Single Entity Agents for Probing Intracellular Molecular Content and Effecting Topical Gene Regulation.

摘要

At the nanoscale, the physical, chemical, and biological properties of materials differ from the properties of individual molecules or bulk matter. Harnessing the unique properties at the nanoscale can lead to the creation of novel and useful materials. Engineered nanomaterials hold particularly great promise for studying biological processes and creating diagnostics and therapeutics, as their sizes are perfectly matched to the biological machines that orchestrate life. This research described here focuses on the design and development of several novel spherical nucleic acid (SNA) nanostructures, the investigation of their interaction with biological systems, and their applications in intracellular molecular content detection and gene regulation.;The first oligonucleotide-based nanoparticle probe, capable of entering cells without transfection agents and quantifying intracellular content in living cells, was designed and synthesized. This aptamer-based SNA gold nanoconjugate embodies the novel cooperative properties of SNA gold nanoparticle conjugates, and its ability to visualize and quantify a variety of intracellular analytes in living cells for the first time, opens opportunities for the development of novel single cell assays for molecular diagnostics and drug screening.;The use of siRNA-based SNA nanoconjugates for gene regulation in dermatology is also reported. These nanoconjugates have the unusual ability to suppress gene expression via topical application, without ancillary assistance. Their ability to knock down epithelia growth factor receptor (EGFR) in vitro and in vivo (mouse models) has been studied and quantified. These nanoconjugates provide alternatives to conventional small molecule drugs for the development of therapeutics for a wide variety of skin diseases.;Although there are future key opportunities and unanswered questions yet to be addressed, the data presented in this thesis should inspire future investigations and lead to discoveries that continue the development of SNA nanoparticle conjugates.