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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Development of stat-3 targeting siRNA nano-carriers for cancer therapy

Alshamsan, Aws 11 1900 (has links)
In many tumors, persistently-active signal transducer and activator of transcription 3 (STAT3) imparts several oncogenic features such as survival, proliferation, angiogenesis, and immune escape. Therefore, STAT3 targeting in cancer and cancer-exposed dendritic cells (DCs) is important for cancer therapy. Our objective is developing delivery modalities of STAT3-targeting small interfering RNA (siRNA) using lipid-modified polyethylenimine (PEI) polyplexes and poly(D,L lactic-co-glycolic) acid (PLGA) nanoparticles (NPs), and evaluating the therapeutic outcomes in vitro and in vivo. Significant increase in siRNA condensation, protection, and cellular uptake by B16.F10 melanoma was seen by stearic-acid-modified PEI (PEI-StA) compared to unmodified PEI. Moreover, PEI-StA increased the STAT3 silencing potency of siRNA compared to PEI. STAT3 knockdown was accompanied with significant induction of interleukin-6 (IL-6) secretion and reduction of vascular endothelial growth factor (VEGF) production and cytotoxicity evidenced by increased Caspase 3 activity in vitro and in vivo, and significant inhibition in tumor growth. Analysis of tumor microenvironment showed CD3+ cells infiltration corresponding to STAT3 knockdown. The levels of CD4+ helper cells, CD8+ cytotoxic cells, and NKT cells significantly increased. DC infiltration and activation significantly increased in tumor mass following STAT3 knockdown as evidenced by high expression of CD86 and CD40. Moreover, IFN-, IL-12, and TNF- significantly increased following STAT3 knockdown by PEI-StA compared to PEI, suggesting Th1-type immunity. Allogenic capacity of DCs isolated from siRNA-treated mice was evidenced by the high T cell proliferation and IL-2 production in mixed lymphocytes reaction (MLR). Then, we explored STAT3 knockdown in DCs exposed to tumor derived factors (TDFs). We investigated encapsulation of siRNA complexes (PEI or PEI-StA) into PLGA NPs (PLGA-P and PLGA-PS). PLGA-P and PLGA-PS had an average diameter of ~ 370 nm and zeta potential of ~ -16 mV. Uptake and endosomal localization was confirmed. After TDFs exposure, DCs showed high STAT3 and low CD86 expression. STAT3 silencing by PLGA-P and PLGA-PS restored DC functionality as evidenced by upregulation of CD86, IL-12, and TNF- and MLR activity. PLGA significantly reduced PEI-associated toxicity. Therefore, STAT3 targeting in B16 cells by siRNA polyplexes of PEI and PEI-StA, or in DCs by PLGA-P and PLGA-PS provide potential strategies for cancer therapy. / Pharmaceutical Sciences
32

Effects of nano-second pulsed electric fields (nsPEF) on human prostate cancer cell line - LNCaP

Donthula, Vinitha. Islam, Naz E. January 2008 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on September 22, 2009). Thesis advisor: Dr. Naz E. Islam. Includes bibliographical references.
33

Etude toxicogénomique de nanovecteurs de silice mésoporeuse : relation entre décoration et toxicité / Toxicogenomic study of mesoporous silica nanocarriers : relationship between surface decoration and toxicity

Pisani, Cédric 20 September 2017 (has links)
Les nanoparticules (NPs) concentrent beaucoup d’espoir en nanomédecine, en particulier les nanoparticules magnétiques de silice mésoporeuse (M-MSN) qui pourraient permettre des avancées en théranostic. Néanmoins l’innocuité de ces NPs recouvertes de décorations leur conférant des propriétés spécifiques, doit être démontrée afin d’éviter des effets néfastes sur les tissus sains, notamment sur le foie, l’organe de transformation des xénobiotiques. L’objectif de cette thèse était donc d’évaluer la toxicité potentielle de M-MSN soit natives, soit recouvertes de polyéthylène glycol (PEG), soit entourées d’une bicouche lipidique de 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC). Pour ce faire un modèle de cellules humaines hépatiques (HepaRG) a été choisi pour effectuer des tests de toxicité in vitro et pour élucider le mode d’action intracellulaire de ces différentes NPs.Les caractéristiques physico-chimiques des M-MSNs natives et décorées ont été mesurées par différentes techniques comme la diffusion dynamique de la lumière (DLS), la microscopie électronique à transmission (TEM) et la microscopie à force atomique (AFM). La toxicité des NPs a été évaluée tout d’abord par des tests de viabilité et par impédance cellulaire en temps réel (xCELLigence).L’étude des profils d’expression génique sur des oligo microarrays à très haute densité (8x60k sondes, Agilent) a ensuite permis d’évaluer, de façon dose- et temps-dépendante, la toxicité de ces NPs. De plus l’utilisation d’une méthodologie originale d’analyse comparative de données massives nous a permis de mettre en évidence les mécanismes moléculaires déclenchés par les NPs dans les hépatocytes. Nous avons déterminé des doses n’induisant aucune toxicité ou une légère toxicité transitoire après 24h, soit une valeur seuil de biocompatibilité avec les cellules HepaRG. Nous avons également montré par TEM le ralentissement de l’internalisation des NPs lorsqu’elles sont PEGylées ainsi que leurs effets transcriptomiques différés par rapport aux NPs natives et lipidiques. Néanmoins, une dose de 80 µg/cm² de M-MSNs, natives ou décorées, déclenche l’enchaînement des évènements de l’AOP (Adverse Outcome Pathway) de la cholestase hépatique. Ce résultat démontre que cette méthodologie est adaptée à la toxicologie prédictive par analyse des réponses biologiques cellulaires après exposition à des substances exogènes.Par ailleurs, les NPs ont tendance à se recouvrir de protéines (corona) en présence de sérum humain. L’analyse par impédance cellulaire montre que des M-MSNs entourées d’une corona de protéines sériques humaines ou bovines ne provoquent pas la même toxicité sur des cellules humaines. Ce résultat pose la problématique d'une potentielle surestimation de la toxicité des nanoparticules lors d’essais in vitro, utilisant classiquement du sérum de veau dans les milieux de cultures.Nous avons entrepris l’étude de la dynamique de la corona (entre 30s et 7 jours) par spectrométrie de masse en tandem. Cette analyse a mis en lumière trois types de comportements protéiques. Le premier cluster contient des protéines abondantes qui se désorbent au cours du temps, le second cluster est composé de protéines qui s’enrichissent progressivement et issues de mêmes familles protéiques comme les apolipoprotéines, et le troisième cluster contient des protéines à enrichissement tardif dans la corona, attirées par leur affinité pour des protéines déjà présentes. Un réseau dynamique d’interactions protéines-protéines, ou intéractome, a pu être cartographié au sein de la corona. Ces travaux posent les bases d’un possible contrôle des protéines de la corona afin de conférer aux nanovecteurs des propriétés de furtivité leur permettant d’atteindre des organes cibles sans être opsonisés. Les techniques utilisées au cours de ce travail, basées sur les analyses de quantités massives de données biologiques, pourraient faire partie de futurs standards d’évaluation de la nanosécurité. / Nanoparticles (NPs) capable of transporting and releasing therapeutic agents to target tissues constitute one of the most exciting areas in nanomedicine, especially magnetic mesoporous silica nanoparticles (M-MSN). M-MSNs may be addressed to tumors thanks to their magnetism and can act as drug carriers thanks to their high specific surface area. Nevertheless, the safety of these NPs with decorations, conferring them specific properties, must be assessed in order to avoid harmful effects on healthy tissues, in particular on the liver, the organ of xenobiotics metabolism.The goal of this thesis was therefore to evaluate the potential toxicity of M-MSN either pristine, or coated with polyethylene glycol (PEG), or surrounded by a lipid bilayer of 1,2-dimyristoyl-sn-glycero-3- Phosphocholine (DMPC). To this end, the human hepatic cell model HepaRG was chosen to realize in vitro toxicity testing and to elucidate the intracellular mode of action of these various NPs.The physico-chemical properties of pristine and covered M-MSNs were measured using different techniques such as dynamic light scattering (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). NPs toxicity was first evaluated by viability testing and real-time cell impedance analysis (xCELLigence).Gene expression profiles were then performed through very high density oligo microarrays (8x60k, Agilent) to evaluate, in a dose- and time-dependent manner, the toxicity of these NPs. In addition, the use of an original methodology for comparative analysis of large biological data allowed us to demonstrate the molecular mechanisms triggered by the NPs in the hepatocytes. We were able to determine the dose not triggering any toxicity as well as the dose inducing a slight transient toxicity after 24h. We thus defined this latter value as a threshold of biocompatibility with HepaRG cells. We also showed by TEM a slower uptake of PEGylated NPs by cells as well as their delayed effects on the transcriptome compared to the pristine and DMPC NPs. Nevertheless, a dose of 80 μg/cm² of pristine or covered M-MSNs triggers the chain of events of the hepatic cholestasis AOP (Adverse Outcome Pathway). This result demonstrates that this methodology is suitable for predictive toxicology by analysis of cellular biological responses after exposure to exogenous substances.Furthermore, NPs tend to be covered with proteins in the presence of serum (corona). Cell impedance analysis shows that M-MSNs surrounded by human or bovine serum proteins coronas do not trigger the same toxicity on human cells. This result raises the problem of a potential overestimation of NPs toxicity to human cells in in vitro testing by using fetal bovine serum in culture media.We undertook a dynamic analysis (between 30 s and 7 days) of the corona formation by tandem mass spectrometry has highlighted three groups of protein with distinct behaviors. The first cluster contains some abundant proteins that desorb over time, the second cluster comprises some protein families such as apolipoproteins, and the third cluster contains late enrichment proteins attracted by other proteins already present in the corona. A dynamic network of protein-protein interactions inside the corona, namely the interactome, was built from the data. This work opens the way to a possible control of the corona in order to provide the nanocarriers with stealth properties allowing them to reach target organs without being opsonized.These techniques used during this thesis and based on analyses of biological big data might be part of the future standards on nanosafety evaluation.
34

The Micellization of Tetrabenazine as a Nanomedicine for Huntington's Disease

Severt, Kailee 01 January 2018 (has links)
Nanomedicine is the fusion between drug therapy and nanotechnology. It is an expanding industry which provides a more efficient and effective way to deliver drugs throughout the body. For individuals suffering from a neurodegenerative disorder, like Huntington’s Disease (HD), current treatments cause major side effects in addition to the disease’s detrimental motor, behavioral and psychiatric symptoms. The goal of the experiment is to encapsulate tetrabenazine, the only FDA approved drug for HD, in a nanoparticle called a micelle. If successful, the new drug nanoparticle can undergo animal testing then clinical trials in hopes of improving patients’ lives.
35

Development of a receptor targeted nanotherapy using a proapoptotic peptide

Sibuyi, Nicole Remaliah Samantha January 2015 (has links)
Philosophiae Doctor - PhD / The prevalence of obesity amongst South Africans is alarming, with more than 29% of men and 56% of women considered to be obese. Angiogenesis, a process for development of new blood vessels play a major role in growth and survival of the adipose tissues. Pharmacological inhibitors of angiogenesis are therefore a sensible strategy to reduce excess body weight. Current anti-obesity drugs have limitations because of their lack of selectivity and specificity, which lead to undesirable side effects and reduced drug efficacy. Future anti-obesity therapeutic strategies should be target-specific, with minimal toxicity towards healthy tissues will be more appropriate for obesity treatment. Targeted nano-therapeutic agents are currently being developed to overcome the drawbacks associated with conventional drug therapies. The nano-based delivery vehicles that specifically target diseased cells are appealing as they could reduce drug toxicity towards healthy tissues and be more effective at lower dosages. The main aim of this study was to develop a receptor-mediated nanotherapy that specifically targets the white adipose tissue vasculature and trigger the death of these cells through apoptosis. The 14 nm gold nanoparticles (AuNPs) were synthesized using theTurkevich method following reduction of gold aurate by sodium citrate salt. Different chemistries were used to functionalise the AuNPs for biological application by conjugating with either vascular targeting peptide or pro-apoptotic peptide on their surface or both. The nanomaterials were characterised by UV-Vis, Zeta potential and transmission electron microscopy (TEM). The sensitivity and specificity of various AuNP conjugates were tested in vitro on colon and breast cancer cell lines. A human (Caco-2) cell line that expresses the receptor for the adipose homing peptide was chosen as an in vitro model system. Cellular toxicity and uptake of the nanoparticles was evaluated using the WST-1 assay, Inductively Coupled Plasma-Optical Emission Spectra (ICP-OES) and TEM. The induction of apoptosis following exposure to the nanoparticles was examined by Western blot and flow cytometric analysis. The anti-proliferative activity of the targeted therapeutic nanoparticles on the cells was more pronounced on the cells expressing the receptor for the adipose homing peptide. The uptake of unfunctionalised AuNPs was higher compared to functionalised nanoparticles, but this did not impair cell viability. The activity of the therapeutic peptide was retained and enhanced following conjugation to AuNPs as shown by Western blot and flow cytometric analysis. The nanotherapy under study demonstrated receptor mediated targeting, and enhanced activity on the cells expressing the receptor. However, the therapeutic and efficacy of the targeted nanotherapy still need to be tested in animal models of obesity to confirm the treatment specificity.
36

A Nano-Sized Approach to Exploiting the Pancreatic Tumor Microenvironment

Confeld, Matthew Ian January 2020 (has links)
Making up just over 3% of all new cancer cases in the United States, pancreatic cancer is not inherently a common malignant disease. Yet, it continuously is shown to be one of the most lethal and common causes of cancer death. Early detection is critical among all cancer types. However, oncologists and researchers have struggled to find effective strategies or tests to detect cancer of the pancreas early on in development. Thus, the cancer is often found late stage and requires significant chemotherapy intervention. These multi-drug treatment cocktails have shown benefit, but only in added months and not years to a patient’s life. Significant adverse effects often limit the full effective doses of treatment. In order to limit these adverse effects, as well as increase the effectiveness of treatment, we have designed, optimized, and tested unique drug carriers known as polymersomes. Using characteristics of the localized environment surrounding pancreatic tumors and the cells found therein, we created targeted therapies that are responsive and relatively selective toward cancerous cells. Herein, are found two distinct polymersomes. The first, is a low oxygen reactive drug carrier with an additional small peptide molecule that is able to penetrate dense tumor tissue and has shown decreased tumor growth of as much as 260% as compared to control samples in an animal model of pancreatic cancer. The chemical make-up of this polymersome allows for extended circulation time and a high accumulation at the tumor site. A second design, uses an intracellular enzyme to destabilize the polymersomes’ structure, which in turn, releases a selected chemotherapy drug near its intended site of action. This strategy, has shown a 10 fold increase in potency of the chemotherapy drug, as compared to when the drug is given alone and showed decreased toxicity to non-cancerous cells. It is certain that thoughtful drug delivery strategies and not just drug molecule design will be instrumental in the paradigm shift of pancreatic cancer from likely death to survival. / NIH grant 1 R01GM 114080; Grand Challenge Initiative; Office of the Dean, College of Health Professions
37

CONFORMATIONALLY SWITCHABLE POLYGLUTAMATES AS A PROSPECTIVE MATERIAL FOR POLYMER THERAPEUTICS DESIGN

Zagorodko, Oleksandr 12 June 2020 (has links)
[ES] Los tratamientos en los que se utilizan Polímeros Terapéuticos ofrecen numerosas ventajas en comparación con los tratamientos convencionales y otros enfoques de nanomedicina. Entre estas ventajas se puede destacar la especificidad para cruzar ciertas barreras biológicas y su capacidad de acumulación pasiva en tumores. Además, la conjugación de fármacos a polímeros ofrece ventajas adicionales tales como una farmacocinética mejorada, multivalencia, co-entrega de fármacos en la proporción deseada y liberación/activación específica en el sitio de acción requerido a través de la aplicación de enlaces polímero-fármaco que responden a estímulos fisiológicos. Uno de los tipos más importantes de polímeros que se utiliza para la administración de fármacos pertenecen a los polielectrolitos polipeptídicos. Su uso se debe principalmente, a su biocompatibilidad, biodegradabilidad, multivalencia y versatilidad estructural, así como a la plasticidad sintética en la modificación de cadenas laterales. La aplicación conjunta de ciencia de polielectrolitos con otras ramas de la química es muy prometedora; sin embargo, aún permanece en un estadío temparano en su desarrollo. Esto es debido a que, el control del autoensamblaje de polielectrolitos sigue siendo una tarea complicada y la investigación en esta área puede resultar muy laboriosa a la hora de encontrar sistemas biocompatibles más avanzados con un único perfil de acción y por supuesto, se abre un nuevo campo de estudio sobre las nuevas propiedades desconocidas de estos. Este tema es novedoso por la posibilidad de realizar diferentes estudios de combinación de polielectrolitos con residuos supramoleculares y representa el estudio de nuevas arquitecturas potencialmente mas complicadas. En la presente tesis doctoral se estudiarán el desarrollo de sistemas de administración de fármacos basados en polielectrolitos supramoleculares con un alto grado de control sobre las propiedades fisicoquímicas, centrándose principalmente en el control de la forma y el tamaño. Se han estudiado en profundidad varias familias de poliglutamatos de forma estrella con núcleos de diferente hidrofobicidad para determinar cómo la estructura del núcleo y la longitud de la cadena de polielectrolitos afectan el mecanismo de autoensamblaje. Una vez que se definieron estas correlaciones, se seleccionaron los candidatos más prometedores para la preparación de dos sistemas de transportede fármacos que consisten en partículas esféricas o en forma de cilindro. Finalmente, también se realizó la conjugación de varios fármacos (fasudil y dinaciclib) como agentes únicos o en combinación a través de diferentes enlaces biodegradables. Las propiedades fisicoquímicas y la actividad in vitro de los conjugados se estudiaron en profundidad y actualmente se están llevando a cabo experimentos in vivo en un modelo de cáncer de mama metastásico triple negativo ortotópico preclínicamente relevante, con los conjugados previamente seleccionados. / [CAT] Els tractaments en els quals s'utilitzen Polímers Terapèutics ofereixen nombrosos avantatges en comparació amb els tractaments convencionals i altres enfocaments amb nanomedicina. Entre aquests avantatges es pot destacar l'especificitat per creuar certes barreres biològiques i la seva capacitat d'acumulació passiva en tumors. A més, la conjugació de fàrmacs a polímers ofereix avantatges addicionals com ara una farmacocinètica millorada, multivalència, co-lliurament de fàrmacs en la proporció desitjada i alliberament / activació específica en el lloc d'acció requerit a través de l'aplicació d'enllaços polímer-fàrmac que responen a estímuls fisiològics. Un dels tipus més importants de polímers que s'utilitza per a l'administració de fàrmacs pertanyen als polielectròlits polipeptídics. El seu ús es deu principalment, ala seua biocompatibilitat, biodegradabilitat, multivalència i versatilitat estructural, així com a la plasticitat sintètica en la modificació de cadenes laterals. L'aplicació conjunta de ciència de polielectròlits amb altres branques de la química és molt prometedora; però, encara roman en un estadi primerenc en el seu desenvolupament. Això és degut al fet que, el control de l'autoensamblatge de polielectròlits segueix sent una tasca complicada i la investigació en aquesta àrea pot resultar molt laboriosa a l'hora de trobar sistemes biocompatibles més avançats amb un únic perfil d'acció i per descomptat, s'obre un nou camp d'estudi sobre les noves propietats desconegudes d'aquests. Aquest tema és nou j que ofereix la possibilitat de realitzar diferents estudis de combinació de polielectròlits amb residus supramoleculars i representa l'estudi de noves arquitectures potencialment més complicades. En la present tesi doctoral s'estudiaran el desenvolupament de sistemes d'administració de fàrmacs basats en polielectròlits supramoleculars amb un alt grau de control sobre les propietats fisicoquímiques, centrant-se principalment en el control de la forma i la mida. S'han estudiat en profunditat diverses famílies de poliglutamatos de forma estrella amb nuclis de diferent hidrofobicitat per determinar com l'estructura delnucli i la longitud de la cadena de polielectròlits afecten el mecanisme de autoensamblatge. Una vegada que es van definir aquestes correlacions, es van seleccionar els candidats més prometedors per a la preparació de dos sistemes de transport de fàrmacs que consisteixen en partícules esfèriques o en forma de cilindre. Finalment, també es va realitzar la conjugació de diversos fàrmacs (fasudil i dinaciclib) com a agents únics o en combinació a través de diferents enllaços biodegradables. Les propietats fisicoquímiques i l'activitat in vitro dels conjugats es van estudiar en profunditat i actualment s'estan duent a terme experiments in vivo en un model ortotòpic de càncer de mama metastàtic triple negatiu preclínicament rellevant, amb els conjugats prèviament seleccionats. / [EN] Treatments based on polymer therapeutics offer numerous advantages when compared to conventional treatments and other nanomedicine approaches. These include passive tumor accumulation and the ability to cross specific biological barriers. Furthermore, polymer conjugation of drugs offers additional advantages such as improved pharmacokinetics, multivalency, co-delivery of drugs at the desired ratio, and specific release/activation at the required site of action via the application of polymer-drug linkers that respond to physiological stimuli. One of the most important types of polymers suitable for drug delivery belong to polypeptide polyelectrolytes, mainly due to their biocompatibility and synthetic plasticity of side chain modification. The merging of polyelectrolyte science with other branches of chemistry seems very promising; however, it still remains in an embryonic state. While the control of polyelectrolyte self-assembly remains a complicated task, research in this area may provide more advanced biocompatible systems with unique profiles of action and new materials with yet unknown properties. The combination of polyelectrolytes with supramolecular moieties represents an especially interesting research topic, with the potential to derived more complicated architectures. This thesis is focused on the development of supramolecular-polyelectrolyte-based drug delivery systems with high degree of control over physicochemical properties, focusing mainly on shape and size. Several families of star-polyglutamates with cores of different hydrophobicity have been studied in depth in order to determine how the core structure and polyelectrolyte chain length affect self-assembly mechanism. Once these correlations were defined, the most promising candidates were selected for preparation of two drug delivery systems consisting of either spherical or rod-like particles. Finally, conjugation of several drugs (fasudil and dinaciclib) as single agents or in combination through different responsive linkers were also performed; physicochemical properties and in vitro activity of the conjugates were studied in depth and in vivo experiments with selected conjugates are currently ongoing in a preclinically relevant orthotopic Triple Negative Metastatic Breast Cancer Model. / Zagorodko, O. (2020). CONFORMATIONALLY SWITCHABLE POLYGLUTAMATES AS A PROSPECTIVE MATERIAL FOR POLYMER THERAPEUTICS DESIGN [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/146228 / TESIS
38

Hybrid Organic-Inorganic Bridged Silsesquioxane Nanoparticles for Cancer Nanomedicine

Fatieiev, Yevhen 10 1900 (has links)
It is well established that cancer is one of the leading causes of death globally. Its complete eradication requires early detection and intensive drug treatment. In many cases it might also require surgery. Unfortunately, current medicine is still more focused on cancer treatment rather than elimination of its reason. The mechanism of tumor emergence and development is quite complicated, although, we are constantly advancing in this field. Nanomedicine is envisioned as the silver bullet against cancer. Thus, nanoscale systems with therapeutic and diagnostic modalities can simultaneously perform several functions: accurate detection of tumor site, precise targeting, and controlled drug release inside abnormal cells and tissues while being nontoxic to healthy ones. Moreover, surface modification of such nanoparticles allows them to be invisible to the immune system and have longer blood circulating time. The performed research in this dissertation is completely based on hybrid organicinorganic bridged silsesquioxane (also known as organosilica) nanomaterials, therefore comprising "soft" organic/bioorganic part which can imitate certain biorelevant structures and facilitates successful escape from the immune system for more efficient accumulation in cancer cells, while "hard" inorganic part serves as a rigid and stable basis for the creation of cargo nanocarriers and imaging agents. This dissertation discusses the 5 critical points of safe biodegradable nanoplatforms, delivery of large biomolecules, and cytotoxicity regarding the shape of nanoparticles. As a result novel fluorescent biodegradable oxamide-based organosilica nanoparticles were developed, light-triggered surface charge reversal for large biomolecule delivery was applied with hollow bridged silsesquioxane nanomaterials, and biocompatibility of periodic mesoporous organosilicas with different morphologies was studied. Furthermore, the current achievements and future perspectives of mesoporous silica organosilica, and silsesquioxane nanoparticles were considered in regards to their biomedical applications and summarized in two reviews.
39

3D Interdigitated Electrode Array (IDEA) Biosensor For Detection Of Serum Biomarker

Bhura, Dheeraj Kumar 01 January 2011 (has links)
Miniaturization, integration and intelligence are the developing trends for sensor,especially for biosensors. The development of microelectronics technology is a powerful engine to full this objective. It is well known that the microelectronic fabrication process in proven technology for fabrication of integrated circuits. Advances in the field of micro-electronics and micro-mechanical devices combined with medical science have led to the development of numerous analytical devices in monitoring of a wide range of analytes. The unique properties of nanoscale materials offer excellent prospects for interfacing biological recognition events with electronic signal transduction and for designing a new generation of bio-electronic devices exhibiting novel functions. Biosensor development has the potential to meet the need for rapid, sensitive, and specic detection of pathogenic bacteria from natural sources. This work focuses on development of one such electrochemical biosensor platform and discusses dierent aspects related to the design of biosensor and biodetection systems. A new transducer for bio sensor applications based on 3-dimensional, comb structured interdigitated electrode arrays was chosen mainly for two reasons. Firstly, this geometry allows the monitoring of both resistivity and dielectric constant of solution, thus making interdigitated electrodes more versatile tools than other kind of transducers. Second, they present short electric eld penetration depths, which make them more sensitive to changes occurring close to their surface (20 - 100 nm above the surface). This fact enables the monitoring of local changes in the vicinity of interest. Binding of analyte molecules to the chemically modied transducer surface induces important changes in the conductivity between the electrodes. Interdigitated electrodes have been employed to detect the presence of Anti-Transglutaminase (TG) antibodies, that are established biomarkers for Celiac disease which is due to gluten allergy. The biosensor was optimized for specific and sensitive detection of this biomarker. The sensor showed a sensitivity down to picomolar(pM) concentration of the biomarker. Gold nanoparticles were further used for signal enhancement so as to bring the sensor performance closer to Enzyme linked immunosorbant assay (ELISA).
40

Supramolecular DNA nanotechnology : discrete nanoparticle organization, three-dimensional DNA construction, and molecule templated DNA assembly

Aldaye, Faisal A. January 2008 (has links)
No description available.

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