Palmitic Acid-Modified Poly-l-Lysine for Non-Viral Delivery of Plasmid DNA to Skin Fibroblasts

Abstract

Palmitic acid conjugates of poly-L-lysine (PLL-PA) were prepared, and their ability to deliver plasmid DNA into human skin fibroblasts was evaluated in vitro. The conjugates were capable of condensing a 4.7 kb plasmid DNA into 50-200 nm particles (mean +/- SD = 112 +/- 34 nm), which were slightly smaller than the particles formed by PLL (mean +/- SD = 126 +/- 51 nm). Both PLL and PLL-PA were readily taken up by the cells, but PLL-PA delivered the plasmid DNA into a higher proportion of cells. DNA delivery was found to be reduced by endocytosis inhibitor Brefeldin A, suggesting an active mechanism of particle uptake. Using enhanced green fluorescent protein (EGFP) as a reporter gene, PLL-PA was found to give the highest number of EGFP-positive cells among several carriers tested, including polyethyleneimine, Lipofectamine-2000, and an adenovirus. Although some carriers gave a higher percentage of EGFP-positive cells than PLL-PA, they were also associated with higher toxicities. We conclude that PLL-PA is a promising gene carrier for non-viral modification of human fibroblasts.

Cationic polymer‐mediated small interfering RNA delivery for P‐glycoprotein down‐regulation in tumor cells

“…22,23 The finding that an efficient siRNA delivery also has been obtained with these polymers opens a new possibility for the use of the lipid-substituted polymers in down-regulating aberrant genes. The limitations of chemotherapy because of MDR are well recognized, 8 and siRNA knockdown of P-gp is a promising option for overcoming this problem.…”

“…The synthesis and characterization of the PLL-StA (degree of substitution, 10 stearic acids per PLL) were described previously by Abbasi et al 22 The synthesis and characterization of PEI-OA (degree of substitution, 4.6 oleic acids per PEI) were described previously by Alshamsan et al 21 MTT Assay for Cytotoxicity MDR1 cells and WT cells were seeded in 24-well plates in 0.5 mL RPMI medium and allowed to attach overnight.…”

“…22,23 Lipid substitution on cationic polymers enhanced the transport of plasmid DNA across cellular membranes. 23 In the current study, we explored the feasibility of this type of carriers for siRNA delivery with the purpose of Pgp down-regulation in a tumor cell model.…”

A comparative evaluation of poly-l-lysine-palmitic acid and Lipofectamine ™ 2000 for plasmid delivery to bone marrow stromal cells

“…Particles smaller than 9 nm can enter the nucleus by diffusion through the nuclear pore complex, whereas larger particles (o28 nm) require active transport in non-dividing cells [37]. The size of the particles formed by complexing pEGFP with PLL or PLL-PA was previously reported to range from 30 to 200 nm [38]. Therefore, pEGFP/polymer complexes were unlikely to enter the nucleus via the nuclear pore complexes, so that their nuclear uptake might have occurred in dividing cells.…”

Selective immobilization of biomolecules onto an activated polymeric adlayer

“…Therefore, one of the key steps in the construction of microarrays is the immobilization of biomolecules onto solid surfaces. Up to date, a variety of surface modification methods, including self-assembled monolayers ͑SAMs͒, [7][8][9][10] poly͑L-lysine͒ coating, 11,12 nitrocellulose adlayers, 13,14 have been utilized to immobilize biomolecules. In particular, SAMs have been widely used and considered as a reliable strategy to construct microarrays on gold surfaces.…”