Quercetin-loaded Liposomes Research Articles

Masking the bitter taste of quercetin by liposomes modified with whey protein isolate: Better to be coated or inserted?

The unsatisfactory bitterness of quercetin restricts its application to healthy food systems. In this study, whey protein isolate (WPI) inserted and coated quercetin-loaded liposomes were compared in reducing quercetin bitterness and improving the stability of quercetin-loaded liposomes. By electronic tongue and sensory evaluation, the liposomes coated by WPI (0.5–3.0 mg/mL) and inserted with WPI (0.5 mg/mL) significantly reduced the bitterness of quercetin compared to physical mixing. It was also found that the encapsulation efficiency was increased by 15.24% after insertion of WPI at 2.0 mg/mL. The environmental stability results showed that both WPI insertion and coating improved the thermal stability of the quercetin-loaded liposomes compared to the physical mixture, and the WPI coated quercetin-loaded liposomes had the best storage stability and tolerance to salt ions. In contrast, WPI insertion improved the ability of liposomes to resist against surfactant. Raman spectra and fluorescence analysis demonstrated that the modification of WPI reduced the free motion of lipid molecules and promoted the ordering at the polar headgroup area and hydrophobic core of the lipid bilayer. These findings have the potential to support the utilization of WPI modified liposomes as promising option for an efficient transportation of bitter bioactive compounds in nutraceutical and functional foods.

Design and advanced characterization of quercetin-loaded nano-liposomes prepared by high-pressure homogenization.

Quercetin-loaded nano-liposomes were prepared by high-pressure homogenization (HPH) at different pressures (up to 150MPa) and number of passes (up to 3) to define the best processing conditions allowing the lowest particle size and the highest encapsulation efficiency (EE). The process at 150MPa for 1 pass was the best, producing quercetin-loaded liposomes with the lowest particle size and 42% EE. Advanced techniques (multi-detector asymmetrical-flow field flow fractionation and analytical ultracentrifugation combined with transmission electron microscopy) were further used for the characterization of the liposomes which were oblong in shape (ca. 30nm). Results highlight the need for several techniques to study nano-sized, polydisperse samples. The potential of quercetin-loaded liposomes against colon cancer cells was demonstrated. Results prove that HPH is an efficient and sustainable method for liposome preparation and highlight the remarkable role of process optimisation as well as the powerfulness of advanced methodologies for the characterisation of nano-structures.

Formulation and Evaluation of Chitosan-PLGA Biocomposite Scaffolds Incorporated with Quercetin Liposomes Made by QbD Approach for Improved Healing of Oral Lesions.

The current research aims to develop and evaluate chitosan-PLGA biocomposite scaffolds in combination with quercetin liposomes to accomplish the desired impact in oral lesions where pharmacotherapeutic agent treatment through circulation could only reach the low content at the target. Optimization of quercetin-loaded liposomes was carried out using 32 factorial design. The preparation of porous scaffolds comprising produced quercetin-loaded liposomes by thin-film method was carried out in the current study using a unique strategy combining solvent casting and gas foaming procedures. The prepared scaffolds were tested for physicochemical properties, in vitro quercetin release study, ex vivo drug permeation and retention research using goat mucosa, antibacterial activity, and cell migration studies on fibroblast L929 cell lines. Improved cell growth and migration were seen in the order control < liposomes < proposed system. The proposed system has been examined for its biological and physicochemical features, and it has the potential to be utilized as an efficient therapy for oral lesions.

Production and Properties of Quercetin-Loaded Liposomes and Their Influence on the Properties of Galactomannan-Based Films

The objective of this work was to prepare different concentrations of liposomes based on lecithin containing quercetin, and evaluate their effect on the properties of galactomannan films obtained from Cassia grandis seeds. Quercetin-loaded lecithin liposomes (QT-LL) were obtained by the ethanol injection method by incorporating quercetin in different concentrations in a previously prepared suspension of lecithin liposomes in water. Following characterization of QT-LLs by zeta potential and dynamic light scattering, QT-LL with 75 µg quercetin/mL suspension was incorporated at different concentrations in galactomannan films. The films obtained were characterized for color, solubility, moisture content (MC), water vapor permeability (WVP), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The size of lecithin liposomes with no quercetin was statistically than those containing quercetin above 50 µg/mL. All the QT-LLs presented a low polydispersity index, even considering their significant differences and similar values for zeta potential. The films displayed a rough surface and the galactomannan structure was confirmed by FTIR. Additionally, the amorphous nature of the polysaccharide was observed by XRD. The films were luminous, with a predominant yellow tendency and low opacity. The incorporation of QT-LL in galactomannan films did not lead to statistical differences for solubility and MC, while significant differences were observed for WVP. Galactomannan films were shown to be a promising structure for the incorporation of lecithin liposomes loaded with quercetin, pointing at promising applications for different applications.

Quercetin-loaded Liposomes Effectively Induced Apoptosis and Decreased the Epidermal Growth Factor Receptor Expression in Colorectal Cancer Cells: An In Vitro Study.

Quercetin is a flavonoid having anti-cancer properties; however, it has low stability, insufficient bioavailability, and poor solubility. This study aimed to load quercetin on nanoliposomes to enhance its efficiency against SW48 colorectal cancer cells. The cytotoxicity of free-quercetin and quercetin-loaded nanoliposomes on the expression of the epidermal growth factor receptor (EGER) gene was investigated. This present in vitro study was conducted at Yasuj University of Medical Sciences (Yasuj, Iran) in 2021. In this in vitro study, the lipid thin-film hydration method was used to synthesize quercetin-loaded liposomes. Additionally, high-performance liquid chromatography (HPLC) analyses, dynamic light scattering (DLS), and transmission electron microscopy (TEM) investigations were used to characterize nanomaterials. Following that, MTT, flow cytometry, and real-time PCR were used to investigate the cytotoxicity of quercetin-loaded liposomes on the colorectal cancer cells SW48 cell line, the incidence of apoptosis, and the expression of the EGFR gene in these cells. Statistical analysis was performed using the SPSS (version 26.0), and the graphs were created with the GraphPad Prism version 8.4.3. P<0.05 was considered statistically significant. The nanoparticles were spherical, homogenous, and 150±10 nm in size. According to HPLC, Quercetin had a 98% loading capacity. Although both free quercetin and quercetin-loaded liposomes indicated significant cytotoxicity against cancer cells (P˂0.001), the combined form was significantly more active (P=0.008). 50 µg/mL of this compound reduced the viability of SW48 cells by more than 80% (IC50 10.65 µg/mL), while the viability of cells treated with free quercetin was only 66% (IC50 18.74 µg/mL). The apoptosis was nearly doubled in the cells treated with quercetin-loaded nanoliposomes compared to free quercetin (54.8% versus 27.6%). EGFR gene expression, on the other hand, was significantly lower in cells treated with quercetin-loaded liposomes than the quercetin alone (P=0.006). When combined with nanoliposomes, quercetin had greater anti-proliferative, apoptotic, and anti-EGFR expression than free quercetin.

Comparison of Polysaccharides as Coatings for Quercetin-Loaded Liposomes (QLL) and Their Effect as Antioxidants on Radical Scavenging Activity.

Liposomes are microstructures containing lipid and aqueous phases employed in the encapsulation and delivery of bioactive agents. Quercetin-loaded liposomes (QLLs) were coated with three different polysaccharides and then tested as radical scavengers. Lactose (LCQLL), chitosan (CCQLL), and inulin (ICQLL) were employed as coating materials. Particle size determined by light scattering, showed primary size of 200 nm for all samples, while a secondary particle size of 600 nm was observed for CCQLL. Scanning electron microscopy (SEM) evidenced particle aggregation with the addition of the polysaccharide coating. Transmission electron microscopy (TEM) revealed the layered microstructure of liposomes composed of at least two layers, and primary particle size below 100 nm. QLL showed higher antioxidant activity than the coated liposomes. This behavior was attributed to the chemical interaction between quercetin and the corresponding coating polysaccharide in the layered structure, which traps the quercetin and keeps it unavailable for radical scavenging. From the three polysaccharides, lactose showed a better performance as coating material in the antioxidant activity, which suggested that the smaller size of the disaccharide molecule resulted in a faster releasing of the quercetin in the solution. Thus, LCQLL is an advantageous way to deliver quercetin for antioxidant purposes, where the low stability in delivered media of quercetin loaded liposomes is commonly compromised.

PHYSICOCHEMICAL CHARACTERIZATION OF QUERCETIN-LOADED LIPOSOMES PREPARED BY SONICATION FOR FUNCTIONAL FOOD APPLICATION

This research was intended to synthesize liposome as a nanocarrier to encapsulate quercetin, which is prone to degradation and susceptible to low bioavailability upon oral administration. The liposomes were synthesized by thin-film hydration method and followed by probe sonication for downsizing. Soy phosphatidylcholine (SPC) and cholesterol (CHOL) were employed as the composition of the phospholipid bilayer. Results indicated a dependence of sonication amplitude and time in the formation of free liposomes (FL). The average size of quercetin-loaded liposomes (QL) prepared was 346.4 nm with a narrow polydispersity index (0.22) and a high magnitude of zeta potential (-49.6 mV). These characterizations depict that a homogenous nanovesicle suspension with high stability was successfully synthesized. Quercetin was incorporated into the liposomes with a high encapsulation efficiency of 90.7% and loading capacity of 9.3%. This viable nanocarrier perhaps will provide ingenious protection for a wider spectrum of active agents in food and biopharmaceutical products.

Bioorthogonal supramolecular cell-conjugation for targeted hitchhiking drug delivery

Cells possess inherent advantages to facilitate targeted payload delivery. Current strategies to conjugate payload carriers to the surface of cells are either via covalent bonds that not only involve complicated synthetic process but also often impair cellular functions, or via biological ligand-receptor interactions that are only specific to particular types of cells. Herein, we report a facile, bioorthogonal supramolecular conjugation strategy to prepare targeted cell-hitchhiking delivery systems, mediated via artificial host–guest interactions between β-cyclodextrin and adamantane, respectively anchored (via insertion) on the surfaces of live cells and payload carriers. In a paw swelling inflammation mouse model, supramolecularly conjugated macrophage-carriers (either cell–cell or cell-nanoparticle systems) were efficiently delivered hand-in-hand to the swelling paw, driven by the inflammatory tropism of macrophage. Furthermore, in an acute lung inflammation model of mouse, supramolecular conjugation of peritoneal macrophage and quercetin-loaded liposomes significantly improved targeting efficiency of the liposomes, and effectively alleviated the lung inflammation through the anti-inflammatory and anti-oxidative effects of quercetin. The cell-friendly, facile, host–guest interactions mediated cellular conjugation may provide the very first general strategy for preparing various cell-hitchhiking delivery systems to meet the needs of diverse biomedical applications.

Preparation, formation mechanism and in vitro dynamic digestion behavior of quercetin-loaded liposomes in hydrogels

Quercetin-loaded liposomes in hydrogels (lipogels) with different texture properties were fabricated, and their formation mechanism, along with the in vitro oral-gastrointestinal fate, were investigated. The hydrogels, composed of chitosan and gelatin, were cross-linked by ionic and covalent bonds, and interacted with liposomes by hydrogen bonds. More fragmentations were obtained from hard lipogels than soft lipogels after simulated oral processing. In the self-developed artificial gastric digestive system and small intestinal compartment, higher level of breakdown and more release of liposomes and quercetin occurred in the soft lipogels. Besides, compared to the liposomes without embedding in hydrogels, the lipogels showed better protective effect of quercetin from gastric release by ~40%. The results showed that the texture and structure played key roles in the lipogels degradation and cargo release during digestion, thus illustrating a considerable approach to control the release of functional molecules and the potential application of the lipogels as a bio-food.

Redispersible Freeze‐dried Quercetin‐loaded Liposomal Formulations Stabilized with Lyoprotectants

Enhanced physical stability of quercetin-loaded liposomes redispersed in water after freeze-drying through four different saccharides used as lyoprotectants.

Liposomal quercetin potentiates maxi-K channel openings in smooth muscles and restores its activity after oxidative stress

The effects of quercetin-loaded liposomes (PCL-Q) and their constituents, that is, free quercetin (Q) and ‘empty’ phosphatidylcholine vesicles (PCL), on maxi-K channel activity were studied in single mouse ileal myocytes before and after H2O2-induced oxidative stress. Macroscopic Maxi-K channel currents were recorded using whole-cell patch clamp techniques, while single BKCa channel currents were recorded in the cell-attached configuration. Bath application of PCL-Q (100 μg/ml of lipid and 3 μg/ml of quercetin) increased single Maxi-K channel activity more than threefold, from 0.010 ± 0.003 to 0.034 ± 0.004 (n = 5; p < 0.05), whereas single-channel conductance increased non-significantly from 138 to 146 pS. In the presence of PCL-Q multiple simultaneous channel openings were observed, with up to eight active channels in the membrane patch. Surprisingly, ‘empty’ PCL (100 μg/ml) also produced some channel activation, although it was less potent compared to PCL-Q, that is, these increased NPo from 0.010 ± 0.003 to 0.019 ± 0.003 (n = 5; p < 0.05) and did not affect single-channel conductance (139 pS). Application of PCL-Q restored macroscopic Maxi-K currents suppressed by H2O2-induced oxidative stress in ileal smooth muscle cells. We conclude that PCL-Q can activate Maxi-K channels in ileal myocytes mainly by increasing channel open probability, as well as maintain Maxi-K-mediated whole-cell current under the conditions of oxidative stress. While fusion of the ‘pure’ liposomes with the plasma membrane may indirectly activate Maxi-K channels by altering channel’s phospholipids environment, the additional potentiating action of quercetin may be due to its better bioavailability.

Design of dipalmitoyl lecithin liposomes loaded with quercetin and rutin and their release kinetics from carboxymethyl cellulose edible films

Quercetin and rutin were encapsulated in liposomes based on dipalmitoyl lecithin. The effect of liposomal formulation stage for flavonol incorporation and the size-reducing method on encapsulation efficiency (EE) of flavonols and physical properties of liposomes were evaluated. In addition, the release mechanism and kinetics of polyphenols from carboxymethyl cellulose edible films were studied through modeling and simulation equations. When flavonols were incorporated during the phospholipid film formation stage, low polydispersity index (0.32 and 0.20) and high EE (88.9 and 74.1%) of quercetin and rutin, respectively, were obtained. Sonication gave liposomes with higher zeta potential (36.9–42.4 mV) than extrusion (13.3–17.1 mV), and quercetin-loaded liposomes were the most stable during 21 days of storage. In CMC films, diffusion coefficients of flavonols were higher for non-encapsulated flavonols than encapsulated flavonols. The release of non-encapsulated quercetin and rutin from CMC films was 25% and 24% higher than in the case of encapsulated quercetin and rutin at day 21. The released mechanism agreed with Fickian diffusion for encapsulated and non-encapsulated quercetin, whereas the release mechanism of encapsulated and non-encapsulated rutin agreed with non-Fickian diffusion. These results highlight the relevance of using liposomes as encapsulation technology, able to preserve polyphenols and control their release in the design of edible films with antioxidant activity for improving food shelf life.

Fabrication and in-vitro evaluation of liposomal quercetin and its optimization

This study intended to explore the influence of formulation factors on the physico-chemical properties of quercetin-loaded liposomes and optimize the fabrication environment. Thin film hydration technique was employed to prepare liposome and optimization was done by 32 factorial designs combined with desirability function. Nine preparations were prepared by using altered drug: lipid and soyphosphatidylcholine: cholesterol (SPC: cholesterol) ratios and assessed for entrapment efficacy and vesicle size. The findings were the mean diameter and drug encapsulation efficiency. Results exhibited that SPC concentration and SPC: cholesterol molar ratio had a solid impact on liposome size. Increasing the lipid ratio produced a reduction in size. The degree of quercetin charging depended on the factors evaluated. Increasing SPC concentration and lipid ratio pointed lyboosted quercetin entrapment. However, higher quercetin concentrations had a negative effect on drug entrapment. Based on this, an optimized design was determined, prepared and investigated. The entrapment efficiency and vesicle size were found to be very adjacent with the predicted values. The formulation was found to be globular shape and also shows sustained release pattern. These results backing the fact that 32 full factorial designs with desirability function might be efficiently used in optimization of quercetin loaded liposome. The overall results showed that SPC concentration and lipid ratio were the key features influencing particle size, while entrapment efficiency was affected primarily by quercetin concentration.

Effect of Quercetin-loaded liposomes on induced oxidative stress in human spermatozoa.

A strategy to circumvent the poor polyphenols bioavailability is to load these compounds into liposomes. We evaluated the in vitro effects of quercetin (Q) and Q-loaded liposomes (QLL, 30, 50, 100μM) on motility, viability and chromatin integrity of swim-up selected human sperm. Antioxidant power was assayed against tert-butylhydroperoxide induced lipid peroxidation (LPO) using C11-BODIPY581/591 fluorescent probe and transmission electron microscopy. QLL showed decreased toxicity for sperm motility and viability and increased DNA damage compared to Q. The percentage of sperm with fluorescence, marker of LPO, was decreased in samples incubated with Q vs QLL (P<0.001). The ultrastructure of acrosomes and membranes was preserved with Q 30/100μM, whereas QLL did not prevent membrane injury. Q alone appeared more effective than Q incorporated into liposomes; however liposomes could be considered as carriers that may convey different compounds inside sperm; they may therefore represent a field of research rich of many applications.

Preparation and optimization of quercetin-loaded liposomes for wound healing, using response surface methodology

The basic objective of this study was to prepare quercetin-loaded liposomes by the thin film hydration method. The liposomal formulation was optimized using response surface methodology (RSM). A rotation speed of 75 rpm and a water bath temperature of 46°C were finalized as the best for optimized drug-loaded liposomal formulation. In vitro characterization of the quercetin-loaded liposomal formulation was done through some parameters including the entrapment efficiency (EE), drug release (DR), and mean particle size; the resulting values of 86.5 ± 0.42%, 76.5%, and146 nm were found to be standard characterized values respectively. It is concluded that quercetin-loaded liposomal formulations achieve sustained release of drug in wound areas.

Effects of quercetin nanoliposomes on C6 glioma cells through induction of type III programmed cell death

BackgroundQuercetin has been shown to induce apoptosis in a number of cancer cell lines, but a quercetin-loaded nanoliposomal formulation with enhanced antitumor activity in C6 glioma cells and its effect on cancer cell death has not been well studied. The aim of this study was to examine if quercetin-loaded liposomes (QUE-NL) has enhanced cytotoxic effects and if such effects involve type III programmed cell death in C6 glioma cells.MethodsC6 glioma cells were treated with QUE-NL and assayed for cell survival, apoptosis, and necrosis. Levels of reactive oxygen species production and loss of mitochondrial membrane potential (ΔΨm) were also determined by flow cytometry assay to assess the effects of QUE-NL. ATP levels and lactate dehydrogenase activity were measured, and Western blotting was used to assay cytochrome C release and caspase expression.ResultsQUE-NL induced type III (necrotic) programmed cell death in C6 glioma cells in a dose-dependent and time-dependent manner. High concentrations of QUE-NL induced cell necrosis, which is distinct from apoptosis and autophagy, whereas liposomes administered alone induced neither significant apoptosis nor necrosis in C6 glioma cells. QUE-NL-induced ΔΨm loss and cytochrome C release had no effect on caspase activation, but decreased ATP levels and increased lactate dehydrogenase activity indicated that QUE-NL stimulated necrotic cell death.ConclusionC6 glioma cells treated with QUE-NL showed a cellular pattern associated with necrosis without apoptosis and was independent of caspase activity. Nonapoptotic cell death induced by high concentrations of QUE-NL for controlling caspase-independent type III programmed cell death may provide the basis for novel therapeutic approaches to overcome avoidance of apoptosis by malignant cells.

Study of quercetin-loaded liposomes as potential drug carriers: in vitro evaluation of human complement activation

Liposomes have been employed as potential drug carriers. However, after their in vivo administration, they can be destabilized by proteins of complement system, contributing to the clearance of vesicles from blood circulation. Antioxidant flavonoids such as quercetin have been reported to be beneficial to human health, but their low water solubility and bioavailability limit their enteric administration. Therefore, the development of appropriate flavonoid-carriers could be of great importance to drug therapy. The aim of the present study was to evaluate the activation of human complement system proteins by liposomes composed of soya phosphatidylcholine (SPC) and cholesterol (CHOL) or cholesteryl ethyl ether (CHOL-OET) loaded with quercetin or not. The consumption of complement, via classical (CP) and alternative (AP) pathways, by different vesicles was evaluated using a hemolytic assay and quantitative determination of iC3b and natural antibodies deposited on empty liposomal surfaces by ELISA. The main results showed that empty liposomes composed of large amounts of CHOL consumed more complement components than the others for both CP and AP. Furthermore, replacement of CHOL with CHOL-OET reduced complement consumption via both CP and AP. Incorporation of quercetin did not change CP and AP consumption. Deposition of iC3b, IgG and IgM in vesicles composed of SPC:CHOL-OET at a molar ratio of 1.5:1 was lower compared to the others. Taken together, these observations suggest that liposomes composed of SPC:CHOL-OET at a molar ratio of 1.5:1 are the most appropriate among the vesicles studied herein to be used as a drug carrier system in further investigations.