Estudio y realización de un neuroprocesador biológico: métodos de aprendizaje

[SPA] La presente tesis se enmarca dentro de dos campos diferentes pero intrínsecamente unidos entre sí en este caso: neurociencia y computación. El objetivo global de esta tesis es la realización de un neuroprocesador biológico empleando como plataforma redes neuronales biológicas cultivadas sobre matrices de microelectrodos. Este objetivo global resulta en una serie de sub-objetivos: (1) Definición y construcción de una plataforma para el soporte en tiempo real de los sistemas de adquisición de registros neuronales, y estimulación eléctrica de los mismos, que se comunique remotamente con un dispositivo robótico. (2) Estudio y propuesta de un método de guiado robótico basado en una plataforma de lazo cerrado que integre la información de los sensores del robot en el neuroprocesador y, en función de la respuesta de éste, direccione el sistema robótico. (3) Normalización y calibración estadística de los registros del neuroprocesador para su adecuación a los distintos algoritmos de guiado robótico y aprendizaje en los cultivos neuronales. (4) Estudio y definición de técnicas de aprendizaje en cultivos neuronales para la realización de conectividad funcional dirigida con objeto de proporcionar nuevos paradigmas de programación en neuroprocesadores biológicos. Con respecto al sub-objetivo (1), se ha propuesto un sistema de experimentación con cultivos neuronales en lazo cerrado y tiempo real que proporciona las herramientas de filtrado, visualización, procesamiento y estimulación de la respuesta electrofisiológica de poblaciones neuronales y su comunicación con un sistema robótico remoto. Para alcanzar el objetivo (2), se ha adaptado el algoritmo de centro de área para guiado robótico a las respuestas funcionales de las poblaciones de neuronas, identificando aquellos electrodos de la matriz cuyas neuronas incrementan en mayor medida sus disparos, como objetivo para el direccionamiento del robot. El cumplimiento del sub-objetivo (3) se ha conseguido al proporcionar técnicas de calibración y normalización estadística de los registros de poblaciones de neuronas que conforman el neuroprocesador, con objeto de suprimir la variabilidad intrínseca de las mismas y a las distintas características de no-homogeneidad tanto en la densidad del cultivo como en las propiedades eléctricas de los distintos electrodos. Finalmente, atendiendo al sub-objetivo (4), se ha propuesto un paradigma de aprendizaje natural, como es el aprendizaje hebbiano, para la conformación de conexiones funcionales entre electrodos que no se encontraban enlazados previamente y conseguir de esta forma el modelado del cultivo para la implementación en su estructura de las funciones a implementar, en este caso las estructuras de Braitenberg.[ENG] This thesis deals with two different fields, inherently related to each other in this case: neuroscience and computation. The overall objective of this thesis is the development of a biological neuroprocessor with cultured biological neural networks using microelectrode arrays as platform. This objective results in a set of specific subobjectives: (1) Define and build a platform for real time support of acquisition systems and electrical stimulation systems of neural registers, which remotely communicates with a robotic device. (2) Study and propose a robotic guidance method based on a close-loop platform which includes the sensory robot information in the neuroprocessor and, according to its response, guides the robotic system. (3) Normalization and statistic calibration of the registers of the neuroprocessor in order to adapt them to different algorithms of robotic guidance and learning in cultured neural networks. (4) Study and define learning techniques in neural cultures for the development of functional connectivity which allows new programming paradigms in biological neuroprocessors. Regarding objective (1), a real-time close-loop experimentation system with neural cultures has been proposed, which provides a complete solution for filtering, visualization, processing and stimulation of electrophysiological response from neural population and communication with a robotic system. In order to reach objective (2), centre of area algorithm for robotic guidance has been adapted to the functional response of neural populations, identifying those electrodes from the array whose neurons increase the most its firing rate, as target for robotic guidance. Objective (3) has been met giving statistic calibration and normalization techniques of neural population registers that conform the neuroprocessor having in mind the goal of supressing the intrinsic variability of those populations and the different nonhomogeneity characteristics, both in culture density and electrical properties of the electrodes. Finally, regarding objective (4), a natural learning paradigm has been proposed, Hebbian learning, to conform functional connections between previously not connected electrodes. In this way, the cultures can be modelled for implementing the desired behaviour in the biological structure, in this case Braitenberg behaviour.Universidad Politécnica de Cartagen

Interaction of Electrode Materials with Neuronal and Glial Cells

Steigende Zahlen von Patienten mit neurodegenerativen Erkrankungen sind ein überzeugender Grund, das menschliche Gehirn und seinen fortschreitenden Verfall zu untersuchen, wobei aber viele essenzielle biochemische Funktionen bisher noch nicht vollends geklärt sind. In vitro Forschung zur Hirnfunktion auf geeigneten Plattformen ist ein vielversprechender Weg, diese Lücke zu schließen. Eigenschaften der brain-machine Grenzfläche müssen erforscht werden, um neue Biomaterialien effektiv für lab-on-a-chip Anwendungen wie bspw. Multielektrodenarrays (MEAs) einzusetzen. Diese brain-on-a-chip Anwendungen können dazu dienen, die Zahl der Tierexperimente zu reduzieren, damit Forschung zu beschleunigen und Kosten zu senken. In dieser Hinsicht erfordert die Miniaturisierung von MEAs für eine detailliertere Messung von neuronalen Funktionen die Entwicklung von neuen Biomaterialien mit vorteilhaften elektrischen Eigenschaften. Die Wechselwirkung dieser Biomaterialien mit Zellen muss untersucht werden, um gute Zelladhäsion, Proliferation und elektrische Kopplung zu gewährleisten. Die vorliegende Arbeit dient der Charakterisierung der Wechselwirkung von humanen neuronalen Zellen und Gliazellen (neuronenartige SH-SY5Y und gliaartige U-87 MG Zellen) mit dem Elektrodenmaterial Titannitrid mit nanokolumnarer Oberfläche (TiN nano) und dessen Vorteile bezüglich elektrischer und bioaktiver Eigenschaften im Vergleich mit Gold (Au) und Indiumzinnoxid (ITO), welche derzeit für MEAs und Neuroelektroden verwendet werden. Das Ziel der Arbeit ist die Implementierung neuer aus der theoretischen Physik, Mathematik und Computerwissenschaft entlehnten Techniken, um eine bildbasierte Methode zu entwickeln, die auf minimalen Experimenten beruht und trotzdem wichtige Hinweise zur Biokompatibiliät eines Materials liefert. Das schließt die Analyse von Zellnetzwerken, Zellverteilung, Adhäsion und elektrochemischer Eigenschaften in mono- und co-Kultur ein. Dazu werden Autokorrelation, selbstlernende Algorithmen und die Analyse nächstgelegener Nachbarn eingesetzt, um einen Weg von klassischen biochemischen Assays weg zu einem rechnerischen Ansatz zu finden. Die Ergebnisse zeigen eine Überlegenheit von Tin nano als potenzielles Biomaterial für lab-on-a-chip Anwendungen und in vivo neuraler Stimulation. Die präsentierte bildbasierte Analysemethode für die Untersuchung von Zellverteilungen erweist sich als wertvolles Werkzeug für die Bewertung von Biokompatibilität. Sie ist universell einsetzbar für verschiedene Zelltypen und quantifiziert die Wechselwirkung von Zellen mit Biomaterialien.Rising numbers of patients with neurodegenerative diseases are a compelling reason to study the human brain and its progressive deterioration but many essential biochemical functions are still under investigation. Conducting research on brain function in vitro with suitable platforms is a promising solution to close these gaps. Characteristics of the brain-machine interface need to be investigated to effectively employ new biomaterials for lab-on-a-chip devices, such as multielectrode arrays (MEAs) for example. These brain-on-a-chip devices will potentially reduce the number of conducted animal experiments and therewith accelerate future research and reduce costs. In this context, miniaturization of MEAs for more detailed measurements of neuronal function calls for new biomaterials with advantageous electrical characteristics. The interaction of these biomaterials with cells needs to be investigated to ensure good cell adhesion, proliferation, and electrical coupling. This thesis aims to study and characterize the interaction of human neuronal and glial cells (neuron-like SH-SY5Y and glia-like U-87 MG cells) with the electrode material titanium nitride with nanocolumnar surface topography (TiN nano) and its advantages in terms of electric and bioactive properties compared to gold (Au) and indium tin oxide (ITO) which are currently employed for MEAs and neuroelectrodes. The overall goal of this study is the implementation of new techniques drawn from theoretical physics, mathematics, and computer science to establish an image-based method that relies on minimal experimental effort but nevertheless yields important evidence of biocompatibility of the material. Analysis includes the investigation of cellular networks, cell distribution, adhesion, and electrochemical properties in mono- and co-culture experiments. To this end, autocorrelation function, self-learning algorithms, and nearest neighbor analysis are deployed to move away from classical biochemical assays toward a more computational approach. Results show the superiority of TiN nano as a potential biomaterial employed for lab-on-a-chip designs as well as for in vivo neural stimulation. The proposed image-based analysis method for the investigation of cellular distribution turns out to be a valuable tool for the assessment of biocompatibility. It is universally applicable to cell types other than neuronal and quantifies the interaction of cells with biomaterials

Investigating computational properties of a neurorobotic closed loop system

This work arises as an attempt to increase and deepen the knowledge of the encoding method of the information by the nervous system. In particular, this study focuses on computational properties of neuronal cultures grown in vitro. Through a neuro-robotic close-loop system composed of either cortical or hippocampal cultures (plated on micro-electrode arrays) on one side and of a robot controlled by the cultures on the other side, it has been possible to analyze experimental dataopenEmbargo per motivi di segretezza e/o di proprietà dei risultati e/o informazioni sensibil

Patterned Cell Cultures For High Throughput Studies Of Cell Electrophysiology And Drug Screening Applications

Over the last decade, the field of tissue and bio-engineering has seen an increase in the development of in vitro high-throughput hybrid systems that can be used to understand cell function and behavior at the cellular and tissue levels. These tools would have a wide array of applications including for implants, drug discovery, and toxicology, as well as for studying cell developmental behavior and as disease models. Currently, there are a limited number of efficient, functional drug screening assays in the pharmacology industry and studies of cell-surface interactions are complicated and invasive. Most cell physiology studies are performed using conventional patch-clamp techniques or random networks cultured on silicon devices such as Microelectrode Arrays (MEAs) and Field Effect transistors (FETs). The objective of this study was to develop high-throughput in vitro platforms that could be used to analyze cell function and their response to various stimuli. Our hypothesis was that by utilizing surface modification to provide external guidance cues for various cell types and by controlling the cell environment in terms of culture conditions, we could develop an in vitro hybrid platform for sensing and testing applications. Such a system would not only give information regarding the surface effects on the growth and behavior of cells for implant development applications, but also allow for the study of vital cell physiology parameters like conduction velocity in cardiomyocytes and synaptic plasticity in neuronal networks. This study outlines the development of these in vitro high throughput systems that have varied applications ranging from tissue engineering to drug development. We have developed a simple and relatively high-throughput method in order to test the physiological effects of varying iii chemical environments on rat embryonic cardiac myocytes in order to model the degradation effects of polymer scaffolds. Our results, using our simple test system, are in agreement with earlier observations that utilized a complex 3D biodegradable scaffold. Thus, surface functionalization with self-assembled monolayers combined with histological/physiological testing could be a relatively high throughput method for biocompatibility studies and for the optimization of the material/tissue interface in tissue engineering. Traditional multielectrode extracellular recording methods were combined with surface patterning of cardiac myocyte monolayers to enhance the information content of the method; for example, to enable the measurement of conduction velocity, refractory period after action potentials or to create a functional reentry model. Two drugs, 1-Heptanol, a gap junction blocker, and Sparfloxacin, a fluoroquinone antibiotic, were tested in this system. 1-Heptanol administration resulted in a marked reduction in conduction velocity, whereas Sparfloxacin caused rapid, irregular and unsynchronized activity, indicating fibrillation. As shown in these experiments, the patterning of cardiac myocyte monolayers increased the information content of traditional multielectrode measurements. Patterning techniques with self-assembled monolayers on microelectrode arrays were also used to study the physiological properties of hippocampal networks with functional unidirectional connectivity, developed to study the mono-synaptic connections found in the dentate gyrus. Results indicate that changes in synaptic connectivity and strength were chemically induced in these patterned hippocampal networks. This method is currently being used for studying long term potentiation at the cellular level. For this purpose, two cell patterns were optimized for cell migration onto the pattern as demonstrated by time lapse studies, and for iv supporting the best pattern formation and cell survival on these networks. The networks formed mature interconnected spiking neurons. In conclusion, this study demonstrates the development and testing of in vitro highthroughput systems that have applications in drug development, understanding disease models and tissue engineering. It can be further developed for use with human cells to have a more predictive value than existing complex, expensive and time consuming methods

Single Layer Graphene Biointerface: Studying Neuronal Network Development and Monitoring Cell Behavior over Time

The objective of my Ph.D. thesis is the investigation of the role of Single Layer Graphene (SLG) as a biointerface for its possible future exploitation in various biomedical applications; in particular for the development of biosensors, substrates for regenerative medicine, interfacing platforms for better recording of electrophysiological activity of neuronal networks, among others. This Ph.D. project is multidisciplinary involving both the material transfer and characterization part from one side and the biological part from another side. The material part offers an in-depth explanation of SLG synthesis, transfer, characterization and functionalization while the biological section sheds light on the studies performed for investigation of the behavior of different types of cell lines on SLG substrates. For better understanding of the sequence of the performed work, I have divided this thesis into separate chapters. In the beginning and end of every chapter, I added an introduction and conclusions related to it. Chapter 1 acts as a general introduction to graphene and graphene-related materials where a detailed explanation on the evolution of those materials as a cell interface is provided leading to the introduction of SLG in the end of this chapter along with its production process. Chapter 2 is oriented on the surface characterization of SLG substrates; in this chapter, I described the SLG transfer method, creation of the micrometric ablated geometric patterns on the transferred substrates using excimer laser micromachining, a technique developed in our lab, then further functionalization of the substrates and finally all the techniques employed for their physicochemical characterization. Chapter 3 is dedicated to the biological part of the project; i.e. studying the behavior of different cell lines on the SLG substrates. In this chapter, I have described and explained the interest of using the selected cell lines and the experiments that were performed on them. Chapter 4 has been devoted to a complete and separate project that I performed in collaboration with the Neuroscience and Brain Technologies department. The main focus of the project was the functionalization of the commercial multi-electrode arrays (MEAs) with SLG and studying the neuronal network activity on them throughout the complete network development. Although the main focus of my Ph.D. project was studying SLG biointerface, I have also been involved in side projects, among which, studying the neuronal-like response of mouse neuroblastoma (N2a) living cells to nanoporous patterns of thin supported anodic alumina which I have described in Appendix A, and studying the surface potential of graphene by polyelectrolyte coating which I have presented in Appendix B. To summarize, this thesis reports an original investigation, since, to the best of our knowledge, there is no report yet about the study of the effect of SLG functionalized MEA on the neuronal network activity throughout the complete network maturation. Furthermore, proliferation curves of different cell lines on SLG versus control substrates have been presented; in addition to physicochemical characterization of ablated and functionalized SLG substrates as means of possible explanation of a certain cellular behavior on graphene

Effect-based in vitro bioassays for lipophilic marine biotoxins : a new strategy to replace the mouse bioassay

Marine biotoxins in fish and shellfish can cause a number of adverse health effects in consumers, such as diarrhoea, amnesia, and death by paralysis. Worldwide, there are monitoring programs for testing shellfish on a regular basis. In some countries, testing is performed by using the so-called mouse bioassay (MBA), an assay raising both ethical and practical concerns because of animal distress and shortcomings in respect to specificity. The MBA may result in both false negatives and false positives. A false negative does not protect the consumers as anticipated and the high amounts of false positives encountered when applying the MBA lead to unnecessary closures of extraction areas, damaging local economies. A full ban of the MBA or its total replacement by analytical chemical methods has failed because these detection methods are unable to detect all toxin analogues and newly emerging toxins and will thus result in false negatives by definition. To fully replace the MBA, there is a clear need for new functional animal-free in vitro assays with specific endpoints that are able to detect both the known and yet unknown marine biotoxins. In Europe a method based on LC-MS/MS has been developed as an alternative for the MBA and is now the reference method for lipophilic marine biotoxins (LMBs) and used in the routine monitoring. However, as outlined above safety is not fully guaranteed when relying only on such a method and, as a result, the MBA is still used for surveillance purposes. The aim of the work presented in this thesis was to develop a new strategy to fully replace the MBA for detecting LMBs without the risk of missing a contaminated sample that can lead to an intoxication. This was achieved by combining effect-based bioassays and a mass spectrometry analysis, including the official EU-RL method. Chapter 1 addresses the safety issues of the marine biotoxins produced by algae, corals and bacteria and summarises the current legislations and recommendations and the methods of detection. In Chapter 2, the neuro-2a bioassay, a cell-based in vitro bioassay that was previously shown to be sensitive for several hydrophilic and lipophilic marine biotoxins, was studied for its ability to screen seafood products for the presence of lipophilic marine biotoxins. All (regulated) LMBs and their analogues were tested, and the neuro-2a bioassay outcomes showed that all these LMBs could be detected at low concentrations. Next, blank and contaminated sample extracts were prepared and tested, showing that matrix effects led to false positive screening outcomes. Therefore, the standard extraction procedure for LMBs with methanol was modified by introducing a clean-up step with n-hexane before further extraction on the SPE-column. First, the possible recovery losses due to this extra n-hexane wash step were assessed, showing that the n-hexane did not lead to recovery losses of the LMBs and that the matrix effect was successfully removed. Finally, the applicability of the neuro-2a bioassay was assessed by testing a broad range of shellfish samples contaminated with various LMBs, including diarrhoeic shellfish poisoning (DSP) toxins. The samples were also analysed by LC-MS/MS. Overall, the neuro-2a bioassay showed screening outcomes that were well in line with the toxin levels as determined by the EU-RL LC-MS/MS reference method. In chapter 3, a study with DNA microarrays was performed to explore the effects of two diarrhoeic and one azaspiracid shellfish toxin, okadaic acid (OA), dinophysistoxin-1 (DTX-1) and azaspiracid-1 (AZA-1) respectively, on the whole genome mRNA expression of undifferentiated intestinal Caco-2 cells. In this chapter the whole genome mRNA expression was analysed in order to reveal the possible modes of action of these toxins and to select genes that can be used as potential markers in new additional bioassays for the detection and identification of these LMBs. It was observed that OA and DTX-1 induced almost identical effects on mRNA expression, which strongly indicates that OA and DTX-1 induce similar toxic effects. Biological interpretation of the microarray data showed that both compounds induced endoplasmic reticulum (ER) stress, hypoxia, and unfolded protein response (UPR). The gene expression profile of AZA-1 resulted in a different expression profile and showed increased mRNA expression of genes involved in cholesterol synthesis and glycolysis, suggesting a different mode of action for this toxin. In chapter 4, twelve marker genes were selected from the previous study and five were used to develop a multiplex qRT-PCR method. This multiplex qRT-PCR method is able to detect three toxin profiles, i.e. a OA/DTX, AZA/YTX and PTX profile. The multiplex capacity of this qRT-PCR is limited to five genes. The use of a multiplex magnetic bead-based assay was explored, allowing the use of all twelve selected marker genes and two reference genes. This 14-plex also resulted in clear profiles with sometimes higher induction factors as obtained by the 5-plex qRT-PCR method. As a result, contaminated samples could easily be distinguished from the blank samples, showing the expected profiles. These multiplex assays can thus detect these LMBs in shellfish samples and the obtained profile indicates the toxin-type present. However, compared with the neuro-2a bioassay, this assay has been shown adequate so far for only a limited number of LMBs (not all LMBs have been tested), and it is more laborious, time consuming and expensive. It should be used in cases were suspect screening outcomes from the neuro-2a bioassay cannot be explained by the toxin levels as measured with the EU-RL LC-MS/MS reference method. In chapter 5, the neuro-2a bioassay as an initial screening assay was combined with the EU-RL LC-MS/MS method for confirmation and it was investigated whether this combination is able to replace the MBA for the detection and quantification of LMBs. Samples that were tested previously in the MBA (in Chile) were used. It turned out that all samples that tested positive in the MBA were also suspect in the neuro-2a bioassay and most of these samples were confirmed to be positive for the presence of LMBs by LC-MS/MS analysis. The results confirm that the combination of the neuro-2a bioassay for screening and the EU-RL LC-MS/MS method for confirmation, is a promising alternative for the unethical MBA. The data even strongly indicated that the MBA alone probably led to false positives and the unnecessary closure of extraction areas or withdrawal of products from the market, a problem not encountered when using the neuro-2a assay in combination with LC-MS/MS. In chapter 6, a fully integrated testing strategy was presented for replacing the MBA, enabling the detection of the hydrophilic marine biotoxins. The steps and methods are discussed, and some points of attention and further developments required are addressed. Taking all together it is concluded that the proposed strategy contributes to a future with a complete animal free alterative testing strategy replacing the MBA.</p

Pesticide residue screening using a novel artificial neural network combined with a bioelectric cellular biosensor

We developed a novel artificial neural network (ANN) system able to detect and classify pesticide residues. The novel ANN is coupled, in a customized way, to a cellular biosensor operation based on the bioelectric recognition assay (BERA) and able to simultaneously assay eight samples in three minutes. The novel system was developed using the data (time series) of the electrophysiological responses of three different cultured cell lines against three different pesticide groups (carbamates, pyrethroids, and organophosphates). Using the novel system, we were able to classify correctly the presence of the investigated pesticide groups with an overall success rate of 83.6%. Considering that only 70,000-80,000 samples are annually tested in Europe with current conventional technologies (an extremely minor fraction of the actual screening needs), the system reported in the present study could contribute to a screening system milestone for the future landscape in food safety control

Nanotopographic device for neural subtypes segregation

Tese de mestrado integrado em Engenharia Biomédica e Biofísica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014A usabilidade de próteses avançadas pode ser melhorada através do aumento do controlo motor sobre a prótese e da resposta sensitiva do paciente. Como a topografia da superfície desempenha um papel importante, ao nível da nanoescala, no crescimento e condução dos axónios, o dispositivo nanotopográfico foi construído com o objetivo de estudar a resposta axonal de neurónios periféricos a diferentes tamanhos de nanogradeamentos. O design inovador deste dispositivo incorpora: (1) câmaras microfluídicas para isolamento axonal; (2) canais fisicamente modificados com vários relevos nos nanogradeamentos; e (3) uma abordagem de bifurcação baseada na nanotopografia. A linha celular F11 (neurónios sensitivos nociceptivos) foi escolhida como modelo para analisar a resposta celular no dispositivo nanotopográfico. Materiais e técnicas otimizadas foram usados para assegurar a qualidade do dispositivo: os canais foram moldados em PDMS e os nanogradeamentos impressos na superfície de COC. Em paralelo, colorações e ensaios bioquímicos foram realizados para avaliar as condições ótimas de cultura das F11, nomeadamente os ensaios de ADN, ATP, e LIVE/DEAD. As potenciais aplicações deste dispositivo nanotopográfico foram apresentadas. A Neurofluídica é um campo em recente desenvolvimento que visa construir dispositivos microfluídicos para a investigação neurobiológica. O dispositivo nanotopográfico tem potencial para ser útil nesta área emergente, fornecendo informação acerca das preferências topográficas de cada tipo de célula. Com base nisto, poderia ser possível obter-se a segregação física de subtipos de neurónios. Em resposta às altas e crescentes taxas de amputações, estes avanços poderiam ser úteis no desenvolvimento de interfaces neuro-protéticas altamente sofisticadas.The usability of advanced prostheses can be improved by increasing the degree of motor control over the prosthesis and sensitive feedback to the patient. As nanoscale surface topographies play an important role in axonal outgrowth and guidance, a nanotopographic device was constructed for studying the axonal response of peripheral neurons to different nanograting sizes. This innovative device design incorporates: (1) microfluidic chambers for axonal isolation; (2) physically modified channels with several nanograting ridges; and (3) a bifurcating nanotopography-based approach. The F11 cell line (nociceptive sensory neurons) was chosen as model to analyse cell response in the nanotopographic device. Optimal materials and techniques were used to assure the quality of the device: Channels were molded on PDMS and nanogratings were printed on the COC surface. In parallel, staining and biochemical assays were performed to evaluate the optimal F11 culture conditions, such as DNA, ATP, and LIVE/DEAD assays. Existing and potential applications of the nanotopographic device were presented. Neurofluidics is an early stage field which develops microfluidic devices for neurobiological research. The nanotopographic device has the potential to be useful in this emerging area by providing insight into topographical preference for each cell type. Based on that, physical segregation of neuron subtypes might be achieved. In response to high and rising amputation rates, these achievements could be useful in the development of highly sophisticated neural-prosthetic interfaces

Improved Analytical Technologies for the Detection of Natural Toxins and Their Metabolites in Food

Food, by nature, is a biological substrate and is therefore capable of supporting the growth of microbials that are potential producers of toxic compounds. Among them mycotoxins, marine biotoxins, plant toxins, cyanogenic glycosides, and toxins occurring in poisonous mushrooms pose not only a risk to both human and animal health but also impact food security and nutrition by reducing people’s access to healthy food. This book collects some of the recent key improvements of analytical methodologies for the detection of natural toxins and their metabolites in food, and highlights the challenges yet to be resolved. Special emphasis is given to emerging or less-investigated toxins, to provide the scientific community with new tools and/or data supporting a better understanding of related food safety issues