Search results for "Liposome"

The influence of tin compounds on the dynamic properties of liposome membranes: A study using the ESR method

2005

AbstractThe influence of organic and inorganic compounds of tin on the dynamic properties of liposome membranes obtained in the process of dipalmitoylphosphatidylcholine (DPPC) sonication in distilled water was investigated. This was carried out by means of the spin ESR probe method. The probes were selected in such a way as to penetrate different areas of the membrane (a TEMPO probe, 5-DOXYL stearic acid, 16-DOXYL stearic acid). Four compounds of tin were chosen: three organic ones, (CH3)4Sn, (C2H5)4Sn and (C3H7)3SnCl, and one inorganic one, SnCl2. The investigated compounds were added to a liposome dispersion, which was prepared prior to that. The concentration of the admixture was change…

Resistance to water and abrasion of a broad-spectrum sunscreen: a prospective, open-label study.

2015

The influence of natural and model forms of humic acids on the dynamic parameters of model membranes

2016

In this paper the influence of humic acid concentrations extracted from Histosols (HA-A) and their model forms (HA-B) separated from humic substances commercially produced by Carl Roth GmbH + Co.KG on the dynamic properties of liposome membranes was determined. Differences in the quality of the humic acids (HA-A and HA-B) were determined by the 1HNMR and FTIR methods. Liposomes from the sonication of egg yolk lecithin (EYL) in an aqueous solution and synthetic Dipalmitoylphosphatidylcholine (DPPC) were used. Fluidity of liposome membranes was determined by the EPR technique with spin probes (TEMPO, 16DOIXYL). The electrical parameters of membranes were found using a Keithley 6517 electromet…

Stabilization of unilamellar catanionic vesicles induced by β-cyclodextrins: A strategy for a tunable drug delivery depot.

2018

The limited stability of catanionic vesicles has discouraged their wide use for encapsulation and controlled release of active substances. Their structure can easily break down to form lamellar phases, micelles or rearrange into multilamellar vesicles, as a consequence of small changes in their composition. However, despite the limited stability, catanionic vesicles possess an attractive architecture, which is able to efficiently encapsulate both hydrophobic and hydrophilic molecules. Therefore, improving the stability of the vesicles, as well as the control on unilamellar structures, are prerequisites for their wider application range. This study focuses on the impact of β-cyclodextrins fo…

COMBINATION OF ARGAN OIL AND PHOSPHOLIPIDS FOR THE DEVELOPMENT OF AN EFFECTIVE LIPOSOME-LIKE FORMULATION ABLE TO IMPROVE SKIN HYDRATION AND ALLANTOIN…

2016

Allantoin is traditionally employed in the treatment of skin ulcers and hypertrophic scars. In the present work, to improve its local deposition in the skin and deeper tissues, allantoin was incorporated in conventional liposomes and in new argan oil enriched liposomes. In both cases, obtained vesicles were unilamellar, as confirmed by cryo-TEM observation, but the addition of argan oil allowed a slight increase of the mean diameter (∼130nm versus ∼85nm). The formulations, especially those containing argan oil, favoured the allantoin accumulation in the skin, in particular in the dermis (∼8.7μg/cm(2)), and its permeation through the skin (∼33μg/cm(2)). The performances of vesicles as skin d…

Nanodesign of new self-assembling core-shell gellan-transfersomes loading baicalin and in vivo evaluation of repair response in skin

2017

Gellan nanohydrogel and phospholipid vesicles were combined to incorporate baicalin in new self-assembling core-shell gellan-transfersomes obtained by an easy, scalable method. The vesicles were small in size (~107 nm) and monodispersed (P.I. ≤ 0.24), forming a viscous system (~24 mPa/s) as compared to transfersomes (~1.6 mPa/s), as confirmed by rheological studies. Gellan was anchored to the bilayer domains through cholesterol, and the polymer chains were distributed onto the outer surface of the bilayer, thus forming a core-shell structure, as suggested by SAXS analyses. The optimal carrier ability of core-shell gellan-transfersomes was established by the high deposition of baicalin in th…

Micellar liquid chromatography for prediction of drug transport.

2000

Abstract The vast majority of well absorbed drugs are transported passively across the cell membranes. Physicochemical descriptors of drug molecules that are believed to influence transcellular transport are routinely used to predict drug absorption by means of complex mathematical models. In this paper, a new in vitro method, based on the retention data in micellar liquid chromatography (MLC), is validated for the prediction of passive drug absorption. The retention of a heterogeneous drugs set in MLC using Brij 35 as surfactant in the mobile phase is compared with the retention data reported in literature obtained in red cell membrane lipid liposomes, human red cell membranes vesicles (ve…

Liposomal-encapsulated doxorubicin plus cyclophosphamide as first-line therapy in metastatic breast cancer: a phase II multicentric study

2007

Abstract Background The objective of this study is to evaluate the efficacy and toxicity of the liposome-encapsulated doxorubicin (TLC D-99) plus cyclophosphamide (CTX) as first-line treatment of metastatic breast cancer in light of the potential cardioprotective effect of TLC D-99 as compared with conventional doxorubicin. Materials and methods Sixty-seven patients as defined according Simon's two-stage phase II design were enrolled. They received TLC D-99 at the dosage of 60 mg/m2 plus CTX 600 mg/m2, with cycles repeated every 3 weeks. Cardiac function was assessed by ultrasonography at baseline and every two cycles. Results The principal characteristics of the 67 enrolled patients were a…

Thermodynamic Study of Small Hydrophobic Ions at the Water–Lipid Interface

2001

Abstract The thermodynamics of binding of two small hydrophobic ions such as norharman and tryptophan to neutral and negatively charged small unilamellar vesicles was investigated at pH 7.4 using fluorescence spectroscopy. Vesicles were formed at room temperature from dimyristoyl phosphatidylcholine (DMPC) or DMPC/dimyristoylphosphatidic acid and DMPC/dimyristoylphosphatidylglycerol. The changes in fluorescence properties were used to obtain association isotherms at variable membrane surface negative charge and at different ionic strengths. The binding of both ions was found to be quantitatively enhanced as the percentage of negative phospholipid increases in the membrane. Also, a decrease …

TTAPE-Me dye is not selective to cardiolipin and binds to common anionic phospholipids nonspecifically

2021

Identification, visualization, and quantitation of cardiolipin (CL) in biological membranes is of great interest because of the important structural and physiological roles of this lipid. Selective fluorescent detection of CL using noncovalently bound fluorophore 1,1,2,2-tetrakis[4-(2-trimethylammonioethoxy)-phenylethene (TTAPE-Me) has been recently proposed. However, this dye was only tested on wild-type mitochondria or liposomes containing negligible amounts of other anionic lipids, such as phosphatidylglycerol (PG) and phosphatidylserine (PS). No clear preference of TTAPE-Me for binding to CL compared to PG and PS was found in our experiments on artificial liposomes, Escherichia coli ins…