Reverse-phase Evaporation Method Research Articles

Encapsulation of Zwitterionic Au Nanocrystals into Liposomes by Reverse Phase Evaporation Method: Influence of the Surface Charge.

Since both liposomes and nanoparticles have shown great potential in application for clinical diagnostics and therapeutics, the perfect combination of the two materials is appealing for further improving the theranostic effect. Therefore, fabrication of liposomes loaded with nanoparticles in a controllable manner is desirable. Detection of various factors affecting encapsulation needs to be assigned. Here, we use zwitterionic Au nanoparticles (Au±NPs) coated with a mixture of 11-mercaptoundecanoic acid and N,N,N-trimethyl(11-mercaptoundecyl) ammonium chloride to study their encapsulation behavior by reversed phase evaporation (REV) method. To produce a reverse emulsion, an organic solution of dipalmitoylphosphatidylcholine (DPPC) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (ammonium salt) (PEG2000-DOPE) is mixed with an aqueous Au±NP colloidal solution under sonication. The pH of the colloidal solution controls the surface charge of the Au±NPs and then tunes the interactions between Au±NPs and phospholipids. At lower pH, the positive surface charges favor Au±NP transfer into the organic phase and consequently prevent their encapsulation into liposomes. The efficiency in encapsulation is markedly improved by increasing the pH of the Au±NP colloidal solution. The highest efficiency is obtained at a pH value slightly larger than the isoelectric point. Further pH increase induces a decrease in encapsulation efficiency. This is due to increase of the repulsive forces between Au±NPs and phospholipids indicating that both the nature (positive or negative) and the amount of surface charge are key parameters in the encapsulation efficiency. We also find that the increase in Au±NP concentration favors the encapsulation process.

Optimization of Preparation Conditions for Lysozyme Nanoliposomes Using Response Surface Methodology and Evaluation of Their Stability.

The main purpose of this study was to optimize the preparation of lysozyme nanoliposomes using response surface methodology and measure their stability. The stabilities of lysozyme nanoliposomes in simulated gastrointestinal fluid (SGF), simulated intestinal fluid (SIF), as well as pH, temperature and sonication treatment time were evaluated. Reverse-phase evaporation method is an easy, speedy, and beneficial approach for nanoliposomes’ preparation and optimization. The optimal preparative conditions were as follows: phosphatidylcholine-to-cholesterol ratio of 3.86, lysozyme concentration of 1.96 mg/mL, magnetic stirring time of 40.61 min, and ultrasound time of 14.15 min. At the optimal point, encapsulation efficiency and particle size were found to be 75.36% ± 3.20% and 245.6 nm ± 5.2 nm, respectively. The lysozyme nanoliposomes demonstrated certain stability in SGF and SIF at a temperature of 37 °C for 4 h, and short sonication handling times were required to attain nano-scaled liposomes. Under conditions of high temperature, acidity and alkalinity, lysozyme nanoliposomes are unstable.

Design of cholesterol arabinogalactan anchored liposomes for asialoglycoprotein receptor mediated targeting to hepatocellular carcinoma: In silico modeling, in vitro and in vivo evaluation

We have developed active targeting liposomes to deliver anticancer agents to ASGPR which will contribute to effective treatment of hepatocellular carcinoma. Active targeting is achieved through polymeric ligands on the liposome surface. The liposomes were prepared using reverse phase evaporation method and doxorubicin hydrocholoride, a model drug, was loaded using the ammonium sulphate gradient method. Liposomes loaded with DOX were found to have a particle size of 200nm with more than 90% entrapment efficiency. Systems were observed to release the drug in a sustained manner in acidic pH in vitro. Liposomes containing targeting ligands possessed greater and selective toxicity to ASGPR positive HepG2 cell lines due to specific ligand receptor interaction. Bio-distribution studies revealed that liposomes were concentrated in the liver even after 3h of administration, thus providing conclusive evidence of targeting potential for formulated nanosystems. Tumor regression studies indicated greater tumor suppression with targeted liposomes thereby establishing superiority of the liposomal system. In this work, we used a novel methodology to guide the determination of the optimal composition of the targeting liposomes: molecular dynamics (MD) simulation that aided our understanding of the behaviour of the ligand within the bilayer. This can be seen as a demonstration of the utility of this methodology as a rational design tool for active targeting liposome formulation.

Evaluation of the physicochemical properties of liposomes as potential carriers of anticancer drugs: spectroscopic study

Vesicle size and composition are a critical parameter for determining the circulation half-life of liposomes. Size influences the degree of drug encapsulation in liposomes. The geometry, size, and properties of liposomes in an aqueous environment have to be described to enable potential applications of liposome systems as drug carriers. The characteristics of multiple thermotropic phase transitions are also an important consideration in liposomes used for analytical and bioanalytical purposes. The aim of this study was to evaluate the physicochemical properties of liposomes which accommodate hydrophilic and amphiphilic drugs used in cancer therapy. The studied liposomes were prepared with the involvement of the modified reverse-phase evaporation method (mREV). The prepared liposomes had a diameter of 70–150 nm. The analyzed compounds were 1-β-d-arabinofuranosylcytosine, cyclophosphamide, and ifosfamide. In literature, there is no information about simultaneous incorporation of cytarabine, ifosfamide, and cyclophosphamide, in spite of the fact that these drugs have been used for more than 30 years. A combination of the examined drugs is used in CODOX-M/IVAC therapy. CODOX-M/IVAC (cyclophosphamide, doxorubicin, high-dose methotrexate/ifosfamide, etoposide, and high-dose cytarabine) is one of the currently preferred intensive-dose chemotherapy regimens for Burkitt lymphoma (BL). The present research demonstrates the pioneering studies of incorporation of ifosfamide into liposome vesicles, location of and competition between the analyzed drugs and liposome vesicles. The applied methods were nuclear magnetic resonance (NMR), atomic force microscopy (AFM), differential scanning calorimetry (DSC). .

Cytotoxicity of Nanoliposomal Cisplatin Coated with Synthesized Methoxypolyethylene Glycol Propionaldehyde in Human Ovarian Cancer Cell Line A2780CP

Purpose: To evaluate the cytotoxicity of pegylated nanoliposomal cisplatin on human ovarian cancer cell line A2780CP.Methods: Synthesized methoxypolyethylene glycol (mPEG) propionaldehyde was characterized by 1Hnuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FTIR) and used as coating agent for the preparation of liposomal nanodrug formulation by reverse phase evaporation method. The characteristics of the nanoparticles were evaluated by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Encapsulation efficiency was determined spectrometrically at 214.42 nm by inductively coupled plasma spectroscopy (ICP-OES). The cytotoxicity of both pegylated nanoliposomal and free cisplatin were evaluated by 3- [4, 5 dimethyl-2-thiazolyl] -2, 5- diphenyltetrazolium bromide (MTT) assay and expressed as half-maximal inhibitory concentration (IC50).Results: The mean diameter and zeta potential of drug-loaded liposomal particles and empty nanoliposomes were 125 ± 2.9 nm and -16.6 mV, 108 ± 2.2 nm and -27.2 mV, respectively, while the cytotoxicity (IC50) of free cisplatin and nanodrug formulation were 93.6 ± 3.1 μg/mL and 67.8 ± 2.3 μg/mL, respectively. In vitro toxicological results indicate that the formulation exhibited approximately 1.4-fold cytotoxicity compared with the free drug. Drug encapsulation efficiency of the nanoliposomes was approximately 98 ± 1 %.Conclusion: The findings show that the cytotoxicity of pegylated nanoliposomal cisplatin is higher than that of free cisplatin in human ovarian cancer cell line A2780CP. In vivo studies are, however, required to ascertain its therapeutic potentials.Keywords: Liposome, Nanodrug, Ovarian cancer, Polyethylene glycol, Cisplatin, Drug delivery, Cytotoxicity

Intravaginal administration of metformin hydrochloride loaded cationic niosomes amalgamated with thermosensitive gel for the treatment of polycystic ovary syndrome: In vitro and in vivo studies

Background and objectiveMetformin hydrochloride (MTF-HCl) is extensively recommended by physicians for the treatment of polycystic ovary syndrome (PCOS). Mechanistically, MTF-HCl activates AMP-dependent kinase-α (AMPK-α) pathway to decrease the glucose production, enhances fatty acid oxidation and elevates the uptake of glucose in tissues. However, despite favourable physicochemical properties, oral administration of MTF-HCl is associated with impaired bioavailability (50–60%), lactic-acidosis and frequent dosing (500mg 2–3 times a day) in PCOS that ultimately influence the patient compliance. Therefore, in present investigation, MTF-HCl loaded unmodified and cationic small unilamellar niosomes were separately amalgamated with thermosensitive gel (MTF-HCl-SUNs-Gel and MTF-HCl-C-SUNs-Gel) for the treatment of PCOS through vaginal route of administration. Methods and resultsMTF-HCl-SUNs and MTF-HCl-C-SUNs were separately prepared by reverse phase evaporation method. The nanovesicle size and zeta-potential of MTF-HCl-C-SUNs were measured to be 210.3±14.8-nm (P<0.05) and +8.7±2.7-mV (P<0.001), significantly higher than 198.5±20.3-nm and −16.6±3.9-mV of MTF-HCl-SUNs, respectively. Moreover, promising results of in vitro characterization parameters like gelation time, gelling temperature, viscosity analysis, percent mucoadhesiveness and drug release of MTF-HCl-C-SUNs-Gel and MTF-HCl-SUNs-Gel ensured the candidature of tailored gels for further in vivo investigations. In this way, treatment of PCOS rats under scheduled dose-dosage regimen with oral MTF-HCl solution, intravaginal MTF-HCl-SUNs-Gel and intravaginal MTF-HCl-C-SUNs-gel exhibited remarkable alterations, recruitment and development of normal follicles in addition to normalization of level of various hormones in PCOS. ConclusionIn conclusion, MTF-C-SUNs-Gel has paved the way for developing intravaginal dosage form of MTF-HCl for the treatment of PCOS.

Preparation of Nonionic Vesicles Using the Supercritical Carbon Dioxide Reverse Phase Evaporation Method and Analysis of Their Solution Properties.

We have previously reported a new preparation method for liposomes using supercritical carbon dioxide (scCO2) as a solvent, referred to as the supercritical carbon dioxide reverse phase evaporation (scRPE) method. In our previous work, addition of ethanol to scCO2 as a co-solvent was needed, because lipid molecules had to be dissolved in scCO2 to form liposomes. In this new study, niosomes (nonionic surfactant vesicles) were prepared from various nonionic surfactants using the scRPE method. Among the nonionic surfactants tested were polyoxyethylene (6) stearylether (C18EO6), polyoxyethylene (5) phytosterolether (BPS-5), polyoxyethylene (6) sorbitan stearylester (TS-106V), and polyoxyethylene (4) sorbitan stearylester (Tween 61). All these surfactants have hydrophilic-lipophilic balance values (HLBs) around 9.5 to 9.9, and they can all form niosomes using the scRPE method even in the absence of ethanol. The high solubility of these surfactants in scCO2 was shown to be an important factor in yielding niosomes without ethanol addition. The niosomes prepared with the scRPE method had higher trapping efficiencies than those prepared using the conventional Bangham method, since the scRPE method gives a large number of unilamellar vesicles while the Bangham method gives multilamellar vesicles. Polyoxyethylene-type nonionic surfactants with HLB values from 9.5 to 9.9 were shown to be optimal for the preparation of niosomes with the scRPE method.

Efficacy of pegylated liposomal etoposide nanoparticles on breast cancer cell lines.

This study aimed to investigate the efficacy of pegylated liposomal etoposide nanoparticles (NPs) against T-47D and MCF-7 breast cancer cell lines. Pegylated liposomal etoposide NPs were prepared by reverse phase evaporation method. The size, size distribution, and zeta potential of the NPs was measured by a Zetasizer instrument. The cytotoxicity of NPs was inspected by methyl thiazol tetrazolium assay. The release pattern of the drug from the vesicles was studied by the dialysis method. Drug loading and encapsulation efficiency (EE) were also measured. The mean size, size distribution, and zeta potential of pegylated liposomal etoposide NPs were 491 ± 15.5 nm, 0.504 ± 0.14, and -35.8 ± 2.5 mV, respectively. Drug loading and EE were 10.3 ± 1.6% and 99.1 ± 2.8%, respectively. The etoposide release in the formulation was estimated at about 3.48% after 48 h. The cytotoxicity effect of etoposide NPs on T-47D and MCF-7 cell lines of breast cancer showed higher antitumor activity as compared with those of the free drug. Liposome-based NPs may hold great potential as a drug delivery system.

Preparation and Properties of Nonionic Vesicles Prepared with Polyglycerol Fatty Acid Esters Using the Supercritical Carbon Dioxide Reverse Phase Evaporation Method.

Previously, we reported a new preparation method for liposomes and niosomes (nonionic vesicles) using supercritical carbon dioxide (scCO2) as the solvent (scRPE method). In this study, niosomes were prepared from polyglycerol fatty acid ester (PG ester)-type nonionic surfactants. These surfactants are made from naturally derived materials and are neither harmful to the human body nor to the environment. Niosomes were prepared using the scRPE method with ethanol as the co-solvent. Through this method, decaglycerol distearate (DG2S) and decaglycerol diisostearate (DG2IS) formed niosomes. On the other hand, decaglycerol monostearate (DG1S), which has a high hydrophilic-lipophilic balance (HLB) value, yielded a solution of spherical micelles, and decaglycerol tristearate (DG3S), which has a low HLB value, yielded a gel-like solution. Niosomes of DG2IS had higher trapping efficiencies and dispersion stabilities than those of DG2S because the membrane fluidity of the DG2IS niosomes was greater than that of the DG2S niosomes. The niosomes obtained in the present study are candidates for cosmetic and pharmaceutical applications because they are formed from nonionic surfactants derived from natural sources, and prepared using the scRPE method, which avoids the use of harmful organic solvents.

Novel glucometer-based immunosensing strategy suitable for complex systems with signal amplification using surfactant-responsive cargo release from glucose-encapsulated liposome nanocarriers

Methods based on surfactant-responsive controlled release systems of cargoes from nanocontainers have been developed for bioanalytical applications, but most were utilized for drug delivery and a few reports were focused on immunoassays. Herein we design an in situ amplified immunoassay protocol for high-efficient detection of aflatoxins (aflatoxin B1, AFB1 used in this case) based on surfactant-responsive cargo release from glucose-encapsulated liposome nanocarriers with sensitivity enhancement. Initially, biotinylated liposome nanocarrier encapsulated with glucose was synthesized using a reverse-phase evaporation method. Thereafter, the nanocarrier was utilized as the signal-generation tag on capture antibody-coating microplate through classical biotin-avidin linkage after reaction with biotinylated detection antibody. Upon addition of buffered surfactant (1X PBS-Tween 20 buffer) into the medium, the surfactant immediately hydrolyzed the conjugated liposome, and released the encapsulated glucose from the nanocarriers, which could be quantitatively determined by using a low-cost personal glucometer (PGM). The detectable signal increased with the increment of target analyte. Under the optimal conditions, the assay could allow PGM detection toward target AFB1 as low as 0.6pgmL−1 (0.6ppt). Moreover, the methodology also showed good reproducibility and high specificity toward target AFB1 against other mycotoxins and proteins, and was applicable for quantitatively monitoring target AFB1 in the complex systems, e.g., naturally contaminated/spiked peanut samples and serum specimens, with the acceptable results. Taking these advantages of simplification, low cost, universality and sensitivity, our design provides a new horizon for development of advanced immunoassays in future point-of-care testing.

Ocular delivery of cyanidin-3-glycoside in liposomes and its prevention of selenite-induced oxidative stress

Context: Cataracts have become the leading cause of blindness around the world, which is mainly mediated by oxidative stress.Objective: N-trimethyl chitosan (TMC)-coated liposomes of cyanidin-3-glycoside (C3G) (C3G-TCL) were prepared to attenuate oxidative stress induced by selenite sodium in rats.Materials and methods: C3G-TCL were prepared by reverse-phase evaporation method and then coated with self-synthesized TMC. The physicochemical properties were determined. A gamma-scintigraphy study was employed to evaluate the precorneal elimination of the radioactive preparations. The transcorneal visualization for fluorescence-labeled samples was determined by confocal laser scanning microscopy (CLSM). The in vivo anti-oxidative study using C3G-TCL was carried out in rats with selenite-induced cataracts by topical administration.Results: The sphere-like morphological characterization of the vesicles was confirmed by TEM, with a size of 158.3 ± 2.8 nm and a zeta potential of 31.7 mV. The encapsulation efficiency was (53.7 ± 0.2) % as measured by ultrafiltration. C3G-TCL showed a 3.3-fold increment in precorneal residence time when compared with that of the 99mTc-solution. A TMC coating enhanced the transepithelial transport of liposomes to a depth of 40-μm in the cornea. Moreover, C3G-TCL could significantly elevate the activity of superoxide dismutase and catalase in lens and also show a considerable reversal of reduced glutathione activity. The lipid peroxidation in lens was strongly prevented when compared with that of groups treated with uncoated C3G-loaded liposomes.Discussion and conclusion: The coating material TMC for liposomes helps improve the anti-oxidative effect of C3G in vivo through prolonged residence time on the cornea and improved permeability in the corneal epithelium.

Cytotoxic effect and mechanism inducing cell death of α-mangostin liposomes in various human carcinoma and normal cells.

The aims of this study were to develop α-mangostin liposomes as well as to evaluate their physicochemical properties and cytotoxic activity. α-Mangostin liposomes were prepared using the reverse-phase evaporation method with lipid composition of phosphatidylcholine to cholesterol at 7 : 3 molar ratios; their physicochemical properties and antiproliferative activity were assessed using an MTT assay in four human carcinoma cells [that is, human lung epithelial carcinoma (Calu-3), human colon carcinoma (HT-29), human breast carcinoma (MCF-7), and human colon carcinoma (Caco-2) cells], and two human normal cells [that is, human dermal fibroblasts (HDF) and human adult low-calcium elevated temperature (HaCaT) keratinocytes]. Determinations of morphological changes and oligonucleosomal DNA fragments were also carried out. The liposomal dispersions obtained were unilamellar vesicles as confirmed by cryotransmission and freeze-fracture electron microscopy with a particle size of 114 nm and a ζ potential of -2.56 mV. The P-NMR spectra showed that α-mangostin molecules orientated in the phospholipid bilayer membrane. The α-mangostin could appreciably be entrapped with an efficiency and loading of 81 and 4%, respectively. The antiproliferative activity of α-mangostin liposomes in various cancer and normal cells showed a dose-dependent inhibition in all treated cell lines. The antiproliferative effect of α-mangostin liposomes was found to be associated with apoptosis, with differences in sensitivity among the cell lines treated.

Chitosan coated vancomycin hydrochloride liposomes: Characterizations and evaluation

The present work evaluated the feasibility of chitosan coated liposomes (c-Lips) for the intravenous delivery of vancomycin hydrochloride (VANH), a water-soluble antibiotic for the treatment of gram-positive bacterial infections like osteomyelitis, arthritis, endocarditis, pneumonia, etc. The objective of this research was to develop a suitable drug delivery system in vivo which could improve therapeutic efficacy and decrease side effects especially nephrotoxicity. Firstly, the vancomycin hydrochloride liposomes (VANH-Lips) were prepared by modified reverse phase evaporation method, then the chitosan wrapped vancomycin hydrochloride liposomes (c-VANH-Lips) nanosuspension was formulated by the method of electrostatic deposition. Based on the optimized results of single-factor screening experiment, the c-VANH-Lips were found to be relatively uniform in size (220.40±3.56nm) with a narrow polydispersity index (PI) (0.21±0.03) and a positive zeta potential (25.7±1.12mV). The average drug entrapment efficiency (EE) and drug loading (DL) were 32.65±0.59% and 2.18±0.04%, respectively. The in vitro release profile of c-VANH-Lips possessed a sustained release Characterization and the release behavior was in accordance with the Weibull equation. Hemolysis experiments showed that its intravenous injection had preliminary safety. In vivo, after intravenous injection to mice, c-VANH-Lips showed a longer retention time and higher AUC values compared with the VANH injection (VANH-Inj) and VANH-Lips. In addition, biodistribution results clearly demonstrated that c-VANH-Lips preferentially decreased the drug distribution in kidney of mice after intravenous injection. These results revealed that injectable c-VANH-Lips may serve as a promising carrier for VANH to increase therapeutic efficacy on gram-positive bacterial infections and reduce nephrotoxicity, which provides significantly clinical value for long-term use of VANH.

Improving lithium carbonate therapeutics by pegylated liposomal technology: an in vivo study

Bipolar disorder is a chronic mental illness which is associated with high risk of self-harm and suicide. Lithium carbonate has been suggested as a medicine to control and cure this disease. To overcome the complications related to taking lithium carbonate, nanotechnology has come to the aid of scientists. In this study, pegylated liposomal lithium carbonate nanoparticles were prepared by the reverse phase evaporation method to improve the drug’s therapeutic characteristics as well as lessening its side effects. In order to synthesize pegylated liposomal lithium carbonate, phosphatidylcholine, polyethylene glycol 3350 (PEG3350), cholesterol, and lithium carbonate were mixed. The characterization of synthesized nanoparticles was determined by Zetasizer. Encapsulation and drug loading efficiency and release pattern studies were determined through spectrophotometry method. In addition, serum lithium and creatinine levels of the samples were analyzed. The mean diameter, size distribution, and zeta potential for pegylated liposomal particles containing lithium carbonate and blank pegylated liposomal were determined by Zetasizer equal to 102 nm, 0.458, and −25.1 mV; 284.2 nm, 0.427, and −28.3 mV, respectively. Drug loading and encapsulation efficiency were calculated to be 32.87 and 97.4 %, respectively. The drug release pattern demonstrated that the half-life of the nanodrug was approximately two times higher than the standard drug. The results related to the analysis of serum lithium and creatinine levels indicated that the efficiency of liposomal drug formulation was increased compared to the standard drug. Based on the findings, the nanodrug enjoyed a half-life two times higher than that of the standard drug and an efficiency level equal to it.

Potential effect of cationic liposomes on interactions with oral bacterial cells and biofilms

Context: Although oral infectious diseases have been attributed to bacteria, drug treatments remain ineffective because bacteria and their products exist as biofilms. Cationic liposomes have been suggested to electrostatically interact with the negative charge on the bacterial surface, thereby improving the effects of conventional drug therapies. However, the electrostatic interaction between oral bacteria and cationic liposomes has not yet been examined in detail.Objective: The aim of the present study was to examine the behavior of cationic liposomes and Streptococcus mutans in planktonic cells and biofilms.Materials and methods: Liposomes with or without cationic lipid were prepared using a reverse-phase evaporation method. The zeta potentials of conventional liposomes (without cationic lipid) and cationic liposomes were −13 and 8 mV, respectively, and both had a mean particle size of approximately 180 nm. We first assessed the interaction between liposomes and planktonic bacterial cells with a flow cytometer. We then used a surface plasmon resonance method to examine the binding of liposomes to biofilms. We confirmed the binding behavior of liposomes with biofilms using confocal laser scanning microscopy.Results: The interactions between cationic liposomes and S. mutans cells and biofilms were stronger than those of conventional liposomes. Microscopic observations revealed that many cationic liposomes interacted with the bacterial mass and penetrated the deep layers of biofilms.Discussion and conclusion: In this study, we demonstrated that cationic liposomes had higher affinity not only to oral bacterial cells, but also biofilms than conventional liposomes. This electrostatic interaction may be useful as a potential drug delivery system to biofilms.

Effect of Erythrodiol, A Natural Pentacyclic Triterpene from Olive Oil, on the Lipid Membrane Properties.

The effect of erythrodiol, a natural pentacyclic triterpene to which humans are exposed through nutrients, on the lipid membranes is studied using liposomes as a membrane model. Empty and erythrodiol-loaded liposomes were prepared by the reverse phase evaporation method followed by the extrusion and by the thin film hydration method. Liposomes were characterized in terms of size and zeta potential and were imaged by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The effect of erythrodiol on thermotropic behavior of DPPC bilayers is also examined by differential scanning calorimetry (DSC). The DSC thermograms suggested that erythrodiol interacted with the polar head groups of phospholipids and may produce a disruption of the ordering of the alkyl chains. The diffraction light scattering analysis showed that erythrodiol-loaded liposomes presented a decrease in the vesicle size when compared to blank liposomes. Images obtained by TEM confirmed the formation of unilamellar and spherical liposomes. AFM images showed spherical vesicles and single lipid bilayers. The latter were more abundant in the preparations containing erythrodiol than in the blank ones. Moreover, erythrodiol-loaded liposomes tended to rupture into single lipid bilayers during scanning. The study may provide a better understanding of pentacyclic triterpenes-membrane interaction.

Formation of magnetoliposomes using self-assembling 1,4-dihydropyridine derivative and maghemite γ-Fe2O3 nanoparticles

This work demonstrates studies of ferromagnetic nanoparticle functionalization by a lipid-like compound, cationic pyridine amphiphile derived from 1,4-dihydropyridine, 1,1'-{[3,5-bis(dodecyloxycarbonyl)-4-phenyl-1,4-dihydropyridine-2,6-diyl]dimethanediyl}dipyridinium dibromide, and determination of optimal conditions for the production of magnetoliposomes. The following methodologies, such as sonication, spontaneous swelling, and reverse-phase evaporation, were used for the preparation of liposomes. Ferrofluid containing γ-Fe2O3 nanoparticles with a positively charged surface was used for the preparation of magnetoliposomes. The obtained soft matter objects were studied by optical microscopy, transmission electron microscopy, and dynamic light scattering techniques. The optimal conditions for the production of magnetoliposomes were found by spontaneous swelling and reverse-phase evaporation methods using ferrofluid with positively charged γ-Fe2O3 nanoparticles and cationic 1,4-dihydropyridine derivative.

Preliminary study on transdermal characteristics and sunface anesthetic effects of lidocaine hydrochloride loaded trans-activator of transcription peptide conjugated nano-niosome in animals

To prepare a new dental topical anesthetics, lidocaine hydrochloride loaded trans-activator of transcription peptide conjugated nano-niosome (LID-TAT-N), and to evaluate its transdermal properties and topical anesthesia effects. LID-TAT-N was prepared using reverse-phase evaporation method, and lidocaine loaded conventional liposome (LID-CL) was prepared in the same manner as positive control. The diameter, ζ potential and encapsulation efficiency of LID-TAT-N and LID-CL were measured. The skin permeation of LID-TAT-N was examined, and compared with LID-CL and lidocaine injection (LID-IJ, as negative control), using a Franz diffusion cell mounted with depilated mouse skin in vitro for 12 hours. Each experiment was repeated six times. The anesthetic effect of the new topical anesthetic was investigated on the cornea of rabbits. The mean diameter of LID-TAT-N was smaller than that of LID-CL [(152.7 ± 10.6) nm vs. (259.5 ± 15.5) nm, P < 0.01]. The 12 h cumulative permeation amount was significantly higher in LID-TAT-N group [(1 340.0 ± 97.5) µg · cm(-2)] than those of LID-CL and LID-IJ groups [(1 060.6 ± 80.2), (282.6 ± 65.1) µg · cm(-2), respectively, P < 0.05]. Rabbit corneal reflex results showed that LID-TAT-N had anesthetic effect and the duration of analgesia [(24.8 ± 2.8) min] was also longer than that of LID-IJ [(14.5 ± 2.3) min, P < 0.05]. LID-TAT-N had good transdermal ability, and the advanced skin penetration feature can improve its tropical anesthetic effect.

Radiofrequency-triggered tumor-targeting delivery system for theranostics application.

In this study, a new type of magnetic tumor-targeting PEGylated gold nanoshell drug delivery system (DOX-TSMLs-AuNSs-PEG) based on doxorubicin-loaded thermosensitive magnetoliposomes was successfully obtained. The reverse-phase evaporation method was used to construct the magnetoliposomes, and then gold nanoshells were coated on the surface of it. The DOX-TSMLs-AuNSs-PEG delivery system was synthesized after SH-PEG2000 modification. This multifunction system was combined with a variety of functions, such as radiofrequency-triggered release, chemo-hyperthermia therapy, and dual-mode magnetic resonance/X-ray imaging. Importantly, the DOX-TSMLs-AuNSs-PEG complex was found to escape from endosomes after cellular uptake by radiofrequency-induced endosome disruption before lysosomal degradation. All results in vitro and in vivo indicated that DOX-TSMLs-AuNSs-PEG is a promising effective drug delivery system for diagnosis and treatment of tumors.

Combined Skin Moisturization of Liposomal Serine Incorporated in Hydrogels Prepared with Carbopol ETD 2020, Rhesperse RM 100 and Hyaluronic Acid.

We investigated the combined moisturizing effect of liposomal serine and a cosmeceutical base selected in this study. Serine is a major amino acid consisting of natural moisturizing factors and keratin, and the hydroxyl group of serine can actively interact with water molecules. Therefore, we hypothesized that serine efficiently delivered to the stratum corneum (SC) of the skin would enhance the moisturizing capability of the skin. We prepared four different cosmeceutical bases (hydrogel, oil-in-water (O/W) essence, O/W cream, and water-in-oil (W/O) cream); their moisturizing abilities were then assessed using a Corneometer®. The hydrogel was selected as the optimum base for skin moisturization based on the area under the moisture content change-time curves (AUMCC) values used as a parameter for the water hold capacity of the skin. Liposomal serine prepared by a reverse-phase evaporation method was then incorporated in the hydrogel. The liposomal serine-incorporated hydrogel (serine level=1%) showed an approximately 1.62~1.77 times greater moisturizing effect on the skin than those of hydrogel, hydrogel with serine (1%), and hydrogel with blank liposome. However, the AUMCC values were not dependent on the level of serine in liposomal serine-loaded hydrogels. Together, the delivery of serine to the SC of the skin is a promising strategy for moisturizing the skin. This study is expected to be an important step in developing highly effective moisturizing cosmeceutical products.