| Autor: |
Putnam D; Department of Chemical Engineering, E25-342, Massachusetts Institute of Technology, Cambridge, MA 02139, USA., Gentry CA, Pack DW, Langer R |
| Jazyk: |
angličtina |
| Zdroj: |
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2001 Jan 30; Vol. 98 (3), pp. 1200-5. Date of Electronic Publication: 2001 Jan 23. |
| DOI: |
10.1073/pnas.98.3.1200 |
| Abstrakt: |
Protein expression after delivery of plasmid DNA to the cell nucleus depends on the processes of transcription and translation. Cytotoxic gene-delivery systems may compromise these processes and limit protein expression. This situation is perhaps most prevalent in current nonviral polycationic gene-delivery systems in which the polycationic nature of the delivery system can lead to cytotoxicity. To approach the problem of creating nontoxic but effective gene-delivery systems, we hypothesized that by optimizing the balance between polymer cationic density with endosomal escape moieties, effective gene transfer with low cytotoxicity could be created. As a model system, we synthesized a series of polymers whose side-chain termini varied with respect to the balance of cationic centers and endosomal escape moieties. Specifically, by polymer-analogous amidation we conjugated imidazole groups to the epsilon-amines of polylysine in varying mole ratios (73.5 mol % imidazole, 82.5 mol % imidazole, and 86.5 mol % imidazole). The primary epsilon-amine terminus of polylysine served as a model for the cationic centers, whereas the imidazole groups served as a model for the endosomal escape moieties. These polymers condensed plasmid DNA into nanostructures <150 nm and possessed little cytotoxicity in vitro. Transfection efficiency, as measured by luciferase protein expression, increased with increasing imidazole content of the polymers in a nonlinear relationship. The polymer with the highest imidazole content (86.5 mol %) mediated the highest protein expression, with levels equal to those mediated by polyethylenimine, but with little to no cytotoxicity. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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