title: Nanoparticle Tracking Analysis for Determination of Hydrodynamic Diameter, Concentration, and Zeta-Potential of Polyplex Nanoparticles.
abstract: Nanoparticle tracking analysis (NTA) is a recently developed nanoparticle characterization technique that offers certain advantages over dynamic light scattering for characterizing polyplex nanoparticles in particular. Dynamic light scattering results in intensity-weighted average measurements of nanoparticle characteristics. In contrast, NTA directly tracks individual particles, enabling concentration measurements as well as the direct determination of number-weighted particle size and zeta-potential. A direct number-weighted assessment of nanoparticle characteristics is particularly useful for polydisperse samples of particles, including many varieties of gene delivery particles that can be prone to aggregation. Here, we describe the synthesis of poly(beta-amino ester)/deoxyribonucleic acid (PBAE/DNA) polyplex nanoparticles and their characterization using NTA to determine hydrodynamic diameter, zeta-potential, and concentration. Additionally, we detail methods of labeling nucleic acids with fluorophores to assess only those polyplex nanoparticles containing plasmids via NTA. Polymeric gene delivery of exogenous plasmid DNA has great potential for treating a wide variety of diseases by inducing cells to express a gene of interest.
authors.affiliation: Department of Biomedical Engineering, Translational Tissue Engineering Center, and Institute for Nanobiotechnology, Johns Hopkins University School of Medicine, 400 N. Broadway, Smith Bldg., Room 5017, Baltimore, MD, 21218, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Wilson
authors.affiliation: Department of Biomedical Engineering, Translational Tissue Engineering Center, and Institute for Nanobiotechnology, Johns Hopkins University School of Medicine, 400 N. Broadway, Smith Bldg., Room 5017, Baltimore, MD, 21218, USA. green@jhu.edu.|Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA. green@jhu.edu.|Department of Ophthalmology, Johns Hopkins University, Baltimore, MD, 21218, USA. green@jhu.edu.|Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, 21218, USA. green@jhu.edu.
authors.forename: Jordan J
authors.initials: JJ
authors.lastname: Green
mesh_terms: D004247:DNA / Q000737:chemistry; D000067493:Dynamic Light Scattering; D005456:Fluorescent Dyes; D057446:Hydrodynamics; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry*; D010957:Plasmids / Q000032:analysis / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012984:Software; D013194:Staining and Labeling; D013223:Statistics as Topic / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D011108:Polymers; D004247:DNA
keywords: Concentration; DNA labeling; Hydrodynamic diameter; Nanoparticle tracking analysis; Zeta-potential