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Drug targeting delivery systems for treatment of Raf-1 induced lung tumors in mice / Trägersystem der Medikamente für Raf1- induzierte Lungentumor in Mäusen anzuzielenAfify, Samar January 2007 (has links) (PDF)
The aim of the present study was to design different dosage forms as carrier systems to deliver sorafenib to the lung of BXB-23 transgenic mice using different routes of administration. Three dosage forms were used one of them was an oil-in-water emulsion and the oral route was chosen for this experiment. The other delivery system was a liposome preparation for intratracheal instillation. In this case the oral route was considered as a control experiment. The last dosage form was PLGA microspheres. Before sorafenib administration it was important to develop a HPLC method to assess sorafenib absorption after its administration and to determine its concentrations in mouse serum. The HPLC method allowed sorafenib quantification in small volumes (30 µl) of mouse serum and tissues. The developed HPLC method was validated resulting in satisfactory selectivity, good linearity, good accuracy and precision over the concentration range examined. Sorafenib was successfully incorporated in a fat emulsion (o/w) using a traditional method resulting in a white homogenous emulsion and no particle aggregation was observed. Sorafenib exhibited antitumor activity on the lung adenoma in BXB-23 transgenic mice when administered orally (2 mg sorafenib per mouse) in the emulsion preparation. The determined effect was an approximately 29 % reduction in the tumor area of the adenoma foci and a proliferation reduction. In order to improve the pharmacological effects of sorafenib on the lung adenoma in BXB-23 mice, the targeting of sorafenib directly to the site of action (the lung) was an attractive concept. For this purpose the intratracheal route was used. Since sorafenib administration by instillation required incorporation of sorafenib in a dosage form suitable for its lipophilic nature, a liposome suspension was the second dosage form used. A lyophilization method was employed for sorafenib liposome preparation utilizing dilauroylphosphatidylcholine (DLPC) which is safe and tolerable for the lung. Incorporation of sorafenib in the liposomes did not influence the particle size and its distribution. The sorafenib liposomes showed high encapsulation efficiency, good stability at 4 °C for one month and satisfactory in vitro release properties and inhibited Raf-1 mediated activation of ERK in cell culture assay. In a pharmacokinetic experiment sorafenib loaded liposomes were instilled directly into the lung. The results revealed that a significant level of sorafenib was achieved in the lung tissues after 2 hours and then reduced after 48 h and remained nearly constant for one week. On the other hand, only traces of sorafenib were found in the mice serum up to 48 h. Subsequently, the pharmacological activity of sorafenib (1 mg per mouse) was studied when delivered in a liposomal suspension intratracheally to treat the lung adenoma of BXB-23 mice. The data of this experiment demonstrated that sorafenib intratracheal instillation resulted in a reduction of tumor area of adenoma foci (67 %) and an elevation of the percent of apoptotic cells. In contrast, prolongation of the treatment period did not further enhance sorafenib activity on the lung adenoma. This previous finding suggested a development of multidrug resistance (MDR) by the adenoma foci cells against sorafenib instillation, which was examined by immunohistochemistry staining. The percent of MDR positive cells was higher after two and three weeks sorafenib liposome instillation treatment than that after one week treatment. The last dosage form used for sorafenib was microspheres, which were prepared by emulsion-diffusion-evaporation method using biodegradable PLGA 50:50 resulting in a white lyophilized powder. The system was characterized physicochemically and revealed a good microspheres yield, high encapsulation efficiency, a homogenous particle size distribution and slow in vitro release of sorafenib. The other strategy studied in the present research project was gene delivery to target the lung bearing tumor of BXB-23 mice using a non-viral vector (polyethylenimine). Polyethylenimine (PEI) was used to investigate its efficiency in transfecting lung bearing tumor of BXB-23 mice model and its ability to transfect the adenoma foci cells. LacZ, which encodes Beta-galactosidase was used in the present study as a reporter gene and was complexed with PEI before delivered intravenously. A high LacZ expression in the alveolar region with some expression in the adenoma foci was observed. On contrary, a low LacZ expression in the alveoli and in the adenoma foci was achieved after instillation of the same polyplex intratracheally. / Das Ziel der vorliegenden Dissertation war es, verschiedene galenische Darreichungsformen als Trägersystem für Sorafenib zu entwickeln, um den direkten Transport des Arzneistoffes zum Zielorgan Lunge von BXB-23 transgenen Mäusen zu ermöglichen. Für die verschiedenen Applikationswege wurden drei Darreichungsformen gewählt. Eine Öl-in-Wasser-Emulsion sollte oral verabreicht werden. Für die intratracheale Instillation wurde ein liposomales Präparat gewählt. Die letzte Darreichungsform stellten PLGA Mikrosphären dar. Um die Absorption von Sorafenib nach Administration bestimmen zu können, wurde die Konzentration des Arzneistoffes im Mäuseserum gemessen. Zur Quantifizierung von Sorafenib in einem geringen Volumen Serum und in Gewebe wurde eine HPLC-Methode entwickelt und validiert. Sorafenib wurde erfolgreich in eine Fettemulsion (o/w) mittels einer traditionellen Methode eingearbeitet. Nach oraler Verabreichung der Emulsion (2 mg/Maus) zeigte Sorafenib auf Lungenadenome eine Antitumor-Aktivität, wobei eine Reduktion der Tumorfläche der Adenomfoci um etwa 29 % und eine Reduktion der Proliferation verzeichnet werden konnte. Zur Verbesserung der pharmakologischen Effekte von Sorafenib auf die Lungenadenome in BXB-23 Mäusen zu verbessern, sollte Sorafenib direkt dem Zielorgan Lunge zugeführt werden. Zu diesem Zweck wurde der intratracheale Administrationsweg gewählt. Da die Instillation von Sorafenibaufgrund seiner lipophilen Natur nur durch Einschluß in eine andere Darreichungsform zu erreichen ist, wurde für die zweite Darreichungsform eine Liposomen-Suspension verwendet. Für die Zubereitung von Sorafenib in Liposomen wurde eine Lyophilisierungsmethode unter Verwendung von DPLC erarbeitet. Die Einschluss-Effektivität der Sorafenib-beladenen Liposomen war hoch und zeigte bei 4°C eine gute Stabilität für einen Monat. Die erzielten Effekte bei der in vitro Freisetzung und die Hemmung der von Raf1-induzierten Aktivierung von ERK in Zellkulturexperimenten lieferten zufrieden stellende Ergebnisse. In einem pharmakokinetischen Experiment wurden mit Sorafenib beladenen Liposomen direkt in die Lunge appliziert. Die Ergebnisse zeigten, dass nach 2 h eine signifikante Konzentration von Sorafenib im Lungengewebe erreicht wurde. Nach 48 h nahm diese Konzentration ab und blieb dann für eine Woche fast konstant. Andererseits wurden bis zu 48 h nach Gabe des Arzneistoffes nur Spuren von Sorafenib im Mäuseserum gefunden. Folglich wurde die pharmakologische Aktivität von Sorafenib (1 mg/Maus) bei intratrachealer Verabreichung in einer liposomalen Suspension untersucht. Die Ergebnisse zeigten, dass die intratracheale Gabe von Sorafenib eine Reduktion der Tumorfläche der Adenomfoci um 67 % bewirkte, sowie eine Erhöhung des prozentualen Anteils apoptotischer Zellen. Eine Verlängerung der Behandlungszeit zeigte keine zusätzliche Verbesserung der Effekte. Dies lies vermuten, dass hier eine Entwicklung von Multidrug-Resistenz in den Adenomfocizellen gegenüber der Instillation von Sorafenib erfolgte. Dies wurde in immunochemischen Anfärbe-Experimenten untersucht. Die Prozentzahl von MDR-positiven Zellen war nach zwei und drei Wochen Instillation von Sorafenib-Liposomen höher als nach einer Woche. Die letzte verwendete Darreichungsform für Sorafenib waren Mikrosphären, die durch Emulsions-Diffusions-Evaporations-Methoden in biologisch abbaubarem PLGA 50:50 hergestellt wurden. Dies ergab ein weißes, lyophilisiertes Pulver. Das System wurde physiochemisch charakterisiert und ergab ein gutes Mikrosphären-Ergebnis, hohe Einschluss-Effektivität, eine homogene Verteilung der Partikelgrößen und eine langsame in vitro Freisetzung von Sorafenib. Die andere untersuchte Strategie war Gen-Delivery, um den Lungentumor von BXB-23 Mäusen mittels eines nicht-viralen Vektors (Polyethylenimin, PEI) anzuzielen. PEI wurde verwendet, um die Effektivität der Transfektion des Lungentumors zu untersuchen und seine Fähigkeit, die Adenomfocizellen zu transfizieren. LacZ, das Beta-Galactosidase codiert, diente bei diesem Experiment als Reportergen und wurde vor intravenöser Gabe mit PEI komplexiert. Eine hohe LacZ-Expression in der alveolaren Region, aber nur eine geringe Expression in den Adenomfoci wurde beobachtet. Im Gegensatz dazu wurde eine geringe Expression von LacZ in den Alveolen und den Adenomfoci nach intratrachealer Instillation des gleichen Polyplex erreicht.
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From Pulling the Trigger to Pushing the Button: Historical Precedents for Targeted Killings and Signature StrikesMencini, Damian January 2014 (has links)
Thesis advisor: Charles Gallagher / Thesis advisor: Peter Krause / Drone strikes are sensational events. The United States Government uses remotely piloted aircraft (or drones) equipped with precisions weapons systems to unilaterally hunt and kill its enemies across the globe. The American public, and many around the world, are startled by the pervasiveness of American lethal force. In many ways, drone strikes are unprecedented. The technology, the frequency of use, and the geographic scope are all by-products of the twenty-first century. However, the United States government has a deep history of debating whether to kill individual enemies, and has a history of authorizing operations to do so. Beneath the rhetoric, the arguments, and the opinions that dominate drone policy today there is something missing: the history. This thesis argues that there are historical precedents for targeted killings and signature strikes in American history that predate the September 11 terrorist attacks and examining these past operations can inform modern policy. / Thesis (BA) — Boston College, 2014. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: History.
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Analysis of translational fidelity in cellular proteinsGarofalo, Raffaella 03 April 2017 (has links)
No description available.
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Engineering nanoparticles using chemical and biological approaches for tumor targeted deliveryNguyen, Tuyen January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Santosh Aryal / Nanotechnology offers exciting options for the site-selective delivery of chemotherapeutics and diagnostic agents using nanoparticles. Varieties of organic and inorganic nanomaterials have been explored extensively as a delivery system either in the form of drug carriers or imaging agents. Successful stories include the clinical translation of anticancer nanomedicines such as PEGylated liposomal doxorubicin (DOXIL®), albumin-bound paclitaxel (Abraxane®), and polymeric micelle loaded paclitaxel (Genexol®), which are currently used in the clinic as one of the first lines for cancer chemotherapies. These conventional nanomedicines rely on passive-drug targeting taking advantage of leaky tumor vasculature, called the Enhanced Permeability and Retention (EPR) effect. However, delivering biologically active components selectively to the diseased cell, for example, cancer, is highly challenging due to the biological barriers in the body including blood pool cells/proteins, heterogeneous microenvironment, and intracellular degradation. Therefore, the goal of this dissertation is to develop nanoplatforms that can deliver the agents of interest in targeted fashion to cancer while bypassing or collaborating with the biological barriers. The design consideration of these nanoplatforms centralizes on using simple chemical reactions and cell biology to engineer nanoparticles. The presented nanoparticles were extensively studied and evaluated for their biological functions using in vitro and in vivo models. These nanoconstructs described herein address current limitations of conventional nanomedicine such as (1) the lack of understanding of the interaction of nanoparticle and biological system, and (2) the lack of an effective targeting strategy to deliver drugs to the cancer cell in the tumors. The significant findings of each system will be highlighted and discussed throughout this dissertation. Results obtained highlight key findings such as NP intracellular fate, maximized tumor accumulation, and unique pharmacokinetics could open the avenues for systemic investigations for personalized medicine and lay the foundation for nanomedicine design to accelerate clinical translation.
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Development of a Monitoring Parameters Guideline for Targeted Therapy in Renal Cell CarcinomaBryant, S. L., Bossaer, John B. 01 December 2010 (has links)
No description available.
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Age as a Predictor of Factors Involved in Targeted School ViolenceRippon, Wendy Leigh 01 January 2017 (has links)
Targeted school violence (TSV) in the United States is increasing, causing a loss of innocent lives and challenges for teachers and students in building rapport. In addition, TSV increases levels of anxiety and makes it difficult for parents and community members to believe students are safe while at school. Several studies have highlighted the fact that age may be a factor in school shootings, calling for future research to determine if age is indeed influential. The problem is to date age has not been established as a predictive factor, even though the extant research is beginning to identify possible variances. Guided by general strain theory and ceremonial violence, this study determined statistical significance between age and select variables in the personal, event, and ecological categories. This information could be illuminating to educators, mental health professionals, and law enforcement for threat assessment purposes. The information was gathered on all TSV members within the United States from 1966 to 2015 through archival data, and the data were analyzed using logistic regression, Pearson's correlation, and Spearman's correlation. Results indicated that, as age increases, the offenders are more likely to have a higher social status, have a mental health and criminal history, carry out their act in the afternoon, and choose a knife as a weapon. In addition, older offenders are less likely to be students and less likely to have been bullied. Implications for social change include modifications to current threat assessment protocol regarding weapon choice and previous mental health or criminal history, which could be utilized to change public policy for mandatory reporting of students identified as at risk. Also, younger offenders are being bullied more often than older offenders and this could add more awareness to antibullying program procedure and earlier mental health intervention.
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Funktionelle Analyse des tumorspezifischen IgG Antikörpers BARB-4 / Functional analysis of the tumor-specific igG antibody BARB-4Rückl, Kilian Thomas January 2012 (has links) (PDF)
Der menschliche Organismus ist zeitlebens von malignen Neoplasien bedroht, die durch lokales oder metastasiertes Wachstum lebensnotwendige Funktionen des Körpers beeinträchtigen können. Als wichtigstes Werkzeug zur Abwehr dieser Neoplasien wurde in den letzten Jahrzehnten die natürliche Immunität aufgedeckt. Besonders die Antikörper der innaten Immunität spielen eine entscheidende Rolle. BARB-4 ist ein humaner, tumorspezifischer Antikörper und Teil dieser natürlichen Immunität. Er wurde mit Hilfe der Hybridomatechnologie aus einem Patienten mit Siegelringkarzinom des Magens isoliert, und ist einer der wenigen Vertreter innater humaner IgG Antikörper. Diese Arbeit gibt einen ersten Überblick über die Bindungsspezifität und die funktionellen Eigenschaften des BARB-4-Antikörpers. In den immunhistochemischen Färbungen konnte die Tumorspezifität des Antikörpers nachgewiesen werden. Bei dem zugehörigen Antigen handelt es sich um eine Variante des TAF15, einem Protein der FET-Familie, die intrazelluläre Aufgaben bei Transkriptionsvorgängen haben, bei denen zudem aber auch eine Beteiligung an Adhäsions- und Migrationsvorgängen vermutet wird. Diese Variante ist bei malignen Zellen an der Oberfläche lokalisiert, was die Ergebnisse der Durchflußzytometrie belegen. Durch konfokale Mikroskopie mit Fluoreszenz-markiertem BARB-4 konnte diese Oberflächenbindung an Tumorzellen bestätigt werden. Im weiteren zeitlichen Verlauf konzentrierte sich der Antikörper im Zellinneren. Die Präsenz des Antikörpers führte bei Versuchen mit Tumorzellen zu einer bemerkenswerten Hemmung der Adhäsions- und Migrationsfähigkeit der Zellen. Beide stellen Schlüsseleigenschaften für die Metastasierung von Tumorzellen dar. Diese Eigenschaften könnten BARB-4 für einen möglichen, therapeutischen Einsatz zur Prävention von Tumormetastasen qualifizieren. / Throughout live, the human body is threatened by malign neoplasms whose local or metastasizing growth can restrict its essential functions. In the last decades, natural immunity was discovered as an instrumental tool in the fight against these neoplasms. Especially antibodies of the innate immune response play a central role in this defense. BARB-4 is part of this repertoire of antibodies. B-cells producing BARB-4 were isolated from a patient suffering from signet ring carcinoma, and propagated using Hybridoma-technology. While most antibodies of the innate immune response are of the IgM subclass, BARB-4 is an IgG antibody. This work offers an assessment of the specificity and functional properties of BARB-4. By using immuno-histochemistry, it couId be shown that BARB-4 specifically binds to human cancer cells. More specifically BARB-4 binds to a variant of TAF15, a member of the FET family of transcriptional regulators. TAF15 is also assumed to be involved in adhesion and cell-migration. Flow-cytometry confirmed its localization to the plasma-membrane, which is unique to this tumor-specific variant of TAF15. Subsequent confocal microscopy showed that after initial binding of TAF15, the BARB-4 antibody is internalized by the bound cancer cells. Remarkably, BARB-4 treatment of cancer cells resulted in the inhibition of their ability to adhere and migrate. As both adhesion and migration are hallmarks of metastasis in cancer cells, BARB-4 is a possible candidate for therapeutic prevention of cancer metastasis.
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Antibody Mediated Radionuclide Targeting of HER-2 for Cancer Diagnostics and Therapy : Preclinical Studies / Antikroppsmedierad målsökning av radionuklider till HER-2 för cancerdiagnostik och terapi : Prekliniska studierPersson, Mikael January 2006 (has links)
<p>Targeted radionuclide therapy (TRT) holds great promise for the treatment of cancer. In TRT, radioactive nuclides are delivered specifically to tumours by molecules that recognise and bind to structures overexpressed by, or specific to, cancer cells. Human epidermal growth factor receptor like protein 2 (HER-2) is an oncogene product overexpressed in e.g. urological, breast, or ovarian cancers that have been correlated to poor prognosis and resistance to hormonal therapy. There is also evidence that tumour cells retain their HER-2 overexpression in metastases.</p><p>Trastuzumab and pertuzumab are two humanised monoclonal antibodies targeting different parts of HER-2. This thesis describes the radiolabelling of these antibodies for use in TRT and diagnostics. The thesis also investigates possible methods for modifying uptake and retention of radioactivity delivered with antibodies binding to HER-2. Modification of the cellular retention of <sup>125</sup>I by using polyhedral boron anion based linker molecules (DABI and NBI) is investigated, and it is shown that linking <sup>125</sup>I to trastuzumab using DABI increases cellular accumulation of radioactivity by 33%. It is also shown that trastuzumab can be efficiently coupled to the positron emitter <sup>76</sup>Br by using NBI. Furthermore, it is shown that cellular uptake of <sup>125</sup>I can be modified by stimulating EGFR (HER-1) with EGF.</p><p>When labelled with the alpha emitter <sup>211</sup>At, trastuzumab could specifically kill cells in vitro. This cell killing effect could be prevented by saturating the receptors of the target cells with non-radiolabelled trastuzumab.</p><p>Pertuzumab was radiolabelled with the low energy beta emitter <sup>177</sup>Lu without losing affinity or immunocompetence. [<sup>177</sup>Lu]pertuzumab was specific to HER-2 in vitro and in vivo. This targeting conjugate was shown to increase median time to tumour progression in mice bearing xenografts of the radioresistant SKOV-3 cell line. </p><p>In conclusion, antibodies against HER-2, especially pertuzumab radiolabelled with <sup>177</sup>Lu, show promise as TRT agents.</p>
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Inhaled Aerosols Targeted via Magnetic Alignment of High Aspect Ratio Particles: An In Vivo and Optimization StudyRedman, Gillian 06 1900 (has links)
An in vivo study with 19 rabbits was completed. Half of the exposed rabbits had a magnetic field placed externally over their right lung. Magnetic resonance images of the lungs were acquired to determine the iron concentrations in the right and left lung of each animal. The right/left ratio increased in the middle and basal regions of the lung. With further optimization, this technique could be an effective method for targeted drug delivery.
Additionally, the feasibility of increasing the length of high aspect ratio particles for improved targeted drug delivery was explored. An ultrasonic nozzle was pulsed into a large evaporation chamber. Individual particles were found to be double the original length. However, due to locally increased humidity the droplets were not dried, except with the use of an orifice to rapidly accelerate and break apart the larger droplets. The complications associated with this method make it an undesirable and unfeasible method of creating longer particles.
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Dual-Targeting of NADP<sup>+</sup>-Isocitrate DehydrogenaseMcKinnon, John David 01 April 2009
Many mitochondrial and chloroplast proteins are encoded in the nucleus and subsequently imported into the organelles via active protein transport systems. While usually highly specific, some proteins are dual-targeted to both organelles. In tobacco (<i>Nicotiana tabacum L.</i>), the cDNA encoding the mitochondrial isoform of NADP+-dependent isocitrate dehydrogenase (NADP+-ICDH) contains two translational ATG start sites, indicating the possibility of two tandem targeting signals. In this work the putative mitochondrial and chloroplastic targeting signals from NADP+-ICDH were fused to a yellow fluorescent protein (YFP) to generate a series of constructs and introduced into tobacco leaves by <i>Agrobacterium</i>-mediated transient transfection. The subsequent sub-cellular locations of the ICDH:YFP fusion proteins were then examined under the confocal microscope. Constructs predicted to be targeted to the chlroplast all localized to the chloroplast. However, this was not the case for constructs that were predicted to be mitochondrial targeted. While some constructs localized to mitochondria, others appeared to be chloroplast localized. This was attributed to an additional 50 amino acid residues of the mature NADP+-ICDH protein which was present in those constructs. In addition, during the process of generating these constructs our sequence analysis indicated a stop codon present at amino acid position 161 of the mature NADP+-ICDH protein from both Xanthi and Petit Havana cultivars of tobacco. This was confirmed by multiple sequencing reactions and created discrepancies with the reported sequence present in the database. The results of this study raise interesting questions with regard to the targeting and processing of NADP+-ICDH.
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