title: Quantitative analysis of synthetic gene delivery vector design properties.
abstract: As intracellular gene delivery pathways are highly complex combinations of multiple potentially rate-limiting cellular and molecular processes, approaches to the design of synthetic delivery vectors focusing on any single barrier individually will likely be suboptimal. We offer here an "integrative systems" approach to vector characterization and design, combining quantitative experiment and computational modeling studies of vector uptake and trafficking kinetics. This model is validated using data for delivery of a green fluorescent protein (GFP)-encoding plasmid by means of Lipofectamine, permitting specification of model parameter values. The model is then used to make a priori predictions on the effect of polymer length in polyplex vectors, with additional parameter values determined from previous independent experimental studies of plasmid release. Comparison with data on GFP expression via these polyplex vectors shows that the model successfully predicts an experimentally observed biphasic dependence of expression efficiency on polymer length and quantifies the contributions of competing effects yielding the optimal intermediate polymer length. Finally, we use the model to predict potential effects of incorporating nuclear localization sequences in these kinds of synthetic vectors, and find that the degree of benefit from these will depend on the values of other key system properties including the vector unpackaging rate constant. Thus, we demonstrate the usefulness of a bioengineering, integrative-systems modeling approach to improved vector design and analysis.
authors.affiliation: Division of Bioengineering & Environmental Health, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Varga
authors.forename: K
authors.initials: K
authors.lastname: Hong
authors.forename: D A
authors.initials: DA
authors.lastname: Lauffenburger
mesh_terms: D001692:Biological Transport; D002411:Cation Exchange Resins / Q000494:pharmacology; D002460:Cell Line; D003198:Computer Simulation; D005069:Evaluation Studies as Topic; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage* / Q000138:chemical synthesis* / Q000235:genetics; D049452:Green Fluorescent Proteins; D006801:Humans; D007700:Kinetics; D008055:Lipids / Q000494:pharmacology; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D008297:Male; D019913:Nuclear Localization Signals; D010957:Plasmids / Q000008:administration & dosage / Q000138:chemical synthesis / Q000235:genetics; D015203:Reproducibility of Results; D014407:Tumor Cells, Cultured
chemical_list: D002411:Cation Exchange Resins; D008055:Lipids; C086724:Lipofectamine; D008164:Luminescent Proteins; D019913:Nuclear Localization Signals; D049452:Green Fluorescent Proteins