Structural characterization of the poly(ethylene glycol) layer of sterically stabilized liposomes by means of FTIR spectroscopy

Varga, Zoltán; Mihály, Judith; Berényi, Szilvia; Bóta, Attila

doi:10.1016/j.eurpolymj.2013.02.025

Cited by 25 publications

(16 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The peaks around 1100 cm -1 were the characteristic peak for stretching in C-C, C-O, and C=O bonds as well as bending vibration in C-C and C-O bonds (Chylińska et al 2016;Muthukumaran & Philip 2016). The band at 1146 cm -1 in Figure 1(a) was the main characteristic of polyethylene glycol (PEG) molecules (Deygen & Kudryashova 2016), which can be further used for determination either it was related to trans conformation or gauche conformation with respective to C-C bond while the asymmetric PO 2 stretching region can be observed by the peak at 1240 cm -1 (Varga et al 2013). The significant peak around 1700 cm -1 was due to the presence of stretching vibration at the C=O bond in all materials Varga et al 2013).…”

Section: Resultsmentioning

confidence: 99%

Pegylated Oleic Acid-Lecithin Liposomes (Poll) for Anticancer Drug Delivery

Suk¹,

Chung²,

Misran³

2020

JSM

View full text Add to dashboard Cite

Cancer is a major health issue, conferring to more than 14.5 million deaths worldwide. Liposomes, self-assembly amphiphilic bilayer molecules, served as excellent alternative vehicles due to their ability to encapsulate both hydrophobic and hydrophilic anticancer drugs. Conventional liposomes, comprised mainly phospholipids are costineffective, unstable, and easily degraded by the external environment. In this study, we introduced PEGylated oleic acid-lecithin liposomes constructed by using C-18 monounsaturated fatty acids (oleic acid) and soy lecithin, in the presence of DOPEPEG2000 in pH7.4, above their glass transition temperature, T g , by employing the simple thin layer lipid hydration method. FTIR spectrum of oleic acid, soy lecithin, and DOPEPEG2000 was studied. The average particle size without further mechanical interference was 1102.3 nm while the zeta potential value was -18 mV, which is compatible with the zeta potential of the red blood cell. The polydispersity index (PDI) was reduced by 46.2% with the incorporation of the DOPEPEG2000. The morphological study using OPM showed the presence of spherical shape liposomes that exhibit the birefringence effect under the light field and Maltese cross under the dark field. Encapsulation of folinic acid, methotrexate, doxorubicin, or irinotecan resulted in greater than 75% encapsulation efficiency (EE). Half-maximal inhibitory concentration, IC 50 , was significantly reduced in POLL as compared to free anticancer drugs. Our data demonstrate POLL may be a promising alternative vehicle to deliver various anticancer drugs to targeted tumour sites. ABSTRAKBarah merupakan isu kesihatan utama yang menyebabkan lebih 14.5 juta kematian di seluruh dunia. Liposom, iaitu molekul swabentuk dwilapis merupakan penghantar alternatif terbaik berikutan kebolehannya untuk mengkapsulkan ubatan anti barah hidrofobik dan hidrofilik. Liposom yang lazimnya diperbuat daripada fosfolipid adalah tidak efektif daripada segi kos, tidak stabil dan mudah terurai oleh persekitaran luar. Dalam kajian ini, kami memperkenalkan liposom asid olik-lesitin berPEG yang terdiri daripada asid lemak tak tepu C-18 (asid olik) dan lesitin soya, dengan kehadiran DOPEPEG2000 dalam pH7.4, pada suhu lebih tinggi daripada suhu peralihan gelas T g , menggunakan metod hidrasi lapisan nipis lipid. Spektrum FTIR asid olik, lesitin soya, dan DOPEPEG2000 juga turut dikaji. Purata saiz partikel adalah 1102.3 nm manakala keupayaan zeta adalah -18 mV, sesuai dengan keupayaan zeta sel darah merah. Indeks polisebaran telah berkurang sebanyak 46.2% dengan penambahan DOPEPEG2000. Kajian morfologi menggunakan Mikroskop Optikal Pengutuban menunjukkan kewujudan liposom berbentuk sfera yang menghasilkan kesan dwibiasan pada medan cerah dan silang Maltese pada medan gelap. Pengkapsulan asid folinik, metotreksat, doksorubisin atau irinotecan menghasilkan lebih 75% kecekapan pengkapsulan. Kepekatan separa rencatan, IC 50 , telah berkurang dengan signifikan pada POLL berbanding ubatan anti barah. Data menunjukkan POLL mungkin ...

show abstract

Section: Resultsmentioning

confidence: 99%

Pegylated Oleic Acid-Lecithin Liposomes (Poll) for Anticancer Drug Delivery

Suk¹,

Chung²,

Misran³

2020

JSM

View full text Add to dashboard Cite

show abstract

“…The broad band that appears near 3500 cm À1 was attributed to the presence of water molecules. At 1600 cm À1 another band appeared, corresponding to the presence of water molecules in the samples 24 . Interesting results have been obtained at about 1800 cm À1 , where a narrow band appears, related to the stretching of the carbonyl group C¼O of the secondary amine attached to the IgG (line blue).…”

Section: Ftir Spectroscopymentioning

confidence: 97%

Surface functionalizing of a lipid nanosystem to promote brain targeting: step-by-step design and physico-chemical characterization

Cózar-Bernal

García-Esteban

Soto

et al. 2015

Pharmaceutical Development and Technology

View full text Add to dashboard Cite

The use of lipid nanosystems as drug delivery to the central nervous system may be advantageous over the current strategies. The aim of this study was to develop and characterize functionalized liposomes for treatment of brain diseases. The covalent method of coupling IgG to liposomes via the derivatized lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-[4-(p-maleimidophenyl)butyramide](MPB-PE) was investigated. Optimized coupling conditions are shown to result in the efficient conjugation of IgG to liposomes containing low concentrations of MPB-PE (3/1 SH:IgG). The qualitative analysis has shown that after the extrusion process, more homogeneous populations of vesicles have been obtained with a nanometric size suitable to be effective to further anchor the protein. Negative values of zeta potential demonstrate that they are stable systems. Lyophilization was used to maintain the stability of the formulation. These very interesting results encourage further investigations to formulate peptide- and protein-loaded immunoliposomes, making targeting of liposomes as an attractive approach for brain drug delivery.

show abstract

“…A higher extent of intramolecular H-bonding of the C-O-C groups of the PEG moiety to a neighboring etheric oxygen results in a greater proportion of the more constrained gauche conformer with an appropriate increase of relative intensity. Thus, the ratio of the trans and gauche conformations can be a marker to characterize the PEG layer structure and, indirectly, the hydration state [26].…”

Section: As Dehydrates Peg Chainsmentioning

confidence: 99%

Aggregation of PEGylated liposomes driven by hydrophobic forces

Bozó

Mészáros

Mihály

et al. 2016

Colloids and Surfaces B: Biointerfaces

View full text Add to dashboard Cite

2 Graphical Abstract 3 Highlights Kosmotropes induce the aggregation and fusion of PEG-liposomes.  The effect depends on both the kosmotrope and PEG concentration.  Aggregation is reversible under certain conditions.  Kosmotropes lead to a dehydration-related conformational change of the PEG polymer.  The likely driving force behind aggregation is the hydrophobic effect. 4 ABSTRACTPolyethylene glycol (PEG) is widely used to sterically stabilize liposomes and improve the pharmacokinetic profile of drugs, peptides and nanoparticles. Here we report that ammonium sulfate (AS) can evoke the aggregation of PEGylated vesicles in a concentration-dependent manner. Liposomes with 5 mol% PEG were colloidally stable at AS concentrations up to 0.7 mM, above which they precipitated and formed micron-size aggregates with irregular shape. While aggregation was reversible up to 0.9 M of AS, above 1 M fusion occurred, which irreversibly distorted the size distribution. Zeta potential of liposomes markedly increased from -71±2.5 mV to 2±0.5 mV upon raising the AS concentration from 0 to 0.1 M, but no considerable increase was seen during further AS addition, showing that the aggregation is independent of surface charge. There was no aggregation in the absence of the PEG chains, and increasing PEG molar % shifted the aggregation threshold to lower AS concentrations. Changes in the FTIR spectral features of PEGylated vesicles suggest that AS dehydrates PEG chains. Other kosmotropic salts also led to aggregation, while chaotropic salts did not, which indicates a general kosmotropic phenomenon. The driving force behind aggregation is likely to be the hydrophobic effect due to salting out the polymer similarly to what happens during protein purification or Hydrophobic Interaction Chromatography. Since liposome aggregation and fusion may result in difficulties during formulation and adverse reaction upon application, the phenomena detailed in this paper may have both technological and therapeutical consequences.

show abstract

Structural characterization of the poly(ethylene glycol) layer of sterically stabilized liposomes by means of FTIR spectroscopy

Cited by 25 publications

References 20 publications

Pegylated Oleic Acid-Lecithin Liposomes (Poll) for Anticancer Drug Delivery

Pegylated Oleic Acid-Lecithin Liposomes (Poll) for Anticancer Drug Delivery

Surface functionalizing of a lipid nanosystem to promote brain targeting: step-by-step design and physico-chemical characterization

Aggregation of PEGylated liposomes driven by hydrophobic forces

Contact Info

Product

Resources

About