Block Copolymer Assemblies of DNA and Gold Nanoparticles: Towards Applications in Photoinitiated Gene Delivery

Abstract

Gene therapies require transportation of fragile genetic material to the defective site within a body. Polymer-based micelles can provide protection while incorporated gold nanoparticles can add additional functionalities. This thesis investigates the incorporation of both nucleic acids and gold nanoparticles into block copolymer nanoparticles manufactured on gas - liquid segmented reactors. In the first of three studies plasmid DNA is incorporated into hydrophobic cores of polymer nanoparticles by the bench top mixing of plasmids and poly(2-vinylpyridine-b-polycaprolactone (P2VP-b-PCL) to create the polyplex and then incorporate the polyplex into larger polycaprolactone-b-poly(ethylene oxide) (PCL-b-PEO) micelles by microfluidics or benchtop mixing. The subsequent polyplex in hydrophobic core (PIHC) micelles are used to transform E. coli DH5ɑ. The second study provides a route to incorporating gold nanoparticles (GNPs) of different shapes into PCL-b-PEO polymer nanoparticles (PNPs) to create GNP-PNPs while preventing coalescence of the GNPs within the larger PNPs. The study explores the limits of microfluidic shear on the GNP-PNPs as the chip is found to destroy GNPs at high flow rate. The cellular uptake of the gold was shown to increase when packaged into micelles. The technique used to discern the cellular uptake is novel and a more economic alternative to mass spectrometry. The final study explores the relation of plasmid size to on chip stability in aqueous and polar organic solvents. The study then shows how decoration of plasmids with P2VP-b-PCL can allow the plasmid to maintain fidelity at all flow rates. Three plasmids were used to test molecular weight effects on shear induced deformation. Ultimately only the smallest plasmid was able to survive the organic solvents and microfluidic shear.