Tailoring functional polymeric gene carriers

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Publication Type dissertation
School or College College of Pharmacy
Department Pharmaceutics & Pharmaceutical Chemistry
Author Benns, Jonathan Michael
Title Tailoring functional polymeric gene carriers
Date 2001-12
Description A systematic approach to determine the parameters that will dictate the design of functional gene carriers has begun to be implemented. Poly(L-histidine) (PLH) was shown to induce membrane fusion at endosomal pH values, whereas poly(L-lysine) (PLL) has been shown to condense plasmid DNA into small particles. N-Ac-poly(L histidine)-graft-poly(L-lysine) (PLH-g-PLL) was synthesized by grafting poly(L-histidine) to poly(L-lysine). PLH-g PLL formed complexes with DNA, where particle sizes ranged from 117 ± 6 nm to 306 ± 77 nm. PLH-g-PLL showed higher transfection efficiency and lower toxicity in 293T cells compared to PLL at all equivalent weight ratios. For the purpose of targeting cancer cells, folate-polyethylene glycol)-folate-grafted-polyethylenimine (FPF-g-PEI) was synthesized at a range of grafting ratios of folate-polyethylene glycol)-folate (FPF) to polyethylenimine (PEI). FPF-g-PEIs have 2.3, 5.2, 9.3 and 20 FPFs grafted to PEI. Molecular weight was ?34,848, 47,266, 64,823 and 110,640 Da, respectively. Atomic force microscopy showed FPF-2.3g-PEI and PEI condensed DNA into oblique spheroid complexes with a diameter of ?150-200 nm. Transfection efficiency was different for CT-26 colon adenocarcinoma cells, KB oral epidermoid and normal smooth muscle cells (SMC). In CT-26 cells, FPF-2.3g-PEI and FPF-5.2g-PEI/pLuc complexes gave higher transfection efficiencies compared to PEI/pLuc complexes. In KB cells folate targeting was observed at low charge ratios, but nonspecific ionic association was observed at neutral charge ratio of FPF-g-PEI/pLuc. Smooth muscle cells showed no folate receptor activity, where PEI/pLuc complexes had superior transfection efficiencies. Free folic acid was shown to inhibit transfection with FPF-2.3g-PEI/pLuc in CT-26 cells. At neutral charge ratio, increase in the concentrations of complexes increased transfection. At 3/1 (+/?) ratio, increase in complex concentrations increased toxicity, and decreased transfection efficiency. Cytotoxicity was determined using an MTT assay. FPF-g-PEIs were less toxic compared to PEI. This decrease in toxicity was observed in all cell lines. Compared to PEI/pLuc complexes at neutral charge ratio, FPF-g-PEI/pLuc complexes were less toxic to the cells. When neutral complex concentrations increased, toxicity did not markedly increase. However, when charged complex concentrations increased, toxicity was increased.
Type Text
Publisher University of Utah
Subject Therapy
Subject MESH Drug Delivery Systems; Gene Therapy; Neoplasms
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "Tailoring Functional Polymeric Gene Carriers". Spencer S. Eccles Health Sciences Library.
Rights Management © Jonathan Michael Benns.
Format Medium application/pdf
Format Extent 2,268,646 bytes
Identifier undthes,4254
Source Original: University of Utah Spencer S. Eccles Health Sciences Library (no longer available).
Master File Extent 2,268,693 bytes
ARK ark:/87278/s68k7bvv
Setname ir_etd
Date Created 2012-04-24
Date Modified 2012-04-24
ID 190627
Reference URL https://collections.lib.utah.edu/ark:/87278/s68k7bvv