Macromolecular Carriers in Nanomedicine and Nanodevices

摘要

Magnetic nano- and micro spheres coated with polymers that have the right combination of characteristics have enormous potential for applications in drug delivery, biological sensor technologies, pathogen diagnostics, antibody-antigen and intracellular targeting, and more recently, for nano- motors and other nano-devices. For in-vivo use in all of these applications, the surface properties of the macromolecular nanospheres or microspheres must be tailored to: 1) disperse them in physiological media, and 2) avoid immune response. Moreover, surfaces that can target specific cell populations or pathogens are also of great interest. This DARPA-AFOSR project has helped to address macromolecular concepts relative to tailoring the surface properties of biodegradable nanospheres and micro spheres for in-vivo blood-contacting applications. The project goals have been to define relationships among chemical composition, processing parameters, nanosphere sizes and size distributions, and surface structure. Our accomplishments include 1) a facile method for achieving magnetite-polylactide nanospheres that can be dispersed in aqueous media; 2) methods for functionalizing the termini of the hydrophilic brushes on the nanospheres in order to conjugate targeting moieties; 3) development of a nanosphere processing approach that yields nanospheres in the desired size range with a narrow distribution of sizes; and 4) maintenance of all of these characteristics with up to approximately 60 weight percent of magnetite incorporated into the nanospheres.