Regioselective labeling of block copolymers, incorporation into nanostructures, and evaluation of biological activity.

摘要

Shell crosslinked (SCK) nanoparticles presenting various surface chemistry and regioselective stable isotope labeling were prepared from strategies involving the controlled assembly of well-defined and regioselectively-functionalized block copolymers. For each of these nanostructured materials, thorough investigation of the structural and physical properties was performed. Biological studies were also conducted to obtain cell viability and immunogenicity data, which have provided fundamental insight for the further investigation of in vitro and in vivo therapeutic applications.; Regioselective placement of functional groups is of critical importance in the subsequent structural and physico-chemical characterization of the assembled nanostructures and has been accomplished by the development of two synthetic methodologies. The first involves controlled polymerizations that incorporate functionality into the block copolymers using combinations of living free radical polymerization strategies, including nitroxide mediated radical polymerization (NMRP) and atom transfer radical polymerization (ATRP), utilizing isotope enriched initiators and/or monomers. Additionally, the effort to incorporate bioactive peptidic species regioselectively into block copolymers was accomplished through the sequential condensation-based peptide growth and living free radical polymerization from a solid support, which produced well-defined end-functionalized peptidic block copolymer precursors. The second strategy involves the subsequent physical and chemical derivatization of the nanostructures following the shell crosslinking reactions. This strategy entails the covalent chemical attachment of peptides and other ligands or, alternatively, the physical sequestration of small molecules within the shell, interface, or core domains.; Both methods of regioselective functionalization provide opportunities for advanced characterization. Stable isotope labels afford the investigation of structural properties and sequestration characteristics of the SCK nanoparticles by solid-state REDOR NMR. Additionally, nanostructures derivatized with various peptidic and other bioactive species have demonstrated the ability to bind surfaces, proteins, cells, and in some cases have shown the ability to transduce cellular plasma membranes. Thorough investigation of the effects of SCKs on cell viability has demonstrated that nanoparticles of various hydrodynamic size, surface charge, and surface functionality have no effect on the viability of cells to which they are exposed. In addition, studies consisting of a three injection immunization series in mice to probe increases in antibody production have shown that the SCKs do not induce significant immunogenic responses.