Search

Recently, metformin (Met) has shown to have antineoplastic properties in cancer treatment by improving hypoxic tumor conditions, and causing reduction in the synthesis of biomolecules, which are vital for cancer growth. However, as an orally administered drug, Met has low bioavailability and rapid renal clearance. Thus, the goal of this study was to vectorize Met inside liposomes in the context of triple negative breast cancer (TNBC), which currently lacks treatment options when compared to other types of breast cancer. Vectorization of Met inside liposomes was done using Bangham method by implementing double design of experiment methodology to increase Met drug loading (minimum-run resolution V characterization design and Box-Behnken design), as it is generally extremely low for hydrophilic molecules. Optimization of Met-loaded liposome synthesis was successfully achieved with drug loading of 190 mg/g (19% w/w ). The optimal Met-liposomes were 170 nm in diameter with low PdI (< 0.1) and negative surface charge (-20 mV), exhibiting sustained Met release at pH 7.4. The liposomal Met delivery system was stable over several months, and successfully reduced TNBC cell proliferation due to the encapsulated drug. This study is one the first reports addressing liposome formulation through thin-film hydration using two design of experiment methods aiming to increase drug loading of Met.

The encapsulation efficiency (EE%) reflects the amount of bioactive components that can be loaded into nanoliposomes. Obtaining a suitable nanoliposome stabiliser may be the key to improving their EE%. In this study, three polyphenols were screened as stabilisers of nanoliposomes with high nisin EE%, with curcumin nanoliposomes (Cu-NLs) exhibiting the best performance (EE% = 95.94%). Characterizations of particle size, PDI and zeta potential indicate that the Cu-NLs had good uniformity and stability. TEM found that nisin accumulated at the edges of the Cu-NLs' phospholipid layer. DSC and FT-IR revealed that curcumin was involved in the formation of the phospholipid layer and altered its structure. FT-IR and molecular docking simulations indicate that the interactions between curcumin and nisin are mainly hydrogen bonding and hydrophobic. In whole milk, Cu-NLs effectively protected nisin activity. This study provides an effective strategy for improving the EE% of nanoliposomes loaded with nisin and other bacteriocins., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

To improve the poor water solubility and oral bioavailability of tyrosol, novel tyrosol liposomes (Tyr-LPs) were prepared by pH-driven method. Fourier transform infrared (FTIR) absorption spectra and X-ray diffraction (XRD) analysis indicated that Tyr-LPs were successfully encapsulated and tyrosol was in an amorphous state in liposomes. When tyrosol content in Tyr-LP was 1.33 mg/ml and the Tyr:LP (mass ratio) = 1:2, favorable dispersibility of Tyr-LP was exhibited, with an instability index of 0.049 ± 0.004, PDI of 0.274 ± 0.003, and the EE of 94.8 ± 2.5 %. In vivo pharmacokinetic studies showed that after oral administration of tyrosol or Tyr-LP (Tyr:LP = 1:2), concentration-versus-time curve (AUC 0-720mins ) and maximum concentration (C max ) values of Tyr-LP was respectively 1.5-fold (P < 0.01) and 2.25-fold (P < 0.01) higher than tyrosol, which indicated that the oral bioavailability of tyrosol was effectively improved in Tyr-LPs. Our study thereby provides theoretical support for the application of Tyr-LP for optimal delivery of tryosol., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The marketed drug Doxorubicin (DOX) and the promising anti-cancer agent 9-( N -piperazinyl)-5-methyl-12( H )-quino[3,4- b ][1,4]benzothiazinium chloride (9-PBThACl) were used to prepare and compare a range of liposomal delivery systems based on dipalmitoylphosphatidylcholine (DPPC). Liposome-assisted drug release was examined using the spectrophotometric method. In order to provide in vitro release characteristics of liposomal conjugates (L DPPC/drug vs. L DPPC/drug/drug ) as well as to evaluate the impact of temperature and pH buffering on the conformation/polarity of the phospholipid bilayer, the encapsulation efficiency of the liposomes entrapping 9-PBThACl and DOX was calculated. In fact, some competition between the investigated molecules was noticed during the entrapment process because relatively high values of the encapsulation efficiency were observed only for the liposomal complexes containing one trapped drug molecule. An averaged absorbance value enabled us to indicate the pH value of the environment (pH ≈ 6.8), at which the physicochemical property profiles of the liposomal complexes were noticeably changed. Moreover, the operational factors limiting the drug release kinetics from the produced liposomes were mathematically modeled. First-order and Bhaskas models ensured satisfactory compliance with the experimental data for the liposomal complexes buffered at pH values of 5.50, 6.00, and 7.40, respectively.

Dried reconstituted vesicle (DRV) liposomes are formulated under mild conditions. The method has the capability to entrap substantially higher amounts of hydrophilic solutes, compared to other passive-loading liposome preparation methods. These characteristics make this liposome type ideal for entrapment of labile substances, such as peptides, proteins, or DNA's (or other nucleotides or oligonucleotides), or in general biopharmaceuticals and sensitive drugs. In this chapter, all possible types of DRV liposomes (in respect to the encapsulated molecule characteristics and/or their applications in therapeutics) are introduced, and preparation methodologies (for each type) are described in detail., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

In the present study, nanoliposomes with tuneable structure elasticity were prepared by reverse-phase evaporation. Both Fluorescence Polarization and Fluorescence Resonance Energy Transfer was employed to characterize the structural elasticity of resultant nanoliposomes. Temozolomide, a kind of hydrophilic drug as the first-line treatment choice for glioblastoma, was encapsulated into nanoliposomes. The results showed that the flexibility of nanoliposomes gradually increased with sodium cholate, while decreasing with cholesterol, Labrafac CC and Labrafac PG adding. Furthermore, the structural flexibility of nanoliposomes was positively correlated with the encapsulation efficiency and release rate and cellular uptake. Our research reveals the structural flexibility of nanoliposomes could affect in vitro characteristics and thereafter in vivo behaviors of nanoliposomes.

Numerous attempts to overcome the poor water solubility of cam ptothecin (CPT) by various nano drug delivery systems are described in various sources in the literature. However, the results of these approaches may be hampered by the incomplete separation of free CPT from the formulations, and this issue has not been investigated in detail. This study aimed to promote the solubility and continuous delivery of CPT by developing long-lasting liposomes using various weights (M.W. 2000 and 5000 Daltons) of the hydrophilic polymer polyethylene glycol (PEG). Conventional and PEGylated liposomes containing CPT were formulated via the lipid film hydration method (solvent evaporation) using a rotary flash evaporator after optimising various formulation parameters. The following physicochemical characteristics were investigated: surface morphology, particle size, encapsulation efficiency, in vitro release, and formulation stability. Different molecular weights of PEG were used to improve the encapsulation efficiency and particle size. The stealth liposomes prepared with PEG 5000 were discrete in shape and with a higher encapsulation efficiency (83 ± 0.4%) and a prolonged rate of drug release (32.2% in 9 h) compared with conventional liposomes (64.8 ± 0.8% and 52.4%, respectively) and stealth liposomes containing PEG 2000 (79.00 ± 0.4% and 45.3%, respectively). Furthermore, the stealth liposomes prepared with PEG 5000 were highly stable at refrigeration temperature. Significant changes were observed using various pharmacokinetic parameters (mean residence time (MRT), half-life, elimination rate, volume of distribution, clearance, and area under the curve) of stealth liposomes containing PEG 2000 and PEG 5000 compared with conventional liposomes. The stealth liposomes prepared with PEG 5000 showed promising results with a slow rate of release over a long period compared with conventional liposomes and liposomes prepared with PEG 2000 , with altered tissue distribution and pharmacokinetic parameters.

Liposomes are an attractive drug delivery platform for a wide variety of pharmaceutical molecules. Encapsulation efficiency, which refers to the amount of drug contained inside liposomes compared with the total amount of drug, is a critical quality attribute of liposome products, as the free drug in a liposomal formulation may cause toxicity or undesired biodistribution. The determination of encapsulation efficiency requires the measurement of at least two of the three drug populations: total drug, encapsulated drug and free drug. However, direct measurement of the encapsulated drug and free drug remains a challenging analytical task. Nanoparticle exclusion chromatography (nPEC), an emerging high-performance liquid chromatography (HPLC) technique, has shown great potential in separating and quantifying the free drug in liposomal formulations. In this study, nPEC was systematically evaluated for two representative liposomal formulations containing either hydrophilic or hydrophobic small molecule drugs. It is reported for the first time that the insoluble free drug suspended in the aqueous formulation can be directly measured by nPEC. This free drug in the suspension sample was quantified with excellent accuracy and precision. On the other hand, the total drug measurement from dissociated liposomes was confirmed by the benchmark methodology of reversed phase liquid chromatography (RPLC). The facile quantitation of free and total drug in the liposome formulation enables the fast and accurate determination of the encapsulation efficiency, which can be used to guide the formulation development and characterize the product quality., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Lupeol liposomes, modified with Gal-PEG-DSPE, were developed following a thin-film dispersion method. Then, the morphology, physicochemical properties, and in vitro release properties of those liposomes were investigated. The scanning electron microscopic images showed that most of the liposomes were spherical particles; they were similar in size and uniformly dispersed. Both lupeol liposomes and Gal-lupeol liposomes exhibited an average particle size of about 100 nm. The encapsulation efficiency was greater than 85%. The encapsulation efficiency of lupeol liposome and Gal-lupeol liposome, stored with 15% sucrose as glycoprotein for 6 months, was higher than 80%; although the particle size increased, they remained within 200 nm. The cell-uptake study demonstrated that the Gal-lupeol-liposome uptake efficiency was the highest in HepG2 cells. The HepG2 cells treated with the Gal-lupeol liposomes had higher apoptotic efficiency than the lupeol liposome and free lupeol. After HepG2 cells were treated with Gal-lupeol liposome, the expressions of AKT/mTOR-related proteins (p-AKT308 and p-AKT473) were also significantly reduced than the lupeol-liposome and free lupeol group. The in vivo targeting studies showed that Gal-NR-L exhibited liver-targeting effects on FVB mice. The pharmacodynamic study was performed by transfecting AKT and c-MET via the high-pressure tail vein of FVB mice. After Gal-lupeol-L administration, the liver index and liver weight of mice were less than those non-targeted group. The histopathological study showed that the lobular structure in the mice liver was clearer, the vacuoles were more obvious, and the cytoplasm was more abundant after Gal-lupeol-L administration. Also, the qRT-PCR study showed that AFP, GPC3, and EpCAM mRNA expression levels were significantly lower than those non-targeted lupeol-liposomes.

This study extends QbD principles to liposomal products containing a hydrophilic active pharmaceutical ingredient (API). The feasibility and advantages of the QbD concept for multivesicular liposome-based systems were demonstrated. We selected the local anesthetic drug bupivacaine as a model compound. Desired properties for three critical attributes of multivesicular liposome drug products, namely, the particle size, morphology, and drug encapsulation efficiency, were defined and evaluated. The liposome preparation process significantly affected both the liposome particle size and drug encapsulation efficiency. In this study, the effects of material attributes and processing parameters during the preparation of liposomes were studied in detail using a microscope and particle size analyzer. We used risk assessment to monitor several factors that substantially affect the encapsulation rate and particle size., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Aims: To encapsulate a purified bacteriocin into a nanovesicles and check its antibacterial effect., Background: Although the use of nano-encapsulated bacteriocins in food matrices is poorly reported, encapsulated nisin can reduce L. monocytogenes counts in whole and skimmed milk and in soft cheese., Objective: The present study deals with the extraction and purification of a bacteriocin from an isolated strain Pediococcus pentosaceus KC692718. A comparative study of the effect of free pediocin and liposome encapsulated pediocin against Listeria sp. was performed., Methods: The purification of the extracted cell free supernatant was subjected to ammonium sulphate precipitation, cation exchange chromatography followed by gel permeation chromatography. The bacteriocin activity and protein concentration were determined using Lowry's method. The characterization of the pure pediocin was done. Liposome like nanovesicle was constructed and the stability of the liposome encapsulated pediocin was checked. Finally, the antibacterial effect was comparatively studied of the free pediocin, liposome, and liposome encapsulated pediocin simultaneously., Results: The pediocin of 3.6kDa was purified with a specific activity of 898.8. AU/mg. It remained stable from pH 2.0-8.0 was found to be moderately stable above 80°C and remain stable for one month when stored at -20°C. The encapsulated pediocin showed stability since it retained 50% of its initial activity. The encapsulated pediocin showed 89% of encapsulation efficiency., Conclusion: The encapsulated pediocin not only improved pediocin stability but also enhanced the controlled release of the antimicrobial substances, enough for inhibiting the foodborne pathogen L. monocytogenes., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Evidences have shown that phytosome assemblies are novel drug delivery system. However, studies of phytosomes in food applications are scarce. The characteristics of milk phospholipid assemblies and their functionality in terms of in vitro digestibility and bioavailability of encapsulated nutrients (ascorbic acid and α-tocopherol) were studied. The phytosomes were fabricated using ethanolic evaporation technique. Spectral analysis revealed that polar parts of phospholipids formed hydrogen bonds with ascorbic acid hydroxyl groups, further, incorporating ascorbic acid or α-tocopherol into the phospholipid assembly changed the chemical conformation of the complexes. Phospholipid-ascorbic acid phytosomes yielded an optimal complexing index of 98.52 ± 0.03% at a molar ratio of 1:1. Phytosomes exhibited good biocompatibility on intestinal epithelial cells. The cellular uptake of ascorbic acid was 29.06 ± 1.18% for phytosomes. It was higher than that for liposomes (24.14 ± 0.60%) and for ascorbic acid aqueous solution (1.17 ± 0.70%)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Decoquinate (DQ) is used for prophylaxis against coccidian infections within the digestive tract of chickens, but DQ is extremely insoluble in water. Hence, improving the water solubility of DQ is extremely important. First, decoquinate nanoliposomes (DQNLs) were prepared by the thin-film dispersion-ultrasonic method. The preparation conditions of DQNLs were optimized using the orthogonal test. The optimal preparation conditions of DQNLs were: a ratio of egg-yolk lecithin:drug (w/w) of 10:1, ratio of egg-yolk lecithin:cholesterol (w/w) of 5:1, rotary-evaporation temperature of 50 ℃, and ultrasound duration of 15 min. The encapsulation efficiency of DQNLs prepared under these conditions reached 99.24 % and drug loading was 5.67 %. The characterization of optimized DQNLs was also done. Transmission electron microscopy of DQNLs showed that they had the characteristic structure of liposomes. The mean particle size was 115.6 nm. The polydispersity index was 0.175. The zeta potential was -39.1 mV. The stability of DQNLs was high upon storage at 4 ℃. In vivo studies demonstrated that the lower dose (5 mg/L) of DQNLs in drinking water obtained the similar anticoccidial efficacy to that of 40 mg/kg DQ in feed against diclazuril-resistance Eimeria tenella isolate. The in vitro inhibitory effect of DQNLs on the sporulation of Eimeria tenella oocysts was dose-dependent. Therefore, the anticoccidial efficacy of DQ was enhanced significantly after being encapsulated into nanoliposomes., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The purpose of this study was to optimize the preparation conditions of podophyllotoxin liposomes (PPT-Lips), and to investigate their effects on PC3 cells. PPT-Lips were prepared by using a thin-film dispersion method. In order to achieve maximum drug encapsulation efficiency (EE), the process and formulation variables were optimized by response surface methodology (RSM). The optimum preparation conditions were cholesterol to lecithin ratio of 3.6:40 (w/w), lipid to drug ratio of 15.8:1 (w/w), and the ultrasonic intensity of 35% (total power of 400 W). The experimental EE of PPT-Lips was 90.425%, which was consistent with the theoretically predicted value. The characterization studies showed that PPT-Lips were well-dispersible spherical particles with an average size of 106 nm and a zeta potential of -10.1 mV. A gradual and time-dependent pattern of PPT from liposomes was found in in vitro drug release with a cumulative release amount up to 70.3% in 24 h. Results of cell viability experiments on PC3 cells demonstrated that PPT-Lips exhibited more effective anticancer activity in comparison with free PPT. Therefore, PPT-Lips represent an efficient and promising drug delivery system for PPT.

Tyrosol, hydroxytyrosol and oleuropein are among the major phenolic compounds in fruits, leaves and oils from Olea europaea L. These natural antioxidants molecules revealed several beneficial effects on human health, but a low bioavailability and accessibility to targeted site. Liposomes are drug/nutraceutical delivery carriers, used for driving bioactive molecules to desired target tissues, decreasing potential side effects and protecting the encapsulated molecule from enzymatic metabolic processes. In this study, zwitterionic liposomes containing tyrosol, hydroxytyrosol and oleuropein were synthesized and characterized for their size and surface charge. Particular attention was devoted to the determination of encapsulation efficiency (EE%), quantifying the loaded Tyr, HTyr and Ole amount, by using three different techniques: direct UV spectrophotometry, High Performance Liquid Chromatography and Trolox Equivalent Antioxidant Capacity assay. The results revealed higher EE% for oleuropein. Cyto-toxicity and cyto-compatibility of liposomes were also tested on human chondrocyte cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In order to optimize the prescription and preparation process of norcantharidin/tetrandrine dual loaded liposomes, the dual drug loaded liposomes were prepared by film dispersion-ultrasonic method using norcantharidin-mesoporous silica nanoparticles（MSN-NCTD）and tetrandrine（Tet）. With particle size and encapsulation efficiency as comprehensive indexes, the influences of phospholipid cholesterol amount, ultrasonic time and ultrasonic power on prescription process were investigated by orthogonal test; the in vitro release characteristics of liposomes were investigated by dialysis method. The results indicated that the best prescription process of prepared norcantharidin/tetrandrine dual loaded liposomes was as follows: phospholipid-cholesterol ratio 2.5:1, ultrasonic time 4 min, ultrasonic power 40%; the encapsulation efficiency was 86.62% and 79.19%respectively for NCTD and Tet;liposomes were well-shaped under the transmission microscope, with average particle size of （207.5±3.6） nm, Zeta potential of （1.345±0.173） mV; and the 48 h cumulative release rates of NCTD and Tet were 85.14% and 85.00% respectively. The experiment results proved that the dual drug loaded liposomes prepared by film dispersion-ultrasonic method had uniform particle size, high encapsulation efficiency and in vitro sustained release characteristics., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

A simple and rapid chromatographic measurement method for determining doxorubicin (DOX) encapsulation efficiency (EE) into PEGylated liposomes using nanoparticle exclusion chromatography (nPEC) was developed. In this work, Doxil ® and two PEGylated liposomes spiked with DOX were employed as model liposomes, and unencapsulated DOX was measured by high performance liquid chromatography with diode-array detector using an N-vinylpyrrolidone modified nPEC column without any sample pretreatment. Only 5 μL of an intact liposomal suspension and 3 min analysis time were required for the determination of the quantity of unencapsulated DOX. The method was validated in terms of linearity, accuracy, precision, and recovery in the range from 0.00-1.0 mg/mL (corresponding to 100-50% EE). Applicability of the method was confirmed using the measurement of time-dependent DOX loading% into the liposomes with the remote loading method using an ammonium sulfate gradient. Furthermore, it was found that the peak area of DOX-loaded liposomes in the chromatogram was proportional to DOX EE%. As this simple and rapid analytical method can measure the EE precisely, it is expected that this method will be applicable to the in-process control of liposome preparation manufacturing and the quality control of the liposome drug products., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aptamer technology has shown much promise in cancer therapeutics for its targeting abilities. However, its potential to improve drug loading and release from nanocarriers has not been thoroughly explored. In this study, we employed drug-binding aptamers to actively load drugs into liposomes. We designed a series of DNA aptamer sequences specific to doxorubicin, displaying multiple binding sites and various binding affinities. The binding ability of aptamers was preserved when incorporated into cationic liposomes, binding up to 15equivalents of doxorubicin per aptamer, therefore drawing the drug into liposomes. Optimization of the charge and drug/aptamer ratios resulted in ≥80% encapsulation efficiency of doxorubicin, ten times higher than classical passively-encapsulating liposomal formulations and similar to a pH-gradient active loading strategy. In addition, kinetic release profiles and cytotoxicity assay on HeLa cells demonstrated that the release and therapeutic efficacy of liposomal doxorubicin could be controlled by the aptamer's structure. Our results suggest that the aptamer exhibiting a specific intermediate affinity is the best suited to achieve high drug loading while maintaining efficient drug release and therapeutic activity. This strategy was successfully applied to tobramycin, a hydrophilic drug suffering from low encapsulation into liposomes, where its loading was improved six-fold using aptamers. Overall, we demonstrate that aptamers could act, in addition to their targeting properties, as multifunctional excipients for liposomal formulations., (Copyright © 2017 Elsevier B.V. All rights reserved.)

As a new kind of drug carries, pH-sensitive liposomes have been widely studied in tumor therapy for their advantages of target ability and sustained-release. Here, we synthesized a pH-sensitive material, N-(3-Aminopropyl)imidazole-cholesterol (IM-Chol) and prepared a novel pH-sensitive liposomes using IM-Chol and phosphatidylcholine. IM-Chol was synthesized through amidation reaction between the amino group of N-(3-Aminopropyl)imidazole and acyl chloride group of cholesteryl chloroformate in a weak base solution. Optimal conditions to prepare liposomes were obtained by the orthogonal experiment with the higher encapsulation efficiency as the evaluation indicator. The properties of liposomes, such as particle size, zeta potential, morphology, encapsulation efficiency, drug release behavior and in vitro cell toxicity were evaluated by transmission electron microscopy (TEM), dynamic light scattering (DLS) and MTT assay respectively. The results showed that the average particle size of IM-Chol liposomes was 141nm (PDI 0.323). Liposomes can assemble into uniform spheres at pH 7.4, but under the condition of pH 5.0, the spherical structure of IM-Chol liposomes was broken, exhibiting pH-sensitive property. In vitro drug releasing studies demonstrated the controlled-release behavior of the curcumin (CUR) in the IM-Chol liposomes. The cumulative release of CUR reached to 72.5% in the first 24h at pH 5.0, faster than that at pH 7.4, which confirmed that the drug carrier displayed pH-sensitive release behaviors. In addition, the MTT assay was employed to test the cytotoxicity of IM-Chol liposomes and CUR IM-Chol liposomes. All cell viabilities were greater than 80% after incubating for 24h, even up to the highest dose of 500mg/L, indicating that IM-Chol liposomes had good biocompatibility. The tumor inhibitory results towards EC109 cells of free CUR and CUR-loaded IM-Chol liposomes indicated that IM-Chol liposomes indeed enhanced the cell killing effect of CUR. These results showed that the novel IM-Chol liposomes prepared in this paper had pH-sensitive property and were expected to play a huge potential in tumor treatment., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Dried reconstituted vesicles (DRV) are liposomes that are formulated under mild conditions and have the capability to entrap substantially high amounts of hydrophilic solutes (compared to other types of liposomes). These characteristics make this liposome type ideal for entrapment of labile substances, as peptide, protein, or DNA vaccines, or in general biopharmaceuticals and sensitive drugs. In this chapter, all possible types of DRV liposomes (with respect to the encapsulated molecule characteristics and/or their applications in therapeutics) are introduced, and preparation methodologies (for each type) are described in detail.

Context: Ropivacaine (RVC) is an aminoamide local anesthetic widely used in surgical procedures. Studies with RVC encapsulated in liposomes and complexed in cyclodextrins have shown good results, but in order to use RVC for lengthy procedures and during the postoperative period, a still more prolonged anesthetic effect is required., Objective: This study therefore aimed to provide extended RVC release and increased upload using modified liposomes., Materials and Methods: Three types of vesicles were studied: (i) large multilamellar vesicle (LMV), (ii) large multivesicular vesicle (LMVV) and (iii) large unilamellar vesicle (LUV), prepared with egg phosphatidylcholine/cholesterol/α-tocopherol (4:3:0.07 mol%) at pH 7.4. Ionic gradient liposomes (inside: pH 5.5, pH 5.5 + (NH4)2SO4 and pH 7.4 + (NH4)2SO4) were prepared and showed improved RVC loading, compared to conventional liposomes (inside: pH 7.4)., Results and Discussion: An high-performance liquid chromatography analytical method was validated for RVC quantification. The liposomes were characterized in terms of their size, zeta potential, polydispersion, morphology, RVC encapsulation efficiency (EE(%)) and in vitro RVC release. LMVV liposomes provided better performance than LMV or LUV. The best formulations were prepared using pH 5.5 (LMVV 5.5in) or pH 7.4 with 250 mM (NH4)2SO4 in the inner aqueous core (LMVV 7.4in + ammonium sulfate), enabling encapsulation of as much as 2% RVC, with high uptake (EE(%) ∼70%) and sustained release (∼25 h)., Conclusion: The encapsulation of RVC in ionic gradient liposomes significantly extended the duration of release of the anesthetic, showing that this strategy could be a viable means of promoting longer-term anesthesia during surgical procedures and during the postoperative period.

Apigenin is an antioxidant that has shown a preventive activity against different cancer and cardiovascular disorders. In this study, we encapsulate apigenin with liposome to tackle the issue of its poor bioavailability and low stability. Apigenin loaded liposomes are fabricated with food-grade rapeseed lecithin in an aqueous medium in absence of any organic solvent. The liposome particle characteristics, such as particle size and polydispersity are optimised by tuning ultrasonic processing parameters. In addition, to measure the liposome encapsulation efficiency accurately, we establish a unique high-performance liquid chromatography technique in which an alkaline buffer mobile phase is used to prevent apigenin precipitation in the column;. salt is added to separate lipid particles from the aqeuous phase. Our results demonstrate that apigenin encapsulation efficiency is nearly 98% that is remarkably higher than any other reported value for encapsulation of this compound. In addition, the average particle size of these liposomes is 158.9 ± 6.1 nm that is suitable for the formulation of many food products, such as fortified fruit juice. The encapsulation method developed in this study, therefore have a high potential for the production of innovative, functional foods or nutraceutical products., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A liposome formulation of the enzyme paraoxonase-1 (PON1) was prepared for purposes of prolonging and maintaining its activity in vivo. Following purification of PON1 from rabbit serum, liposomes containing PON1 (L-PON1) were prepared using a film-dispersion method with a soybean phospholipid-cholesterol mixture (5 : 1, w/w). The pharmacokinetic behaviour of conventional injectable PON1 and L-PON1 was compared following a single intravenous injection in rats. The enzyme activity of PON1 and its pharmacokinetic parameters were calculated based on a two-compartment model following conventional injection. The level of PON1 encapsulation in L-PON1 was 86.20 ± 3.12%. The particle size distribution of L-PON1 was a narrow unimodal form, with an average diameter of 126 nm. The results suggest that compared with conventional injectable PON1, L-PON1 has an improved half-life and enhanced enzyme activity in rats. In conclusion, PON1 can be encapsulated into a lipid bilayer for enhanced stability., (© 2014 Wiley Publishing Asia Pty Ltd.)

Spray drying is a well-established, energy efficient, and scalable process widely used in the food industry, however it may lead to thermal degradation of susceptible compounds, such as (poly)phenols, resulting in biological activity loss to some extent. In this study, we aimed to improve the physicochemical stability and bioaccessibility of (poly)phenols from Rosa pimpinellifolia fruit extract (Rosa extract) loaded in liposomes by generating solid particles via spray drying. Liposomes were conjugated with chitosan (Ch) and whey protein (Wp) to optimize the biopolymer concentrations by monitoring mean particle diameter, polydispersity index, and surface charge. The mean diameter of liposomes ranged between 135 and 210 nm upon optimal addition of Ch (0.4%, w/v) and Wp (4.0%, w/v) which also increased the entrapment efficiency of (poly)phenols from 74.2 to 77.8% and 79.1%, respectively. After spray drying, about 65–76% of the antioxidant capacity were retained in biopolymer-conjugated liposomes (Ch or Wp) while the retention rate was 48% in only spray-dried extract (Rosa extract powder). Compared to unencapsulated Rosa extract, spray drying (Rosa extract powder) and conjugation with Ch (Ch-Lip powder) or Wp (Wp-Lip powder) significantly increased the bioaccessibility of (poly)phenols and preserved their antioxidant capacity. Based on the findings of this study, Ch- or Wp-conjugation of liposomes prior to spray drying could improve physicochemical stability and protect (poly)phenols loaded in liposomes against processing stress and passage through the digestive tract. Further in vitro and in vivo investigations on a variety of bioactive compounds may draw more attention to their potential as functional foods. [ABSTRACT FROM AUTHOR]

This study aimed to optimize a liposomal formulation to enhance the stability of a phenolic-rich extract from green walnut husk. Liposomes were prepared using varying concentrations of phosphatidylcholine (0.15–2% w/v), extract (0–1.3% v/v), and sodium laurate (0–0.2% w/v) via ethanol injection and sonication. Characterization included visual appearance, particle size, polydispersity index, surface charge, encapsulation efficiency, and morphology. Stable liposomes were achieved at 0.15% and 0.3% w/v phosphatidylcholine, although with low encapsulation efficiency (<40%). The addition of 0.2% (w/v) sodium laurate improved the stability, especially at higher phosphatidylcholine concentrations, enhancing the electrostatic repulsion. Optimal concentrations of 2% w/v phosphatidylcholine, 0.2% w/v sodium laurate, and 0.6% v/v extract were determined. The liposomes exhibited a spherical unilamellar morphology with a size of 97.5 ± 0.9 nm and a negative surface charge of –39.8 ± 0.9 mV. These nanoliposomes showed 79.7 ± 0.7% encapsulation efficiency and remained stable under pH, temperature, ionic strength, and storage time variations. Overall, the liposomes proved effective in preserving the natural phenolics of walnut husks under challenging environmental conditions. [ABSTRACT FROM AUTHOR]

The food borne pathogen Enterobacter cloacae contribute to food borne illness in humans. Biofilm formation in Enterobacter cloacae makes them more resistant to antibiotics. The main goal of the research is to prevent biofilm-forming Enterobacter cloacae by encapsulating nisin in liposomes using nanotechnology. The isolate was identified by 16S rRNA gene sequencing, and the biofilm-formed were characterized. Nisin was selected based on sensitivity testing. A microvesicle encapsulation method was used to encapsulate nisin in liposomes. Bacterial control was determined by colony forming units in an in vitro bioassay. Inhibition and eradication of Enterobacter cloacae was investigated using a microbial biofilm highthroughput antimicrobial susceptibility test using the Calgary biofilm apparatus. The food borne pathogen Enterobacter cloaca was isolated from the skin of grapes. After characterizing the biofilm formation on the isolate, the results showed that Enterobacter cloacae has the highest biofilm formation in tryptic broth (TSB) and brain heart infusion medium (BHI). In the antibiotic susceptibility test, the isolate is inhibited by antibiotics when presented in high concentrations. High-throughput analysis was performed using the Calgary biofilm apparatus, and the results showed that the nisinloaded liposome exhibited good inhibition compared to antibiotics. One mM concentration of nisin (3.3 mg/10 mL) was used to encapsulate them in liposomes using a microvesicle encapsulation method. The results showed a tremendous inhibition of the food borne pathogen Enterobacter cloacae by the colony-forming units. This liposomal encapsulation of nisin promises high inhibition and can also be used for food safety. [ABSTRACT FROM AUTHOR]

Curcumin is an antioxidant that can effectively eliminate free radicals. However, as its oral bioavailability is low, an effective delivery method is required. Phospholipid-based liposomes can encapsulate lipophilic drugs, such as curcumin, while liposome, cholesterol, and gum Arabic (GA) can enhance the internal and external stability of drug membranes. This present study used concentrations of cholesterol (Cchol) and GA (CGA), ranging from 0 to 10, 20, 30, and 40% as well as 0 to 5, 10, 15, 20, 30, and 40%, respectively, to encapsulate curcumin in a GA–cocoliposome (CCL/GA) matrix and test its efficacy in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). The absence of new characteristic peaks in the Fourier transform infrared (FTIR) spectra results indicate the presence of non-covalent interactions in the CCL/GA encapsulation. Furthermore, increasing the Cchol decreased the encapsulation efficiency (EE), loading capacity (LC), and antioxidant activity (IR) of the CCL/GA encapsulation but increased its release rate (RR). Conversely, increasing CGA increased its EE and IR but decreased its LC and RR. The two conditions applied confirmed this. Liposomal curcumin had the highest IR in SIF (84.081%) and the highest RR in SGF (0.657 ppm/day). Furthermore, liposomes loaded with 10% Cchol and 20% CGA performed best in SIF, while those loaded with 10% Cchol and 30% CGA performed best in SGF. Lastly, the CCL/GA performed better in SIF than SGF. [ABSTRACT FROM AUTHOR]

Ginsenoside Rg1 (Rg1), a monomer saponin component, is one of the components with the highest content in total saponins of Panaxnotoginseng. It had various pharmacological effects. The bioavailability of oral tablets is only 1–20 %, and it is eliminated quickly in the blood. The development of new dosage forms and new routes of administration of ginsenoside Rg1 with sustained release and high bioavailability has become a significant problem to be solved. The Rg1 liposomes study used a thin film dispersion ultrasound method for its preparation. This study focused the pharmacokinetic parameters of ginsenoside Rg1 liposomes in rats through the lung perfusion method. Ginsenoside Rg1 liposomes were round and uniform in shape, the particle size was 2–3 μm, and the encapsulation efficiency of ginsenoside Rg1 liposome was 51.2 %. Results showed that, after pulmonary administration of ginsenoside Rg1, the time of ginsenoside Rg1 detected by Rg1 liposomes was longer than that of Rg1 solution, the relative bioavailability of ginsenoside Rg1 liposome lung administration AUC liposome/AUC solution = 122.67 %. These results provided the scientific theoretical and experimental basis for further development of new dosage forms and new routes of administration of ginsenoside Rg1.

In this study, a novel polysaccharide liposome was prepared using garlic polysaccharides, soybean lecithin and cholesterol and structurally characterized. The optimal preparation conditions of garlic polysaccharide liposomes were determined by single-factor and response surface tests using the film-material ratio, lipid-drug ratio and ultrasonic time as factors and the encapsulation efficiency as response values. The obtained liposomes were characterized in terms of micromorphology, particle size, UV spectrum, IR spectrum and stability. The results showed that the optimal preparation conditions of garlic polysaccharide liposomes were as follows: Film-material ratio of 4:1, lipid-drug ratio of 24:1, ultrasonic time of 14 min, with the maximum encapsulation efficiency of 61.00%±0.73%. The obtained liposomes appeared as spherical vesicles with uniform dispersion and good stability. Their particle size, polymer dispersity index and zeta potential were 213.50±1.85 nm, 0.187±0.005 and −21.07±1.27 mV, respectively. UV and IR spectra confirmed that garlic polysaccharides were successfully encapsulated into the lipid material through electrostatic interactions, without the formation of new chemical bonds. After 28 days of storage at 4 ℃, the particle size of garlic polysaccharide liposomes increased from 211.13±0.54 nm to 225.70±0.65 nm, the PDI increased from 0.187±0.003 to 0.236±0.001, and the encapsulation efficiency decreased from 60.96%±0.32% to 56.97%±0.74%, exhibiting a relative stability. Therefore, the garlic polysaccharide liposomes prepared in this study had high encapsulation efficiency, small particle size, good dispersion and high stability, which could provide a reference for the development of garlic polysaccharide derivatives.

Liposomes are self-assembled spherical systems composed of amphiphilic phospholipids. They can be used as carriers of both hydrophobic and hydrophilic substances, such as the anti-aging and wound-healing copper-binding peptide, GHK-Cu (glycyl-L-histidyl-L-lysine). Anionic (AL) and cationic (CL) hydrogenated lecithin-based liposomes were obtained as GHK-Cu skin delivery systems using the thin-film hydration method combined with freeze–thaw cycles and the extrusion process. The influence of total lipid content, lipid composition and GHK-Cu concentration on the physicochemical properties of liposomes was studied. The lipid bilayer fluidity and the peptide encapsulation efficiency (EE) were also determined. Moreover, in vitro assays of tyrosinase and elastase inhibition were performed. Stable GHK-Cu-loaded liposome systems of small sizes (approx. 100 nm) were obtained. The bilayer fluidity was higher in the case of cationic liposomes. As the best carriers, 25 mg/cm3 CL and AL hydrated with 0.5 mg/cm3 GHK-Cu were selected with EE of 31.7 ± 0.9% and 20.0 ± 2.8%, respectively. The obtained results confirmed that the liposomes can be used as carriers for biomimetic peptides such as copper-binding peptide and that the GHK-Cu did not significantly affect the tyrosinase activity but led to 48.90 ± 2.50% elastase inhibition, thus reducing the rate of elastin degeneration and supporting the structural integrity of the skin. [ABSTRACT FROM AUTHOR]

The present study aims to formulate and evaluate the physicochemical characteristics of the resveratrol-laminarin encapsulated liposomal formulation. Resveratrol is a phytoalexin with numerous biological effects like antidiabetic, anti-oxidant, anti-cancer, and anti-inflammatory properties. A polysaccharide extracted from brown algae called laminarin possesses anti-tumor, anti-oxidant, anti-coagulant, anti-inflammatory, and antiobesity properties. Resveratrol, a hydrophobic drug, is entrapped in the liposomal bilayer, and laminarin, a hydrophilic drug, is enclosed in the hydrophilic core. The preparation and characteristics of resveratrol-laminarin-loaded liposomes, including their particle size, zeta potential, entrapment efficiency, and in-vitro release kinetics, were investigated in this study. The thin film lipid hydration method was used to prepare the liposome using soy phospholipids and cholesterol in a 6:1 ratio. Downsizing of the prepared liposomes was carried out by homogenization and sonication techniques. The liposome had a particle size of 120.7 nm after sonication, and a zeta potential of -33.4 mV was observed. The highest entrapment efficiency recorded for resveratrol is 90.69%, and 83.64% for laminarin. Biophysical characterisation of the prepared liposomes was carried out by scanning electron microscope and UV-visible spectrophotometry. The release study of resveratrol and laminarin was observed for six hours. A stable and steady release of the compounds was observed. The stability of the liposomes stored at 4°C was analyzed after three months of preparation. In conclusion, the prepared liposomal formulations exhibited good physicochemical characteristics and are of great therapeutic value in the future. [ABSTRACT FROM AUTHOR]

The impacts of liposomal encapsulation on the bitterness of salmon frame protein hydrolysate (SFPH) and salmon frame protein plastein (SFPP) with the aid of ultrasound (20% amplitude, 750 W) for different time intervals (30, 60 and 120 s) were investigated. Liposomes loaded with 1% protein hydrolysate (L-PH1) and 1% plastein (L-PT1) showed the highest encapsulation efficiency and the least bitterness (p < 0.05). Ultrasonication for longer times reduced encapsulation efficiency (EE) and increased bitterness of both L-PH1 and L-PT1 along with a reduction in particle size. When comparing between L-PH1 and L-PT1, the latter showed less bitterness due to the lower bitterness in nature and higher entrapment of plastein in the liposomes. In vitro release studies also showed the delayed release of peptides from L-PT1 in comparison to the control plastein hydrolysate. Therefore, encapsulation of liposomes with 1% plastein could be an efficient delivery system for improving the sensory characteristics by lowering the bitterness of protein hydrolysates. [ABSTRACT FROM AUTHOR]

Liposomes are self-assembled spherical systems composed of amphiphilic phospholipids. They can be used as carriers of both hydrophobic and hydrophilic substances, such as the anti-aging and wound-healing copper-binding peptide, GHK-Cu (glycyl-L-histidyl-L-lysine). Anionic (AL) and cationic (CL) hydrogenated lecithin-based liposomes were obtained as GHK-Cu skin delivery systems using the thin-film hydration method combined with freeze–thaw cycles and the extrusion process. The influence of total lipid content, lipid composition and GHK-Cu concentration on the physicochemical properties of liposomes was studied. The lipid bilayer fluidity and the peptide encapsulation efficiency (EE) were also determined. Moreover, in vitro assays of tyrosinase and elastase inhibition were performed. Stable GHK-Cu-loaded liposome systems of small sizes (approx. 100 nm) were obtained. The bilayer fluidity was higher in the case of cationic liposomes. As the best carriers, 25 mg/cm3 CL and AL hydrated with 0.5 mg/cm3 GHK-Cu were selected with EE of 31.7 ± 0.9% and 20.0 ± 2.8%, respectively. The obtained results confirmed that the liposomes can be used as carriers for biomimetic peptides such as copper-binding peptide and that the GHK-Cu did not significantly affect the tyrosinase activity but led to 48.90 ± 2.50% elastase inhibition, thus reducing the rate of elastin degeneration and supporting the structural integrity of the skin.

Copyright of Acta Edulis Fungi is the property of Acta Edulis Fungi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Abstract]: Objective: A novel imperatorin (IMP)-liposome-hydrogel formulation was developed to increase skin permeation efficiency and improve the bioavailability of IMP after topical delivery. Methods: IMP loading into liposomes was optimized, and liposomes were entrapped in a polymer hydrogel consisting of carbomer. Liposomes were also used as a control formulation. The physical properties and percent encapsulation efficiency were evaluated. The adhesive strength of the gel was tested. The in vitro percutaneous permeability, percutaneous penetration mechanism, and irritant evaluation were investigated. Results: Compared to liposomes, the preparation of IMP-liposomes-gel has excellent adhesion properties and sustained drug release on the skin surface. Conclusion: These findings suggest developing liposome gels for potential percutaneous drug carrier systems.

The impacts of liposomal encapsulation on the bitterness of salmon frame protein hydrolysate (SFPH) and salmon frame protein plastein (SFPP) with the aid of ultrasound (20% amplitude, 750 W) for different time intervals (30, 60 and 120 s) were investigated. Liposomes loaded with 1% protein hydrolysate (L-PH1) and 1% plastein (L-PT1) showed the highest encapsulation efficiency and the least bitterness (p < 0.05). Ultrasonication for longer times reduced encapsulation efficiency (EE) and increased bitterness of both L-PH1 and L-PT1 along with a reduction in particle size. When comparing between L-PH1 and L-PT1, the latter showed less bitterness due to the lower bitterness in nature and higher entrapment of plastein in the liposomes. In vitro release studies also showed the delayed release of peptides from L-PT1 in comparison to the control plastein hydrolysate. Therefore, encapsulation of liposomes with 1% plastein could be an efficient delivery system for improving the sensory characteristics by lowering the bitterness of protein hydrolysates.

Lupeol liposomes, modified with Gal-PEG-DSPE, were developed following a thin-film dispersion method. Then, the morphology, physicochemical properties, and in vitro release properties of those liposomes were investigated. The scanning electron microscopic images showed that most of the liposomes were spherical particles; they were similar in size and uniformly dispersed. Both lupeol liposomes and Gal-lupeol liposomes exhibited an average particle size of about 100 nm. The encapsulation efficiency was greater than 85%. The encapsulation efficiency of lupeol liposome and Gal-lupeol liposome, stored with 15% sucrose as glycoprotein for 6months, was higher than 80%; although the particle size increased, they remained within 200 nm. The cell-uptake study demonstrated that the Gal-lupeol-liposome uptake efficiency was the highest in HepG2 cells. The HepG2 cells treated with the Gal-lupeol liposomes had higher apoptotic efficiency than the lupeol liposome and free lupeol. After HepG2 cells were treated with Gal-lupeol liposome, the expressions of AKT/mTOR-related proteins (p-AKT308 and p-AKT473) were also significantly reduced than the lupeol-liposome and free lupeol group. The in vivo targeting studies showed that Gal-NR-L exhibited liver-targeting effects on FVB mice. The pharmacodynamic study was performed by transfecting AKT and c-MET via the highpressure tail vein of FVB mice. After Gal-lupeol-L administration, the liver index and liver weight of mice were less than those non-targeted group. The histopathological study showed that the lobular structure in the mice liver was clearer, the vacuoles were more obvious, and the cytoplasm was more abundant after Gal-lupeol-L administration. Also, the qRT-PCR study showed that AFP, GPC3, and EpCAM mRNA expression levels were significantly lower than those non-targeted lupeol-liposomes. [ABSTRACT FROM AUTHOR]

The number of studies conducted with liposomes to reduce side effects in systemic administration of chemotherapeutic agents is increasing day by day. One of these chemotherapeutic agents, 5-Fluorouracil (5-FU) is a good candidate for encapsulating into the liposomes; however, it has been difficult to obtain liposomal 5-FU with high encapsulation efficiency. The various factors such as preparation method (thin film hydration method and passive loading with small volume incubation method), drug amount (10 mg, 7.5 mg, and 5 mg), hydration volume (3.5 mL and 2 ml), and incubation volume (2 mL and 1 mL) were investigated to optimize the formulation of 5-FU encapsulated liposomes. Liposomes were characterized according to particle size, polydispersity index (PDI), zeta potential, and encapsulation efficiency (EE%). The in vitro release study was carried out using Franz diffusion cell. Based on the optimization of formulation, the average drug EE% and the mean particle size of 5-FU-loaded liposomes were found to be 25% and 188.6 nm. In vitro drug release of 5-FU-loaded liposomes (SVI-4) presented a biphasic release of 5-FU, and this behavior was in accordance with the first-order equation. According to the results, 5-FU can be effectively loaded into liposomes prepared by passive loading with small volume incubation method. [ABSTRACT FROM AUTHOR]

A strategic pathway in creating high-potent medical products is with targeted therapeutic systems that are based on nanoparticles of various structure. Such particles are capable of providing a targeted effect and an increase in bioavailability of the medical products. A special place among modern targeted drug delivery systems is held by liposomal nanoparticles which have apparent advantages over nanoparticles of an another type The problem number one for pharmacy lies in developing specific methods of control of nanosize drug delivery systems. This research is dedicated to the development and validation of a technique for determining encapsulation efficiency of cytochrome C in liposomes. The subject of research comprised the obtained liposomal form of cytochrome C, placebo emulsion, and cytochrome C solution. The research was conducted in compliance with the ICH and FDA requirements and recommendations in relation to the development of HPLC methods of control of liposomal preparations. A method has been developed to enable the determination of encapsulation efficiency of cytochrome C in liposomal preparations and to allow for identifying the composition of liposomal nanoparticles of cytochrome C. This HPLC method has been validated in terms of specificity, limit of detection, and robustness in compliance with the recommended criteria. The technique may find its application in quality control of liposomal form of cytochrome C and in control points manufacturing process.

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

INTRODUCTION: Vaccinium myrtillus L. leaves contain bioactive components, such as polyphenols, stilbenes, iridoid glycosides, fatty acids, and fibers. However, polyphenols possess low solubility, stability, and bioavailability, thus the encapsulation of the mentioned active principles in different carriers is necessary. Liposomes are widely used as a carrier for the encapsulation, preservation, and controlled release of polyphenols in various products. Therefore, the aims of the presented research are the development and characterization of V. myrillus leaf extract-loaded liposomes via the determination of encapsulation efficiency, particle size, polydispersity index (PDI), zeta potential, and mobility. EXPERIMENTAL: The liposomes with encapsulated extract were prepared employing the proliposome procedure. Encapsulation efficiency was indirectly calculated by the polyphenol concentration determined in the supernatant. Particle size, PDI, zeta potential, and mobility were measured by the photon correlation spectroscopy in Zetasizer. Every measurement was examined three times at 25°C. RESULTS AND DISCUSSION: The encapsulation efficiency of polyphenols was >85 %. The liposomes contained only phospholipids resulting in a more rigid membrane providing the prevention of the leakage of the encapsulated polyphenols, as well as a higher encapsulation efficiency. The diameter and PDI of the liposomes were 5408.7±56.4 and 0.249±0.049 nm, respectively confirming that higher liposomal vesicles possessed lower PDI values. The zeta potential and mobility were -5.02±0.25 mV and -0.315±0.016 µmcm/Vs, respectively. Zeta potential possessed negative values that are related to the exposure of the phosphate group lying in an outer plane concerning the choline groups. The mobility of liposomes represents a function of the size, zeta potential, and lipid composition. The liposomal vesicles with lower membrane fluidity also show low mobility. The changes in the mobility of the liposomes were attributed to the membrane fluidity and ability to deform. Additionally, when flavonoids (also presented in V. myrtillus extract) are adsorbed at the surface of the liposomes, it can decrease their mobility. CONCLUSIONS: The beneficial effects of bioactive principles from V. myrtillus leaves on human health and their sensitivity highlight the application of liposomal particles as a carrier for V. myrtillus extract and their potential implementation in foods, functional foods, pharmaceutics, and cosmetics. [ABSTRACT FROM AUTHOR]

The focus of this study was on the development, physicochemical characterisation and evaluation of the antioxidant activity of cape gooseberry calyx extract loaded into nanoliposomal systems. Various nanoliposomes were prepared and optimised using the ethanol injection method and characterised based on particle size, polydispersity and zeta potential measurements. Subsequently, the encapsulation efficiency and in vitro release profile of the natural antioxidant extract (NAE) were evaluated, and its antioxidant activity was assessed using the oxygen radical absorbance capacity assay. The results revealed that NAE-loaded nanoliposomes described desired quality features (e.g., particle size of < 200 nm, polydispersity index of < 0.3, zeta potential of > −40 mV and encapsulation efficiency of ∼70%). Furthermore, it was found that NAE release is controlled by various stages, and its antioxidant activity improves by around 30% when loaded into the nanoliposomes, suggesting that it could be a promising antioxidant functional raw material. • The major antioxidant compound of the cape gooseberry extract is rutin flavone. • The optimized method allows developing nanoliposomes with desired quality characteristics. • Nanoliposomal systems encapsulate around 70% of the Natural Antioxidant Extract. • Natural antioxidant extract release is complex and given by a four-stage mechanism. • Nanoliposomes describe appropriate stability and remain the antioxidant effect over time. [ABSTRACT FROM AUTHOR]

Dual centrifugation (DC) is a novel in-vial homogenization technique for the preparation of liposomes in small batch sizes under gentle and sterile conditions which allows encapsulation efficiencies (EE) for water soluble compounds of >50%. Since liposome size, size distribution (PDI), and EE depend on the lipid concentration used in the DC process, a screening method to find optimal lipid concentrations for a defined lipid composition was developed. Four lipid mixtures consisting of cholesterol, hydrogenated or non-hydrogenated egg PC, and/or PEG-DSPE were screened and suitable concentration ranges could be identified for optimal DC homogenization. In addition to the very fast and parallel liposome preparation of up to 40 samples, the screening process was further accelerated by the finding that DC generates homogeneously mixed liposomes from a macroscopic lipid mixture without the need to initially prepare a molecularly mixed lipid film from an organic solution of all components. This much simpler procedure even works for cholesterol containing lipid blends, which could be explained by a nano-milling of the cholesterol crystals during DC homogenization. Furthermore, EE determination was performed by time-resolved fluorescence measurements of calcein-loaded liposomes without removing the non-entrapped calcein. The new strategy allows the rapid characterization of a certain lipid composition for the preparation of liposomes within a working day.

This research highlights the capacity of a newly introduced centrifugation process to form liposomes from water-in-fluorocarbon nano-emulsions stabilized with phospholipids to incorporate macromolecular and sensitive active pharmaceutical ingredients (API). The encapsulation efficiency of the produced liposomes, incorporating fluorescein-sodium, bovine serum albumin and fluorecein isothiocyanate dextran as model APIs, is determined by applying Vivaspin® centrifugation filtration and quantified by UV-Vis spectroscopy. It was found that higher densities of the fluorocarbons used as the hydrophobic phase enable a higher encapsulation efficiency and that an efficiency of up to 98% is possible depending on the used phospholipid. Among the engineering aspects of the process, a comparison between different membrane substances was performed. Efficiency increases with a higher phospholipid concentration but decreases with the addition of cholesterol. Due to the higher bending modulus, liposome formation is slowed down by cholesterol during liposome closure leading to a greater leakage of the model API. The encapsulation of bovine serum albumin and dextran, both investigated under different osmotic conditions, shows that an efflux negatively affects the encapsulation efficiency while an influx increases the stability. Overall, the process shows the potential for a very high encapsulation efficiency for macromolecules and future pharmaceutical applications.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objectives] To effectively solve the problem of poor oral bioavailability of total flavonoids in Kang Zhu Gan Lu (ZYZH), a new hypoglycemic Tibetan solid preparation, ZYZH oral proliposome was prepared by modern preparation method, and its hypoglycemic effect was evaluated. [Methods] ZYZH proliposome was prepared by carrier deposition method, and its particle morphology and Zeta potential were detected. Taking encapsulation efficacy as indictor, the optimal prescription and preparation process of ZYZH oral proliposome were screened by orthogonal experiment. In addition, the hypoglycemic activity of ZYZH oral liposome in alloxan-induced hyperglycemic mice was studied. [ Results] The repose angle, average particle size, encapsulation efficiency, and Zeta potential of ZYZH proliposome are 34. 2°, (442.5±3.5) nm, 67.7% and (-47.2 ±3.4) mV, respectively. Compared with the model group, the fasting blood glucose level of the hyperglycemic mice significantly declined (P<0.01), and their body weight changed insignificantly after four weeks of oral administration of ZYZH proliposome (P >0.05). [Conclusions] The preparation process of ZYZH oral proliposome is characterized by simple operation, high encapsulation efficiency and good stability. The new hypoglycemic Tibetan drug ZYZH oral liposome has obvious hypoglycemic effect on alloxan-induced hyperglycemic mice. [ABSTRACT FROM AUTHOR]