title: Effect of polyplex morphology on cellular uptake, intracellular trafficking, and transgene expression.
abstract: Nanoparticle morphology has been shown to affect cellular uptake, but there are few studies investigating the impact of particle shape on biologic drug delivery. Recently, our group synthesized a series of N-(2-hydroxypropyl) methacrylamide (HPMA)-oligolysine brush polymers for nucleic acid delivery that varied in oligolysine peptide length and polymer molecular weight. Interestingly, a 50% longer peptide (K15) transfected very poorly compared to the optimized polymer comprised of K10 peptide despite similar chemical composition and molecular weight. We hypothesized that differences in particle morphology contributed to the differences in plasmid DNA delivery. We found that particles formed with plasmid DNA and a polymer with the longer oligolysine peptide (pHK15) had larger aspect ratios than particles formed with optimized polymer (pHK10). Even though both formulations showed similar percentages of cellular association, particles of a higher aspect ratio were internalized to a lesser extent. Furthermore, the rod-like particles accumulated more in endosomal/lysosomal compartments, leading to delayed nuclear delivery. Other parameters, such as particle surface charge, unpackaging ability, uptake mechanism, intracellular trafficking, and the presence of heparan sulfate proteoglycans did not significantly differ between the two polymer formulations. These results indicate that, for this system, polyplex morphology primarily impacts nucleic acid delivery efficiency through differences in cellular internalization rates.
authors.affiliation: Department of Bioengineering and Molecular Engineering & Sciences Institute, University of Washington , 3720 15th Avenue NE, Box 355061, Seattle, Washington 98195, United States.
authors.forename: Julie
authors.initials: J
authors.lastname: Shi
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Choi
authors.forename: Brian
authors.initials: B
authors.lastname: Chou
authors.forename: Russell N
authors.initials: RN
authors.lastname: Johnson
authors.forename: Joan G
authors.initials: JG
authors.lastname: Schellinger
authors.forename: Suzie H
authors.initials: SH
authors.lastname: Pun
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics; D016503:Drug Delivery Systems; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D019812:Heparan Sulfate Proteoglycans / Q000737:chemistry; D006801:Humans; D008239:Lysine / Q000737:chemistry; D008247:Lysosomes / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D050997:Nanomedicine; D053758:Nanoparticles / Q000737:chemistry*; D009696:Nucleic Acids / Q000008:administration & dosage / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011108:Polymers / Q000737:chemistry; D014162:Transfection; D019076:Transgenes; D014867:Water / Q000737:chemistry
chemical_list: D019812:Heparan Sulfate Proteoglycans; D009696:Nucleic Acids; D010455:Peptides; D011108:Polymers; D014867:Water; D004247:DNA; D008239:Lysine