Cellular uptake pathways of lipid-modified cationic polymers in gene delivery to primary cells

Hsu, Charlie Yu Ming; Uludağ, Hasan

doi:10.1016/j.biomaterials.2012.06.093

Cited by 70 publications

(71 citation statements)

References 62 publications

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“…The confocal images are similar to those observed in a recent study, although those researchers used lipid-modified cationic polymers as the delivery system. 36–37 …”

Section: Resultsmentioning

confidence: 99%

Novel Gemini cationic lipids with carbamate groups for gene delivery

et al. 2014

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To obtain efficient non-viral vectors, a series of Gemini cationic lipids with carbamate linkers between headgroups and hydrophobic tails were synthesized. They have the hydrocarbon chains of 12, 14, 16 and 18 carbon atoms as tails, designated as G12, G14, G16 and G18, respectively. These Gemini cationic lipids were prepared into cationic liposomes for the study of the physicochemical properties and gene delivery. The DNA-bonding ability of these Gemini cationic liposomes was much better than their mono-head counterparts (designated as M12, M14, M16 and M18, respectively). In the same series of liposomes, bonding ability declined with an increase in tail length. They were tested for their gene-transferring capabilities in Hep-2 and A549 cells. They showed higher transfection efficiency than their mono-head counterparts and were comparable or superior in transfection efficiency and cytotoxicity to the commercial liposomes, DOTAP and Lipofectamine 2000. Our results convincingly demonstrate that the gene-transferring capabilities of these cationic lipids depended on hydrocarbon chain length. Gene transfection efficiency was maximal at a chain length of 14, as G14 can silence about 80 % of luciferase in A549 cells. Cell uptake results indicate that Gemini lipid delivery systems could be internalised by cells very efficiently. Thus, the Gemini cationic lipids could be used as synthetic non-viral gene delivery carriers for further study.

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“…The confocal images are similar to those observed in a recent study, although those researchers used lipid-modified cationic polymers as the delivery system. 36–37 …”

Section: Resultsmentioning

confidence: 99%

Novel Gemini cationic lipids with carbamate groups for gene delivery

et al. 2014

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“…Previous results show that the endocytosis pathway is dependent on both cell-line and vector type. [36][37][38][39][40] Entry of the non-viral vectors into the nucleus is paramount for transfection (i.e. protein production).…”

Section: Introductionmentioning

confidence: 99%

Intracellular Trafficking Pathways for Nuclear Delivery of Plasmid DNA Complexed with Highly Efficient Endosome Escape Polymers

et al. 2014

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Understanding the pathways for nuclear entry could see vast improvements in polymer design for the delivery of genetic materials to cells. Here, we use a novel diblock copolymer complexed with plasmid DNA (pDNA) to determine both its cellular entry and nuclear pathways. The diblock copolymer (A-C3) is specifically designed to bind and protect pDNA, release it at a specific time, but more importantly, rapidly escape the endosome. The copolymer was taken up by HEK293 cells preferentially via the clathrin-mediated endocytosis (CME) pathway, and the pDNA entered the nucleus to produce high gene expression levels in all cells after 48 h, a similar observation to the commercially available polymer transfection agent, PEI Max. This demonstrates that the polymers must first escape the endosome and then mediate transport of pDNA to the nucleus for occurrence of gene expression. The amount of pDNA within the nucleus was found to be higher for our A-C3 polymer than PEI Max, with our polymer delivering 7 times more pDNA than PEI Max after 24 h. We further found that entry into the nucleus was primarily through the small nuclear pores and did not occur during mitosis when the nuclear envelope becomes compromised. The observation that the polymers are also found in the nucleus supports the hypothesis that the large pDNA/polymer complex (size ~200 nm) must dissociate prior to nucleus entry and that cationic and hydrophobic monomer units on the polymer may facilitate active transport of the pDNA through the nuclear pore.

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“…Phospholipids-based liposomal vesicles have evolved as a promising tool for delivery of drug, genes and nutrients due to intensive investigations for decades [1-4]. Stability of liposomes has been a key issue which limit its application as most liposomes with phosphatidylcholine (PC) as primary components have low stability [4-6].…”

Section: Introductionmentioning

confidence: 99%

Facile Synthesis of Phosphatidyl Saccharides for Preparation of Anionic Nanoliposomes with Enhanced Stability

et al. 2013

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Physical stability during storage and against processing such as dehyration/rehydration are the cornerstone in designing delivery vehicles. In this work, mono-, di- and tri-saccharides were enzymatically conjugated to phosphatidyl group through a facile approach namely phospholipase D (PLD) mediated transphosphatidylation in a biphasic reaction system. The purified products were structurally identified and the connectivities of carbohydrate to phosphatidyl moiety precisely mapped by 1H, 31P, 13C NMR pulse sequences and LC-ESI-FTMS. The synthetic phosphatidyl saccharides were employed as the sole biomimetic component for preparation of nanoliposomes. It was found that the critical micelle concentration (CMC) of phosphatidyl saccharides increases as more bulky sugar moiety (mono- to tri-) is introduced. Phosphatidyl di-saccharide had the largest membrane curvature. In comparison to the zwitterionic phosphatidylcholine liposome, all phosphatidyl saccharides liposomes are anionic and demonstrated significantly enhanced stability during storage. According to the confocal laser scan microscopy (CLSM) and atom force microscopy (AFM) analyses, the nanoliposomes formed by the synthetic phosphatidyl saccharides also show excellent stability against dehydration/rehydration process in which most of the liposomal structures remained intact. The abundance hydroxyl groups in the saccharide moieties might provide sufficient H-bondings for stabilization. This work demonstrated the synthesized phosphatidyl saccharides are capable of functioning as enzymatically liable materials which can form stable nanoliposomes without addition of stabilizing excipients.

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Cellular uptake pathways of lipid-modified cationic polymers in gene delivery to primary cells

Cited by 70 publications

References 62 publications

Novel Gemini cationic lipids with carbamate groups for gene delivery

Novel Gemini cationic lipids with carbamate groups for gene delivery

Intracellular Trafficking Pathways for Nuclear Delivery of Plasmid DNA Complexed with Highly Efficient Endosome Escape Polymers

Facile Synthesis of Phosphatidyl Saccharides for Preparation of Anionic Nanoliposomes with Enhanced Stability

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