Rebekah A. Drezek - US grants

0221544
Drezek
The proposed project leverages recent advances in nanoparticle technologies to develop innovative contrast agents which can be optically interrogated using noninvasive approaches and targeted to specific molecular signatures of disease. The contrast agents proposed - nanoshells and nanoemitters - possess ideal optical and chemical properties for optical imaging. The optical response of these particles can be precisely and systematically varied over a broad band including the visible and infrared spectral regions. The extremely agile. tunabilityof the optical resonance is completely unique to nanoshells: in no other molecular or nanoparticle structure can the resonance of the optical extinction properties be systematically. designed. Moreover, the nanoparticles are highly biocompatible and proteins (such as antibodies) are readily conjugated to their surfaces. To develop the potential of nanoparticles as contrast agents for optical imaging, the investigators will study a novel class of exogenous contrast agents designed and optimized to address the clinically important problem of detection of pre.invasive neoplasias.

0321275
Raphael
The ability to label individual molecules inside of living cells with fluorescent probes has revolutionized our understanding of basic cell biology and opened new opportunities to bioengineer living cells. Laser scanning confocal microscopy has proved to be a powerful and versatile technique for studying fluorescent molecules in cells. Rice University recognized the importance of this technique, and purchased a Zeiss LSM 410 confocal microscope in 1993. This microscope has supported numerous research projects in cell biology and bioengineering. However, there are serious limitations in the current technology, including limited ability to resolve molecules with overlapping emission spectra and the damage to cells that occurs with laser excitation. The importance and magnitude of these issues led Carl Zeiss, Inc. to expend a significant amount of time and resources to develop a user-friendly system that can overcome these problems. Zeiss recently integrated powerful new technologies, including novel algorithms for resolving overlapping emission spectra and the ability to use multi-photon laser excitation, into their new confocal microscope. The new system is called the 510 LSM META/NLO.

DESCRIPTION (provided by applicant): The overall goal of this initiative is to investigate the cellular uptake, trafficking, and sub-cellular localization of different classes and subtypes of nanoparticles (NPs) with well-defined physiochemical properties for the creation of a reference table that relates the sub-cellular distribution of NPs to their intrinsic physiochemical properties across a range of cell lines. The subcellular fate of NPs is relevant both in terms of the therapeutic efficacy and biosafety of the NPs. The effective impact of size, shape, charge, and chemical composition of nanomaterials, in the presence of serum opsonins, on both cellular entry and subsequent subcellular localization will be investigated. The expected outcome of this project is to create a reference table that accelerates the transition of nanomaterials from the bench to the clinic by rapidly expanding our knowledge of the effect of a material's intrinsic characteristics on its intracellular destination. The final product, a comprehensive table of NPs and their subcellular locations, will guide the future development of NP drug delivery systems for rapid expansion of biomedical applications, including cancer therapy, cardiovascular imaging, and gene therapy. PUBLIC HEALTH RELEVANCE: What this project seeks to deliver is a multi-dimensional reference table that relates the subcellular distribution and toxicity of NPs to their intrinsic physiochemical properties across a range of diverse cells and cell lines. It is our hope that the data generated from this project will serve as a resource for future research and encourage model development and new insights into nanotechnologies for imaging and drug delivery.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The detection of a gold nanoparticle contrast agent and LSI

DESCRIPTION (provided by applicant): This training program provides a new type of experienced interdisciplinary scientist in the field of nanobiology, combining the tools, ideas and materials of nanoscience with biology to enable new approaches to research problems and develop novel diagnostic and therapeutic strategies. This new training program builds upon a very successful, interdisciplinary training initiative, supported for a limited duration of five years by the NIH Roadmap Initiative. Trainees from this program are uniquely prepared to explore the interplay between current nanoscience applications in high technology and biotechnology and biomedical applications for clinical and research medicine. Just as early molecular biology heralded a new era in both biological sciences and technology, nanobiology is poised to exploit the adventitious interface between nanoscience and biology. The Nanobiology Interdisciplinary Graduate Training Program (NIGTP) takes advantage of the strong history of multi-institutional, multi-disciplinary training efforts in the Keck Center of the Gulf Coast Consortia. This allows seamless organization of trans-institutional training programs. Bringing together six institutions - Baylor College of Medicine, Rice University, University of Houston, the University of Texas Health Science Center at Houston, University of Texas M. D. Anderson Cancer Center, and the University of Texas Medical Branch at Galveston - the NIGTP faculty bring significant expertise in nanobiology. Fifty faculty are included in this program, with over $63M awarded in research funding related to nanobiology and outstanding graduate research opportunities. Trainees will participate in a highly interdisciplinary curriculum to provide deep knowledge and also the connections between the disciplines. Trainees will also be required to have mentors in two different disciplines, with a mini-sabbatical period in the co-mentor's laboratory as an essential part of the multi-disciplinary training experience. Trainees will also participate in weekly seminars and journal club and will present their research at an annual retreat. RELEVANCE: The interface between nanotechnology, biology, and medicine is a new frontier for scientific exploration and for the creation of new and improved diagnostic and therapeutic tools to detect, treat, cure, and prevent human diseases. This grant would support an established interdisciplinary graduate training program in nanotechnology for biology and medicine.

The rapid identification of pathogens is essential for clinical diagnostics and biodefense. Given timely information, clinicians can prescribe better treatments and slow the rise of drug resistant bacteria, and U.S. biosurveillance efforts can track the emergence and spread of both existing and newly evolved pathogens. While most rapid diagnostic tests have sensors that are each specialized to detect only one kind of pathogen, this research effort is developing new DNA sensing techniques to efficiently detect large numbers of pathogens with just a few sensors. By minimizing the number of necessary sensors, new pathogen surveillance devices could be portable and inexpensive for routine use. The technology additionally provides an approach to detecting emerging novel pathogens without the need to create and deploy new test kits. In addition to furthering development of new pathogen identification technologies, the project develops a hands-on experimental module exploring this methodology and implements it in a biosensing and imaging course serving undergraduate and graduate engineering students at Rice University.

This research effort applies compressed sensing which allows just a few DNA probes to (1) give each species a fingerprint response and (2) unmix these fingerprint signals when a few pathogens are in the same sample. Compressed sensing assumes that the sample is sparse. Sparsity occurs because although there may be dozens or hundreds of possible species to account for, any single sample from a patient or the environment will have only a few pathogens of interest for relevant applications. For pathogen detection, DNA probes each bind multiple times to microbial species. The number of binding events between a few probes and the microbes gives each of hundreds of species a ?fingerprint? response, much like how 10 digits can give everyone in the U.S. a unique phone number. The first aim of this project is to develop a new DNA signal amplification technique that allows fewer binding events to be detectable. This amplification strategy also lets signals be positive or negative, effectively allowing fingerprint signals to spread further apart. The enhanced incoherence of the sensors is known to be very helpful for compressed sensing. The second aim is to use new technologies in microfluidics to capture individual pathogen cells in very small droplets and acquire fingerprint signals from each droplet separately. By analyzing every droplet, this project pushes towards single-cell resolution which would enable its broader application in any task that demands the characterization of unknown microbes.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.