EAGER: Protein-Metallic Nanoparticles for Biosensing and Targeted Cell Ablation

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

1107176 Spano The goals of this project are: 1) to construct an innovative proteinbased nanometer-sized self-assembling delivery system ("adaptosome") containing metal particles that will be used for specific cell targeting and 2) to characterize and refine these structures by Raman spectroscopy. The Localized Surface Plasmon (LSP) and Surface enhanced Raman Scattering (SERS) properties of these metal-protein hybrid nanoparticles will be exploited for their inherent signal amplification and transduction properties. These properties have direct application for molecule and cell identification and for non-destructive sensing. The adaptosome will be a superior molecular probe capable of precise target cell identification in tissues. The adaptosome can be used for local inactivation and degradation of targeted molecules and cells. To achieve these goals a new protein shell based on in vitro self-assembling gene transfer agent (GTA) prohead system will be constructed and modified with the peptides designed to mediate specific attachment to, uptake into, and movement across cell membranes. Highly sensitive molecule identification will be accomplished by monitoring the vibrational signatures in the local tissue/cellular environment of the particles when bound to the target. Inactivation of target cells by visible and near IR light when it is needed will be possible. Experimental analyses of the formation and propagation of local electromagnetic fields in specific biological environments will allow for rational construction of protein shells and precise selection of nanoparticle size and structure. Spectroscopic testing of the constructed adaptosomes will be performed both in vitro and in situ to optimize the structure of the protein shell in the generation of an LSP and, more specifically, to elucidate the effect of the internal structural organization and pattern of the protein on the metal nanoparticles. Information gathered from modeling and spectroscopic analysis will substantially accelerate the proposed research by a priori elimination of non-working structures and will be used to refine the design principles during construction of the particles. Intellectual Merit: The members of this team bring to bear expertise in separate disciplines and will interact in a direct, cohesive way. This team has collaborated successfully for several years on the generation of bio-inspired devices for energy generation. The work described in this proposal will lead to the construction of an innovative biosensor and drug delivery system based on protein encapsulated metallic nanoparticles. The product of the work itself will have its most direct application in the development of chemical and biological sensors and cancer therapy, through cellspecific targeting. It will also impact areas of modeling of bio-inorganic interfaces, mathematical optimization theory, and in the physical chemistry of protein-nanoparticle assembly and interaction. Broader Impact: This proposal is focused on a major unsolved problem in the current field of chemical and biological defense and in medicine, namely how to target biosensors or therapeutic agents to tissues and specific cells. Construction of this cell target-specific probe capable of delivery of a therapeutic agent will open the door to practical application of innovative principles of chemical and biological sensing and will facilitate exploration of new avenues in patient-addressed personalized medicine. The strategy of the utilization of metallic nanoparticles and their inherent SERS diagnostics that accompanies them will lead to the development of a sub-cellular labeling system with greatly increased sensitivity and versatility. The proposed system will allow for simultaneous identification of a non-predefined unlimited number of molecules (including previously unknown targets) based on their Raman signature. The knowledge that will be gained from developing the ideas presented in this project will contribute broadly to several areas in the emerging fields of nanomedicine, protein-metal interactions, nanoplasmonics, and nanobiology.