Two of the most commonly diagnosed malignancies in men and women are cancers of the prostate and breast, respectively. Though many advances have been made in reducing the overall morbidity and mortality associated with these diseases, the high number of deaths that still occur emphasizes the need for safer and more effective therapeutic options. To this end, our lab was the first to describe the use of RNA aptamers to specifically deliver cytotoxic siRNAs to PSMA positive prostate cancer cells. This reagent, termed an aptamer-siRNA chimera, was shown to be an effective targeted cancer therapeutic upon intratumoral injection in a pre-clinical, xenograft, mouse model of prostate cancer. However, further work was needed to realize the full clinical potential of RNA aptamer-siRNA chimeras as a targeted therapeutic modality. The thesis laid out herein, describes work performed to optimize aptamer-siRNA technology in order to enable clinical translation and to increase the scope of this technology (i.e. increase the cancer types for which this technology can be used). We describe several improvements to our first generation PSMA aptamer-siRNA chimera which, include: decreasing the overall nucleotide content to aid in chemical synthesis, altering the siRNA structure to improve RNAi processing and addition of a 20kDa PEG moiety to increase pharmacokinetics/pharmacodynamics. All of these modifications lead to a more effective reagent at lower doses. Importantly, we demonstrate that our optimized reagent is now effective upon systemic administration in an in vivo mouse model of prostate cancer. In addition, we have also identified new aptamers to the receptor tyrosine kinase (RTK) EphA2. Given the broad expression of this RTK on various cancers, this work seeks to extend the scope of targeted aptamer therapeutics beyond that of prostate cancer. Finally, we demonstrate a novel aptamer selection methodology termed cell-internalization SELEX. This approach allowed us to select for aptamers that specifically targeted and internalize into HER2 expressing cells. This allowed us to readily translate all identified aptamers into aptamer-siRNA chimeras. We show that all chimeras tested were able to sensitize HER2+ breast cancer cells to low- dose cisplatin treatment. Taken together, the work described in this thesis significantly advances the field of targeted cancer therapeutics. Importantly, by demonstrating cancer cell-specific delivery of siRNA, our technology overcomes one of the most significant hurdles to the therapeutic use of siRNAs, delivery.

An essential guide that puts the focus on method developments and applications in aptamers In recent years, aptamer-based systems have been developed for a wide-range of analytical and medical applications. Aptamers for Analytical Applications offers an introduction to the topic, outlines the common protocols for aptamer synthesis, as well as providing information on the different optimization strategies that can obtain higher affinities to target molecules. The contributors?noted experts on the topic?provide an in-depth review of the characterization of aptamer-target molecule interaction and immobilization strategies and discuss the developments of methods for all the relevant applications. The book outlines different schemes to efficiently immobilize aptamers on substrates as well as summarizing the characterization methods for aptamer-ligand complexes. In addition, aptamer-based colorimetric, enzyme-linked, fluorescent, electrochemical, lateral flow and non-labeling analytical methods are presented. The book also reflects state-of-the-art and emerging applications of aptamer-based methods. This important resource: -Provides a guide to aptamers which provide highly specific and sensitive molecular recognition, with affinities in the range of antibodies and are much cheaper to produce -Offers a discussion of the analytical method developments and improvements with established systems and beyond -Offers a comprehensive guide to all the relevant application areas -Presents an authoritative book from contributors who are noted experts in the field Written for analytical chemists, biochemists, analytical researchers, Aptamers for Analytical Applications is a comprehensive book that adopts a methodological point of view to the important aspects of aptamer generation and modification with a strong emphasis on method developments for relevant applications.

This volume provides protocol references covering recent developments in the aptamer field. Within the last decade, aptamers have become more and more popular, and their sophisticated biophysical properties together with their ability to be easily modified and, thus, adapted to various regimens makes them a very promising class of compounds. Divided into three sections, the book covers selection, a series of analytical methods to assess biophysical properties of aptamer-target interactions, as well as various applications of aptamers. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Practical and easy to follow, Nucleic Acid Aptamers: Selection, Characterization, and Application provides a state-of-the-art summary of recent developments in the aptamer field and will be a helpful resource for scientists in the life sciences working with aptamers as tools to elucidate biological systems.

Gram-negative Escherichia coli (E. coli) bacteria are the most numerous commensal aerobic germs located in the human colon. Diarrhea caused by E. coli pathogenic strains is a major cause of death in developing countries, especially the sub-Saharan and South Asian areas. Some strains cause diarrhea, and all of them may produce an infectious disease. This book includes ten chapters covering the main aspects of infections related to E. coli, their pathogenic mechanisms, treatments, and resistance to diverse antibiotics.

The sequencing of the human genome and subsequent elucidation of the molecular pathways that are important in the pathology of disease have provided unprecedented opportunities for the development of new therapeutics. Nucleic acid-based drugs have emerged in recent years to yield extremely promising candidates for drug therapy to a wide range of diseases. Advances in Nucleic Acid Therapeutics is a comprehensive review of the latest advances in the field, covering the background of the development of nucleic acids for therapeutic purposes to the array of drug development approaches currently being pursued using antisense, RNAi, aptamer, immune modulatory and other synthetic oligonucleotides. Nucleic acid therapeutics is a field that has been continually innovating to meet the challenges of drug discovery and development; bringing contributions together from leaders at the forefront of progress, this book depicts the many approaches currently being pursued in both academia and industry. A go-to volume for medicinal chemists, Advances in Nucleic Acid Therapeutics provides a broad overview of techniques of contemporary interest in drug discovery.

Rapid antigen tests became popular during the COVID-19 pandemic as affordable diagnostic tools to help control the spread of infection, thanks to their cost-effectiveness and simplicity of use. These features enabled their widespread employment at point-of-care, even in those countries where access to care is still limited. The advantages of this diagnostic approach have been demonstrated in practical applications and have envisaged their utilization in other diagnostic fields in which access to prevention is beneficial, such as in the fight against neglected diseases and cancer. As such, the need to further improve the performance of rapid antigen assays is urgent. At the same time, the replacement of natural bioligands with synthetic ones to increase sustainability is likely to support the future development of the technique. The boundaries of applications of rapid antigen tests are still expanding towards several fields, beyond clinical diagnostics to food safety, forensics, and veterinary testing. This book provides a comprehensive overview of rapid antigen testing, discussing both its benefits and limitations.