Selective nanoparticles for antimicrobial therapies and MRI diagnostics

Mark Andrew Hoppens, Louisiana State University and Agricultural and Mechanical College

Abstract

Early diagnosis and treatment of an infection and the selectivity of the treatment method are three parameters, which if optimized will greatly enhance a patient’s prognosis. Thus these three components have been, and continue to be extensively studied. Advances in biosynthesis and nanofabriciation have provided researchers with new tools with which to improve diagnostic and therapeutic techniques. Of these, inorganic nanoparticles (NPs) have shown great promise. Metallic nanoparticles have been demonstrated to successfully serve as antimicrobials, platforms for the transportation of therapeutic molecules, CT and MRI contrast agents, and thermal ablation. The recent paradigm of theranostics proposes substances that serve both diagnostic as well as therapeutic functions. Metallic nanoparticles are well suited as substrates for multifunctional particles for several reasons including; offering high-density surface ligand conjugation, a reduction in payload degradation, a method of target transfection, and the possibility of controlled release. Additionally, metallic nanoparticles have the benefits of tunable morphologies, large surface area-to-volume ratios, physiologically robust chemistries, and ease of bulk synthesis. Furthermore, functional ligands bound to the NP surface and provide additional functionality such as enhanced solubility, selectivity, and antimicrobial efficacy. This report includes two studies which explore the synthesis and functionality of a theranostic conjugate nanoparticle. Studies were conducted to assess the development of a diagnostic antimicrobial nanoparticle (DAN) comprised of an iron oxide MRI contrast core, an antimicrobial colloidal silver shell, and a selective antimicrobial ceragenin surfactant (CSA-124). The composition of each component of the DAN has been characterized and its functionality evaluated. Preliminary data has suggested that such a theranostic nanoparticle can successfully be synthesized and its ability as an MRI contrast agent and antimicrobial shows great promise.