Stability, biocompatibility and antioxidant activity of PEG-modified liposomes containing resveratrol

Formulation of Piperine-Chitosan-Coated Liposomes: Characterization and In Vitro Cytotoxic Evaluation

The present research work is designed to prepare and evaluate piperine liposomes and piperine–chitosan-coated liposomes for oral delivery. Piperine (PPN) is a water-insoluble bioactive compound used for different diseases. The prepared formulations were evaluated for physicochemical study, mucoadhesive study, permeation study and in vitro cytotoxic study using the MCF7 breast cancer cell line. Piperine-loaded liposomes (PLF) were prepared by the thin-film evaporation method. The selected liposomes were coated with chitosan (PLFC) by electrostatic deposition to enhance the mucoadhesive property and in vitro therapeutic efficacy. Based on the findings of the study, the prepared PPN liposomes (PLF3) and chitosan coated PPN liposomes (PLF3C1) showed a nanometric size range of 165.7 ± 7.4 to 243.4 ± 7.5, a narrow polydispersity index (>0.3) and zeta potential (−7.1 to 29.8 mV). The average encapsulation efficiency was found to be between 60 and 80% for all prepared formulations. The drug release and permeation study profile showed biphasic release behavior and enhanced PPN permeation. The in vitro antioxidant study results showed a comparable antioxidant activity with pure PPN. The anticancer study depicted that the cell viability assay of tested PLF3C2 has significantly (p < 0.001)) reduced the IC₅₀ when compared with pure PPN. The study revealed that oral chitosan-coated liposomes are a promising delivery system for the PPN and can increase the therapeutic efficacy against the breast cancer cell line.

Surfactant Assisted Rapid-Release Liposomal Strategies Enhance the Antitumor Efficiency of Bufalin Derivative and Reduce Cardiotoxicity

Background

BF211, a derivative of bufalin (BF), shows significantly improved solubility and potent antitumor efficiency compared to BF. Unfortunately, the unwanted toxicity such as cardiotoxicity caused by unspecific distribution has hindered its clinical use.

Methods

PEGylated BF211 liposomes (BF211@Lipo) were designed and optimizely prepared based on the pre-prescription research. In vitro and in vivo cardiotoxicity was evaluated. In vivo pharmacokinetics and biodistribution of BF211@Lipo were investigated. In vivo antitumor activity and toxicity were evaluated in HepG2 cell xenograft models. The rapid-release triggered by Poloxamer 188 (P188) was assessed in vitro and in vivo.

Results

The optimized BF211@Lipo displayed a spherical morphology with a size of (164.6 ± 10.3) nm and a high encapsulation efficiency of (93.24 ± 2.15) %. The in vivo concentration–time curves of BF211 loaded in liposomes showed a prolonged half-life in plasma and increased tumor accumulation. No obvious abnormality in electrocardiograms was observed in guinea pigs even at 9 mg/kg. Moreover, to improve the efficient release of BF211@Lipo, a surfactant-assisted rapid-release strategy was developed, and the release-promoting mechanism was revealed by the fluorescence resonance energy transfer (FRET) and fluorescence nanoparticle tracking analysis (fl-NTA) technology. Sequential injection of BF211@Lipo and P188 could ignite the “cold” liposomes locally in tumor regions, facilitating the burst release of BF211 and enhancing the therapeutic index.

Conclusion

Our progressive efforts that begin with preparation technology and dosage regimen enable BF211 to like a drug, providing a promising nano platform to deliver the cardiac glycosides and alleviate the side effects by decreasing unspecific biodistribution.

Quality by Design Approach for the Development of Liposome Carrying Ghrelin for Intranasal Administration

The therapeutic use of peptides has increasingly recognized in the development of new therapies. However, the susceptible enzymatic cleavage is a barrier that needs to overcome. Nose-to-brain delivery associated with liposomes can protect peptides against biodegradation and improve the accessibility to brain targets. The aim was to develop a liposomal formulation as ghrelin carrier. The quality by design (QbD) approach was used as a strategy for method development. The initial risk assessments were carried out using a fishbone diagram. A screening design study was performed for the critical material attributes/critical process parameters (CMAs/CPPs) on critical quality attributes (CQAs). Liposomes were obtained by hydrating phospholipid films, followed by extrusion or homogenization, and coated with chitosan. The optimized liposome formulation was produced by high-pressure homogenization coated with chitosan, and the resulted were liposomes size 72.25 ± 1.46 nm, PDI of 0.300 ± 0.027, the zeta potential of 50.3 ± 1.46 mV, and encapsulation efficiency of 53.2%. Moreover, chitosan coating improved performance in ex vivo permeation and mucoadhesion analyzes when compared to the uncoated liposome. In this context, chitosan coating is essential for the performance of the formulations in the ex vivo permeation and mucoadhesion analyzes. The intranasal administration of ghrelin liposomes coated with chitosan offers an innovative opportunity to treat cachexia.

Preparation of Fraxetin Long Circulating Liposome and Its Anti-enteritis Effect

This study sought to improve the oral bioavailability and enhance the anti-enteritis effect of fraxetin by incorporating it into long circulating liposomes (F-LC-Lipo). The optimal formulation of F-LC-Lipo was obtained via orthogonal design. The particle size, morphology, encapsulation efficiency, stability, and anti-enteritis effect of F-LC-Lipo were evaluated. The particle size of F-LC-Lipo was 166.65 ± 8.75 nm with entrapment efficiency (EE) of 92.18 ± 0.17%. The release rate in different dissolution media (pH 1.2 HCl, DDW, and pH 7.4 PBS) was significantly higher than that of fraxetin solution. Compared with the free fraxetin solution, F-LC-Lipo increased oral bioavailability of fraxetin by 4.43 times (443%). More importantly, F-LC-Lipo could improve the levels of interleukin-1 beta (IL-1β), IL-6, malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), prostaglandin E2 (PEG2), and IL-10 in rats with enteritis. Overall, these results suggested that LC-Lipo may serve as a potential carrier for improving the solubility and oral bioavailability of fraxetin as well as improving its enteritis effect.

Advancements in liposome technology: Preparation techniques and applications in food, functional foods, and bioactive delivery: A review

Liposomes play a significant role in encapsulation of various bioactive compounds (BACs), including functional food ingredients to improve the stability of core. This technology can be used for promoting an effective application in functional food and nutraceuticals. Incorporation of traditional and emerging methods for the developments of liposome for loading BACs resulted in viable and stable liposome formulations for industrial applications. Thus, the advance technologies such as supercritical fluidic methods, microfluidization, ultrasonication with traditional methods are revisited. Liposomes loaded with plant and animal BACs have been introduced for functional food and nutraceutical applications. In general, application of liposome systems improves stability, delivery, and bioavailability of BACs in functional food systems and nutraceuticals. This review covers the current techniques and methodologies developed and practiced in liposomal preparation and application in functional foods.

The Formation of Chitosan-Coated Rhamnolipid Liposomes Containing Curcumin: Stability and In Vitro Digestion

There is growing interest in developing biomaterial-coated liposome delivery systems to improve the stability and bioavailability of curcumin, which is a hydrophobic nutraceutical claimed to have several health benefits. The curcumin-loaded rhamnolipid liposomes (Cur-RL-Lips) were fabricated from rhamnolipid and phospholipids, and then chitosan (CS) covered the surface of Cur-RL-Lips by electrostatic interaction to form CS-coated Cur-RL-Lips. The influence of CS concentration on the physical stability and digestion of the liposomes was investigated. The CS-coated Cur-RL-Lips with RL:CS = 1:1 have a relatively small size (412.9 nm) and positive charge (19.7 mV). The CS-coated Cur-RL-Lips remained stable from pH 2 to 5 at room temperature and can effectively slow the degradation of curcumin at 80 °C; however, they were highly unstable to salt addition. In addition, compared with Cur-RL-Lips, the bioavailability of curcumin in CS-coated Cur-RL-Lips was relatively high due to its high transformation in gastrointestinal tract. These results may facilitate the design of a more efficacious liposomal delivery system that enhances the stability and bioavailability of curcumin in nutraceutical-loaded functional foods and beverages.

Enhanced cellular uptake and cytotoxicity of vorinostat through encapsulation in TPGS-modified liposomes

Vorinostat (VOR) is known as one of the histone deacetylase inhibitors (HDACi) for cancer treatment, and the FDA approves it for cutaneous T cell lymphoma therapy. Poor solubility, permeability, and less anti-cancer activity are the main challenges for the effective delivery of VOR against various cancers. So, our team assumed that the surface-coated liposomes might improve the physicochemical properties of biopharmaceutics classification system class IV drugs such as VOR. The present study aimed to enhance the cytotoxicity and improve cellular uptake using TPGS-coated liposomes in breast cancer cells. Liposomes were fabricated by the film hydration following the probe ultra-sonication method. OR-LIPO and TPGS-VOR-LIPO showed an average particle size of 211.97 ± 3.42 nm with PDI 0.2168 ± 0.006 and 176.99 ± 2.06 nm with PDI 0.175 ± 0.018, respectively. TPGS-coated liposomes had better stability and revealed more than 80 % encapsulation efficiency than conventional liposomes. Transmission electron microscopy confirmed the TPGS coating around liposomes. Moreover, TPGS-coated liposomes enhanced the solubility and showed sustained release of VOR over 48 h. DSC and PXRD analysis also reveal an amorphous state of VOR within the liposomal formulation. MTT assay result indicates that the superior cytotoxic effect of surface-modified liposomes contrasts with the conventional and free VOR solution, respectively. Fluorescence microscopy and flow cytometry results also presented an enhanced cellular uptake of TPGS-coated liposomes against breast cancer cells, respectively. The current investigation's final results declared that TPGS-coated liposomes are promising drug carriers for the effective delivery of hydrophobic drugs for cancer therapy.

Liposomes-In-Hydrogel Delivery System Enhances the Potential of Resveratrol in Combating Vaginal Chlamydia Infection

Chlamydia trachomatis is the most common cause of bacterial sexually transmitted infections and causes serious reproductive tract complications among women. The limitations of existing oral antibiotics and treatment of antimicrobial resistance require alternative treatment options. We are proposing, for the first time, the natural polyphenol resveratrol (RES) in an advanced delivery system comprising liposomes incorporated in chitosan hydrogel, for the localized treatment of C. trachomatis infection. Both free RES and RES liposomes-in-hydrogel inhibited the propagation of C. trachomatis in a concentration-dependent manner, assessed by the commonly used in vitro model comprising McCoy cells. However, for lower concentrations, the anti-chlamydial effect of RES was enhanced when incorporated into a liposomes-in-hydrogel delivery system, with inhibition of 78% and 94% for 1.5 and 3 µg/mL RES, respectively for RES liposomes-in-hydrogel, compared to 43% and 72%, respectively, for free RES. Furthermore, RES liposomes-in-hydrogel exhibited strong anti-inflammatory activity in vitro, in a concentration-dependent inhibition of nitric oxide production in the LPS-induced macrophages (RAW 264.7). The combination of a natural substance exhibiting multi-targeted pharmacological properties, and a delivery system that provides enhanced activity as well as applicability for vaginal administration, could be a promising option for the localized treatment of C. trachomatis infection.

Lipid-based Nanoplatforms in Cancer Therapy: Recent Advances and Applications

Though modern available cancer therapies are effective, they possess major adverse effects, causing non-compliance to patients. Furthermore, the majority of the polymeric-based medication platforms are certainly not universally acceptable, due to their several restrictions. With this juxtaposition, lipid-based medication delivery systems have appeared as promising drug nanocarriers to replace the majority of the polymer-based products because they are in a position to reverse polymer as well as, drug-associated restrictions. Furthermore, the amalgamation of the basic principle of nanotechnology in designing lipid nanocarriers, which are the latest form of lipid carriers, has tremendous chemotherapeutic possibilities as tumor-targeted drug-delivery pertaining to tumor therapy. Apart from this, it is reported that nearly 40% of the modern medication entities are lipophilic. Moreover, research continues to be efficient in attaining a significant understanding of the absorption and bioavailability of the developed lipids systems.

Liposome-Mediated Inhibition of Inflammation by Hydroxycitrate

Hydroxycitrate (HCA), a main organic acid component of the fruit rind of Garcinia cambogia, is a natural citrate analog that can inhibit the ATP citrate lyase (ACLY) enzyme with a consequent reduction of inflammatory mediators (i.e., nitric oxide (NO), reactive oxygen species (ROS), and prostaglandin E₂ (PGE₂)) levels. Therefore, HCA has been proposed as a novel means to prevent, treat, and ameliorate conditions involving inflammation. However, HCA presents a low membrane permeability, and a large quantity is required to have a biological effect. To overcome this problem, HCA was formulated in liposomes in this work, and the enhancement of HCA cell availability along with the reduction in the amount required to downregulate NO, ROS, and PGE₂ in macrophages were assessed. The liposomes were small in size (~60 nm), monodispersed, negatively charged (−50 mV), and stable on storage. The in vitro results showed that the liposomal encapsulation increased by approximately 4 times the intracellular accumulation of HCA in macrophages, and reduced by 10 times the amount of HCA required to abolish LPS-induced NO, ROS, and PGE₂ increase. This suggests that liposomal HCA can be exploited to target the citrate pathway involved in inflammatory processes.

Nanoformulations to Enhance the Bioavailability and Physiological Functions of Polyphenols

Polyphenols are micronutrients that are widely present in human daily diets. Numerous studies have demonstrated their potential as antioxidants and anti-inflammatory agents, and for cancer prevention, heart protection and the treatment of neurodegenerative diseases. However, due to their vulnerability to environmental conditions and low bioavailability, their application in the food and medical fields is greatly limited. Nanoformulations, as excellent drug delivery systems, can overcome these limitations and maximize the pharmacological effects of polyphenols. In this review, we summarize the biological activities of polyphenols, together with systems for their delivery, including phospholipid complexes, lipid-based nanoparticles, protein-based nanoparticles, niosomes, polymers, micelles, emulsions and metal nanoparticles. The application of polyphenol nanoparticles in food and medicine is also discussed. Although loading into nanoparticles solves the main limitation to application of polyphenolic compounds, there are some concerns about their toxicological safety after entry into the human body. It is therefore necessary to conduct toxicity studies and residue analysis on the carrier.

Long-Circulating Thermosensitive Liposomes for the Targeted Drug Delivery of Oxaliplatin

Introduction

Oxaliplatin (L-OHP) is a well-known third-generation platinum anticancer drug with severe systemic- and neuro-toxicity. The main objective of the current research was to develop a targeted long-circulating thermosensitive smart-release liposome (LCTL) system for better therapeutic efficacy and less toxicity.

Methods

The reverse-phase evaporation method (REV) was used to prepare L-OHP loaded LCTL (L-OHP/LCTL). The physical characteristics were evaluated including encapsulation efficiency (EE), size, zeta potential and stability. The release behavior, cytotoxicity and in vivo evaluation were also carried out.

Results

EE of LCTL was around 25% with a uniform size distribution, and LCTL achieved almost complete release at 42°C while it was only 10% at 37°C. Moreover, the LCTL showed significantly higher cytotoxicity at 42°C than that at 37°C. The in vivo results indicated LCTL could target tumors and enhance retention for more than 24 h, thereby enhancing anti-tumor efficacy on 4T1-bearing mice.

Discussion

These results indicated that LCTL not only possessed a prolonged circulation time but it also enhanced accumulation and achieved selective release at the tumor sites. Conclusively, LCTL could serve as a promising carrier for oxaliplatin delivery to treat solid tumors.

Transdermal Delivery of Small-Sized Resveratrol Nanoparticles to Epidermis Using Anionic Phospholipids

Composite nanoparticles composed of anionic phospholipid of 1,2-dipalmitoyl- sn-glycero-3-phosphorylglycerol (DPPG) and resveratrol (Res) were successfully prepared by mixing them in water and a subsequent heating/cooling process. Small-sized DPPG-Res nanoparticles (<60 nm) could be prepared by ultrasonic fragmentation. Upon addition of size-controlled fluorescently labeled Res (FLRes) nanoparticles stabilized with DPPG (DPPG-FLRes) to rat skin tissue, FLRes molecules infiltrated into the epidermis layer permeating stratum corneum.

Liposomes as carriers of resveratrol and vitamin E: Evaluating ameliorative antioxidant effect using chemical and cellular test systems

Resveratrol (RES) in combination with antioxidant vitamins is reported to be more effective in protecting the cells from oxidative stress rather than any of these antioxidants alone. In continuation to our previous work using resveratrol and vitamin C, our main aim was to evaluate the antioxidant restorative effect using chemical and cellular test systems on resveratrol co-encapsulated vitamin E (VE) within liposomes. Z-average size was less than 135 nm, polydispersity index < 0.3; zeta potential > than ± 30 mV and encapsulation efficiency of RES and VE > 90% and 79% respectively. Chemiluminescence measurement indicated that the antioxidative activity of RES could be increased when VE was additionally loaded into liposomes. Inhibition of AAPH induced luminol enhanced chemiluminescence displayed 90% improvement (P < 0.001) in comparison to control; on the other hand 70% luminescence inhibition of ROS production in isolated blood leukocytes (P < 0.001) was observed. Intracellular oxygen-derived radicals measured by flow cytometry using 2'-7'-dichlorodihydrofluorescein diacetate demonstrated about 1.7 fold (P < 0.05) and 1.5 fold (P < 0.001) enhancement of radical scavenging activity in buffy coats under basal conditions and human umbilical vein endothelial cells after stimulation by H₂O₂ respectively. The cellular systems evidenced the ability of liposome loaded antioxidants to scavenge ROS in the extra and intracellular space, confirming enhanced antioxidative effectivity of RES in the presence of VE, which did not occur in combination with vitamin C. Hence it might be possible to improve the antioxidative effectivity of RES by other/additional antioxidants.

The Impact of Germination on Sorghum Nutraceutical Properties

Sorghum is a gluten-free cereal representing a staple food in many countries of Africa, where germination is traditionally used for the preparation of several sorghum-based products. This study focused on the effect of germination on total phenolic content, in vitro and ex vivo antioxidant activity, and antihypertensive action of sorghum from Togo. Total phenolic content was estimated as Folin–Ciocalteu reducing capacity, while antioxidant activities were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) in vitro tests and ex vivo by the cellular antioxidant activity (CAA) assay on human erythrocytes. The antihypertensive effect of germinated and non-germinated sorghum peptides fraction was evaluated as angiotensin-converting enzyme (ACE) inhibitory activity. Despite our findings demonstrated no impact of germination on the total phenolic content, non-germinated sorghum showed significantly higher in vitro antioxidant activities than the germinated one; further, non-germinated sorghum displayed significantly higher ACE inhibition than germinated sorghum that, instead, at lower doses, exhibited better erythrocytes protection from peroxyl radicals. In conclusion, the germination process negatively impacted the in vitro antioxidant activity and the antihypertensive effect of sorghum while improved erythrocytes protection. This study evidenced better nutraceutical potential of non-germinated sorghum that, besides good antioxidant activity, represents an important source of ACE-inhibitory peptides. However, the germination process might have positively impacted the profile of bioactive compounds involved in the protection of human erythrocytes from oxidative damage.

Mastering the Tools: Natural versus Artificial Vesicles in Nanomedicine

Naturally occurring extracellular vesicles and artificially made vesicles represent important tools in nanomedicine for the efficient delivery of biomolecules and drugs. Since its first appearance in the literature 50 years ago, the research on vesicles is progressing at a fast pace, with the main goal of developing carriers able to protect cargoes from degradation, as well as to deliver them in a time- and space-controlled fashion. While natural occurring vesicles have the advantage of being fully compatible with their host, artificial vesicles can be easily synthetized and functionalized according to the target to reach. Research is striving to merge the advantages of natural and artificial vesicles, in order to provide a new generation of highly performing vesicles, which would improve the therapeutic index of transported molecules. This progress report summarizes current manufacturing techniques used to produce both natural and artificial vesicles, exploring the promises and pitfalls of the different production processes. Finally, pros and cons of natural versus artificial vesicles are discussed and compared, with special regard toward the current applications of both kinds of vesicles in the healthcare field.

Surface decoration of neohesperidin-loaded nanoliposome using chitosan and pectin for improving stability and controlled release

The aim of this study was to improve the physicochemical stability of neohesperidin (NH) using nanoliposomal encapsulation in association with surface decoration strategy employing chitosan (CH) and pectin (P). Different nanoliposomal systems, i.e. NH-loaded nanoliposome (NH-NL), CH-coated NH-NL (CH-NH-NL), and P-coated CH-NH-NL (P-CH-NH-NL) were characterized through DLS, HPLC, TEM, and FTIR. The results confirmed good encapsulation efficiency (>90%) and successful layer formation with nano-sized and spherical carrier. Both CH-NL and P-CH-NL exhibited better physicochemical stability than NL under storage, thermal, pH, ionic, UV, oxidative, and serum conditions. In vitro mucin adsorption study revealed that CH-NL (60%) was more effective in mucoadhesion followed by P-CH-NL (46%) and NL (41%). Furthermore, P-CH-NL showed better performance in NH retention under different food simulants compared to CH-NH-NL and NH-NL, in which the release was mainly governed by the diffusion process. Thus, the P-CH conjugated nanoliposome could be a promising nano-carrier for neohesperidin.

Biocompatibility of Biomaterials for Nanoencapsulation: Current Approaches

Nanoencapsulation is an approach to circumvent shortcomings such as reduced bioavailability, undesirable side effects, frequent dosing and unpleasant organoleptic properties of conventional drug delivery systems. The process of nanoencapsulation involves the use of biomaterials such as surfactants and/or polymers, often in combination with charge inducers and/or ligands for targeting. The biomaterials selected for nanoencapsulation processes must be as biocompatible as possible. The type(s) of biomaterials used for different nanoencapsulation approaches are highlighted and their use and applicability with regard to haemo- and, histocompatibility, cytotoxicity, genotoxicity and carcinogenesis are discussed.

Recent Advances in Nanoencapsulation of Phytochemicals to Combat Obesity and Its Comorbidities

An increasing epidemic of obesity has become a serious public health concern primarily because it contributes to pathogenesis of many chronic diseases including type 2 diabetes, cardiovascular disease, hepatobiliary disease, obstructive sleep apnea, kidney disease, some types of cancer, among others. Consumption of a variety of phytochemicals has emerged as a promising potential for combating obesity and its comorbidities. However, the generally low aqueous solubility, stability, bioavailability, and target specificity of phytochemicals, along with their side-effects and toxicity seen when used at high doses, have restricted their clinical applications. As a solution, phytochemicals can be encapsulated into nanoparticles to increase their stability and solubility, enhance their bioavailability, protect them from premature degradation in the body, prolong their circulation time, and thus enhance their antiobesity activity. In this perspective, we summarize the problems and limitations of the prominent phytochemicals (epigallocatechin gallate, trans-resveratrol, curcumin, and quercetin), the major biocompatible and biodegradable nanoparticles, and the efficacy of nanoencapsulated forms of these phytochemicals in combating obesity and its comorbidities.

Recent Strategies in Resveratrol Delivery Systems

Resveratrol, a natural polyphenolic stilbenoid widely found in grapes and wines, displays beneficial properties such as cardio-protective, antioxidant and anti-inflammatory activities. Trans-resveratrol (RSV) is the most bioactive and more abundant stereoisomer found in nature. Despite the positive properties of RSV, there are various factors that limit its effectiveness, including low aqueous solubility, low oral bioavailability and chemical instability. During the last years, an increasing number of strategies such as nano and micro encapsulation have been developed in order to overcome these limitations and enhance the use of RSV in nutritional and pharmaceutical applications. This Review summarizes the advances and main properties of several RSV carriers and delivery systems reported during the last 5 years.

Hura crepitans L. Extract: Phytochemical Characterization, Antioxidant Activity, and Nanoformulation

The purpose of this study was to improve the knowledge on Hura crepitans L., a plant belonging to the Euphorbiaceae family that, on the one hand, is known to be toxic, but on the other, is a source of polyphenols with health-promoting effects. Different green extraction methods were applied, varying solvent, temperature, and duration of extraction, which can influence the phytochemical profile and biological activity of plant extracts, and the extracts were fully characterized. Aqueous extracts exhibited a superior antioxidant activity, as indicated by different spectrophotometric tests, and were cytoprotective to HepG2 cells used as model cells. Liquid chromatography-mass spectrometry analyses were performed to identify the secondary metabolites involved in these effects and demonstrated that solvent, duration, and temperature indeed influenced the extraction of polyphenols. Furthermore, the most promising extract, in terms of antioxidant potential, was incorporated into liposomes with the aim of promoting cell interaction and enhancing the antioxidant activity.

Supercritical fluid assembly of albendazole liposomes targeting gastrin-releasing peptide receptor overexpressing tumors

Aim: To develop albendazole (ABZ)-loaded bombesin(6-14) (BBN(6-14)) functionalized liposomes for targeting GRPR to enhance delivery to cancer cells. Materials & methods: ABZ-loaded liposomes were formulated using supercritical CO2 technology; functionalized with a GRPR-targeted lipid-anchored BBN(6-14) peptide; and evaluated for effects on cell viability, particle size and targeted cell uptake. Results: BBN(6-14)-coated ABZ liposomes decreased cell viability compared with nonfunctionalized ABZ liposomes. The level of GRPR expression positively correlated with intracellular uptake and decreased cell viability. The reduced cell viability, higher cell uptake and GRPR expression were observed in the order PC-3 > Caco-2 > HepG2 cells. Conclusion: BBN(6-14)-functionalized ABZ liposomes showed enhanced reduction in cell viability compared with nonfunctionalized ABZ liposomes.

Lipid Vesicles Loaded with an HIV-1 Fusion Inhibitor Peptide as a Potential Microbicide

The effective use of fusion inhibitor peptides against cervical and colorectal infections requires the development of sustained release formulations. In this work we comparatively study two different formulations based on polymeric nanoparticles and lipid vesicles to propose a suitable delivery nanosystem for releasing an HIV-1 fusion inhibitor peptide in vaginal mucosa. Polymeric nanoparticles of poly-d,l-lactic-co-glycolic acid (PLGA) and lipid large unilamellar vesicles loaded with the inhibitor peptide were prepared. Both formulations showed average sizes and polydispersity index values corresponding to monodisperse systems appropriate for vaginal permeation. High entrapment efficiency of the inhibitor peptide was achieved in lipid vesicles, which was probably due to the peptide's hydrophobic nature. In addition, both nanocarriers remained stable after two weeks stored at 4 °C. While PLGA nanoparticles (NPs) did not show any delay in peptide release, lipid vesicles demonstrated favorably prolonged release of the peptide. Lipid vesicles were shown to improve the retention of the peptide on ex vivo vaginal tissue in a concentration sufficient to exert its pharmacological effect. Thus, the small size of lipid vesicles, their lipid-based composition as well as their ability to enhance peptide penetration on vaginal tissue led us to consider this formulation as a better nanosystem than polymeric nanoparticles for the sustained delivery of the HIV-1 fusion inhibitor peptide in vaginal tissues.

The effect of lipid phase on liposome stability upon exposure to the mechanical stress

Mechanical properties of a lipid bilayer are parameters determined mainly for giant unilamellar vesicles (GUVs). It is not clear if values obtained on the GUV model can be directly translated to submicron large unilamellar vesicles (LUVs). This ambiguity is a major obstacle in exploring the effect of lipid bilayer mechanics on membrane associated processes and effectiveness of liposome-based targeted drug delivery systems. In presented work extrusion, which is a common method to prepare LUVs, was used to study liposomes preparation and stability upon exposure to mechanical stress. The effect of parameters of the extrusion process (temperature, membrane pore size, extrusion force and volumetric flux) on the properties of liposome suspension (average liposome size, polydispersity index and lipid recovery ratio) was determined for model liposomes composed of DPPC lipid. The state of the DPPC lipid bilayer depends on temperature, therefore, the effect of lipid bilayer mechanics on the extrusion process can be quantitated without altering membrane composition. The extrusion process was carried out with the automated extruder delivering quantitative data on the extrusion force and volumetric flux. Obtained results have been interpreted in terms of mechanical properties of the lipid bilayer. Determined mechanical properties of the lipid bilayer and its dependence on temperature are in good agreement with the literature results determined for GUVs. This shows that mechanical properties of the lipid bilayer does not depend on the liposome size in the range from 100 nm to hundreds of microns.

Sorafenib-Loaded Long-Circulating Nanoliposomes for Liver Cancer Therapy

A type of sorafenib- (SOR-) loaded long-circulating nanoliposome was constructed, and the targeting performance and antitumor effects of the prepared liposome were evaluated in the present study. Polyethylene glycol- (PEG-) modified long-circulating nanoliposomes (LC-NPs) were designed and prepared using reverse evaporation, and the LC-NPs were used for delivering sorafenib (LC-PEG-SOR-NPs). Then, the anti-VEGFR antibody as a targeting moiety was chemically coupled with LC-PEG-SOR-NPs to form liver cancer-targeted nanoliposomes (anti-VEGFR-LC-PEG-SOR-NPs). The drug entrapment and loading efficiency were measured. And the cancer-targeting performance and therapeutic efficiency were evaluated both in vitro and in vivo. The anti-VEGFR-LC-PEG-SOR-NPs with an average of 119.8 ± 4.2 nm showed a uniform spherical structure. The drug entrapment and loading efficiency were 92.5% and 18.5%, respectively. The killing efficiency of anti-VEGFR-LC-PEG-SOR-NPs was up to 18% after incubating with liver cancer cells for 72 h. Furthermore, the anti-VEGFR-LC-PEG-SOR-NPs could actively target at the tumor region and could efficiently inhibit tumor growth with negligible side effects. This newly designed nanoliposomes had desirable dispersibility, high drug entrapment efficiency, tumor targeting and therapeutic efficiency, and good safety. As a biocompatible nanocomposite, it was promising to become a novel and useful tumor-targeting nanodrug for liver cancer therapy.

Resveratrol: a review of plant sources, synthesis, stability, modification and food application

Resveratrol, a stilbene molecule belonging to the polyphenol family, is usually extracted from a great many natural plants. The technologies of preparation and extraction methods are developing rapidly. As resveratrol has many beneficial properties, it has been widely utilized in food and medicine industry. In terms of its structure, it is susceptible to degradation and can undergo chemical changes during food processing. Different studies have therefore given more attention to various aspects of resveratrol, including anti-aging, anti-oxidant, and anti-cancer activity. This review classifies the study of resveratrol, considers plant sources, synthesis, stability, common reactions, and food applications, and provides references to boost its food and medical utilization. © 2019 Society of Chemical Industry.

Does Fermentation Really Increase the Phenolic Content in Cereals? A Study on Millet

Millet is underutilized in Europe, despite its advantages compared to other common cereals. In Asia and Africa, millet is mainly eaten in fermented form; its consumption has beneficial properties on human health. Three millet batches were compared in terms of free and bound phenols by High Performance Liquid Chromatography-Diode Array Detector-Mass Spectrometry (HPLC-DAD-MS). The richest one in terms of bound phenols was selected for testing via a basic (0.1 M NaOH) and an acidic (1.2 M H₂SO₄) hydrolysis, in which 149.3 and 193.6 mg/100 g of phenols were recovered, respectively. The ability of fermentation, with yeast and Lactobacilli, to increase the content of phenolic compounds was verified. Five withdrawalswere performed to verify the influence of fermentation time on the total phenolic content. The greatest phenolic content was observed after 72 h. Fermentation increased the cinnamic acids and flavonoids contents by approximately 30%. Vitexin and vitexin 2″-O-rhamnoside contents were significantly higher in the fermented millet; these compounds partially inhibit the protein tyrosine phosphatase enzyme, which is overexpressed in type-2 diabetes. A molecular dynamic simulation showed the two flavonoids to be allosteric inhibitors. The phenolic extract from fermented millet demonstrated a higher level of antioxidant protection on human erythrocytes by ex vivo cellular antioxidant activity in red blood cells. In this context, functional foods based on fermented millet could represent a new trend in European markets.

Ocular Formulation Based on Palmitoylethanolamide-Loaded Nanostructured Lipid Carriers: Technological and Pharmacological Profile

The present work was aimed for the preparation of a stable nanostructured lipid carrier (NLC) system for the delivery of N-palmitoylethanolamide (PEA) to the back of the eye. PEA is an interesting natural compound showing anti-inflammatory and neuroprotective activities. The limits of PEA (poor solubility and high instability) justify its nanoencapsulation into drug delivery systems. Two different well-known techniques were compared to formulate NLC: the high shear homogenization technique (HSH) and the method based on a combination of HSH technique and ultrasonication (HSH/US). Nanoparticles were evaluated in relation to mean size, homogeneity, surface charge, and physical stability by Turbiscan technology. Retinal distribution of PEA was carried out in a rat eye after single instillation of PEA-NLC ophthalmic formulation. The novel formulation delivered remarkable levels of PEA to the retina. Lastly, topical administration of PEA-NLC ophthalmic formulation was able to significantly inhibits retinal tumor necrosis factor-α (TNF-α) levels in streptozotocin-induced diabetic rats. The present findings suggest that the novel ophthalmic formulation may be useful for the treatment of retinal diseases such as diabetic retinopathy. Clinical studies are in progress to evaluate this possibility.

Recent Developments in the Reduction of Oxidative Stress through Antioxidant Polymeric Formulations

Reactive oxygen and nitrogen species (RONS) are produced endogenously in our body, or introduced through external factors, such as pollution, cigarette smoke, and excessive sunlight exposure. In normal conditions, there is a physiological balance between pro-oxidant species and antioxidant molecules that are able to counteract the detrimental effect of the former. Nevertheless, when this homeostasis is disrupted, the resulting oxidative stress can lead to several pathological conditions, from inflammation to cancer and neurodegenerative diseases. In this review, we report on the recent developments of different polymeric formulations that are able to reduce the oxidative stress, from natural extracts, to films and hydrogels, and finally to nanoparticles (NPs).

The interaction between resveratrol and two forms of copper as carbonate and nanoparticles on antioxidant mechanisms and vascular function in Wistar rats

BACKGROUND

Experimental studies have emphasized that cardiovascular alterations can be improved by the long-term use of resveratrol (trans-3,5,4'-trihydroxystilbene; RSV) as well as dietary copper (Cu) intake.

METHODS

Male Wistar rats were supplemented for 8 weeks with Cu (6.5 mg/kg diet) as either nanoparticles (40 nm, CuNPs) or carbonate (CuCO3). Half of the studied animals were supplemented with RSV (500 mg/kg diet). Vascular function and blood plasma antioxidant status, expressed as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), lipid hydroperoxides (LOOH) and malondialdehyde (MDA) were analyzed. The activity of ceruloplasmin (Cp), lipid profile, fasting glucose, and concentrations of Cu and zinc (Zn) were analyzed.

RESULTS

RSV supplementation resulted in the elevated activity of SOD and decreased CAT, GPx and LDL-cholesterol in both groups. RSV supplementation on CuNPs increased the participation of vasoconstrictor prostanoids and decreased ACh-induced vasodilation, while the participation of hyperpolarizing mechanism(s) was restored by activating KATP channels. Blood plasma glucose was decreased. RSV supplementation on CuCO3 enhanced ACh- and SNP-induced vasodilation and decreased NA-induced vasoconstriction. The lipid profile was improved, as well as Zn concentration. Meanwhile, Cu and Cp, and the markers of lipid peroxidation, reflected as LOOH and MDA, were decreased.

CONCLUSION

The use of RSV during CuCO3 intake improves vascular responses, the lipid profile and the antioxidant mechanism(s). The beneficial role of RSV was not observed in the CuNP group and decreased ACh-induced vasodilation and increased participation of vasoconstrictor prostanoids in the vascular regulation were noticed.

A novel tumor-targeted thermosensitive liposomal cerasome used for thermally controlled drug release

Drug carriers with tumor targeting and controlled release have strong prospects for application in safe and efficient chemotherapy. Among various carriers, liposomes have good biocompatibility and can enhance the uptake of drugs by cancer cells. However, traditional liposomes have no specific targeting to cancer cells and are prone to insufficient stability, causing early leakage of the drug. Accordingly, organic-inorganic hybrid phospholipid and thermosensitive phospholipid are deliberately introduced into a liposome system to enhance the morphological and structural stability of the liposomes while realizing thermally controlled drug release. Furthermore, modification with a targeting ligand (WSG-peptide) can endow liposomes with active targeting to ovarian carcinoma cells. First, WSG-peptide was grafted onto the hydrophilic terminal of phospholipid molecules, and the organic-inorganic hybrid cerasome-forming lipid (CFL) was synthesized via a two-step chemical reaction. Then, the WSG-grafted thermosensitive liposomal cerasome (c-LIP-WSG) was prepared by thin-film hydration method. The results showed that the c-LIP-WSG had excellent structural stability both in storage and in a simulated circulation environment. In vitro drug release confirmed that the liposomes exhibited thermally controlled release. Cell uptake experiments and living fluorescence imaging of SKOV-3 tumor-bearing nude mice confirmed that the WSG-peptide modified liposomes were provided with specific targeting properties for ovarian carcinoma.

Characteristics, Biological Properties and Analytical Methods of Trans-Resveratrol: A Review

Trans-resveratrol (TR) is the biological active isomer of resveratrol and the one responsible for therapeutic effects; both molecules are non-flavonoid phenolics of the stilbenes class found mainly in berries and red grapes. TR biological properties lie in modulation of various enzymatic classes. It is a promising candidate to novel drugs due its applications in pharmaceutical and cosmetic industries, such as anticarcinogenic, antidiabetic, antiacne, antioxidant, anti-inflammatory, neuroprotective, and photoprotector agent. It has effects on bone metabolism, gastrointestinal tract, eyes, kidneys, and in obesity treatment as well. Nevertheless, its low solubility in water and other polar solvents may be a hindrance to its therapeutic effects. Various strategies been developed to overcome these issues, such as the drug delivery systems. The present study performed a research about methods to identify TR and RESV in several samples (raw materials, wines, food supplements, drug delivery systems, and blood plasma). Most of the studies tend to analyze TR and RESV by high performance liquid chromatography (HPLC) coupled with different detectors, even so, there are reports of the use of capillary electrophoresis, electron spin resonance, gas chromatography, near-infrared luminescence, UV-Vis spectrophotometer, and vibrational spectrophotometry, for this purpose. Thus, the review evaluates the biological activity of TR and demonstrates the currently used analytical methods for its quantification in different matrices.

Co-delivery of curcumin and doxorubicin in PEGylated liposomes favored the antineoplastic C26 murine colon carcinoma microenvironment

Our recent studies have demonstrated that the antitumor efficacy of doxorubicin (DOX), administered in long-circulating liposomes (LCL), could be considerably improved after its co-encapsulation with curcumin (CURC). Thus, the question addressed within this article is whether LCL-CURC-DOX can be exploited more efficiently than liposomal DOX for future colorectal cancer therapy. Therefore, we investigated the physicochemical and biological properties of LCL-CURC-DOX and the mechanisms of its antitumor activity in C26 murine colon carcinoma in vivo. Our results proved that the developed nanoformulation based on the co-encapsulation of CURC and DOX met the requirements of a modern drug delivery system for future cancer therapy, demonstrating enhanced antitumor activity on C26 colon carcinoma in vivo. The antitumor efficacy of LCL-CURC-DOX relied on suppressive effects on main protumor processes such as angiogenesis, inflammation, oxidative stress, invasion and resistance to apoptosis, and on the dysregulation of Th1/Th2 cell axis which favored the antineoplastic phenotype of cells in tumor microenvironment (TME). The development of multitargeted strategies aiming at stimulating antitumor effects within the tumor milieu and counteracting the escape mechanisms of cancer cells would be beneficial in the management of colon cancer in the future.

The effect of salt stress on resveratrol and piceid accumulation in two Vitis vinifera L. cultivars

Salinity is one of the most important abiotic stresses, especially in arid regions. Such devastating constraint is converted mainly to oxidative burst. Thus, plants have to develop strategies to scavenge salt-related regenerated oxidant molecules. In the present work, fully aged plants derived from two Vitis vinifera L. cultivars, the Tunisian autochthonous tolerant genotype Razegui and the salt sensitive Syrah, were analyzed regarding their short term response to 100 mM NaCl, in hydroponic cultures. The ratio [ASA/ASA + DHA] was calculated on the basis of the oxidation of ascorbic acid (ASA) into dehydroascorbic acid (DHA) in leaves. Results proved that oxidative stress was generated. This led to the accumulation of malondialdehyde which referred to a lipid peroxidation mainly in the sensitive Syrah. In order to cope with these oxidative disturbances, trans-resveratrol as well as its glucosides trans-piceid and cis-piceid have been de novo synthesized in the sensitive variety. Razegui stilbene concentrations were presented here for the first time and unexpectedly did not show a very important variation during the salt elicitation.

Preparation and Evaluation of Liposomes Co-Loaded with Doxorubicin, Phospholipase D Inhibitor 5-Fluoro-2-Indolyl Deschlorohalopemide (FIPI) and D-Alpha Tocopheryl Acid Succinate (α-TOS) for Anti-Metastasis

Tumor metastasis has become a key obstacle to cancer treatment, which causes high mortality. Nowadays, it involves multiple complex pathways, and conventional treatments are not effective due to fewer targets. The aims of the present study were to construct a novel liposome delivery system co-loading a specific PLD inhibitor 5-fluoro-2-indolyldes-chlorohalopemide (FIPI) in combination with antitumor drug doxorubicin (DOX) and functional excipient D-alpha tocopheryl acid succinate (α-TOS) for anti-metastasis. In this study, the liposomes containing three components (DFT-Lip) with different physicochemical properties were successfully prepared by film dispersion method combined with pH-gradient method. Physicochemical parameters such as particles size, potential, encapsulation efficiency, stability, and release profiles were investigated. In vitro and in vivo anti-metastasis effectiveness against highly metastatic breast cancer MDA-MB-231 cell line was evaluated. The liposomes showed uniform particle size (approximately 119 nm), high drug encapsulation efficiency (> 90%), slow release characteristics and stability. In vitro anti-tumor cell metastasis study demonstrated DFT-Lip could greatly inhibit motility, migration and invasion of MDA-MB-231 cells compared to other liposomes, predicting a synergistic anti-tumor metastasis effect between FIPI with α-TOS in liposomes. In vivo anti-metastasis study showed that DFT-Lip prevented the initiation and the progression of metastasis of high metastatic breast cancer. These results suggested that the liposomes containing DOX, FIPI, and α-TOS might be a promising strategy for metastatic tumor therapy in clinics.