Diameter Of Liposomes Research Articles

Preparation of New Liposomal Daunorubicin and Evaluation of its Anti-colorectal Cancer in HCT116 Cells

Background: Colorectal cancer (CRC) is the third most common cause of cancerrelated deaths worldwide. To develop more effective anti-CRC drugs, this research evaluated the impact of synthesized liposomal daunorubicin on HTC116 colon cancer cell line. Methods: Liposomal daunorubicin (LDNR) was synthesized by the thin layer hydration method and size was determined by dynamic light diffraction (DLS). MTT assay was used to determine the cytotoxicity and IC50 of LDNR against the HCT116 CRC cell line. Relative mRNA expression of the NF-κB gene and apoptosis were evaluated in 24 hours treatments of HCT116 cells by qRT-PCR and flow cytometry, respectively. Results: The hydrodynamic diameter of liposomes containing daunorubicin (DNR) was determined 25.2 nm. MTT assay showed a 38% decrease in HCT116 cells viability after 24-hour treatment with the DNR (0.5 μM). The lowest (0.125 μM) and highest (2 μM) dose of LDNR showed 20.4% and 71.6% cytotoxicity, respectively. LDNR showed dose-dependent cytotoxicity with the IC50 of 0.87 μM. The phase contrast microscope evaluation confirmed the LDNR cytotoxicity. The DNR and LDNR (0.87 μM) decreased relative mRNA levels of NF-κB 63% (P= 0.023) and 99.6% (P=0.003), respectively. The percentage of apoptotic cells in the DNR and LDNR increased by 27.1% (P<0.0001) and 49.7% (P<0.0001), respectively. Conclusion: DNR increases the rate of apoptosis by decreasing the NF-κB gene expression in HCT116 cells. These effects are intensified in the liposomal form. Therefore, the LDNR produced in this research can be considered in the treatment of CRC.

Kinesin-1-transported liposomes prefer to go straight in 3D microtubule intersections by a mechanism shared by other molecular motors

Kinesin-1 ensembles maneuver vesicular cargoes through the three-dimensional (3D) intracellular microtubule (MT) network. To define how such cargoes navigate MT intersections, we first determined how many kinesins from an ensemble on a lipid-based cargo simultaneously engage a MT, and then determined the directional outcomes (straight, turn, terminate) for liposome cargoes at perpendicular MT intersections. Run lengths of 350-nm diameter liposomes decorated with up to 20, constitutively active, truncated kinesin-1 KIF5B (K543) were longer than single motor transported cargo, suggesting multiple motor engagement. However, detachment forces of lipid-coated beads with ~20 kinesins, measured using an optical trap, showed no more than three simultaneously engaged motors, with a single engaged kinesin predominating, indicating anticooperative MT binding. At two-dimensional (2D) and 3D in vitro MT intersections, liposomes frequently paused (~2 s), suggesting kinesins simultaneously bind both MTs and engage in a tug-of-war. Liposomes showed no directional outcome bias in 2D (1.1 straight:turn ratio) but preferentially went straight (1.8 straight:turn ratio) in 3D intersections. To explain these data, we developed a mathematical model of liposome transport incorporating the known mechanochemistry of kinesins, which diffuse on the liposome surface, and have stiff tails in both compression and extension that impact how motors engage the intersecting MTs. Our model predicts the ~3 engaged motor limit observed in the optical trap and the bias toward going straight in 3D intersections. The striking similarity of these results to our previous study of liposome transport by myosin Va suggests a "universal" mechanism by which cargoes navigate 3D intersections.

Ion-Mediated Structural Discontinuities in Phospholipid Vesicles.

Despite intense research, methods for controlling soft matter's spontaneous self-assembly into well-defined layers remain a significant challenge. We observed ion-induced structural discontinuities of phospholipid vesicles that can be exploited for controlled self-assembly of soft materials, using DOPC and NaCl as a model system. The observations were made for the 0.25 wt % lipid concentration. We used dynamic light scattering, zeta-potential measurement, cryo-electron microscopy, small-angle X-ray, and small-angle neutron scattering to understand the reason for the discontinuities. For salt concentrations below 8 mM, we observed a decrease in the liposome diameter with increased NaCl concentration. Above 8 mM, we measured a discontinuity; the radius increases within a very narrow salt concentration range within less than 0.1 mM and then decreases for values greater than 8 mM. At 75 mM, the radius becomes constant until it grows again at around 500 mM. Microscopy and scattering experiments show a transition from unilamellar to bilamellar at 8 mM and to trilamellar at 75 mM. At 500 mM, we found a heterogeneous liposome system with many different bilayer numbers. All the experimental observations indicate that declining solvent quality and increasing osmotic pressure direct lipids to expel preferentially to the inner compartment. Upon reaching a critical concentration, excess lipids can form a new bilayer. This spontaneous self-assembly process causes simultaneous shrinkage of the aqueous core and expansion of the vesicle. This approach opens an intriguing path for controlling the self-assembly of bioinspired colloids.

The influence of the chlorine atom on the biological activity of 2′-hydroxychalcone in relation to the lipid phase of biological membranes - Anticancer and antimicrobial activity

The study investigates the effect of the presence of a chlorine atom in the 2′-hydroxychalcone molecule on its interaction with model lipid membranes, in order to discern its potential pharmacological activity. Five chlorine derivatives of 2′-hydroxychalcone were synthesized and evaluated against liposomes composed of POPC and enriched with cationic (DOTAP) or anionic (POPG) lipids. The physicochemical properties of the compounds were initially simulated using SwissAdame software, revealing high lipophilicity (ilogP values: 2.79–2.90). The dynamic light scattering analysis of liposomes showed that chloro chalcones induce minor changes in the diameter of liposomes of different surface charges. Fluorescence quenching assays with a TMA-DPH probe demonstrated the strong ability of the compounds to interact with the lipid bilayer, with varying quenching capacities based on chlorine atom position. FTIR studies indicated alterations in carbonyl, phosphate, and choline groups, suggesting a transition area localization rather than deep penetration into the hydrocarbon chains. Additionally, dipole potential reduction was observed in POPC and POPC-POPG membranes, particularly pronounced by derivatives with a chlorine atom in the B ring. Antibacterial and antibiofilm assays revealed enhanced activity of derivatives with a chlorine atom compared to 2′-hydroxychalcone, especially against Gram-positive bacteria. The MIC and MBIC50 values showed increased efficacy in the presence of chlorine with 3′-5′-dichloro-2′-hydroxychalcone demonstrating optimal antimicrobial and antibiofilm activity. Furthermore, antiproliferative assays against breast cancer cell lines indicated higher activity of B-ring chlorine derivatives, particularly against MDA-MB-231 cells. In general, the presence of a chlorine atom in 2′-hydroxychalcone improves its pharmacological potential, with derivatives showing improved antimicrobial, antibiofilm, and antiproliferative activities, especially against aggressive breast cancer cell lines. These findings underscore the importance of molecular structure in modulating biological activity and highlight chalcones with a chlorine as promising candidates for further drug development studies.

Chloride intracellular channel (CLIC) proteins function as fusogens

Chloride Intracellular Channel (CLIC) family members uniquely transition between soluble and membrane-associated conformations. Despite decades of extensive functional and structural studies, CLICs’ function as ion channels remains debated, rendering our understanding of their physiological role incomplete. Here, we expose the function of CLIC5 as a fusogen. We demonstrate that purified CLIC5 directly interacts with the membrane and induces fusion, as reflected by increased liposomal diameter and lipid and content mixing between liposomes. Moreover, we show that this activity is facilitated by acidic pH, a known trigger for CLICs’ transition to a membrane-associated conformation, and that increased exposure of the hydrophobic inter-domain interface is crucial for this process. Finally, mutation of a conserved hydrophobic interfacial residue diminishes the fusogenic activity of CLIC5 in vitro and impairs excretory canal extension in C. elegans in vivo. Together, our results unravel the long-sought physiological role of these enigmatic proteins.

Effect of Spray Drying on Physicochemical Stability and Antioxidant Capacity of Rosa pimpinellifolia Fruit Extract-Loaded Liposomes Conjugated with Chitosan or Whey Protein During In Vitro Digestion

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.

Vortex fluidic regulated phospholipid equilibria involving liposomes down to sub-micelle size assemblies.

Conventional channel-based microfluidic platforms have gained prominence in controlling the bottom-up formation of phospholipid based nanostructures including liposomes. However, there are challenges in the production of liposomes from rapidly scalable processes. These have been overcome using a vortex fluidic device (VFD), which is a thin film microfluidic platform rather than channel-based, affording ∼110 nm diameter liposomes. The high yielding and high throughput continuous flow process has a 45° tilted rapidly rotating glass tube with an inner hydrophobic surface. Processing is also possible in the confined mode of operation which is effective for labelling pre-VFD-prepared liposomes with fluorophore tags for subsequent mechanistic studies on the fate of liposomes under shear stress in the VFD. In situ small-angle neutron scattering (SANS) established the co-existence of liposomes ∼110 nm with small rafts, micelles, distorted micelles, or sub-micelle size assemblies of phospholipid, for increasing rotation speeds. The equilibria between these smaller entities and ∼110 nm liposomes for a specific rotational speed of the tube is consistent with the spatial arrangement and dimensionality of topological fluid flow regimes in the VFD. The prevalence for the formation of ∼110 nm diameter liposomes establishes that this is typically the most stable structure from the bottom-up self-assembly of the phospholipid and is in accord with dimensions of exosomes.

Trypanocidal activity of liposomal isotretinoin and loratadine formulations

We previously identified the antihistamine loratadine (LTD) and the medication for severe acne isotretinoin (ISO), as repositioned drugs for Chagas disease that showed strong activity against Trypanosoma cruzi. In this study, we evaluated the trypanocidal efficiency of LTD and ISO using liposomes that increase their low water solubility and facilitate their internalization allowing the reduction of the drug effective dose.Liposomes were prepared with phosphatidylcholine and cholesterol, and coated with chitosan. The average diameter, polydispersity index and Zeta-potential of LTD, ISO and unloaded liposomes were characterized by dynamic light scattering. The drug encapsulation efficiency in vesicles was determined by high performance liquid chromatography. Their trypanocidal effects were evaluated on the T. cruzi parasites.ISO and LTD liposomes inhibited epimastigote proliferation and trypomastigote viability of T. cruzi, and both formulations were significantly more potent than benznidazole, the drug currently used to treat Chagas disease. We also showed that the storage stability of ISO, that represents a relevant issue, was improved after encapsulated it in liposomes.This encapsulation of LTD and ISO in liposomes that significantly increased their trypanocidal effect and stability, encourage the use of carriers as drug delivery systems.

Selective Endocytic Uptake of Targeted Liposomes Occurs within a Narrow Range of Liposome Diameters.

Cell surface receptors facilitate signaling and nutrient uptake. These processes are dynamic, requiring receptors to be actively recycled by endocytosis. Due to their differential expression in disease states, receptors are often the target of drug-carrier particles, which are adorned with ligands that bind specifically to receptors. These targeted particles are taken into the cell by multiple routes of internalization, where the best-characterized pathway is clathrin-mediated endocytosis. Most studies of particle uptake have utilized bulk assays rather than observing individual endocytic events. As a result, the detailed mechanisms of particle uptake remain obscure. To address this gap, we employed a live-cell imaging approach to study the uptake of individual liposomes as they interact with clathrin-coated structures. By tracking individual internalization events, we find that the size of liposomes rather than the density of the ligands on their surfaces primarily determines their probability of uptake. Interestingly, targeting has the greatest impact on endocytosis of liposomes of intermediate diameters, with the smallest and largest liposomes being internalized or excluded, respectively, regardless of whether they are targeted. These findings, which highlight a previously unexplored limitation of targeted delivery, can be used to design more effective drug carriers.

Effect of curvature on bilayer thickness of liposome suspensions in water

The bilayer thickness of different sizes of SOPC lipid liposomes is measured using small-angle neutron scattering (SANS) at 30 °C and a model is developed to estimate the bilayer thickness of liposome based on its diameter. Three different sizes of liposome suspensions are prepared by extruding the suspension through 30 nm, 100 nm, and 200 nm membrane pore sizes. The bilayer thickness of liposomes is measured for these suspensions using small-angle neutron scattering and the results show a slight reduction in bilayer thickness as liposome size increases. The average diameter of liposomes in these extruded suspensions varies from 59 nm to 109 nm as measured by dynamic light scattering. A model is developed that calculates the bilayer thickness depending on the diameter of the liposome. The model shows a decrease in bilayer thickness as liposome size increases. However, the calculated bilayer thickness drops to a very small extent with the increase in liposome diameter. We also study the effect of the addition of ethanol on the bilayer thickness of liposomes. SANS measurements find that the bilayer thickness of liposomes decreases after adding ethanol to liposome suspensions. The decrease in bilayer thickness in ethanol is of similar extent for various sizes of liposomes and it reduces by 12%–15% at a concentration of 20 vol% ethanol.

Storage Stability of Atheroglitatide, an Echogenic Liposomal Formulation of Pioglitazone Targeted to Advanced Atheroma with a Fibrin-Binding Peptide.

We have conducted a stability study of a complex liposomal pharmaceutical product, Atheroglitatide (AGT), stored at three temperatures, 4, 24, and 37 °C, for up to six months. The six parameters measured were functions of liposomal integrity (size and number), drug payload (loading efficiency), targeting peptide integrity (conjugation efficiency and specific avidity), and echogenicity (ultrasound-dependent controlled drug release), which were considered most relevant to the product's intended use. At 4 °C, liposome diameter trended upward, indicative of aggregation, while liposome number per mg lipid and echogenicity trended downward. At 24 °C, peptide conjugation efficiency (CE) and targeting efficiency (TE, specific avidity) trended downward. At 37 °C, CE and drug (pioglitazone) loading efficiency trended downward. At 4 °C, the intended storage temperature, echogenicity, and liposome size reached their practical tolerance limits at 6 months, fixing the product expiration at that point. Arrhenius analysis of targeting peptide CE and drug loading efficiency decay at the higher temperatures indicated complete stability of these characteristics at 4 °C. The results of this study underscore the storage stability challenges presented by complex nanopharmaceutical formulations.

Nanoliposomal VEGF-R2 peptide vaccine acts as an effective therapeutic vaccine in a murine B16F10 model of melanoma

BackgroundThe vascular endothelial growth factor receptor-2 (VEGFR-2) plays an important role in melanoma development and progression. Peptide vaccines have shown great potential in cancer immunotherapy by targeting VEGFR-2 as a tumor-associated antigen and boosting the immune response against both tumor cells and tumor endothelial cells. Despite this, the low efficiency of peptide vaccines has resulted in moderate therapeutic results in the majority of studies. Enhancing the delivery of peptide vaccines using nanoliposomes is an important strategy for improving the efficacy of peptide vaccines. In this regard, we designed VEGFR-2-derived peptides restricted to both mouse MHC I and human HLA-A*02:01 using immunoinformatic tools and selected three peptides representing the highest binding affinities. The peptides were encapsulated in nanoliposomal formulations using the film method plus bath sonication and characterized for their colloidal properties.ResultsThe mean diameter of peptide-encapsulated liposomes was around 135 nm, zeta potential of − 17 mV, and encapsulation efficiency of approximately 70%. Then, vaccine formulations were injected subcutaneously in mice bearing B16F10-established melanoma tumors and their efficiency in triggering immunological, and anti-tumor responses was evaluated. Our results represented that one of our designed VEGFR-2 peptide nanoliposomal formulations (Lip-V1) substantially activated CD4+ (p < 0.0001) and CD8+ (P < 0.001) T cell responses and significantly boosted the production of IFN-γ (P < 0.0001) and IL-4 (P < 0.0001). Furthermore, this formulation led to a significant decrease in tumor volume (P < 0.0001) and enhanced survival (P < 0.05) in mice.ConclusionOur findings suggest that the nanoliposomal formulation containing VEGFR-2 peptides could be a promising therapeutic vaccination approach capable of eliciting strong antigen-specific immunologic and anti-tumor responses.

Sodium Thiosulphate-Loaded Liposomes Control Hydrogen Sulphide Release and Retain Its Biological Properties in Hypoxia-like Environment.

Hypoxia, or insufficient oxygen availability is a common feature in the development of a myriad of cardiovascular-related conditions including ischemic disease. Hydrogen sulphide (H2S) donors, such as sodium thiosulphate (STS), are known for their cardioprotective properties. However, H2S due to its gaseous nature, is released and cleared rapidly, limiting its potential translation to clinical settings. For the first time, we developed and characterised liposome formulations encapsulating STS and explored their potential for modulating STS uptake, H2S release and the ability to retain pro-angiogenic and biological signals in a hypoxia-like environment mirroring oxygen insufficiency in vitro. Liposomes were prepared by varying lipid ratios and characterised for size, polydispersity and charge. STS liposomal encapsulation was confirmed by HPLC-UV detection and STS uptake and H2S release was assessed in vitro. To mimic hypoxia, cobalt chloride (CoCl2) was administered in conjunction with formulated and non-formulated STS, to explore pro-angiogenic and metabolic signals. Optimised liposomal formulation observed a liposome diameter of 146.42 ± 7.34 nm, a polydispersity of 0.22 ± 0.19, and charge of 3.02 ± 1.44 mV, resulting in 25% STS encapsulation. Maximum STS uptake (76.96 ± 3.08%) from liposome encapsulated STS was determined at 24 h. Co-exposure with CoCl2 and liposome encapsulated STS resulted in increased vascular endothelial growth factor mRNA as well as protein expression, enhanced wound closure and increased capillary-like formation. Finally, liposomal STS reversed metabolic switch induced by hypoxia by enhancing mitochondrial bioenergetics. These novel findings provide evidence of a feasible controlled-delivery system for STS, thus H2S, using liposome-based nanoparticles. Likewise, data suggests that in scenarios of hypoxia, liposomal STS is a good therapeutic candidate to sustain pro-angiogenic signals and retain metabolic functions that might be impaired by limited oxygen and nutrient availability.

Influence of impulse magnetic fields of extremely low frequencies on H2O2- and Fe2+-induced free radical lipid oxidation in liposomal suspensions

Background: For a long time, special attention in experimental biology and medicine is paid to free radical processes involving reactive oxygen species. In electromagnetic biology, the interest in free radical oxidation in biological membranes has increased significantly due to the discovery of spin mechanisms of magnetic fields on free radical processes. In the present day, these mechanisms are considered to be key in the processes of magnetoreception in living organisms. Liposomes, as the simplest models of biological membranes, are often used to study the primary mechanisms of action of different factors on the structural and functional properties of membranes. However, the influence of ecological significant extremely low-frequency magnetic fields on free radical oxidation in liposomal suspensions has not been studied enough. Objectives: The elucidation of the peculiarities of the influence of the extremely low frequency pulsed magnetic fields (ELF PMF) on H2O2- and Fe2+-induced peroxidation of natural phospholipids in liposomal suspensions. Materials and methods: The liposomal suspensions in phosphate buffer pH=7.4 were used. According to the literature and own results on light scattering the average diameter of liposomes was about 500Å. Ultra-weak chemiluminescence of liposomal suspensions was recorded using a device that operated in the mode of single photons counting. It consisted of a light-insulated cuvette unit where the test samples were placed, as well as a temperature sensor and a solenoid, which was used to create the PMF. Optical contact of the test samples with the photoelectron multiplier was carried out using a light guide. The recording system consisted of a broadband photomultiplier tube detector — FEU-130, which was at a temperature of –20°C. The pulse analyzer AI-256 was used to separate the useful signal that corresponded to the registration of single chemiluminescence light quanta. The voltage on the photomultiplier tube detector was applied in the range of current-voltage characteristics of this detector, in which a random voltage fluctuation had a minimal effect on the measurement of the useful signal. The number of light quanta that were recorded for defined time intervals characterized the overall intensity of the process of free radical oxidation of lipids in the experimental samples. The pulsed magnetic field was created using a solenoid coil located in the cuvette part. PMF was created using a serial generator G6-28. The magnetic field pulses were rectangular in shape with variable polarity for a period of oscillations. The induction of PMF was monitored using microteslameter G-79. The series of extremely low frequencies (5–80 Hz) and induction (5–500 μT) of PMF was chosen due to their environmental and physiological significance. Results: PMF of different frequencies with induction of 5 and 50 μT did not affect (p&gt;0.05) H2O2- and Fe2+-induced lipid oxidation in liposomal suspensions. Statistically significant changes (p&lt;0.05) were revealed only when liposomal suspensions were exposed to PMF with induction of 500 μT. It was found that the action of PMF with the frequency of 8 Hz 500 μT significantly inhibited H2O2-induced and enhanced Fe2+-induced chemiluminescence. This effect is associated with inhibition of the decomposition and with the accumulation of phospholipid hydroperoxides, which decompose and recombine in the presence of Fe2+ ions, which is accompanied by stronger chemiluminescence. The study of the dependence of the dynamics of the chemiluminescence intensity on the frequency of the PMF indicates the presence of a certain dependence of the effects in the range of up to 30 Hz. However, the inhibitory effect of PMF for the H2O2-induced oxidation phase is not always accompanied by a statistically significant increase in the amplitude of Fe2+-dependent light flash of chemiluminescence that indicates the general inhibitory effect of PMF at a certain frequency. Conclusions: PMF of extremely low frequencies statistically significantly affects the free radical oxidation in liposomal suspensions only at inductions exceeding several hundred microteslas. This indicates the effect of PMF on free radical processes for the conditions of the selected membrane model is realized mainly through spin interactions that determine the recombination of free radicals. The decrease of induction by one or two orders of magnitude, as well as increasing in frequency of the PMF above 50 Hz, leads to a decrease in the effectiveness of the influence of this physical factor on the intensity of lipid-free radical oxidation in liposomal suspensions. The most sensitive to the influence of ELF PMF is the phase of H2O2-induced free radical oxidation of lipids.

Enhancement of the Transdermal Delivery of Nonsteroidal Anti-inflammatory Drugs Using Liposomes Containing Cationic Surfactants

New hybrid liposomes based on cationic amphiphiles with different structures of the head group (cetyltrimethylammonium bromide (CTAB), 3-hexadecyl-1-hydroxyethylimidazolium bromide (IA-16(OH)), 1-(butylcarbamoyl)oxyethyl-3-hexadecylimidazolium bromide (IAC 16(Bu)), and hexadecylmethylpyrrolidinium bromide (PR-16)) were developed for transdermal administration of nonsteroidal anti-inflammatory drugs. The different surfactant/lipid compositions were studied to obtain stable liposomes with high functionality. The hydrodynamic diameter of cationic liposomes was ∼110 nm. An admixture of cationic surfactants and PC liposomes improves the physicochemical properties of vesicles and transdermal diffusion rate and prolongs the release of drugs. Liposomal diclofenac sodium (DS) and ketoprofen (KP) were tested (using Franz cells) for transdermal penetration. Drug diffusion monitoring for 48 h demonstrated that the maximum DS and KP penetration through the synthetic membranes (Strat-M) is characterized by values of 255 ± 2 and 186 ± 3 μg/cm2, respectively. The influence of the surfactant head group on the properties (stability, release profile, permeability) of cationic liposomes was shown for the first time. While the drug specificity is evident for the rate of release, the permeability increases as follows: conventional liposomes < CTAB/PC < PR-16/PC < IAC-16(Bu)/PC < IA-16(OH)/PC for both medicines. The rat paw edema model was used to assess the anti-inflammatory effect of the IA-16(OH)/PC leader formulation in vivo. It was found that liposomal DS and KP are effective for relieving rat paw edema. It should be noted that DS-loaded hybrid liposomes demonstrated the highest therapeutic efficacy compared to conventional vesicles.

Hybrid liposome/metal–organic framework as a promising dual-responsive nanocarriers for anticancer drug delivery

In this work, liposome-coated iron (III) benzene-1,3,5-tricarboxylate (Fe-BTC) metal–organic framework is examined as a promising pH/Ultrasound dual-responsive nanocarriers for doxorubicin (DOX) delivery. The successful coating of the MOF particles (Lip-Fe-BTC) with the phospholipid bilayer (PBL) was established by direct fusion into the synthesized liposomes. The liposome coating was verified using several techniques, including dynamic light scattering (DLS) and transmission electron microscopy (TEM). The DLS measurements showed an increase in the average particle diameter of liposomes from 150 nm to 163.1 nm for Lip-Fe-BTC particles. The Fe-BTC particles had the highest average particle diameter (287.3 nm). These results demonstrated that the PBL reduced the aggregation of the particles and improved their dispersity in the release medium. The TGA results demonstrated the MOF’s excellent thermal stability. Furthermore, the nanocarrier’s loading efficiency and capacity were determined to be ~90% and ~13.5 wt%, respectively. The in-vitro DOX release experiments demonstrated that the DOX-loaded Fe-BTC and liposome-coated Fe-BTC particles showed good pH and US dual-responsive capability, making them promising nanocarriers for drug delivery. The application of US enhanced DOX release from both Fe-BTC and liposome-coated Fe-BTC. In the case of Fe-BTC-DOX particles, the application of US enhanced the DOX release to around 38% and 67%, at pH levels of 7.4 and 5.3, respectively. Similarly, DOX release from the Lip-Fe-BTC-DOX particles reached ~35% and ~53%, at pH levels of 7.4 and 5.3, respectively. The MTT assay showed the biocompatibility and low cytotoxicity of these nanocarriers below 100 µg/ml.

Impact of critical process parameters and critical material attributes on the critical quality attributes of liposomal formulations prepared using continuous processing

Liposomes were one of the earliest drug delivery vehicles used for anti-cancer therapeutics and similarly, lipid-based nanoparticles have been used for abundance of applications as gene therapies. The methods to produce these particles have remained relatively unchanged until the recent emergence of continuous manufacturing. Continuous processing enables accelerated development of nanoparticle formulations while providing a scalable manufacturing solution. For this work a continuous processing platform for the production of lipid and polymeric-based nanoparticle formulations has been developed at the University of Connecticut. This research focuses on the formation of liposomes encompassing multiple design of experiments (DoEs) to identify functional relationships between critical process parameters (CPPs), critical material attributes (CMAs), and critical quality attributes (CQAs) for liposomal formulations produced using this continuous processing platform. Liposomes of various sizes and of low polydispersity index (PDI) were produced with different material attributes under various processing conditions. In general, lower mole percentages of cholesterol produced larger particles whereas the mole percent of phosphatidylglycerol did not seem to have a s impact on the size of the liposomes that were produced. The results showed that similarly sized liposomes could be produced with different processing conditions allowing for the flexibility to operate in regions most suitable for formulation components that may be sensitive to certain processing conditions. For example, if the target size of a formulation is 100 nm but the active pharmaceutical ingredient is sensitive to temperature, then the formulation can be manufactured at high (55 °C) or low (30 °C) depending on its characteristics. Additionally, the relationships between CMAs and CPPs were different from conventional liposomal manufacturing methods, allowing for more flexibility when using a continuous processing system. Models that can effectively predict the hydrodynamic diameter of monodispersed liposomes produced using continuous processing were developed. The models developed from the DoEs in this study may be useful for accelerated development of new lipid formulations as well as facilitate the translation from traditional manufacturing methods to continuous manufacturing for products already on the market.

On the synergy/antagonism of selected terpenes in the effect on lipid membranes studied in model systems

In this work the influence of the mixtures of four terpenes on the lipid monolayers and bilayers imitating bacteria membrane was analyzed. The aim of these investigations was to verify possible synergistic/antagonistic effects occurring between terpenes and affecting their influence on membranes. The studies were performed for major and minor components of the hop essential oil, namely: β-myrcene, α-humulene, E-β-Farnesene and limonene. The experiments on monolayers were based on the studies on penetration of terpenes and their mixtures into model systems, on the surface pressure-area measurements, and Brewster angle microscopy studies, while for bilayers they involved the hydrodynamic diameter, zeta potential and steady-state fluorescence anisotropy measurements of liposomes. Based on the collected results it was concluded that the synergy occurring between selected terpenes increases the effect of their mixtures on monolayers and bilayers as compared to particular components. Among the studied mixed terpene systems the equimolar myrcene/humulene/farnesene/limonene system was found to penetrate the most strongly into the monolayer and change its morphology as well as to make the bilayer more fluid. Additionally, from the comparison of these results with those published for the hop oil it was summarized that neither the studied mixtures nor the individual studied terpenes change the properties of the model membranes as effectively as the total extract. Thus, the action of the hop oil on membrane is not determined by its major components but it is rather the result of the interactions and synergy between major and minor components.

Modeling myosin Va liposome transport through actin filament networks reveals a percolation threshold that modulates transport properties.

Myosin Va (myoVa) motors transport membrane-bound cargo through three-dimensional, intracellular actin filament networks. We developed a coarse-grained, in silico model to predict how actin filament density (3-800 filaments) within a randomly oriented actin network affects fluid-like liposome (350 nm vs. 1750 nm) transport by myoVa motors. Five thousand simulated liposomes transported within each network adopted one of three states: transport, tug-of-war, or diffusion. Diffusion due to liposome detachment from actin rarely occurred given at least 10 motors on the liposome surface. However, with increased actin density, liposomes transitioned from primarily directed transport on single actin filaments to an apparent random walk, resulting from a mixture of transport and tug-of-wars as the probability of encountering additional actin filaments increased. This phase transition arises from a percolation phase transition at a critical number of accessible actin filaments, Nc. Nc is a geometric property of the actin network that depends only on the position and polarity of the actin filaments, transport distance, and the liposome diameter, as evidenced by a fivefold increase in liposome diameter resulting in a fivefold decrease in Nc. Thus in cells, actin network density and cargo size may be regulated to match cargo delivery to the cell’s physiological demands.

PD62-11 THERAPEUTIC EFFECT OF LIPOSOMAL DELIVERY OF HYDROGEN SULFIDE AND XENON ON ERECTILE FUNCTION AFTER CAVERNOUS NERVE INJURY

You have accessJournal of UrologySexual Function/Dysfunction: Basic Research & Pathophysiology (PD62)1 Sep 2021PD62-11 THERAPEUTIC EFFECT OF LIPOSOMAL DELIVERY OF HYDROGEN SULFIDE AND XENON ON ERECTILE FUNCTION AFTER CAVERNOUS NERVE INJURY Baibing Yang, Dustin Luse, Song Gao, Shaolin Huang, Yong-jian Geng, and Run Wang Baibing YangBaibing Yang More articles by this author , Dustin LuseDustin Luse More articles by this author , Song GaoSong Gao More articles by this author , Shaolin HuangShaolin Huang More articles by this author , Yong-jian GengYong-jian Geng More articles by this author , and Run WangRun Wang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002099.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Erectile dysfunction (ED) is a neurovascular disorder mediated by dysfunction of the nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway, and poor relaxation of corpus cavernosum smooth muscle. The two gaseous molecules, hydrogen sulfide (H2S) and xenon (Xe), have been shown to exert neurovascular protective effects in the setting of ischemic and traumatic injuries. Administration of H2S and Xe has been shown to reduce infarct sizes and improve function in animal models of cerebral ischemia–reperfusion injury. The current study tested the hypothesis that to a similar extent, H2S and Xe both can preserve erectile function after cavernous nerve injury. METHODS: A model of cavernous nerve injury ED was employed using bilateral cavernous nerve crush (BCNC) on adult male Sprague Dawley rats. The experimental and control groups were BCNC + saline, BCNC + H2S, BCNC + Xe treatment and a sham surgery control group. H2S treatment was used as positive control, which has been reported to improve erectile function through smooth muscle relaxation. H2S and Xe were packed in echogenic liposomes (ELIPs, liposome diameter ranged from 800 nm to several microns) respectively and injected through the rat tail vein (5mg ELIPs). Gas was released from ELIPs under ultrasound exposure at the root of penis. Intracavernosal pressure (ICP) and mean arterial pressure (MAP) were examined after ultrasound exposure and recorded for all groups. RESULTS: Rats injured by BCNC showed erectile dysfunction evidence by reduced ICP/MAP. Treatment with H2S and Xe blocked the BCNC adverse impact on erectile function by 1.83- and 1.75-fold increases respectively when compared with BCNC group. CONCLUSIONS: Liposomal delivery of H2S and Xe demonstrates potential as a novel therapy for ED after cavernous nerve injury. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e1076-e1076 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Baibing Yang More articles by this author Dustin Luse More articles by this author Song Gao More articles by this author Shaolin Huang More articles by this author Yong-jian Geng More articles by this author Run Wang More articles by this author Expand All Advertisement Loading ...