Particle Size Of Liposomes Research Articles

The Impact of Solvent Selection: Strategies to Guide the Manufacturing of Liposomes Using Microfluidics.

The aim of this work was to assess the impact of solvent selection on the microfluidic production of liposomes. To achieve this, liposomes were manufactured using small-scale and bench-scale microfluidics systems using three aqueous miscible solvents (methanol, ethanol or isopropanol, alone or in combination). Liposomes composed of different lipid compositions were manufactured using these different solvents and characterised to investigate the influence of solvents on liposome attributes. Our studies demonstrate that solvent selection is a key consideration during the microfluidics manufacturing process, not only when considering lipid solubility but also with regard to the resultant liposome critical quality attributes. In general, reducing the polarity of the solvent (from methanol to isopropanol) increased the liposome particle size without impacting liposome short-term stability or release characteristics. Furthermore, solvent combinations such as methanol/isopropanol mixtures can be used to modify solvent polarity and the resultant liposome particle size. However, the impact of solvent choice on the liposome product is also influenced by the liposome formulation; liposomes containing charged lipids tended to show more sensitivity to solvent selection and formulations containing increased concentrations of cholesterol or pegylated-lipids were less influenced by the choice of solvent. Indeed, incorporation of 14 wt% or more of pegylated-lipid was shown to negate the impact of solvent selection.

A Multifunctional Lipid Incorporating Active Targeting and Dual-Control Release Capabilities for Precision Drug Delivery.

Active targeting and precise control of drug release based on nanoparticle therapies are urgently required to precisely treat cancer. We have custom-synthesized a functional lipid (termed Fa-ONB) by introducing a folic acid-targeting group into an o-nitro-benzyl ester lipid. As designed, the liposomes formed by Fa-ONB combine active targeting and dual trigger release capabilities, which help to improve drug efficacy and reduce the toxicity of traditional liposomes. We first verified that both pH-induced hydrolysis and light treatment were able to cleave the Fa-ONB lipid. We then prepared a series of liposomes (termed FOBD liposomes) by compounding the Fa-ONB lipid with DOPC at different ratios. After encapsulation of doxorubicin (DOX), we found that the particle size of DOX-loaded FOBD liposomes (DOX/FOBD) first increased (290 to 700 nm) and then decreased again (to 400 nm) under continuous UV irradiation (120 min). The photocatalytic release efficiency under different pH conditions was investigated by dialysis experiments, and it was found that the release efficiency in an acidic environment was significantly increased relative to neutral pH. This pH-triggered release response helps distinguish pathological tissues such as lysosomal compartments and tumors. The light-induced formation of a DOX precipitate increases in efficiency with increasing UV exposure time as well as with increasing environmental acidity or alkalinity. In addition, confocal imaging and flow cytometry showed that the ability of FOBD lipids to actively target HeLa cells increased with increasing Fa-ONB lipid content. Real-time in vivo fluorescence small animal experiments proved targeting to tumors and pH- and photo-induced release properties. Furthermore, therapeutic experiments using a mouse model found a significant tumor inhibitory effect for DOX/FOBD55 liposomes with UV irradiation, clearly demonstrating the benefit of light treatment: the tumor size of the control (PBS) group was 7.59 times that of the light treatment group. Therefore, this research demonstrates the benefits of combining triggerable release functions and effective active tumor targeting in one small lipid molecule for precise cancer treatment.

Dual-targeting liposomes with active recognition of GLUT5 and αvβ3 for triple-negative breast cancer

At present, chemo- and radiotherapies remain to be the mainstream methods for treating triple-negative breast cancer (TNBC), which is known for poor prognosis and high rate of mortality. Two types of novel dual-targeting TNBC liposomes (Fru-RGD-Lip and Fru+RGD-Lip) that actively recognize both fructose transporter GLUT5 and integrin αvβ3 were designed and prepared in this work. Firstly, a Y-shaped Fru-RGD-chol ligand, where a fructose and peptide Arg-Gly-Asp (RGD) were covalently attached to cholesterol, was designed and synthesized. Then, the Fru-RGD-Lip was constructed by inserting Fru-RGD-chol into liposomes, while Fru+RGD-Lip was obtained by inserting both Fru-chol and RGD-chol (with the molar ratio of 1:1) into liposomes. The particle size, zeta potential, encapsulation efficiency and serum stability of the paclitaxel-loaded liposomes were characterized. The results indicated that the paclitaxel-loaded Fru-RGD-Lip had the strongest growth inhibition against GLUT5 and αvβ3 overexpressed MDA-MB-231 and 4T1 cells. The cellular uptake of Fru-RGD-Lip on MDA-MB-231 cells and 4T1 cells was 3.19- and 3.23-fold more than that of the uncoated liposomes (Lip). The uptake of Fru+RGD-Lip was slightly lower, giving a 2.81- and 2.90-fold increase than that of Lip in two cell lines, respectively. The mechanism study demonstrated that the cellular uptake of both dual-targeting liposomes was likely to be recognized and mediated by GLUT5 and αvβ3 firstly, then endocytosed through comprehensive pathways in an energy-dependent manner. Moreover, Fru-RGD-Lip displayed the maximum accumulation, which was 2.62-fold higher than that of Lip for instance, at the tumor sites compared to other liposomes using in vivo imaging. Collectively, the liposomes co-modified by fructose and RGD have enormous potential in the development of targeted TNBC treatment, especially the covalently modified Fru-RGD-Lip, making it a promising multifunctional liposome.

Cyanidin-3-o-glucoside liposome: Preparation via a green method and antioxidant activity in GES-1 cells

Cyanidin-3-O-glucoside (C3G) liposomes was used to improve the stability and antioxidant activity of C3G through a green thin-film dispersion method. The characteristics, stability and the effect of C3G liposomes on GES-1 cells were explored. Results showed that the particle size and encapsulation efficiency (EE%) of C3G liposomes were 258.9 ± 5.06 nm and 77.5%, respectively. DPPH assay showed that liposomes encapsulation can improve the antioxidant of C3G, while the ABTS assay was opposite. Stability study showed the C3G liposome were unstable under extended storage time. The effects of C3G liposomes on GES-1 cells showed that C3G liposomes can decrease the ROS levels of GES-1 and had negligible effects on cell viability and mitochondrial structure. These findings suggested that liposomes could be used as a carrier system to improve the stability of C3G.

Transdermal lipid vesicular delivery of iloperidone: Formulation, in vitro and in vivo evaluation

The objective of present study was to develop and evaluate lipid vesicular transdermal system of iloperidone. Liposomes were prepared successfully using thin film hydration method. With aim of enhancing permeation, cholesterol from liposomes was replaced with transcutol to give PEVs. Liposomes and PEVs were evaluated for particle size, shape, entrapment efficiency, viscosity and release study. The vesicles were incorporated in 0.5% of Carbopol gel and evaluated. Particle size of liposomes and PEVs was found between 200−300 nm and entrapment efficiency was found 80–90%w/w. The transdermal gels were homogeneous, spreadable having acceptable pH and drug content between 90–100%.In ex vivo studies, both liposomes and PEVs showed relatively higher skin deposition and permeation of Iloperidone than the plain drug without vesicles. The in vivo pharmacokinetics studies showed relative bioavailability of the PEV loaded gel as 62% and 166% when compared to the oral drug and gel without vesicles respectively. Pharmacodynamic studies showed FRT and HRT delay responses of the transdermal gel systems were significant[p < 0.05] as compared to control at the end of 24 hs. Thus, it can be concluded that transdermal delivery system can be a promising approach for sustained delivery of Iloperidone.

Effects of environmental pH and ionic strength on the physical stability of cinnamaldehyde-loaded liposomes

The physical stability of cinnamaldehyde-loaded liposomes was investigated under various conditions including different storage time, storage temperature, pH and ionic strength of external environment, as well as variations in hydration media. Results showed that the average diameter of liposomes increased first and remained constant, the retention rate (RR) decreased while the liposomes stored at higher temperature exhibited a lower RR during the storage period of 9 days. Furthermore, liposomes under acidic conditions (pH ≤ 6) exhibited a decreased particle size with an increased RR. As for the ionic strength of the external environment and hydration media, the particle size of liposomes increased, whereas the RR and encapsulation efficiency (EE) decreased as ionic strength increased. Atomic force microscopy (AFM) further proved that high ionic strength could result in instability of liposomes. However, the particle size of liposomes in the external environment composed of ion solution were far more than those in the hydration media, which indicated that the liposomes prepared in ion solution could resist instability caused by changes in external ionic strength. These results also provided a guidance for the application of liposomes in different environments and selectively preparing desired liposomes by modulating the pH and ionic strength of environment.

Preparation and evaluation of four kinds of mixed essential oil liposomes in Jieyu Anshen Formula

In order to increase the stability and solubility of essential oil in Jieyu Anshen Formula, this study was to prepare the essential oil into liposomes. In this experiment, the method for the determination of encapsulation efficiency of liposomes was established by ultraviolet spectrophotometer and dextran gel column. The encapsulation efficiency and particle size of liposomes were used as evaluation indexes for single factor investigation and Box-Behnken design-response surface method was used to optimize the design. Then the optimal formulation of volatile oil liposome was characterized using methyleugenol, elemin, β-asarone and α-asarone as index components. Finally, the in vitro transdermal properties of liposomes were studied by modified Franz diffusion cell. The results showed that the concentration of lecithin, the mass ratio of lecithin to volatile oil, and the stirring speed were the three most significant factors affecting the liposome preparation. The optimum formulation of volatile oil liposome was as follows: the concentration of lecithin was 7 g·L~(-1); mass ratio of lecithin to volatile oil was 5∶1; and the stirring speed was 330 r·min~(-1). Under such conditions, the prepared liposomes had blue emulsion light, good fluidity, half translucent, with particle size of(102.6±0.35) nm, Zeta potential of(-17.8±0.306) mV, permeability of(1.67±1.01)%, and stable property if liposome was stored at 4 ℃. 24 h after percutaneous administration, the cumulative osmotic capacity per unit time was(30.485 2±1.238 9),(34.794 8±0.928 3),(26.677 1±1.171 7),(3.066 2±0.175 3) μg·cm~(-2)respectively for methyleugenol, elemin, β-asarone and α-asarone. In vitro transdermal behaviors of methyleugenol, elemin, β-asarone and α-asarone in liposomes were all consistent with Higuchi equation. The prepared volatile oil liposomes met the relevant quality requirements, providing a reference for further research on preparation of multi-component Chinese medicine essential oil liposomes.

The use of chitosan-coated flexible liposomes as a remarkable carrier to enhance the antitumor efficacy of 5-fluorouracil against colorectal cancer

Surface-coated nanocarriers have been extensively used to enhance the delivery of anticancer drugs and improve their therapeutic index. In this study, chitosan (CS)-coated flexible liposomes (chitosomes) containing 5-fluorouracil (5-FU) were designed and characterized for use as a novel approach to target colon cancer cells. 5-FU-loaded flexible liposomes (F1, F2, and F3) and 5-FU-loaded chitosomes (F4, F5, and F6) were prepared using film hydration and electrostatic deposition techniques, respectively. The particle size, polydispersity index (PDI), zeta potential, entrapment efficiency (EE%), morphology, and in vitro drug release ability, and cytotoxicity of the formulations were determined. The results revealed that the size of chitosomes ranged from 212 to 271 nm with a positive surface charge of 6.1 to 14.7 mV, whereas the particle size of liposomes ranged from 108 to 234 nm with negative surface charges of −2.3 to −16.3. F3 and F6 had a spherical shape with a rough surface structure. The in vitro drug release study revealed that chitosomes retard 5-FU release as opposed to the 5-FU solution and liposomes. The cytotoxicity study using a colon cancer cell line (HT-29) showed that 5-FU-loaded chitosomes were more effective in killing cancer cells in a sustained manner than liposomes and the 5-FU solution. Chitosomes were therefore successfully developed as nanocarriers of 5-FU, with potential cytotoxicity for colorectal cancer cells.

Characterization of chrysanthemum essential oil triple-layer liposomes and its application against Campylobacter jejuni on chicken

For improving stability of liposomes, the chitosan and pectin modified chrysanthemum essential oil (CHEO) liposomes were prepared. The average particle size of CHEO liposome was 132.4 nm with polymer dispersity index (PDI) of 0.152, zeta potential of −37.6 mV. Results showed that the formation of CHEO liposomes was efficient (encapsulation efficiency 42.73%) and loading content was 1.28 mg/mL. A modified layer-by-layer electrostatic deposition method was followed to prepare CHEO triple-layer liposomes. Chitosan was used as second layer then pectin as third layer of liposomes. The optimal concentrations of chitosan and pectin were 0.050 mg/mL. Particle size of CHEO triple-layer liposomes increased to 2148.4 nm with PDI of 0.183. Zeta potential was −15.3 mV. Results of FTIR confirmed that CHEO triple-layer liposomes were fabricated successfully. Phospholipids oxidation, release rate and storage stability of CHEO triple-layer liposomes were also analyzed at different temperature (4, 12, 25, 37 °C) in storage period (15 days), which revealed CHEO triple-layer liposomes were more stable than single-layer and double-layer liposomes (p < 0.05). Besides, CHEO triple-layer liposomes possessed high antibacterial activity against Campylobacter jejuni on chicken during 14-days storage at a temperature range (4–37 °C), without impact on the quality of chicken.

Antimicrobial activity of lysozyme-nisin co-encapsulated in liposomes coated with polysaccharides

Natural antimicrobials are an innovative alternative for food safety and encapsulation can improve their controlled release and stability. In the present work, lysozyme and its combination with nisin were encapsulated into phosphatidylcholine (PC) liposomes coated with pectin or polygalacturonic acid. The mean particle sizes of liposomes encapsulating lysozyme were 92, 116, and 97 nm for PC, PC-pectin and PC-polygalacutronic acid, respectively. Co-encapsulation of lysozyme and nisin resulted in particle sizes of 86, 77, and 80 nm, respectively. The formulations showed high encapsulation efficiency (77–87%), zeta potential around −30 mV, and spherical structures were observed by transmission electron microscopy. Liposomes encapsulating lysozyme inhibited Listeria monocytogens, but not Salmonella Enteritidis, while liposomes co-encapsulating the mixture nisin/lysozyme inhibited both bacteria. The PC-pectin liposomes were more efficient in inhibiting Listeria spp. when compared to the other liposomes tested. The antimicrobial activity was assessed at 37 °C using milk as model, showing that PC-pectin liposomes reduced the population of L. monocytogenes by 2 log CFU/mL in whole milk and 5 log CFU/mL in skim milk. Under refrigeration temperature, PC-pectin liposomes reduced the population of L. monocytogenes to below detection limit for up to 25 days in skim milk, indicating that liposomes containing polysaccharides can be a promising technology for the controlled release of lysozyme and nisin in foods.

Liposome-embedded, polymeric scaffold for extended delivery of galantamine

The purpose of this study was to construct a liposome-embedded, polymeric scaffold (LEPS) that is capable of delivering an alkaloid drug, galantamine. The LEPS was engineered by embedding drug-loaded functionalized liposomes (particle size: 100–158 nm, zeta potential: −34 mV) into a depot chitosan, Eudragit® RSPO, and polyvinyl alcohol (CEP) scaffold. Swelling, erosional dynamics, porosity/diffusion and particle size influenced the release behaviour of the drug-loaded functionalized liposomes post-embedment into the depot CEP scaffold of the LEPS. High accumulation of galantamine (GAL; ∼50–90%) validated that drug-loaded functionalized liposomes were still intact following release from the LEPS in simulated physiological conditions over 50 days. PC12 neuronal cell proliferation was supported on the surface of the LEPS. The Lactate Dehydrogenase (LDH) level, which is associated with cell membrane damage/injury induced by the drug-loaded functionalized liposomes, for CEP scaffold and LEPS, were ±15%, ±30% and ±32%, respectively, confirming no significant cytotoxic effects over 28 days. High accumulation of the GAL and FITC intracellularly validated that synthetic peptide potency was maintained following delivery of the drug-loaded functionalized liposomes post-escape from the LEPS.

Liposomes consisting of pluronic F127 and phospholipid: Effect of matrix on morphology, stability and curcumin delivery

We prepared liposomes consisting of different ratios of phospholipid and pluronic F127 (F127-Lps), then evaluated the effect of matrix on the morphology, stability and carriers’ property of liposomes. The particle size of liposomes was significantly decreased after pluronic F127 modification. Pluronic F127 at low ratio may incorporate into liposomes and form spherical and lamellar structure, while pluronic F127 at high ratio can form mixed aggregates with spherical micelles and lamellar vesicles. The membrane stability of liposomes was enhanced with increasing of pluronic F127 ratio. Curcumin was encapsulated into F127-Lps (cur-F127-Lps) with an entrapment efficiency of 89%. The higher the ratio of pluronic F127 was, the slower the release rate of curcumin. First order model was the main release mechanism for curcumin loaded liposomes. These results are useful for designing liposome-based food delivery systems that can be used in functional foods.

Development of a flow-through USP 4 apparatus drug release assay for the evaluation of amphotericin B liposome

AmBisome® is a liposomal formulation of amphotericin B (Amp B), a complex parenteral antifungal product with no US FDA approved generic version available to date. For generic Amp B liposomal product development, examination of the drug release profile is important for product quality control and analytical comparability evaluation with the reference listed drug. Yet, there is no standardized in vitro drug release (IVR) assay currently available for Amp B liposomes. In this study, we describe the development of a USP-4 apparatus-based IVR assay capable of discriminating liposomal Amp B formulations based on the drug release profile. The goal of the IVR assay development was to identify release media compositions and assay temperatures capable of facilitating 70–100% of drug release from AmBisome® in 24 h without Amp B precipitation or disruption of liposome structure. We found that an addition of 5% w/v of γ-cyclodextrin to the release media of 5% sucrose, 10 mM HEPES, and 0.01% NaN3 (pH = 7.4) prevented Amp B precipitation and facilitated drug release. Increased IVR assay temperature led to increased drug release rate, and 55 °C was selected as the highest temperature that induced drug release close to our target without causing product precipitation. The developed IVR assay was used to discriminate between drug release rates from AmBisome® and micellar Amp B products like Fungizone® and Fungcosome. The IVR assay was also capable of discriminating between Amp B liposomes with the same composition as AmBisome® but prepared by either extrusion or homogenization processes, both of which resulted in measurable liposomal particle size heterogeneity and Amp B concentration differences. Finally, the USP-4 IVR assay was used to compare Amp B release profiles between AmBisome® and two generic products approved in India, Amphonex® (Bharat Serums and Vaccines Ltd.) (f2 = 66.3) and Phosome® (Cipla Ltd.) (f2 = 55.4). Taken together, the developed USP-4 IVR assay can be a useful tool for drug release profile characterization in generic liposomal Amp B formulation development.

A novel 5-Fluorouracil targeted delivery to colon cancer using folic acid conjugated liposomes.

The aim of this study was to develop and characterize 5-Fluorouracil (5FU) containing targeted liposomes in order to enhance the efficacy and safety of the drug. Folic acid (FA) was used as a targeting ligand. The in vitro cytotoxicity of formulation against HT-29, Caco-2, CT26, HeLa and MCF-7 cell lines was evaluated using MTT assay. Mechanism of cell death induced by targeted liposomes was further investigated via the production of reactive oxygen species (ROS), change in mitochondrial membrane potential (ΔΨm), release of cytochrome c and activity of caspase 3/7. The in vivo tumor inhibition study was also performed after administration of drug and targeted 5FU liposome. The encapsulation efficiency (EE%) of the optimized formulation was 39.71%. Particle size of liposomes was around 174 nm and the nanoparticles were found to be spherical in shape. Differential Scanning Calorimetry (DSC) results indicated that the drug remained in an amorphous state in liposomes. According to the MTT results, targeted liposomes exhibited higher cytotoxicity than 5FU and liposomal 5FU. Targeted liposomes were found to trigger necrosis in HT-29 cells; while, in HeLa cells, targeted liposomes activated apoptotic pathway by collapse of ΔΨm, increased activity of cytochrome c as well as caspases activity. in vivo results showed that targeted liposomes reduced tumor volume significantly in comparison with 5FU (169.00 mm3 tumor volume vs 326.40 mm3). From these findings, it can be concluded that folic acid targeted liposomes may provide a new platform for selective delivery of drugs to cancer cells.

Inhalable liposomes of Glycyrrhiza glabra extract for use in tuberculosis: formulation, in vitro characterization, in vivo lung deposition, and in vivo pharmacodynamic studies

Objective: The current study involves the development of liposomal dry powder for inhalation (LDPI) containing licorice extract (LE) for use in tuberculosis.Significance: The current epidemiology of tuberculosis along with the increasing emergence of resistant forms of tuberculosis necessitates the need for developing alternative efficacious medicines for treatment. Licorice is a medicinal herb with reported activity against Mycobacterium tuberculosis.Methods: Liposomes with LE were prepared by thin film hydration technique and freeze dried to obtain LDPI. The comprehensive in vitro and in vivo characterization of the LDPI formulation was carried out.Results: The particle size of liposomes was around 210 nm with drug entrapment of almost 75%. Transmission electron microscopy revealed spherical shape of liposome vesicles. The flow properties of the LDPI were within acceptable limits. Anderson Cascade Impactor studies showed the mean median aerodynamic diameter, geometric standard deviation and fine particle fraction of the LDPI to be 4.29 µm, 1.23, and 54.68%, respectively. In vivo lung deposition studies of LDPI in mice showed that almost 46% of the drug administered reaches the lungs and 16% of administered drug is retained in the lungs after 24 hours of administration. The in vivo pharmacodynamic evaluation of the LDPI showed significant reduction in bacterial counts in lungs as well as spleen of TB-infected mice.Conclusions: LE LDPI thus has a promising potential to be explored as an effective anti-tubercular medicine or as an adjunct to existing anti-tubercular drugs.

RGD-modified nanoliposomes containing quercetin for lung cancer targeted treatment.

PurposeThe aim of this study was to prepare RGD-modified nanoliposomes containing quercetin (QCT) distearoyl-L-a-phosphatidylethanolamine-polyethylene glycol 2000-RGD-liposomes ([DSPE]-PEG2000-RGD-LPs/QCT) for lung cancer targeting treatment.MethodsThe physicochemical parameters of (DSPE)-PEG2000-RGD-LPs/QCT were characterized in terms of the particle size, zeta potential, morphology, entrapment efficiency, drug loading, and in vitro release behavior. In vivo, pharmacokinetics and antitumor studies of prepared formulations were also evaluated.ResultsIn this study, QCT was found to be easily dispersed in lipid solution and entrapped by the thin-film hydration method. The encapsulation ratio and drug loading of prepared LPs were 89.2%±7.4% and 9.2%±1.3% and the mean diameter was 93.4±7.2 nm from 3 batches. The results of in vitro experiments showed that the particle size of liposomes was suitable for the fenestrated vasculatures of cancer tissues via the enhanced permeability retention effect. In vitro, a relatively slow QCT release profile was observed in (DSPE)-PEG2000-RGD-LPs, and the release mechanism fit with the Higuchi equation better. In vivo imaging results indicated that RGD-modified LPs had very good tumor targeting ability. (DSPE)-PEG2000-RGD-LPs/QCT showed a significant antitumor activity in mice with A549 tumors.ConclusionThrough this study, it was found that the RGD-modified LPs loaded with QCT could potentially be a very promising lung-targeted preparation.

Environmental stress stability of pectin-stabilized resveratrol liposomes with different degree of esterification

Based on the hydrogen bonding ability of polysaccharides and phospholipids and steric hindrance, nanoliposomes (LPs), pectin-coated resveratrol liposomes (LMP-LPs and HMP-LPs) with different esterification degrees (DE = 30%, 70%) were prepared. The entrapment efficiency was 78 ± 5%. The addition of pectin with different degree of esterification (DE = 0%, 30%, 70%) increased the particle size of liposomes from 102 nm to 122 nm and 140 nm and negative charge change from −13.63 mV to −20.96 mV and −30.11 mV respectively. This is mainly due to the adsorption of pectin on the liposome surface. Some environmental factors such as pH, ionic strength and temperature have a significant effect on the appearance, particle size and leakage rate of liposomes. Experiments have shown that the leakage rate of low-methoxy pectin-coated liposomes resveratrol is lower, and this work provides useful information on the use of low-methoxy pectin for controlling food release.

In vitro Evaluation of the Effects of Fluconazole and Nano-Fluconazole on A. flavus and Aspergillus fumigatus Isolates

Background: Increasing azole resistance among Aspergillus strains was observed over the last decade. For this reason, viable alternatives for the current medicines are required. Objectives: The current study aimed at producing fluconazole-loaded liposomal nanoparticles and comparing in vitro antifungal activity of fluconazole and nano-fluconazole on Aspergillus flavus and A. fumigatus species isolated from patients and poultry. Methods: Fifty isolates of A. flavus and A. fumigatus were collected from visceral and superficial fungal lesions of humans as well as pulmonary fungal infection of poultry. Liposomal nanoparticles were prepared by thin-film hydration method, using soybean lecithin, cholesterol, and fluconazole in a ratio of 10:1:1. The nanoparticles were analyzed in terms of size, zeta potential, and morphology. Antifungal susceptibility testing was carried out to examine and evaluate the minimum inhibitory concentration (MIC) of fluconazole and nano-fluconazole against Aspergillus species by the standard method of broth microdilution as described in CLSI (the clinical and laboratory standards institute) -M38A2. Results: The particle size of liposomes containing fluconazole was 88.9 ± 12.1 nm and its zeta potential was -20.12 ± 1.88 mv. Nano-liposomes containing fluconazole significantly reduced the MIC against A. flavus (P = 0.0005) and A. fumigatus (P < 0.0001). Conclusions: The results of the current in vitro study showed that nano-fluconazole has better antifungal effects than the common form of drug on A. flavus and A. fumigatus species. The current study showed the antifungal activity of nano-drugs.

Optimizing liposomes for delivery of Bowman-Birk protease inhibitors - Platforms for multiple biomedical applications.

One of the major challenges in the administration of therapeutic proteins involves delivery limitations. Liposomes are well-known drug delivery systems (DDS) that have been used to overcome this drawback; nevertheless, low protein entrapment efficiency (EE) still limits their wide biomedical application on a commercial scale. In the present work, different methods for protein entrapment into liposomes were tested in order to obtain tailored DDS platforms for multiple biomedical applications. The protein used as model was the Black-eyed pea Trypsin and Chymotrypsin Inhibitor (BTCI), a member of the Bowman-Birk protease inhibitor family (BBIs), which has been largely explored for its potential application in many biomedical therapies. We optimized reverse-phase evaporation (REV) and freeze/thaw (F/T) entrapment methods, using a cationic lipid matrix to entrap expressive amounts of BTCI (∼100 μM) in stable liposomes without affecting its protease inhibition activity. The influence of various parameters (e.g. entrapment method, liposome composition, buffer type) on particle size, charge, polydispersity, and EE of liposomes was investigated to provide an insight on how to control such parameters in view of obtaining a high entrapment yield. In addition, BTCI liposome platforms obtained herein showed to be versatile vesicles, allowing surface modification with moieties/polymers of interest (e.g. PEG, transferrin). The aforementioned results are relevant to focusing on the entrapment of other promising BBIs or protein agents sharing similar structural features. These findings encourage future studies to investigate the advantages of using the liposome platforms presented herein to broaden the use of this type of DDS for BBI biomedical applications.

Folic acid-modified liposomal drug delivery strategy for tumor targeting of 5-fluorouracil

The aim of this study was to develop a liposomal formulation to selectively target cancer cells. Liposomes were prepared using thin layer method and folic acid (FA) was applied for targeted delivery of 5FU to cancer cells. Liposomes prepared were characterized for encapsulation efficiency (EE%), morphology and their particle size. Cellular uptake, cytotoxicity study and ROS production were evaluated using CT26 cell line. Hemolysis test was performed on rat red blood cells (RBCs). Moreover, the efficacy of targeted liposomes were investigated by in vivo antitumor activity and tissue toxicities were studied by histological examination. The EE% and average particle size of liposomes were 67.88±1.84% and 114.00±4.58nm, respectively. TEM image revealed that liposomes were spherical in shape. Targeted liposomes showed higher cellular uptake, lower IC50 (12.02μM compared to 39.81μM for liposomal 5FU and 39.81μM for free 5FU) and higher ROS production than free drug (62,271.28 vs 2369.55 fluorescence intensity) on cancer cells. Results of hemolysis assay confirmed the blood biocompatibility of the liposomes. Moreover, folate targeted liposomes showed better tumor inhibition than free drug (88.75mm3 tumor volume vs 210.00mm3) and no tissue abnormalities were found in histological examination. It can be concluded that folate targeted liposomes provide an effective and safe strategy for colon cancer targeted chemotherapy.