R4 peptide-pDNA nanoparticle coated HepB vaccine microparticles: sedimentation, partitioning, and spray freeze dry...

Broad therapeutic application of nucleic acid micro- and nanoparticles will require bioprocesses capable of achieving high loads of structurally intact and functionality active DNA. Here we report condensation of pDNA into nanoparticles by sedimentation through R4 peptide and partitioning at a hydrophobic interface. > or = 90% coating efficiency onto microparticles is achieved via this combined bioprocess with the pDNA retaining 85-90% intact supercoil after bioprocessing. SEM analyses of the microparticles produced therefrom reveals bound pDNA and R4 peptide nanoparticles. HPLC and chemical analyses afford quantification of the particle-associated pDNA and R4 peptide along with lactose, raffinose, or trehalose carbohydrate stabilizer, surface coatings uniformly applied by spray freeze-drying. Administration of these particles by gene gun demonstrates delivery to the nucleus of expressive nanoparticles and into rodents and pigs pronounced immunogenicity even after bioprocessing and accelerated degradation. These data support the discovery of a robust bioprocess platform for preparing macromolecule bound bioparticles with potential relevance beyond simple preparation of bioactive DNA vaccine.