RT Journal Article
T1 A delocalizable cationic headgroup together with an oligo-oxyethylene spacer in gemini cationic lipids improves their biological activity as vectors of plasmid DNA
A1 Kumar, Krishan
A1 Barrán-Berdón, Ana
A1 Datta, Sougata
A1 Muñoz Úbeda, Mónica
A1 Aicart-Ramos, Clara
A1 Kondaiah, Paturu
A1 Junquera González, María Elena
A1 Bhattacharya, Santanu
A1 Aicart Sospedra, Emilio
AB Lipoplex nano-aggregates constituted of plasmid DNA (pDNA) pEGFP-C3 and mixed cationic liposomes, consisting of several percentages of a gemini cationic lipid (GCL) of the 1,2-bis(hexadecyl imidazolium) oxyethylene series, referred to as (C16Im)2(C2O)n, with oxyethylene spacers (n = 1, 2 or 3) between the imidazolium cationic groups and the DOPE zwitterionic helper lipid, have been characterized by various biophysical and biological approaches carried out at several GCL compositions (α), and either the mass or the effective charge ratio of the lipoplex. The electrochemical study by ζ-potential confirms that the three GCLs yield a 10% lower effective charge than the nominal one, while compacted pDNA yields only a 25% effective negative charge. The SAXS study reveals, irrespective of the spacer length (n) and effective charge ratio (ρeff), the presence of two lamellar structures, i.e., one (Lα,main) in the whole GCL composition and another (Lα,DOPE,rich) with higher periodicity values that coexists with the previous one at low GCL composition (α = 0.2). The cryo-TEM analysis shows two types of multilamellar structures consisting of cationic lipidic bilayers with pDNA sandwiched between them: a cluster-type (C-type) at low α = 0.2 and a fingerprint-type (FP-type) at α ≥ 0.5, both with similar interlamellar spacing (d) in agreement with the Lα,main structure determined by SAXS. Transfection efficacies (TEs) of each lipid mixture were determined in four different cell lines (HEK293T, HeLa, Caco-2 and A549) at several α and ρeff values in the absence and presence of serum (FBS). The optimized formulations (α = 0.2 and ρeff = 2.0) substantially transfect cells much better than a commercial transfection reagent, Lipofectamine 2000 and previously studied efficient lipoplexes containing other cationic head groups or spacers both in the absence and presence of serum. The activity of optimized formulations may be attributed to the combination of several factors, such as: (a) the fusogenic character of DOPE which results in higher fluidity of the lipoplexes at α = 0.2, (b) the coexistence of two lamellar structures at α = 0.2 that synergizes the TE of these lipid vectors, and mainly (c) the higher biocompatibility of the GCLs reported in this work due to the presence of two imidazolium cationic groups together with an oligo-oxyethylene spacer. The length of the spacer in the GCL seems to have less impact, although (C16Im)2(C2O)n/DOPE-pDNA lipoplexes with n = 1 and 3 show higher gene transfection than n = 2. All the optimum formulations reported herein are all highly efficient with negligible levels of toxicity, and thus, may be considered as very promising gene vectors for in vivo applications.
PB The Royal Society of Chemistry
SN 2050-750X
YR 2015
FD 2015
LK https://hdl.handle.net/20.500.14352/92277
UL https://hdl.handle.net/20.500.14352/92277
LA eng
NO Kumar, K.; Barrán-Berdón, A. L.; Datta, S.; Muñoz-Úbeda, M.; Aicart-Ramos, C.; Kondaiah, P.; Junquera, E.; Bhattacharya, S.; Aicart, E. A delocalizable cationic headgroup together with an oligo-oxyethylene spacer in gemini cationic lipids improves their biological activity as vectors of plasmid DNA. J. Mater. Chem. B 2015, 3, 1495-1506 DOI:10.1039/C4TB01948B
DS Docta Complutense
RD 11 abr 2025