This proposal describes an integrated approach for interdisciplinary research, education, and outreach in nanotechnology and biomedical engineering. The objective of the research is to develop an innovative and nontoxic delivery platform that will enable cell specific delivery of small interference RNAs (siRNAs) to silence their targeted oncogenes both in vitro and in vivo. The other objective of this research is to seek an extensive understanding of the fundamental physicochemical characteristics, especially nanomechanical properties, of siRNA nanoparticles with their biological performance. To reach these goals, the proposal has three associated specific aims: (1) To develop a novel approach for assembly and delivery of siRNA without toxicity using labile Au nanoparticles modified with several low generation dendrimers. (2) To engineer the surface of siRNA nanoparticles for target delivery, and to study the mechanical properties of the individual siRNA nanoparticles (both with and without Au nanoparticles encapsulated, and both engineered and non-engineered). (3) To determine structure/property-biodistribution, biological potency, and toxicity relationships of the siRNA nanoparticles in vitro and in vivo.
Intellectual Merit: A novel siRNA assembly approach where Au nanopartices (Au NPs) will be used to dramatically enhance non toxic, low-generation dendrimers to efficiently condense siRNA to discrete nanoparticles. However, the Au NPs can be controlled "in" or "out" of the final siRNA complexes, which is the key difference from previous reports. The potential toxic problem accompanied with the Au NPs will be solved by selectively removing the Au NPs before the siRNA complexes are delivered. In addition, to satisfy the requirements for in vivo targeted delivery of siRNA through a systemic route, the formed siRNA nanoparticles will be engineered by a layer-by-layer modular approach to enable them for spatially- and temporally- controlled release in specific sub-cellular compartments. These properties will add additional therapeutic activities and further decrease the side effects of RNAi-based therapy.
In addition to the physicochemical properties, the nanomechanical properties of the individual siRNA nanoparticles from various formulations will be studied by single force microscopy. By combining the biological investigation of these siRNA nanoparticles, this proposal will link, for the first time, the physicochemical properties and the nanomechanical properties of the siRNA nanoparticles with their cellular internalization, circulation, biodistribution, and therefore, their targeting and therapeutic efficacy during in vitro and in vivo systemic delivery. The improved understanding of these relationships will lead to future design and development of new materials and strategies for efficient and safe delivery of siRNA, and therefore help to realizing its full therapeutic potentials. Successful completion of this research will also provide critical understanding how we can utilize information obtained from various multifunctional nanomedicine platforms which are constructed by engineered inorganic nanocarriers (relatively hard) to guide the development of efficient organic nanocarriers (relatively soft) and vice versa.
Broader Impacts: The proposed investigations are fundamentally and practically important for efficient and safe siRNA delivery. The proposal focuses on design multifunctional siRNA nanoparticles capable of cell specific delivery and silencing of gene expression of EZH2 genes for breast cancer therapy. Given the widespread applications of siRNA in numerous fundamental and therapeutic applications, the knowledge gained from this project will have far reaching scientific and economic impacts on pharmaceutical and biotechnology industry and health care. The educational plan will bring nanoscience tools and concepts to a wide range of students on two campus of Rutgers known as the most diverse in the nation. The inherently interdisciplinary nature of this research will produce students with exceptional training in nanotechnology, biomedical engineering, molecular biology, and drug delivery. Research activities designed for undergraduates and high school students will promote more gifted minority students into the nanoscience ranks. Extensive outreach to the Newark area, a minority-dominated region, will raise the public awareness of the impact of nanoscience and nanotechnology.
