1,404 research outputs found
Non-invasive, innovative and promising strategy for breast cancer diagnosis based on metabolomic profile of urine, cancer cell lines and tissue
The work presented in this thesis aimed to establish the metabolomic profile of urine and breast cancer (BC) tissue from BC patients (samples cordially provided by Funchal Hospital), in addition to BC cell lines (MCF-7, MDA-MB-231, T-47D) as a powerful strategy to identify metabolites as potential BC biomarkers, helping on the development of non-invasive approaches for BC diagnosis and management. To achieve the main goal and obtain a deeper and comprehensive knowledge on BC metabolome, different analytical platforms, namely headspace solid-phase microextraction (HSSPME) combined with gas chromatography-quadrupole mass spectrometry (GC-qMS) and nuclear magnetic ressonance (1H NMR) spectroscopy were used. The application of multivariate statistical methods - principal component analysis (PCA) and orthogonal partial least square – discriminant analysis (OPLS-DA), to data matrix obtained from the different target samples allowed to find a set of highly sensitive and specific metabolites metabolites, namely, 4-heptanone, acetic acid and glutamine, able to be used as potential biomarkers in BC diagnosis. Significant group separation was observed in OPLS-DA score plot between BC and CTL indicating intrinsic metabolic alterations in each group. To attest the robustness of the model, a random permutation test with 1000 permutations was performed with OPLS-DA. The permutation test yielded R2 (represents goodness of fit) and Q2 values (represents predictive ability) with values higher than 0.717 and 0.691, respectively. Several metabolic pathways were dysregulated in BC considering the analytical approaches used. The main pathways included pyruvate, glutamine and sulfur metabolisms, indicating that there might be an association between the metabolites arising from the type of biological sample of the same donor used to perform the investigation. The integration of data obtained from different analytical platforms (GC-qMS and 1H NMR) for urinary and tissue samples revealed that five metabolites (e.g., acetone, 3-hexanone, 4-heptanone, 2methyl-5-(methylthio)-furan and acetate), were found significant using a dual analytical approach.O trabalho apresentado nesta tese teve como objetivo estabelecer o perfil metabolómico da urina e do tecido da mama de doentes com cancro de mama (BC) (amostras cordialmente fornecidas pelo Hospital do Funchal), além das linhas celulares de BC (MCF-7, MDA-MB-231, T -47D) como uma poderosa estratégia para identificar metabolitos como potenciais biomarcadores de BC, auxiliando no desenvolvimento de abordagens não invasivas para o diagnóstico e a gestão da patologia. Para obter um conhecimento mais profundo e abrangente do metaboloma de BC, diferentes plataformas analíticas, nomeadamente a microextração em fase sólida em modo headspace (HS-SPME) combinada com a cromatografia em fase gasosa acoplada à espectrometria de massa (GC-qMS) e espectroscopia de ressonância magnética nuclear (1H RMN), foram usadas para atingir o objetivo principal. A aplicação de métodos estatísticos multivariados - análise de componentes principais (PCA) e análise discriminante de mínimos quadrados parciais ortogonais (OPLS-DA) à matriz de dados obtida a partir das diferentes amostras alvo, permitiu estabelecer um grupo de metabolitos sensíveis e específicos, nomeadamente a 4-heptanona, o ácido acético e a glutamina, possíveis de serem utilizados como potenciais biomarcadores no diagnóstico de BC. Uma separação significativa entre os grupos BC e CTL foi observada pelo OPLS-DA, indicando alterações metabólicas em cada grupo. Para verificar a robustez do modelo, foi realizado um teste de permutação aleatória com 1000 permutações com o sistema OPLS-DA. Valores de R2 (representa o ajuste) e Q2 (representa a capacidade preditiva) superiores a 0,717 e 0,691, foram obtidos utilizando o teste da permutação. Diversas vias metabólicas estavam desreguladas no BC considerando as abordagens analíticas utilizadas. As principais vias incluíram os metabolismos do piruvato e glutamina, indicando que poderá haver uma associação entre os metabolitos derivados do tipo de amostra biológica do mesmo doador utilizado para realizar a investigação. A integração de dados obtidos pelas diferentes plataformas analíticas (GC-qMS e 1H RMN) para amostras urinárias e de tecido revelou cinco metabolitos significativos usando a dupla abordagem analítica. (i.e., acetona, 3-hexanona, 4-heptanona, 2-metil-5- (metiltio) - furano e acetato)
G-Quadruplex Aptamer Beacon for Detection of Prostate Cancer Biomarker
The prostate is the major male reproductive gland involved in male fertility and plays
an important role in triggering of molecular pathways relevant to fertility success.
Unfortunately, in Portugal prostate cancer is the most common cancer type among
men, being asymptomatic in earlier stages. Thus, is important early detection of
disease.
NCL is a multifunctional protein involved in multiple biological processes under both
physiological and pathological processes and can have several cellular localizations.
Cell surface protein overexpression was found restricted to cancer cells, namely in
prostate cancer cells. Thus, we can consider NCL as a potential biomarker for cancer
diagnosis and a target for cancer treatment. The AS1411 is an aptamer capable to
recognise and binds specifically NCL and have a therapeutic effect on cancer cells
through of induction of antiproliferative activity. Beyond its therapeutic use, AS1411
can be used in imaging and diagnostic, particularly on aptasensors development. One
of the most relevant characteristics of this aptamer is the ability to fold in a G4
conformation, a secondary structure of nucleic acids. G4 structure confers stabilization
to sequence and availability to bind NCL.
Thus, in this work is presented the first approach of use AS1411 aptamer to prostate
cancer diagnosis, namely through the design of molecular beacon (MB) designated by
AS1411N5. Initially, biophysical characterization of AS1411-N5 was done by circular
dichroism, nuclear magnetic resonance or fluorometric spectroscopies. Additionally, it
was performed microfluidic experiments, to detect NCL using AS1411-N5 in biological
samples.
The results demonstrated that the proposed AS1411-N5 adopt a G4 structure and it is
capable to bind with specificity and selectivity NCL, even in plasma of human patients
with prostate cancer.A próstata é a maior glândula reprodutiva masculina e tem um papel importante nas
vias moleculares relevantes para o sucesso da fertilização. Infelizmente, em Portugal o
cancro da próstata é o cancro mais comum entre os homens, sendo assintomático em
estadios iniciais. Assim é imperativo a deteção precoce da doença.
A nucleolina (NCL) é uma proteína multifuncional envolvida em múltiplos processos
biológicos sob condições fisiológicas e patológicas, podendo ter várias localizações
celulares. A sobre-expressão da proteína na superfície das células é apenas encontrada
em células cancerosas, nomeadamente as do cancro da próstata. Assim a NCL pode ser
considerada como um potencial biomarcador para o diagnóstico e tratamento do
cancro da próstata. O AS411 é um aptamero capaz de reconhecer e ligar especificamente
a esta proteína, e de ter um efeito terapêutico nas células cancerosas ao induzir
atividade antiproliferativa. Além do uso terapêutico, a sequência pode ser utilizada na
imagiologia e diagnóstico, particularmente através do desenvolvimento de
aptasensores. Uma das características mais relevantes do aptamero AS1411 é a
capacidade de adotar a configuração de G-quadruplex (G4), uma estrutura secundária
dos ácidos nucleicos. As estruturas G4 conferem estabilização à sequência e capacidade
de ligar à NCL quando adota esta estrutura.
Assim, neste trabalho é apresentada uma primeira abordagem do uso do AS1411 no
diagnóstico do cancro da próstata, nomeadamente através da construção de uma sonda
a partir da sequência deste aptamero designado por AS1411N5. Inicialmente foi
efetuada a caracterização biofísica do AS1411-N5 a nível da estrutura e interação com o
alvo, recorrendo às espectroscopias dicroísmo circular e ressonância magnética
nuclear, e ensaios fluorométricos. Adicionalmente foram efetuadas experiências de
microfluídica, para o uso do AS1411N5 como sonda de deteção da NCL.
Estes resultados demonstraram, que o AS1411-N5adota a estrutura G4 e é capaz de ligar
especificamente e com seletividade com a NCL, mesmo em amostras biológicas
Development of New Smart Materials and Spinning Systems Inspired by Natural Silks and Their Applications
Silks produced by spiders and silkworms are charming natural biological materials with highly optimized hierarchical structures and outstanding physicomechanical properties. The superior performance of silks relies on the integration of a unique protein sequence, a distinctive spinning process, and complex hierarchical structures. Silks have been prepared to form a variety of morphologies and are widely used in diverse applications, for example, in the textile industry, as drug delivery vehicles, and as tissue engineering scaffolds. This review presents an overview of the organization of natural silks, in which chemical and physical functions are optimized, as well as a range of new materials inspired by the desire to mimic natural silk structure and synthesis
Recent Developments and Practical Feasibility of Polymer-Based Antifouling Coatings
While nature has optimized its antifouling strategies over millions of years, synthetic antifouling coatings have not yet reached technological maturity. For an antifouling coating to become technically feasible, it should fulfill many requirements: high effectiveness, long-term stability, durability, ecofriendliness, large-scale applicability, and more. It is therefore not surprising that the search for the perfect antifouling coating has been going on for decades. With the discovery of metal-based antifouling paints in the 1970s, fouling was thought to be a problem of the past, yet its untargeted toxicity led to serious ecological concern, and its use became prohibited. As a response, research shifted focus toward a biocompatible alternative: polymer-based antifouling coatings. This has resulted in numerous advanced and innovative antifouling strategies, including fouling-resistant, fouling-release, and fouling-degrading coatings. Here, these novel and exciting discoveries are highlighted while simultaneously assessing their antifouling performance and practical feasibility
Recent Developments and Practical Feasibility of Polymer-Based Antifouling Coatings
While nature has optimized its antifouling strategies over millions of years, synthetic antifouling coatings have not yet reached technological maturity. For an antifouling coating to become technically feasible, it should fulfill many requirements: high effectiveness, long-term stability, durability, ecofriendliness, large-scale applicability, and more. It is therefore not surprising that the search for the perfect antifouling coating has been going on for decades. With the discovery of metal-based antifouling paints in the 1970s, fouling was thought to be a problem of the past, yet its untargeted toxicity led to serious ecological concern, and its use became prohibited. As a response, research shifted focus toward a biocompatible alternative: polymer-based antifouling coatings. This has resulted in numerous advanced and innovative antifouling strategies, including fouling-resistant, fouling-release, and fouling-degrading coatings. Here, these novel and exciting discoveries are highlighted while simultaneously assessing their antifouling performance and practical feasibility
Layered double hydroxides in bioinspired nanotechnology
Layered Double Hydroxides (LDHs) are a relevant class of inorganic lamellar nanomaterials that have attracted significant interest in life science-related applications, due to their highly controllable synthesis and high biocompatibility. Under a general point of view, this class of materials might have played an important role for the origin of life on planet Earth, given their ability to adsorb and concentrate life-relevant molecules in sea environments. It has been speculated that the organic-mineral interactions could have permitted to organize the adsorbed molecules, leading to an increase in their local concentration and finally to the emergence of life. Inspired by nature, material scientists, engineers and chemists have started to leverage the ability of LDHs to absorb and concentrate molecules and biomolecules within life-like compartments, allowing to realize highly-efficient bioinspired platforms, usable for bioanalysis, therapeutics, sensors and bioremediation. This review aims at summarizing the latest evolution of LDHs in this research field under an unprecedented perspective, finally providing possible challenges and directions for future research
Highly ordered nanowire arrays on plastic substrates for ultrasensitive flexible chemical sensors
The development of a robust method for integrating high-performance semiconductors on flexible plastics could enable exciting avenues in fundamental research and novel applications. One area of vital relevance is chemical and biological sensing, which if implemented on biocompatible substrates, could yield breakthroughs in implantable or wearable monitoring systems. Semiconducting nanowires (and nanotubes) are particularly sensitive chemical sensors because of their high surface-to-volume ratios. Here, we present a scalable and parallel process for transferring hundreds of pre-aligned silicon nanowires onto plastic to yield highly ordered films for low-power sensor chips. The nanowires are excellent field-effect transistors, and, as sensors, exhibit parts-per-billion sensitivity to NO_2, a hazardous pollutant. We also use SiO_2 surface chemistries to construct a 'nano-electronic nose' library, which can distinguish acetone and hexane vapours via distributed responses. The excellent sensing performance coupled with bendable plastic could open up opportunities in portable, wearable or even implantable sensors
Soft Materials for Wearable/Flexible Electrochemical Energy Conversion, Storage, and Biosensor Devices
none6Next-generation wearable technology needs portable flexible energy storage, conversion, and biosensor devices that can be worn on soft and curved surfaces. The conformal integration of these devices requires the use of soft, flexible, light materials, and substrates with similar mechanical properties as well as high performances. In this review, we have collected and discussed the remarkable research contributions of recent years, focusing the attention on the development and arrangement of soft and flexible materials (electrodes, electrolytes, substrates) that allowed traditional power sources and sensors to become viable and compatible with wearable electronics, preserving or improving their conventional performances.openBocchetta, P.; Frattini, D.; Ghosh, S.; Mohan, A.M.V.; Kumar, Y.; Kwon, Y.Bocchetta, P.; Frattini, D.; Ghosh, S.; Mohan, A. M. V.; Kumar, Y.; Kwon, Y
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Label-Free Protein Analysis Using Liquid Chromatography with Gravimetric Detection.
The detection and analysis of proteins in a label-free manner under native solution conditions is an increasingly important objective in analytical bioscience platform development. Common approaches to detect native proteins in solution often require specific labels to enhance sensitivity. Dry mass sensing approaches, by contrast, using mechanical resonators, can operate in a label-free manner and offer attractive sensitivity. However, such approaches typically suffer from a lack of analyte selectivity as the interface between standard protein separation techniques and micro-resonator platforms is often constrained by qualitative mechanical sensor performance in the liquid phase. Here, we describe a strategy that overcomes this limitation by coupling liquid chromatography with a quartz crystal microbalance (QCM) platform by using a microfluidic spray dryer. We explore a strategy which allows first to separate a protein mixture in a physiological buffer solution using size exclusion chromatography, permitting specific protein fractions to be selected, desalted, and subsequently spray-dried onto the QCM for absolute mass analysis. By establishing a continuous flow interface between the chromatography column and the spray device via a flow splitter, simultaneous protein mass detection and sample fractionation is achieved, with sensitivity down to a 100 μg/mL limit of detection. This approach for quantitative label-free protein mixture analysis offers the potential for detection of protein species under physiological conditions.ERC
EPSRC
Frances and Augustus Newman Foundation
Oppenheimer Early Career Fellowship
Nanotechnologies Doctoral Training Centre
Fluidic Analytics Lt
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