Novel reducible linear L-lysine-modified copolymers as efficient nonviral vectors.
The development of biodegradable gene delivery systems with high transfection efficiencies is paramount to the clinical translation of nonviral gene carriers. Therefore, to produce a biocompatible, reducible, effective and non-toxic gene delivery system, we have designed and synthesized novel reducible linear L-lysine modified copolymers (LLCs) as an alternative to high molecular weight poly(L-lysine) (PLL). The molecular weight (MW) of the copolymers was found to be approximately 3.2kDa with a polydispersity index of approximately 1.2. Gel retardation assays showed complete condensation of DNA at N/P ratios greater than 20/1 and exceptional LLC/pDNA polyplex stability during incubation with DNase I. Release of DNA from the polyplexes only occurred in the presence of the reducing agent dithiothreitol (DTT). The particle sizes of LLC/pDNA polyplexes were found to be between 100 and 231 nm with surface charges of 0.8-17 mV respectively. The transfection efficiencies of the polyplexes as determined with a luciferase assay showed that LLC polyplexes produced five times higher transfection efficiencies in HDF cells, three times higher transfection efficiencies in MCF-7 cells, and four times higher transfection efficiencies in MA cells as compared to the optimal PLL control. The LLC/pDNA polyplexes showed significantly lower cytotoxicities as compared to the control in HDF, MCF-7 and MA cells at certain N/P ratios. Therefore, these results suggest that these novel LLCs are efficient, reducible and biocompatible polymers for nonviral gene delivery.
Nounou
Mohamed Ismail
MI
Department of Pharmacological and Pharmaceutical Sciences, 1441 Moursund Street, University of Houston, Texas Medical Center Campus, Houston, Texas 77030, USA.
Emmanouil
Kalyopy
K
Chung
Samuel
S
Pham
Thu
T
Lu
Zhuoyuan
Z
Bikram
Malavosklish
M
D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D045744:Cell Line, Tumor; D002470:Cell Survival; D004247:DNA / Q000008:administration & dosage*; D006801:Humans; D008239:Lysine / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D010957:Plasmids / Q000008:administration & dosage; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D014162:Transfection
D001672:Biocompatible Materials; D011108:Polymers; D004247:DNA; D008239:Lysine