Hybrid Liposomes Research Articles

Hybrid Erythrocyte Liposomes: Functionalized Red Blood Cell Membranes for Molecule Encapsulation.

The modification of erythrocyte membrane properties provides a new tool towards improved drug delivery and biomedical applications. The fabrication of hybrid erythrocyte liposomes is presented by doping red blood cell membranes with synthetic lipid molecules of different classes (PC, PS, PG) and different degrees of saturation (14:0, 16:0-18:1). The respective solubility limits are determined, and material properties of the hybrid liposomes are studied by a combination of X-ray diffraction, epi-fluorescent microscopy, dynamic light scattering (DLS), Zeta potential, UV-vis spectroscopy, and Molecular Dynamics (MD) simulations. Membrane thickness and lipid orientation can be tuned through the addition of phosphatidylcholine lipids. The hybrid membranes can be fluorescently labelled by incorporating Texas-red DHPE, and their charge modified by incorporating phosphatidylserine and phosphatidylglycerol. By using fluorescein labeled dextran as an example, it is demonstrated that small molecules can be encapsulated into these hybrid liposomes.

Substrate-Sorting Nanoreactors Based on Permeable Peptide Polymer Vesicles and Hybrid Liposomes with Synthetic Macromolecular Channels.

Vesicles with molecular permeability have attracted considerable attention as biomedical materials, e.g., as biocatalytic nanoreactors for drug delivery and artificial cells. However, their applications are limited by their low permeability for enzyme substrates. Here, we report the synthesis of oligo(aspartic acid)-b-poly(propylene oxide) polymer vesicle nanoreactors with a negatively charged surface, which are preferentially permeable for cationic and neutral compounds. The permeation of cationic substrates is accelerated by the electrostatic effect, which increases the apparent rate of the enzymatic reaction. Notably, the polymer can be incorporated into a phospholipid membrane, where it acts as a synthetic molecular channel. The obtained results clearly suggest that imparting the vesicle surface with an anionic charge represents a simple and versatile approach to substrate sorting and enhances molecular permeability. This study can thus be expected to open new avenues for the design of vesicles with molecular permeability that may serve as biocatalytic nanoreactors in artificial cells and drug delivery applications.

One-Step Assembly of TiO2-Liposomes Based on Interfacial Sol-Gel Process within Lipid Bilayer.

There is a growing interest in the use of hybrid liposomes for various biochemical and biomedical applications. In this study, we report the first preparation and characterization of a class of TiO2-reinforced liposomes by a one-step assembly approach. The amphiphilic natural structure of lipids is exploited to localize a hydrophobic molecule, namely, precursor tetrabutyl titanate (TBOT), in the mid-plane of the liposomal bilayer assemblies in the aqueous phase. In situ TiO2 nanoshell formation is driven by subsequent interfacial hydrolysis of TBOT and the ensuing condensation within the hydrophobic interstices of the lipid bilayer. The core-shell structure, like cell and wall, is demonstrated by means of scanning electron microscopy and transmission electron microscopy images, and the formation of the TiO2 shell is confirmed using energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. To study the structural evolution of the hybrid liposomes during titania formation, fluorescence probe technique and surface pressure versus molecular area (π- A) isotherms are designed. The results demonstrate that the incorporation of TBOT into the mid-membrane of the lipid and titania in the core of the membrane strengthened the assembly of the lipid bilayer. We further demonstrate that titania shell improved the stability and release property of liposomes. We expect that the reported new TiO2-coated liposomes by co-assembly will be valuable in designing hybrid liposomes, exhibiting integrative capacity for drug encapsulation, compartment reaction, and photocatalysis.

Novel hybrid liposomal formulations based on imidazolium-containing amphiphiles for drug encapsulation.

Novel liposomes based on 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and imidazolium-containing amphiphiles with various length of hydrophobic tail at various molar ratio of components have been fabricated. Obtained formulations were characterized using dynamic and electrophoretic light scattering as well as transmission electron microscopy techniques. It has been established, that DPPC liposomes modification by these cationic amphiphiles resulted in zeta potential increase from +3 mV to +45-70 mV and improve its stability for a long time (more than 6 months, whereas unmodified liposomes have been destructed after 2 weeks of storage). Hydrodynamic diameter of prepared hybrid liposomes was in the range of 70-100 nm depending on its composition. Fabricated hybrid carriers have been used for drug (metronidazole) encapsulation. It has been shown, that superior encapsulation characteristics (encapsulation efficiency was 75%) exhibited hybrid liposomes composed from octadecyl derivative. Increase of the time of total release of encapsulated drug from hybrid liposomes in comparison with unencapsulated drug by 1.7 times has been demonstrated.

Lipids and Polymers Mediated CRISPR/Cas9 Gene Editing

CRISPR (the clustered, regularly interspaced, short palindromic repeat)/Cas9 nuclease system is the most commonly used method for gene editing, with the advantages of simple operation, high efficiency and high specificity, and has been used in various animals and crops. In this article, we review the latest development in the delivery technology of CRISPR/Cas9 based on lipids and polymers. We discuss the comparative advantages of commercial liposomes, new cationic lipidoid nanoparticles and hybrid liposomes as vectors for the delivery of genes encoding Cas9 and sgRNA, as well as many successful examples of polymer nanoparticles or polymer hybrid nanocarriers. We also introduce research ideas for the construction of non-viral vectors to better modify the structure of lipids and polymers, or to combine several biomaterials in order to better suit the CRISPR/Cas9 delivery. Furthermore, we consider the limitations of the non-viral carriers suitable for the delivery of the CRISPR/Cas9 system, and propose to overcome these obstacles through developing novel gene editing delivery vectors for clinical research.

Inhibitory effect of hybrid liposomes on the growth of liver cancer stem cells

PurposeCancer stem cells (CSCs), also known as tumor-initiating cells, are involved in tumor progression, metastasis, and drug resistance. Hybrid liposomes (HLs) are nano-sized liposomal particles that can be easily prepared by ultrasonicating a mixture of vesicular and micellar molecules in buffer solutions. In this study, we investigated the inhibitory effects of HL on the growth of CSC subpopulations in liver cancer cells (HepG2) in vitro. MethodsHLs composed of 90 mol% L-α-dimyristoylphosphatidylcholine and 10 mol% polyoxyethylene(23) dodecyl ether were prepared by sonication. Cell viability was determined by the trypan blue exclusion assay. In liver cancer cells, CSCs were identified by the presence of the cell surface marker proteins CD133 and EpCAM by flow cytometry. A soft agar colony formation assay was performed using HepG2 cells pretreated with HLs. ResultsHLs selectively inhibited liver cancer cell growth without affecting normal hepatocytes. Additionally, HLs induced apoptosis of HepG2 cells by a"ctivating caspase-3. Notably, the CD133(+)/EpCAM(+) CSC sub-population of liver cancer cells treated with HLs was reduced. Furthermore, HLs markedly decreased the number of colony-forming cells. Finally, we confirmed the fusion and accumulation of HLs into the cell membranes of CSCs using a fluorescently labeled lipid (NBDPC). Significant accumulation of HL/NBDPC into the CSCs (particularly EpCAM(+) cells) occurred in a dose-dependent manner. ConclusionThese results suggest that HLs are a novel nanomedical therapeutic agent for targeting CSCs in liver cancer therapy.

Theranostics with Hybrid Liposomes in an Orthotopic Graft Model Mice of Breast Cancer.

This study aimed to elucidate the therapeutic effects of hybrid liposomes (HL) composed of L-α-dimyristylphosphatidylcholine (DMPC) and polyoxyethylene [25] dodecyl ether (C12(EO)25) and the ability of HL-containing fluorescent probe to detect cancer in orthotopic graft model mice of breast cancer (MDA-MB-453). HL composed of 90 mol% DMPC and 10 mol% C12(EO)25 were prepared by the sonication method. Anti-tumor activities of HL were investigated in vivo using orthotopic graft-bearing mice of MDA-MB-453 cells. With regard to the therapeutic effects of HL for breast cancer, HL inhibited the growth of MDA-MB-453 cells and induced apoptosis. Intravenous administration of HL resulted in a remarkable reduction of relative tumor weight in orthotopic graft model mice of breast cancer. The TUNEL assay revealed that this effect was due to induction of apoptosis. With regard to detection (diagnosis) of breast cancer, enhanced accumulation of HL carrying a fluorescence probe (Indocyanine green; ICG) was observed for MDA-MB-453 cells, although no accumulation of HL/ICG was obtained for normal breast cells. Enhanced accumulation of HL/ICG into the tumor of orthotopic graft model mice of breast cancer was observed. HL and HL/ICG could be theranostic targets since they showed therapeutic effects and ability to detect (diagnose) cancer in an orthotopic graft model mouse of breast cancer (MDA-MB-453).

Hybrid liposomes showing enhanced accumulation in tumors as theranostic agents in the orthotopic graft model mouse of colorectal cancer

Hybrid liposomes (HLs) can be prepared by simply sonicating a mixture of vesicular and micellar molecules in a buffer solution. This study aimed to elucidate the therapeutic effects and ability of HLs to detect (diagnosis) cancer in an orthotopic graft mouse model of colorectal cancer with HCT116 cells for the use of HLs as theranostic agents. In the absence of a chemotherapeutic drug, HLs exhibited therapeutic effects by inhibiting the growth of HCT116 colorectal cancer cells in vitro, possibly through an increase in apoptosis. Intravenously administered HLs also caused a remarkable reduction in the relative cecum weight in an orthotopic graft mouse model of colorectal cancer. A decrease in tumor size in the cecal sections was confirmed by histological analysis using HE staining. TUNEL staining indicated an induction of apoptosis in HCT116 cells in the orthotopic graft mouse model of colorectal cancer. For the detection (diagnosis) of colorectal cancer by HLs, the accumulation of HLs encapsulating a fluorescent probe (ICG) was observed in HCT116 cells in the in vivo colorectal cancer model following intravenous administration. These data indicate that HLs can accumulate in tumor cells in the cecum of the orthotopic graft mouse model of colorectal cancer for a prolonged period of time, and inhibit the growth of HCT116 cells.

Nanomedicine for cancer diagnosis and therapy: advancement, success and structure-activity relationship.

Multifunctional nanoparticles (NPs), composed of organic and inorganic materials, have been explored as promising drug-delivery vehicles for cancer diagnosis and therapy. The success of nanosystems has been attributed to its smaller size, biocompatibility, selective tumor accumulation and reduced toxicity. The relationship among numbers of molecules in payload, NP diameter and encapsulation efficacy have crucial role in clinical translation. Advancement of bioengineering, and systematic fine-tuning of functional components to NPs have diversified their optical and theranostic properties. In this review, we summarize wide varieties of NPs, such as ultrasmall polymer-lipid hybrid NPs, dendrimers, liposomes, quantum dots, carbon nanotubes, gold NPs and iron oxide NPs. We also discuss their tumor targetability, tissue penetration, pharmacokinetics, and therapeutic and diagnostic properties. [Formula: see text].

The construction and characterization of hybrid paclitaxel-in-micelle-in-liposome systems for enhanced oral drug delivery

In this study, novel paclitaxel (PTX) loaded hybrid liposomes for oral PTX delivery were prepared through incorporating PTX loaded polyion complex micelles comprised of positively charged Pluronic F127-Polyethylenimine (PF127-PEI) copolymer and negatively charged sodium cholate (CA) into liposomes consisted of phospholipid molecules. According to the results, this kind of PTX-loaded hybrid liposomes showed improved PTX encapsulation efficiency, sustained PTX release, and enhanced PTX absorption in intestine. The mechanism for enhancing absorption was demonstrated in connection with inhibition of the efflux mediated by multidrug resistance protein, intestinal P-gp. In pharmacokinetic study, the absolute oral bioavailability of PTX loaded in hybrid liposomes had reached to 37.91%. All of these results demonstrated that the application of this novel PTX loaded hybrid liposomes is a strategy with great potential for highly effective oral PTX delivery.

'Nano-in-nano' hybrid liposomes increase target specificity and gene silencing efficiency in breast cancer induced SCID mice.

Gene silencing has immense potential in the treatment of cancer. However, enhancement of its efficiency requires the development of specifically targeted and safe carrier systems. Cationic carriers are generally limited by their immunogenicity. Hence, in this study, we report hybrid liposomes encapsulating Poly (L-lysine)-siRNA complex to silence epithelial cell adhesion molecule (EpCAM), highly expressed in epithelial cancers. The hybrid liposomes LL1 (Egg PC:DSPE-PEG, 10:0) and hybrid immunoliposomes LL2 (Egg PC:DSPE-PEG, 8:2) linked with EpCAM antibody as the targeting ligand showed an encapsulation efficiency of 70% and 86%, respectively. LL2 liposomes with a zeta potential of -26mV exhibited good colloidal stability in phosphate buffered saline containing bovine serum albumin and fetal bovine serum at 37°C. Cell uptake studies showed increased uptake of the LL2 when compared to LL1 liposomes. Finally, the hybrid immunoliposomes were evaluated for their efficacy in regressing the tumor volume in SCID mice. Eight doses each of 0.15mg/kg, which is among the lowest reported siRNA concentrations, were administered to the animals. About 45% reduction in tumor volume was achieved after 28days in the mice treated with LL2 when compared with the positive control and LL1 treated groups. Thus, our results demonstrate that the 'nano-in-nano' concept of encapsulating poly (l-Lysine) complexed EpCAM siRNA in immunoliposomes may be a promising strategy to treat EpCAM-positive epithelial cancers, especially as an adjuvant therapy.

Nanohybrid magnetic liposome functionalized with hyaluronic acid for enhanced cellular uptake and near-infrared-triggered drug release

The aim of this work is to prepare and evaluate a novel lipid-polymer hybrid liposomal nanoplatform (hyaluronic acid-magnetic nanoparticle-liposomes, HA-MNP-LPs) as a vehicle for targeted delivery and triggered release of an anticancer drug (docetaxel, DTX) in human breast cancer cells. We first synthesize an amphiphilic hyaluronic acid hexadecylamine polymer (HA-C16) to enhance the targeting ability of the hybrid liposome. Next, HA-MNP-LPs are constructed to achieve an average size of 189.93±2.74nm in diameter. In addition, citric acid-coated magnetic nanoparticles (MNPs) are prepared and embedded in the aqueous cores while DTX is encapsulated in the hydrophobic bilayers of the liposomes. Experiments with coumarin 6 loaded hybrid liposomes (C6/HA-MNP-LPs) show that the hybrid liposomes have superior cellular uptake in comparison with the conventional non-targeting liposomes (C6/MNP-LPs), and the result is further confirmed by Prussian blue staining. Under near-infrared laser irradiation (NIR, 808nm), the HA-MNP-LPs aqueous solution can reach 46.7°C in 10min, and the hybrid liposomes released over 20% more drug than the non-irradiated liposomes. Using a combination of photothermal irradiation and chemotherapy, the DTX-loaded hybrid liposomes (DTX/HA-MNP-LPs) significantly enhance therapeutic efficacy, with the IC50 value of 0.69±0.10μg/mL, which is much lower than the values for DTX monotherapy. Consequently, the prepared hybrid nanoplatform may offer a promising drug delivery vehicle with selective targeting and enhanced drug release in treating CD44-overexpressing cancers.

Melting Behavior of Zipper-Structured Lipopeptides in Lipid Bilayer.

A zipper-structured lipopeptide is expected to play a role of "intelligent valve" in the lipid bilayer. In this paper, a series of zipper-structured lipopeptides have been designed for preparing thermocontrollable hybrid liposomes. Their conformational transition as a function of temperature in lipid bilayer has been investigated for understanding the influences of molecular structure and bilayer property on biofunction. The melting temperatures Tm of the lipopeptides have been found to depend on their molecular structures. When the lipopeptides have been doped in bilayer, an increase of size of alkyl chain increases the stability of the α-helix resulting in a decrease in fluidity of lipid bilayer. However, an increase of amino groups at N-terminal is found to decrease the stability of the spatial structure. The thermocontrollability of the "valve" in lipid bilayer is confirmed by drug release experiments under different temperatures. Meanwhile, effects of bilayer properties on the thermosensitivity of lipopeptides have also been investigated. Results show the Tm of lipopeptide doped in bilayer decreases with the increase of membrane fluidity. Furthermore, the reversibility of the thermocontrolled "valve" is also proven by release drug under intermittent temperatures. It could be concluded that the molecular structure of the lipopeptide, as well as the property of bilayer, give great influence on the biofunction of the hybrid liposomes.

Apoptotic and Anti-invasive Effects of Hybrid Liposomes without Drugs against Human Breast Cancer Cells In Vitro

Hybrid Liposomes (HL) composed of 90 mol% L-α-dimyristoylphosphatidylcholine (DMPC) and 10 mol% polyoxyethylene (25) dodecyl ether (C12(EO)25) was examined to study the stimulation of apoptosis and antiinvasive actions against in vitro cultured human breast cancer (MCF-7) cells. The results obtained from the study reveals that HL suppressed the growth of MCF-7 cells without any drugs. Apoptosis for MCF-7 cells after subjecting them to HL treatment was noticed. To study the non-invasive actions of HL on the drifting of MCF-7 cells, we exercised Wound scratch assay. Non-invasive effects of HL on the migration of MCF-7 cells were obtained on the basis of wound scratch assay. HL suppressed the pseudopodium formation of MCF-7 cells. The study to determine the non-invasive effects of HL against MCF-7 cells were done by matrigel invasion assay which gave positive results due to inhibition of MT1MMP/MMP14 by HL.

The impact of metal complex lipids on viscosity and curvature of hybrid liposomes.

A morphology transformation of hybrid liposomes was shown to occur from spherical vesicles to tubular micelles when increasing the ratio of the metal complex lipid present. Phase transition temperatures increased while viscosities decreased, indicating that the hybrids exhibit stronger interaction between heads but weaker interaction between alkyl chains than occurs in pristine liposomes.

Monte Carlo simulations of the distributions of intra- and extra-vesicular ions and membrane associated charges in hybrid liposomes composed of negatively charged tetraether and zwitterionic diester phospholipids

Here, we model a negatively charged lipid vesicle, composed of a mixture of bipolar tetraether and diester (or diether) phospholipid molecules, by a spherical shell that has zero ion permeability. We take into consideration all the charge-charge interactions between intra-vesicular ions, extra-vesicular ions, and membrane lipid associated charges. Monte Carlo simulations result in homogeneous and double-exponential ion distribution, respectively, in the intra- and extra-vesicular space. The extra-vesicular ion concentration close to the membrane surface is proportional to the total amount of the membrane charges (Nm) and is independent of the partitioning of the membrane charges between the outer (Nom) and inner membrane (Nim) surface. This result shows that one should not disregard the effect of the charges on the inner membrane surface when calculating the ion distributions around a charged vesicle. If the partitioning of the membrane charges is not restricted (i.e., lipid flip-flop is allowed), then at different Nm, the Nom/Nim ratio remains constant and the value of Nom/Nim, as a consequence of the interaction between every charges of the model, is close to, but significantly higher than, the ratio of the outer to the inner surface area of the membrane. These results indicate that the amount and the orientation of the negatively-charged tetraether lipids in the membrane are important determinants of membrane properties in tetraether/zwitterionic diester phospholipid liposomes. Finally we compared the results of our discrete charge model and continuous models based on the solutions of the Poisson-Boltzmann equation and pointed out qualitative similarities and sometimes major quantitative differences between these two types of models.

Therapeutic Effects of Hybrid Liposomes Against Xenograft Mouse Model of Colorectal Cancer In Vivo Due to Long-term Accumulation.

To examine therapeutic effects of hybrid liposomes (HL) composed of L-α-dimyristylphosphatidylcholine (DMPC) and polyoxyethylene (25) dodecyl ether (C12(EO)25) against human colorectal cancer (WiDr) cells in vitro and in vivo. HL composed of 90 mol% DMPC and 10 mol% C12(EO)25 were prepared by the sonication method. Therapeutic effects of HL in the subcutaneous xenograft model mice of colorectal cancer were examined in vivo. Inhibitory effects of HL on the growth of WiDr cells were obtained along with apoptosis measurement. Selective accumulation of HL, including a fluorescence probe (indocyanine green; (ICG)), was observed for WiDr cells using a fluorescence microscope. Remarkable reduction of tumor volume in xenograft model of mice topically HL-treated without drugs after the subcutaneous inoculation of WiDr cells was verified in vivo. Induction of apoptosis in tumor cells of xenograft mice topically administered with HL was observed in micrographs on the basis of terminal deoxynucleotidyl tranferase-mediated dUTP-biotin nick end labeling (TUNEL) method. Accumulation of HL, including ICG, for long-term into the tumor was obtained in the xenograft model. Therapeutic effects of HL without any drugs in the murine xenograft model after subcutaneous inoculation of human colorectal cancer were revealed for the first time in vivo due to long-term accumulation.

Hybrid liposomes composed of amphiphilic chitosan and phospholipid: Preparation, stability and bioavailability as a carrier for curcumin

Hybrid liposomes, composed of amphiphilic chitosan and phospholipid, were prepared and used to evaluate the effect of amphiphilic polymers on the properties of liposomes. Successful preparation of the hybrid liposomes was confirmed using physicochemical characteristics, including morphology, particle size and zeta potential. Physical stability studies (exposure to solutions of increasing ionic strength and heat treatment) indicated that the hybrid liposomes had better ionic stability than amphiphilic chitosan-based polymeric liposomes and higher thermal stability than traditional phospholipid liposomes. Curcumin was then encapsulated in the hybrid liposomes. Compared with phospholipid liposomes, the hybrid liposomes displayed better storage stability and more sustained curcumin release. Cellular uptake experiments showed that the hybrid liposomes significantly increased the bioavailability of curcumin. The study highlights the potential of well-designed stable hybrid liposomes that increase the stability and bioavailability of lipophilic bioactive, such as curcumin.

Recent Advances of Using Hybrid Nanocarriers in Remotely Controlled Therapeutic Delivery

The development of hybrid biomaterials has been attracting great attention in the design of materials for biomedicine. The nanosized level of inorganic and organic or even bioactive components can be combined into a single material by this approach, which has created entirely new advanced compositions with truly unique properties for drug delivery. The recent advances in using hybrid nanovehicles as remotely controlled therapeutic delivery carriers are summarized with respect to different nanostructures, including hybrid host-guest nanoconjugates, micelles, nanogels, core-shell nanoparticles, liposomes, mesoporous silica, and hollow nanoconstructions. In addition, the controlled release of guest molecules from these hybrid nanovehicles in response to various remote stimuli such as alternating magnetic field, near infrared, or ultrasound triggers is further summarized to introduce the different mechanisms of remotely triggered release behavior. Through proper chemical functionalization, the hybrid nanovehicle system can be further endowed with many new properties toward specific biomedical applications.

The effect of oil-water partition coefficient on the distribution and cellular uptake of liposome-encapsulated gold nanoparticles

The shape, size, and surface features of nanoparticles greatly influence the structure and properties of resulting hybrid nanosystems. In this work, gold nanoparticles (GNPs) were modified via S-Au covalent bonding by glycol monomethyl ether thioctate with poly(ethylene glycol) methyl ether of different molecular weights (i.e., 350, 550, and 750Da). These modified GNPs (i.e., GNP350, GNP550, and GNP750) showed different oil-water partition coefficients (Kp), as detected using inductively coupled plasma-atomic emission spectroscopy. The different Kp values of the gold conjugates (i.e., 13.98, 2.11, and 0.036 for GNP350, GNP550, and GNP750, respectively) resulted in different conjugate localization within liposomes, as observed by transmission electron microscopy. In addition, the cellular uptake of hybrid liposomes co-encapsulating gold conjugates and Nile red was evaluated using intracellular fluorescence intensity. The results indicated that precise GNP localization in the hydrophilic or hydrophobic liposome cavity could be achieved by regulating the GNP oil-water partition coefficient via surface modification; such localization could further affect the properties and functions of hybrid liposomes, including their cellular uptake profiles. This study furthers the understanding not only of the interaction between liposomes and inorganic nanoparticles but also of adjusting liposome-gold hybrid nanostructure properties via the surface chemistry of gold materials.