterization.

6.
Nutrients ; 15(4)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36839323

RESUMO

Few observational studies investigated the relationship between single food groups and disease activity in rheumatoid arthritis (RA). Within a recent Italian cross-sectional study (365 patients, median age: 58.46 years, 78.63% females), we focused on two food groups, olive oil and nuts, representing vegetable sources of fatty acids. Disease activity was measured with Disease Activity Score on 28 joints based on C-reactive protein (DAS28-CRP) and the Simplified Disease Activity Index (SDAI). Robust linear and logistic regression models included tertile-based consumption categories of each food group and several confounders. Stratified analyses were performed by disease severity or duration. Higher consumption of both food groups exerted a favorable effect on disease activity, significant only for olive oil (Beta: -0.33, p-value: 0.03) in the linear regression on the overall sample. This favorable effect was stronger in the more severe or long-standing forms of RA (p-value for heterogeneity <0.05, especially for disease severity). Significant ORs were as low as ~0.30 for both food groups, strata (i.e., more severe and long-standing RA), and disease activity measures. Mean DAS28-CRP significantly decreased by ~0.70 for olive oil and ~0.55 for nuts in the two strata; mean SDAI significantly decreased by 3.30 or more for olive oil in the two strata. Globally, the beta coefficients doubled, and the ORs halved (in absolute values) for both food groups, reaching significance in 12 of the 16 available models fitted to the more severe or long-standing RA strata. More compromised forms of RA may benefit from increasing consumption of olive oil, olives, and nuts.


Assuntos
Artrite Reumatoide , Nozes , Feminino , Humanos , Pessoa de Meia-Idade , Masculino , Azeite de Oliva/análise , Nozes/química , Estudos Transversais , Proteína C-Reativa/análise , Índice de Gravidade de Doença
7.
Autoimmun Rev ; 21(7): 103117, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35595049

RESUMO

The current ideal goal of rheumatoid arthritis (RA) management is to resolve joint and systemic inflammation by using pharmacological interventions, assuming this will correspondingly lead to overall well-being. Nonetheless, it has emerged that a substantial number of RA patients do not reach optimal disease control, thus suggesting the holistic management of subjective symptoms might be overlooked. This poses significant medical challenges; hence the proposal of incorporating lifestyle interventions as part of a multidimensional approach. Among these aspects, both patients and physicians perceive the important role of nutrition. This review shall examine how caffeine, one of the most studied bioactive components of the most widely consumed beverages, may potentially interfere with RA management. In particular, the mechanism by which caffeine affects RA pathogenesis, as a trigger for RA onset or flare, including its influence on rheumatic drug metabolism and the most common RA comorbidities and constitutional symptoms are outlined, highlighting important knowledge gaps and unmet research needs.


Assuntos
Artrite Reumatoide , Cafeína , Artrite Reumatoide/etiologia , Cafeína/efeitos adversos , Comorbidade , Humanos , Inflamação/complicações
8.
Front Pharmacol ; 13: 841785, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35242041

RESUMO

Evidence about the relevance of the complement system, a highly conserved constituent of the innate immunity response that orchestrates the elimination of pathogens and the inflammatory processes, has been recently accumulated in many different rheumatologic conditions. In rheumatoid arthritis, complement, mainly the classical pathway, contributes to tissue damage especially in seropositive subjects, with complement activation occurring in the joint. Data about complement pathways in psoriatic arthritis are dated and poorly consistent; among patients with Sjögren syndrome, hypocomplementemia exerts a prognostic role, identifying patients at risk of extra-glandular manifestations. Hints about complement involvement in systemic sclerosis have been recently raised, following the evidence of complement deposition in affected skin and in renal samples from patients with scleroderma renal crisis. In vasculitides, complement plays a dual role: on one hand, stimulation of neutrophils with anti-neutrophil cytoplasmic antibodies (ANCA) results in the activation of the alternative pathway, on the other, C5a induces translocation of ANCA antigens, favouring the detrimental role of antibodies. Complement deposition in the kidneys identifies patients with more aggressive renal disease; patients with active disease display low serum levels of C3 and C4. Even though in dermatomyositis sC5b-9 deposits are invariably present in affected muscles, data on C3 and C4 fluctuation during disease course are scarce. C3 and C1q serum levels have been explored as potential markers of disease activity in Takayasu arteritis, whereas data in Behçet disease are limited to in vitro observations. Pregnancies in women with rheumatologic conditions are still burdened by a higher rate of pregnancy complications, thus the early identification of women at risk would be invaluable. A fine-tuning of complement activation is required from a physiological progression of pregnancy, from pre-implantation stages, through placentation to labour. Complement deregulation has been implicated in several pregnancy complications, such as recurrent abortion, eclampsia and premature birth; low complement levels have been shown to reliably identify women at risk of complications. Given its physiologic role in orchestrating pregnancy progression and its involvement as pathogenic effector in several rheumatologic conditions, complement system is an attractive candidate biomarker to stratify the obstetric risk among women with rheumatologic conditions.

9.
Chem Soc Rev ; 39(1): 241-63, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20023851

RESUMO

Peptides are particularly attractive as molecular building blocks in the bottom-up fabrication of supramolecular structures based on self-assembly and have potential in many important applications in the fields of biotechnology and bioengineering. In the first part of this critical review the main categories of peptide-based amphiphiles will be discussed by showing some relevant examples, which demonstrate the importance of amphiphilic peptides as molecular building blocks for nanostructures. In the second part of this review we will review the cross-disciplinary role of peptide-based supramolecular nanoarchitectures ranging from chemistry to biology, medicine, materials science, and engineering through discussing several examples of applied nanomaterials (216 references).


Assuntos
Nanotecnologia/métodos , Peptídeos/química , Sequência de Aminoácidos , Animais , Humanos , Dados de Sequência Molecular , Nanoestruturas/química , Peptídeos/síntese química , Peptídeos/metabolismo , Engenharia de Proteínas
10.
Medicine (Baltimore) ; 100(9): e24372, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33655912

RESUMO

RATIONALE: Severe refractory idiopathic inflammatory myopathy (IIM) represents a challenge for the clinician. The lack of efficacy of available tools reflects our incomplete insight into the molecular events sustaining the inflammatory tissue damage in these patients. We present the first case of refractory IIM treated with anti-dipeptidyl peptidase-4 (DPP-4)/cluster of differentiation 26 (CD26) monoclonal antibody. PATIENT CONCERNS: A 55-year old man presented with proximal muscle weakness, diffuse erythematous skin lesions which rapidly evolved into ulcerations, dysphagia and dysphonia. DIAGNOSIS: Increased serum creatine kinase levels and histological findings at muscle and skin biopsies were compatible with the diagnosis of dermatomyositis (DM). Several lines of treatment failed to control the disease including steroids, mycophenolate mofetil, tacrolimus, intravenous immunoglobulins and rituximab. Despite therapy, the patient also had recurrent intestinal vasculitis causing bowel perforation. Concurrently, DPP-4/CD26 expression in the patient's skin and skeletal muscle was observed. INTERVENTIONS: The patient was treated with begelomab, a murine immunoglobulin G2b monoclonal antibody against DPP-4/CD26. OUTCOMES: Dysphagia, skin lesions and intestinal vasculitis resolved and the patient experienced a significant improvement of his quality of life. CONCLUSION: Blockade of DPP-4/CD26, which is expressed on T cells and mediates T cell activation and function, is safe and might be effective in patients with refractory DM.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Dermatomiosite/tratamento farmacológico , Dipeptidil Peptidase 4/imunologia , Inibidores da Dipeptidil Peptidase IV/imunologia , Imunoglobulina G/imunologia , Dermatomiosite/imunologia , Humanos , Masculino , Pessoa de Meia-Idade
11.
Chembiochem ; 11(16): 2311-7, 2010 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-20941725

RESUMO

Autotaxin (ATX), or ecto-nucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2), is a secreted lysophospholipase D that hydrolyses lysophosphatidylcholine into the lipid mediator lysophosphatidic acid (LPA), a mitogen and chemoattractant for many cell types. ATX has been implicated in tumour progression and inflammation, and might serve as a biomarker. Here we describe the development of a fluorescent activity-based probe that covalently binds to the active site of ATX. The probe consists of a lysophospholipid-based backbone linked to a trapping moiety that becomes reactive after phosphate ester hydrolysis, and a Cy5 fluorescent dye to allow visualisation of active ATX. The probe reacts specifically with the three known isoforms of ATX, it competes with small-molecule inhibitors for binding to ATX and allows ATX activity in plasma to be determined. Our activity-based reporter will be useful for monitoring ATX activity in biological fluids and for inhibitor screening.


Assuntos
Inibidores Enzimáticos/química , Corantes Fluorescentes/química , Complexos Multienzimáticos/metabolismo , Fosfodiesterase I/metabolismo , Pirofosfatases/metabolismo , Domínio Catalítico , Inibidores Enzimáticos/síntese química , Corantes Fluorescentes/síntese química , Humanos , Complexos Multienzimáticos/antagonistas & inibidores , Complexos Multienzimáticos/genética , Fosfodiesterase I/antagonistas & inibidores , Fosfodiesterase I/genética , Diester Fosfórico Hidrolases , Ligação Proteica , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Pirofosfatases/antagonistas & inibidores , Pirofosfatases/genética , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
12.
Adv Healthc Mater ; 9(13): e2000470, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32431096

RESUMO

Patterned surfaces have proved effective in guiding stem cells commitment to a specific lineage by presenting highly ordered biophysical/biochemical cues at the cellmaterial interface. Their potency in controlling cell fate can be significantly empowered by encoding logic of space and time control of signal presentation. Here, azopolymeric photoactive interfaces are proposed to present/withdraw morphophysical signals to living cells using a green light trigger in a non-invasive spatio-temporal controlled way. To assess the potency of these dynamic platforms in controlling cell decision and fate, topography changes are actuated by light at specific times to reverse the fate of otherwise committed human mesenchymal stem cells (hMSC) toward osteoblastic lineage. It is first proved by dynamic change from ordered parallel patterning to flat or grid surfaces, that it is possible to induce cyclic cellular and nuclear stretches. Furthermore, by culturing hMSCs on a specific pattern known to prime them toward osteoblast lineage, the possibility to reroute or reverse stem cell fate decision by dynamic modulation of morphophysical signal is proved. To conclude, dynamic topographies can control the spatial conformation of hMSCs, modulate lineage reversal even after several weeks of culture and redirect lineage specification in response to light-induced changes in the microenvironment.


Assuntos
Células-Tronco Mesenquimais , Diferenciação Celular , Linhagem da Célula , Humanos , Osteoblastos
13.
Eur J Pediatr Surg ; 30(5): 452-458, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31587243

RESUMO

INTRODUCTION: Consensus on the best postnatal radiological evaluation of congenital lung malformations (CLMs) is still lacking. In recent years, the interest on magnetic resonance imaging (MRI) has grown, but its role is still unknown. AIM: The aim of the study was to identify the best preoperative diagnostic assessment for CLM. MATERIALS AND METHODS: All patients with a prenatal suspicion of CLM between January 2014 and February 2018 were studied. Asymptomatic newborns underwent MRI, during spontaneous sleep without contrast. Patients with a positive MRI were scheduled for computed tomography (CT) within the fourth month of life. Thoracoscopic resection was performed in cases with a pathological CT. MRI, CT, and surgical findings were compared based on dimension, localization, and features of the CLM using the Cohen's kappa test (K). RESULTS: A total of 20 patients were included (10 males). No difference was found in the diameter and site of the lesions always localized in the same side (K = 1) and in the same pulmonary lobe (K = 1). Infants who underwent thoracoscopic resection included: three congenital pulmonary airway malformations (CPAMs), five extralobar and eight intralobar sequestrations (bronchopulmonary sequestrations [BPSs]), three bronchogenic cysts, and one congenital emphysema. The concordance between MRI and CT and between radiological investigations and pathology was satisfactory for the greatest part of the studied variables. MRI showed sensitivity of 100%, specificity of 82%, positive predictive value of 50% and negative predictive value of 100% for CPAM and 77, 100, 100, and 80% for BPS, respectively. CONCLUSION: MRI proved to be a reliable diagnostic investigation for CLM with high sensitivity and specificity. Early MRI in spontaneous sleep without contrast and preoperative contrast CT scan is a valuable preoperatory assessment.


Assuntos
Pulmão/anormalidades , Pulmão/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Anormalidades do Sistema Respiratório/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Lactente , Pulmão/cirurgia , Masculino , Valor Preditivo dos Testes , Cuidados Pré-Operatórios/métodos , Anormalidades do Sistema Respiratório/cirurgia
14.
Sci Rep ; 10(1): 15329, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948792

RESUMO

Surface topography is a key parameter in regulating the morphology and behavior of single cells. At multicellular level, coordinated cell displacements drive many biological events such as embryonic morphogenesis. However, the effect of surface topography on collective migration of epithelium has not been studied in detail. Mastering the connection between surface features and collective cellular behaviour is highly important for novel approaches in tissue engineering and repair. Herein, we used photopatterned microtopographies on azobenzene-containing materials and showed that smooth topographical cues with proper period and orientation can efficiently orchestrate cell alignment in growing epithelium. Furthermore, the experimental system allowed us to investigate how the orientation of the topographical features can alter the speed of wound closure in vitro. Our findings indicate that the extracellular microenvironment topography coordinates their focal adhesion distribution and alignment. These topographic cues are able to guide the collective migration of multicellular systems, even when cell-cell junctions are disrupted.


Assuntos
Técnicas de Cultura de Células/instrumentação , Células Epiteliais/citologia , Animais , Compostos Azo/química , Movimento Celular , Colágeno/química , Cães , Adesões Focais , Técnicas de Inativação de Genes , Junções Intercelulares , Células Madin Darby de Rim Canino , Propriedades de Superfície , Proteína da Zônula de Oclusão-1/genética
15.
ACS Appl Mater Interfaces ; 10(1): 91-97, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29260543

RESUMO

In materials science, there is a considerable interest in the fabrication of highly engineered biomaterials that can interact with cells and control their shape. In particular, from the literature, the role played by physical cell confinement in cellular structural organization and thus in the regulation of its functions has been well-established. In this context, the addition of a dynamic feature to physically confining platforms aiming at reproducing in vitro the well-known dynamic interaction between the cells and their microenvironment would be highly desirable. To this aim, we have developed an advanced gelatin-based hydrogel that can be finely micropatterned by two-photon polymerization and stimulated in a controlled way by light irradiation thanks to the presence of an azobenzene cross-linker. Light-triggered expansion of gelatin microstructures induced an in-plane nuclear deformation of physically confined NIH-3T3 cells. The microfabricated photoactuable gelatin shown in this work paves the way to new "dynamic" caging culture systems that can find applications, for example, as "engineered stem cell niches".


Assuntos
Compostos Azo/química , Animais , Gelatina , Hidrogéis , Camundongos , Células NIH 3T3 , Engenharia Tecidual
16.
Acta Biomater ; 63: 317-325, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28927933

RESUMO

Understanding cellular behavior in response to microenvironmental stimuli is central to tissue engineering. An increasing number of reports emphasize the high sensitivity of cells to the physical characteristics of the surrounding milieu and in particular, topographical cues. In this work, we investigated the influence of dynamic topographic signal presentation on sprout formation and the possibility to obtain a space-time control over sprouting directionality without growth factors, in order to investigate the contribution of just topography in the angiogenic process. To test our hypothesis, we employed a 3D angiogenesis assay based on the use of spheroids derived from human umbilical vein endothelial cells (HUVECs). We then modulated the in situ presentation of topographical cues during early-stage angiogenesis through real-time photopatterning of an azobenzene-containing polymer, poly (Disperse Red 1 methacrylate) (pDR1m). Pattern inscription on the polymer surface was made using the focused laser of a confocal microscope. We demonstrate that during early-stage angiogenesis, sprouts followed the pattern direction, while spheroid cores acquired a polarized shape. These findings confirmed that sprout directionality was influenced by the photo-inscribed pattern, probably through contact guidance of leader cells, thus validating the proposed platform as a valuable tool for understanding complex processes involved in cell-topography interactions in multicellular systems. STATEMENT OF SIGNIFICANCE: The complex relationship between endothelial cells and the surrounding environment that leads to formation of a newly formed vascular network during tissue repair is currently unknown. We have developed an innovative in vitro platform to study these mechanisms in a space and time controlled fashion simulating what happens during regeneration. In particular, we combine a "smart" surface, namely a polymer film, with a three-dimensional living cell aggregate. The polymer is activated by light through which we can design a path to guide cells toward the formation of a new vessel. Our work lies at the intersection of stimuli-responsive biointerfaces and cell biology and may be particularly inspiring for those interested in designing biomaterial surface related to angiogenesis.


Assuntos
Compostos Azo/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos da radiação , Luz , Neovascularização Fisiológica/efeitos da radiação , Polímeros/farmacologia , Fusão Celular , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Lasers , Neovascularização Fisiológica/efeitos dos fármacos , Esferoides Celulares/citologia , Imagem com Lapso de Tempo
17.
Chem Commun (Camb) ; (30): 3193-5, 2006 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-17028740

RESUMO

A generic method for the efficient in-situ modification of liposomes is described based on "click" chemistry, and a simple colorimetric assay is developed for monitoring the reaction.


Assuntos
Alcinos/química , Azidas/química , Cobre/química , Colorimetria , Ciclização , Transferência Ressonante de Energia de Fluorescência , Lipossomos/química , Estrutura Molecular , Soluções , Propriedades de Superfície
18.
ACS Appl Mater Interfaces ; 7(38): 21503-10, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26372777

RESUMO

Physical and chemical characteristics of materials are important regulators of cell behavior. In particular, cell elasticity is a fundamental parameter that reflects the state of a cell. Surface topography finely modulates cell fate and function via adhesion mediated signaling and cytoskeleton generated forces. However, how topographies alter cell mechanics is still unclear. In this work we have analyzed the mechanical properties of peripheral and nuclear regions of NIH-3T3 cells on azopolymer substrates with different topographic patterns. Micrometer scale patterns in the form of parallel ridges or square lattices of surface elevations were encoded on light responsive azopolymer films by means of contactless optical methods. Cell mechanics was investigated by atomic force microscopy (AFM). Cells and consequently the cell cytoskeleton were oriented along the linear patterns affecting cytoskeletal structures, e.g., formation of actin stress fibers. Our data demonstrate that topographic substrate patterns are recognized by cells and mechanical information is transferred by the cytoskeleton. Furthermore, cytoskeleton generated forces deform the nucleus, changing its morphology that appears to be related to different mechanical properties in the nuclear region.


Assuntos
Compostos Azo/farmacologia , Citoesqueleto/metabolismo , Polímeros/farmacologia , Animais , Citoesqueleto/efeitos dos fármacos , Módulo de Elasticidade/efeitos dos fármacos , Elasticidade/efeitos dos fármacos , Imageamento Tridimensional , Camundongos , Microscopia de Força Atômica , Microscopia Confocal , Células NIH 3T3 , Propriedades de Superfície
19.
Chempluschem ; 80(10): 1547-1555, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31973390

RESUMO

Photoresponsive surfaces were developed by modifying glass slides with switchable Gly-Arg-Gly-Asp-Ser (GRGDS) peptides to investigate light-controlled cell adhesion. The GRGDS peptide sequence was attached to an azobenzene moiety and then "clicked" to silanized glass substrates. The photoresponsive behavior of such cell-instructive materials (CIMs) was first checked by contact angle technique and by recording local changes in wettability owing to the isomerization of the azobenzene domain upon light stimulus. "On-off" switching was observed for at least five cycles when illuminated consecutively with UV and visible-light sources. Finally, cell-adhesion studies with human umbilical vein endothelial cells (HUVECs) validated our system as an effective light-responsive CIM platform and the possibility of dynamically controlled cell adhesion in situ was envisioned.

20.
ACS Appl Mater Interfaces ; 7(31): 16984-91, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-25876082

RESUMO

Topography of material surfaces is known to influence cell behavior at different levels: from adhesion up to differentiation. Different micro- and nanopatterning techniques have been employed to create patterned surfaces to investigate various aspects of cell behavior, most notably cellular mechanotransduction. Nevertheless, conventional techniques, once implemented on a specific substrate, fail in allowing dynamic changes of the topographic features. Here we investigated the response of NIH-3T3 cells to reversible topographic signals encoded on light-responsive azopolymer films. Switchable patterns were fabricated by means of a well-established holographic setup. Surface relief gratings were realized with Lloyd's mirror system and erased with circularly polarized or incoherent light. Cell cytoskeleton organization and focal adhesion assembly proved to be very sensitive to the underlying topographic signal. Thereafter, pattern reversibility was tested in air and wet environment by using temperature or light as a trigger. Additionally, pattern modification was dynamically performed on substrates with living cells. This study paves the way toward an in situ and real-time investigation of the material-cytoskeleton crosstalk caused by the intrinsic properties of azopolymers.


Assuntos
Compostos Azo/química , Holografia , Polímeros/química , Animais , Adesão Celular , Citoesqueleto/metabolismo , Luz , Camundongos , Microscopia de Força Atômica , Microscopia Confocal , Células NIH 3T3 , Propriedades de Superfície , Temperatura
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