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Successful stem cell applications could have a significant impact on the medical field, where many lives are at stake. However, the translation of stem cells to the clinic could be improved by overcoming challenges in stem cell transplantation and inâ vivo retention at the site of tissue damage. This review aims to showcase the most recent insights into developing hydrogels that can deliver, retain, and accommodate stem cells for tissue repair. Hydrogels can be used for tissue engineering, as their flexibility and water content makes them excellent substitutes for the native extracellular matrix. Moreover, the mechanical properties of hydrogels are highly tuneable, and recognition moieties to control cell behaviour and fate can quickly be introduced. This review covers the parameters necessary for the physicochemical design of adaptable hydrogels, the variety of (bio)materials that can be used in such hydrogels, their application in stem cell delivery and some recently developed chemistries for reversible crosslinking. Implementing physical and dynamic covalent chemistry has resulted in adaptable hydrogels that can mimic the dynamic nature of the extracellular matrix.
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Hidrogéis , Engenharia Tecidual , Hidrogéis/química , Engenharia Tecidual/métodos , Matriz Extracelular , Células-TroncoRESUMO
Ovarian cancer ranks fifth in cancer-related deaths among women. Since ovarian cancer patients are often asymptomatic, most patients are diagnosed only at an advanced stage of disease. This results in a 5-year survival rate below 50%, which is in strong contrast to a survival rate as high as 94% if detected and treated at an early stage. Monitoring serum biomarkers offers new possibilities to diagnose ovarian cancer at an early stage. In this study, nanobodies targeting the ovarian cancer biomarkers human epididymis protein 4 (HE4), secretory leukocyte protease inhibitor (SLPI), and progranulin (PGRN) were evaluated regarding their expression levels in bacterial systems, epitope binning, and antigen-binding affinity by enzyme-linked immunosorbent assay and surface plasmon resonance. The selected nanobodies possess strong binding affinities for their cognate antigens (KD~0.1-10 nM) and therefore have a pronounced potential to detect ovarian cancer at an early stage. Moreover, it is of utmost importance that the limits of detection (LOD) for these biomarkers are in the pM range, implying high specificity and sensitivity, as demonstrated by values in human serum of 37 pM for HE4, 163 pM for SLPI, and 195 pM for PGRN. These nanobody candidates could thus pave the way towards multiplexed biosensors.
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Neoplasias Ovarianas , Anticorpos de Domínio Único , Humanos , Feminino , Detecção Precoce de Câncer , Carcinoma Epitelial do Ovário , Neoplasias Ovarianas/diagnóstico , Biomarcadores Tumorais , ProgranulinasRESUMO
Single-domain antibodies, known as nanobodies, have great potential as biorecognition elements for sensors because of their small size, affinity, specificity, and robustness. However, facile and efficient methods of nanobody immobilization are sought that retain their maximum functionality. Herein, we describe the direct immobilization of nanobodies on gold sensors by exploiting a modified cysteine strategically positioned at the C-terminal end of the nanobody. The experimental data based on secondary ion mass spectrometry, circular dichroism, and surface plasmon resonance, taken together with a detailed computational work (molecular dynamics simulations), support the formation of stable and well-oriented nanobody monolayers. Furthermore, the nanobody structure and activity is preserved, wherein the nanobody is immobilized at a high density (approximately 1 nanobody per 13 nm2). The strategy for the spontaneous nanobody self-assembly is simple and effective and possesses exceptional potential to be used in numerous sensing platforms, ranging from clinical diagnosis to environmental monitoring.
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Anticorpos Imobilizados/química , Anticorpos Imobilizados/genética , Técnicas Biossensoriais/métodos , Ouro/química , Engenharia de Proteínas , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/genética , Simulação de Dinâmica Molecular , Conformação ProteicaRESUMO
Metabolism encompasses the biochemical processes that allow healthy cells to keep energy, redox balance and building blocks required for cell development, survival, and proliferation steady. Malignant cells are well-documented to reprogram their metabolism and energy production networks to support rapid proliferation and survival in harsh conditions via mutations in oncogenes and inactivation of tumor suppressor genes. Despite the histologic and genetic heterogeneity of tumors, a common set of metabolic pathways sustain the high proliferation rates observed in cancer cells. This review with a focus on lung cancer covers several fundamental principles of the disturbed glucose metabolism, such as the "Warburg" effect, the importance of the glycolysis and its branching pathways, the unanticipated gluconeogenesis and mitochondrial metabolism. Furthermore, we highlight our current understanding of the disturbed glucose metabolism and how this might result in the development of new treatments.
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An expression strategy is presented in order to produce nanobodies modified with a clickable alkyne functionality at their C-terminus via the intein-mediated protein ligation (IPL) technique. The protocol focuses on the cytoplasmic expression and extraction of a nanobody-intein-chitin binding domain (CBD) fusion protein in E. coli SHuffle® T7 cells, in the commonly used Luria-Bertani (LB) medium. The combination of these factors results in a high yield and nearly complete alkynation of the nanobody at its C-terminus via IPL. The resulting alkynated nanobodies retain excellent binding capacity toward the nanobody targeted antigen. The presented protocol benefits from time- and cost-effectiveness and allows for a feasible upscaling of functionalized (here alkynated) nanobodies. The production of high quantities of site-specifically modified nanobodies paves the way to (1) novel biosurface applications that demand for homogeneously oriented nanobodies having their active site fully accessible for target (e.g., biomarker) binding, and (2) innovative applications such as localized drug delivery and image guided surgery by covalent "click" chemistry coupling of these alkynated nanobodies to a multitude of azide-containing counterparts as there are drug containing polymers and contrast labeling agents.
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Química Click/métodos , Inteínas/genética , Engenharia de Proteínas/métodos , Anticorpos de Domínio Único/química , Quitina/química , Quitina/genética , Ligação Proteica/genética , Domínios Proteicos/genética , Anticorpos de Domínio Único/genéticaRESUMO
Lung cancer cells are well-documented to rewire their metabolism and energy production networks to support rapid survival and proliferation. This metabolic reorganization has been recognized as a hallmark of cancer. The increased uptake of glucose and the increased activity of the glycolytic pathway have been extensively described. However, over the past years, increasing evidence has shown that lung cancer cells also require glutamine to fulfill their metabolic needs. As a nitrogen source, glutamine contributes directly (or indirectly upon conversion to glutamate) to many anabolic processes in cancer, such as the biosynthesis of amino acids, nucleobases, and hexosamines. It plays also an important role in the redox homeostasis, and last but not least, upon conversion to α-ketoglutarate, glutamine is an energy and anaplerotic carbon source that replenishes tricarboxylic acid cycle intermediates. The latter is generally indicated as glutaminolysis. In this review, we explore the role of glutamine metabolism in lung cancer. Because lung cancer is the leading cause of cancer death with limited curative treatment options, we focus on the potential therapeutic approaches targeting the glutamine metabolism in cancer.
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Glutamina/metabolismo , Neoplasias Pulmonares/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Redes e Vias Metabólicas/efeitos dos fármacos , Terapia de Alvo Molecular , Metástase Neoplásica , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Type 1 diabetes mellitus (T1DM) is one of the most common pediatric diseases and its incidence is rising in many countries. Recently, it has been shown that metabolites other than glucose play an important role in insulin deficiency and the development of diabetes. The aim of our study was to look for discriminating variation in the concentrations of small-molecule metabolites in the plasma of T1DM children as compared to non-diabetic matched controls using proton nuclear magnetic resonance (1H-NMR)-based metabolomics. METHODS: A cross-sectional study was set-up to examine the metabolic profile in fasting plasma samples from seven children with poorly controlled T1DM and seven non-diabetic controls aged 8-18 years, and matched for gender, age and BMI-SDS. The obtained plasma 1H-NMR spectra were rationally divided into 110 integration regions, representing the metabolic phenotype. These integration regions reflect the relative metabolite concentrations and were used as statistical variables to construct (train) a classification model in discriminating between T1DM patients and controls. RESULTS: The total amount of variation explained by the model between the groups is 81.0% [R2Y(cum)] and within the groups is 75.8% [R2X(cum)]. The predictive ability of the model [Q2(cum)] obtained by cross-validation is 50.7%, indicating that the discrimination between the groups on the basis of the metabolic phenotype is valid. Besides the expected higher concentration of glucose, the relative concentrations of lipids (triglycerides, phospholipids and cholinated phospholipids) are clearly lower in the plasma of T1DM patients as compared to controls. Also the concentrations of the amino acids serine, tryptophan and cysteine are slightly decreased. CONCLUSIONS: The present study demonstrates that metabolic profiling of plasma by 1H-NMR spectroscopy allows to discriminate between T1DM patients and controls. The metabolites that significantly differ between both groups might point to disturbances in biochemical pathways including (1) choline deficiency, (2) increased gluconeogenesis, and (3) glomerular hyperfiltration. Although the sample size of this study is still somewhat limited and a validation should be performed, the proof of principle looks promising and justifies a deeper investigation of the diagnostic possibilities of 1H-NMR metabolomics in follow-up studies. Trial registration NCT03014908. Registered 06/01/2017. Retrospectively registered.
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INTRODUCTION: Low-dose computed tomography, the currently used tool for lung cancer screening, is characterized by a high rate of false-positive results. Accumulating evidence has shown that cancer cell metabolism differs from that of normal cells. Therefore, this study aims to evaluate whether the metabolic phenotype of blood plasma allows detection of lung cancer. METHODS: The proton nuclear magnetic resonance spectrum of plasma is divided into 110 integration regions, representing the metabolic phenotype. These integration regions reflect the relative metabolite concentrations and were used to train a classification model in discriminating between 233 patients with lung cancer and 226 controls. The validity of the model was examined by classifying an independent cohort of 98 patients with lung cancer and 89 controls. RESULTS: The model makes it possible to correctly classify 78% of patients with lung cancer and 92% of controls, with an area under the curve of 0.88. Important moreover is the fact that the model is convincing, which is demonstrated by validation in the independent cohort with a sensitivity of 71%, a specificity of 81%, and an area under the curve of 0.84. Patients with lung cancer have increased glucose and decreased lactate and phospholipid levels. The limited number of patients in the subgroups and their heterogeneous nature do not (yet) enable differentiation between histological subtypes and tumor stages. CONCLUSIONS: Metabolic phenotyping of plasma allows detection of lung cancer, even in an early stage. Increased glucose and decreased lactate levels are pointing to an increased gluconeogenesis and are in accordance with recently published findings. Furthermore, decreased phospholipid levels confirm the enhanced membrane synthesis.