Strategy to provide a useful solution to effective delivery of dihydroartemisinin: Development, characterization and in vitro studies of liposomal formulations

2-Monoacylglycerol Mimetic Liposomes to Promote Intestinal Lymphatic Transport for Improving Oral Bioavailability of Dihydroartemisinin

Purpose

Reducing the first-pass hepatic effect via intestinal lymphatic transport is an effective way to increase the oral absorption of drugs. 2-Monoacylglycerol (2-MAG) as a primary digestive product of dietary lipids triglyceride, can be assembled in chylomicrons and then transported from the intestine into the lymphatic system. Herein, we propose a biomimetic strategy and report a 2-MAG mimetic nanocarrier to target the intestinal lymphatic system via the lipid absorption pathway and improve oral bioavailability.

Methods

The 2-MAG mimetic liposomes were designed by covalently bonding serinol (SER) on the surface of liposomes named SER-LPs to simulate the structure of 2-MAG. Dihydroartemisinin (DHA) was chosen as the model drug because of its disadvantages such as poor solubility and high first-pass effect. The endocytosis and exocytosis mechanisms were investigated in Caco-2 cells and Caco-2 cell monolayers. The capacity of intestinal lymphatic transport was evaluated by ex vivo biodistribution and in vivo pharmacokinetic experiments.

Results

DHA loaded SER-LPs (SER-LPs-DHA) had a particle size of 70 nm and a desirable entrapment efficiency of 93%. SER-LPs showed sustained release for DHA in the simulated gastrointestinal environment. In vitro cell studies demonstrated that the cellular uptake of SER-LPs primarily relied on the caveolae- rather than clathrin-mediated endocytosis pathway and preferred to integrate into the chylomicron assembly process through the endoplasmic reticulum/Golgi apparatus route. After oral administration, SER-LPs efficiently promoted drug accumulation in mesenteric lymphatic nodes. The oral bioavailability of DHA from SER-LPs was 10.40-fold and 1.17-fold larger than that of free DHA and unmodified liposomes at the same dose, respectively.

Conclusion

SER-LPs improved oral bioavailability through efficient intestinal lymphatic transport. These findings of the current study provide a good alternative strategy for oral delivery of drugs with high first-pass hepatic metabolism.

A cochleate formulation optimized by D-optimal mixture design enhances oral bioavailability of Revaprazan

A cochleate formulation was developed to enhance the oral bioavailability of revaprazan (RVP). Dimyristoyl phosphatidylcholine (DMPC) liposome containing dicetyl phosphate (DCP) successfully formed a cochleate after treatment with CaCl2, whereas that containing sodium deoxycholate did not. Cochleate was optimised using a D-optimal mixture design with three independent variables-DMPC (X1, 70.58 mol%), cholesterol (X2, 22.54 mol%), and DCP (X3, 6.88 mol%)-and three response variables: encapsulation efficiency (Y1, 76.92%), released amount of free fatty acid at 2 h (Y2, 39.82%), and released amount of RVP at 6 h (Y3, 73.72%). The desirability function was 0.616, showing an excellent agreement between the predicted and experimental values. The cylindrical morphology of the optimised cochleate was visualised, and laurdan spectroscopy confirmed the dehydrated membrane interface, showing an increased generalised polarisation value (approximately 0.5) over small unilamellar vesicle of RVP (RVP-SUV; approximately 0.1). The optimised cochleate showed greater resistance to pancreatic enzyme than RVP-SUV. RVP was released in a controlled manner, achieving approximately 94% release in 12 h. Following oral administration in rats, the optimised cochleate improved the relative bioavailability of RVP by approximately 274%, 255%, and 172% compared to RVP suspension, a physical mixture of RVP and the cochleate, and RVP-SUV, respectively. Thus, the optimised cochleate formulation might be a good candidate for the practical development of RVP.

Curcumin or quercetin loaded nutriosomes as oral adjuvants for malaria infections

Artemisinin, curcumin or quercetin, alone or in combination, were loaded in nutriosomes, special phospholipid vesicles enriched with Nutriose FM06®, a soluble dextrin with prebiotic activity, that makes these vesicles suitable for oral delivery. The resulting nutriosomes were sized between 93 and 146 nm, homogeneously dispersed, and had slightly negative zeta potential (around -8 mV). To improve their shelf life and storability over time, vesicle dispersions were freeze-dried and stored at 25 °C. Results confirmed that their main physico-chemical characteristics remained unchanged over a period of 12 months. Additionally, their size and polydispersity index did not undergo any significant variation after dilution with solutions at different pHs (1.2 and 7.0) and high ionic strength, mimicking the harsh conditions of the stomach and intestine. An in vitro study disclosed the delayed release of curcumin and quercetin from nutriosomes (∼53% at 48 h) while artemisinin was quickly released (∼100% at 48 h). Cytotoxicity assays using human colon adenocarcinoma cells (Caco-2) and human umbilical vein endothelial cells (HUVECs) proved the high biocompatibility of the prepared formulations. Finally, in vitro antimalarial activity tests, assessed against the 3D7 strain of Plasmodium falciparum, confirmed the effectiveness of nutriosomes in the delivery of curcumin and quercetin, which can be used as adjuvants in the antimalaria treatment. The efficacy of artemisinin was also confirmed but not improved. Overall results proved the possible use of these formulations as an accompanying treatment of malaria infections.

An Update on Advancements and Challenges in Inhalational Drug Delivery for Pulmonary Arterial Hypertension

A lethal condition at the arterial–alveolar juncture caused the exhaustive remodeling of pulmonary arterioles and persistent vasoconstriction, followed by a cumulative augmentation of resistance at the pulmonary vascular and, consequently, right-heart collapse. The selective dilation of the pulmonary endothelium and remodeled vasculature can be achieved by using targeted drug delivery in PAH. Although 12 therapeutics were approved by the FDA for PAH, because of traditional non-specific targeting, they suffered from inconsistent drug release. Despite available inhalation delivery platforms, drug particle deposition into the microenvironment of the pulmonary vasculature and the consequent efficacy of molecules are influenced by pathophysiological conditions, the characteristics of aerosolized mist, and formulations. Uncertainty exists in peripheral hemodynamics outside the pulmonary vasculature and extra-pulmonary side effects, which may be further exacerbated by underlying disease states. The speedy improvement of arterial pressure is possible via the inhalation route because it has direct access to pulmonary arterioles. Additionally, closed particle deposition and accumulation in diseased tissues benefit the restoration of remolded arterioles by reducing fallacious drug deposition in other organs. This review is designed to decipher the pathological changes that should be taken into account when targeting the underlying pulmonary endothelial vasculature, especially with regard to inhaled particle deposition in the alveolar vasculature and characteristic formulations.

Dimeric Artesunate Glycerophosphocholine Conjugate Nano-Assemblies as Slow-Release Antimalarials to Overcome Kelch 13 Mutant Artemisinin Resistance

Current best practice for the treatment of malaria relies on short half-life artemisinins that are failing against emerging Kelch 13 mutant parasite strains. Here, we introduce a liposome-like self-assembly of a dimeric artesunate glycerophosphocholine conjugate (dAPC-S) as an amphiphilic prodrug for the short-lived antimalarial drug, dihydroartemisinin (DHA), with enhanced killing of Kelch 13 mutant artemisinin-resistant parasites. Cryo-electron microscopy (cryoEM) images and the dynamic light scattering (DLS) technique show that dAPC-S typically exhibits a multilamellar liposomal structure with a size distribution similar to that of the liposomes generated using thin-film dispersion (dAPC-L). Liquid chromatography-mass spectrometry (LCMS) was used to monitor the release of DHA. Sustainable release of DHA from dAPC-S and dAPC-L assemblies increased the effective dose and thus efficacy against Kelch 13 mutant artemisinin-resistant parasites in an in vitro assay. To better understand the enhanced killing effect, we investigated processes for deactivation of both the assemblies and DHA, including the roles of serum components and trace levels of iron. Analysis of parasite proteostasis pathways revealed that dAPC assemblies exert their activity via the same mechanism as DHA. We conclude that this easily prepared multilamellar liposome-like dAPC-S with long-acting efficacy shows potential for the treatment of severe and artemisinin-resistant malaria.

Tunneling Nanotubes: A New Target for Nanomedicine?

Tunneling nanotubes (TNTs), discovered in 2004, are thin, long protrusions between cells utilized for intercellular transfer and communication. These newly discovered structures have been demonstrated to play a crucial role in homeostasis, but also in the spreading of diseases, infections, and metastases. Gaining much interest in the medical research field, TNTs have been shown to transport nanomedicines (NMeds) between cells. NMeds have been studied thanks to their advantageous features in terms of reduced toxicity of drugs, enhanced solubility, protection of the payload, prolonged release, and more interestingly, cell-targeted delivery. Nevertheless, their transfer between cells via TNTs makes their true fate unknown. If better understood, TNTs could help control NMed delivery. In fact, TNTs can represent the possibility both to improve the biodistribution of NMeds throughout a diseased tissue by increasing their formation, or to minimize their formation to block the transfer of dangerous material. To date, few studies have investigated the interaction between NMeds and TNTs. In this work, we will explain what TNTs are and how they form and then review what has been published regarding their potential use in nanomedicine research. We will highlight possible future approaches to better exploit TNT intercellular communication in the field of nanomedicine.

Artemisinin-Type Drugs in Tumor Cell Death: Mechanisms, Combination Treatment with Biologics and Nanoparticle Delivery

Artemisinin, the most famous anti-malaria drug initially extracted from Artemisia annua L., also exhibits anti-tumor properties in vivo and in vitro. To improve its solubility and bioavailability, multiple derivatives have been synthesized. However, to reveal the anti-tumor mechanism and improve the efficacy of these artemisinin-type drugs, studies have been conducted in recent years. In this review, we first provide an overview of the effect of artemisinin-type drugs on the regulated cell death pathways, which may uncover novel therapeutic approaches. Then, to overcome the shortcomings of artemisinin-type drugs, we summarize the recent advances in two different therapeutic approaches, namely the combination therapy with biologics influencing regulated cell death, and the use of nanocarriers as drug delivery systems. For the former approach, we discuss the superiority of combination treatments compared to monotherapy in tumor cells based on their effects on regulated cell death. For the latter approach, we give a systematic overview of nanocarrier design principles used to deliver artemisinin-type drugs, including inorganic-based nanoparticles, liposomes, micelles, polymer-based nanoparticles, carbon-based nanoparticles, nanostructured lipid carriers and niosomes. Both approaches have yielded promising findings in vitro and in vivo, providing a strong scientific basis for further study and upcoming clinical trials.

Preparation of Liposomal Formulations for Ocular Delivery of Thymoquinone: In Vitro Evaluation in HCEC-2 e HConEC Cells

Thymoquinone (TQ) is the main constituent of Nigella sativa L. essential oil. In vitro studies have shown its protective effect against H₂O₂-induced oxidative stress in human retinal pigment epithelium cells, and in vivo experiments have demonstrated its effect in decreasing corneal neovascularization and reducing the inflammation in an experimental dry eye model in mice. Its therapeutic use is limited by poor bioavailability, low solubility, and scarce permeability. In this study, two liposomal formulations have been developed, both of which consist of phosphatidylcholine and Plurol Oleique, a liquid lipid, and one of which is coated with 0.1% w/v hyaluronic acid (HA) to increase both TQ solubility and its ocular therapeutic potential. Each formulation has a size <200 nm and an EE% around 70%, determined by scattering techniques and the HPLC-DAD analytical method, respectively, and they result in a 2-fold increase in TQ solubility. HA-coated liposomes are stable over 2 months at +4 °C, and coated and uncoated liposomes present a gradual and prolonged release of TQ. Two cell lines, human corneal epithelial cells (HCEC-2) and human conjunctival epithelial cells (HConEC) were used to investigate the safety of the liposomal formulations. Uptake studies were also performed using fluorescent liposomes. Both liposomes and, in particular, HA-coated liposomes reduce the TQ toxicity observed at high doses in both HCEC-2 and HConEC cells, and both formulations increase the absorption at the cellular level and especially at the nucleus level, with a more pronounced effect for HA-coated liposomes.

Enhanced oral permeability of Trans-Resveratrol using nanocochleates for boosting anticancer efficacy; in-vitro and ex-vivo appraisal

Hepatocellular carcinoma (HCC) is a prevalent liver cancer representing the fourth most lethal cancer worldwide. Trans-Resveratrol (T-R) possesses a promising anticancer activity against HCC. However, it suffers from poor bioavailability because of the low solubility, chemical instability, and hepatic metabolism. Herein, we developed T-R-loaded nanocochleates using a simple trapping method. Nanocarriers were optimized using a comprehensive in-vitro characterization toolset and evaluated for the anticancer activity against HepG2 cell line. T-R-loaded nanocochleates demonstrated monodispersed cylinders (163.27 ± 2.68 nm and 0.25 ± 0.011 PDI) and -46.6 mV ζ-potential. They exhibited a controlled biphasic pattern with minimal burst followed by sustained release for 72 h. Significant enhancements of Caco-2 transport and ex-vivo intestinal permeation over liposomes, with 1.8 and 2.1-folds respectively, were observed. Nanocochleates showed significant reduction of 24 h IC₅₀ values compared to liposomes and free T-R. Moreover, an efficient knockdown of anti-apoptotic (Bcl-2) and cancer stemness (NANOG) genes was demonstrated. To the best of our knowledge, we are the first to develop T-R loaded nanocochleates and scrutinize its potential in suppressing NANOG expression, 2-folds lower, compared to free T-R. According to these auspicious outcomes, nanocochleates represent a promising nanoplatform to enhance T-R oral permeability and augment its anticancer efficacy in the treatment of HCC.

Murine pharmacokinetics and antimalarial pharmacodynamics of dihydroartemisinin trimer self-assembled nanoparticles

Currently, conjugation of artemisinin-derived dimers, trimers, and tetramers is a viable strategy for developing new effective antimalarial candidates. Furthermore, nanotechnology is an effective means to achieve intravenous administration of hydrophobic drugs. In this paper, an ester-linked dihydroartemisinin trimer (DHA₃) was synthesized and further prepared as self-assembled nanoparticles (DHA₃NPs) by a one-step nanoprecipitation method. The pharmacokinetics and antimalarial pharmacodynamics of DHA₃NPs were studied in rats and mice infected with Plasmodium yoelii BY265 (PyBY265). DHA₃NPs had a regular spherical shape with a uniform size distribution of 140.27 ± 3.59 nm, entrapment efficiency (EE) of 99.63 ± 0.17%, and drug loading efficiency (DL) of 79.62 ± 0.11%. The in vitro release characterization revealed that DHA₃NPs were easily hydrolysed into DHA in an esterase environment. The pharmacokinetics study demonstrated that the area under the concentration-time curve (AUC_0-t) of DHA in DHA₃NPs group was 2070.52 ± 578.76 h×ng×mL^-1, which was higher than that of DHA and artesunate (AS) control groups (AUC_0-t values of 724.18 ± 94.32 and 448.40 ± 94.45 h×ng×mL^-1, respectively) (P < 0.05). The antimalarial pharmacodynamics in vivo suggested that DHA₃NP_S (ED₉₀ 7.82 ± 1.16 μmol×(kg×day)^-1) had a superior antimalarial effect compared with that of control groups (ED₉₀ values of 14.68 ± 0.98 (DHA) and 14.34 ± 1.96 (AS) μmol×(kg×day)^-1) (P < 0.05). In addition, DHA₃NP_S reduced the recurrence ratio and improved the cure ratio and survival time. In summary, DHA₃NPs exhibited promising pharmacokinetic characteristics and antimalarial pharmacodynamics in vivo.

Development of Nanoliposomes Loaded with Carbon Dioxide Serenoa repens (Saw Palmetto) Extract

Liposomes represent, among the nanocarriers, the most useful ones for dermatological use, and their composition, charge, size strongly influence their performance in topical drug delivery systems, with possible accumulation of the loaded drugs in the hair follicles. Recently, a saw palmetto carbon dioxide (CO₂) extract has been reported useful for the treatment of hair loss because of the inhibition of 5α-reductase enzyme, responsible of the conversion of testosterone to the most potent androgen, the 5α-dihydrotestosterone. In this work, the formation of nano-sized liposomes and the encapsulation efficiency of saw palmetto CO₂ extract were investigated by light scattering techniques, microscopy and HPLC. The vesicles were loaded with 0.1% w/v saw palmetto CO₂ extract and were small in size (mean size of 145±5 nm). In addition, they were homogeneously dispersed (polydispersity index ≤0.27) and negatively charged (mean value -36.2±3.1 mV). The developed nanoliposomes could represent suitable drug delivery systems to treat the hair loss.

Hydroxyethyl cellulose hydrogel for skin delivery of khellin loaded in ascosomes: Characterization, in vitro/in vivo performance and acute toxicity

Aim of this work was to prepare and characterize a hydroxyethyl cellulose hydrogel loaded with ascosomes, nanovesicles based on phosphatidylcholine plus ascorbyl octanoate (ASC8) or ascorbyl decanoate (ASC1), and khellin (2 mg/mL), for topical use. ASC10 vesicles were selected for the hydrogel formulation because of the best biopharmaceutical characteristics, namely size of 115 nm, PDI of 0.26, ζ-potential of -40.1 meV, EE% of 90.2%. After 24 h the in vitro release of khellin was more than 80%, while the ex-vivo skin permeation of khellin after application of the vesicles was 42% of the dose. The hydrogel formulations had a pH value of 5, viscosity properties were different according to the different temperatures and in addition, they presented characteristics of non-Newtonian fluids with a pseudoplastic shear thinning behaviour according to the Herschel-Bulkley equation. These hydrogels combine the advantages of a suitable viscosity for dermal use (hydrogel matrix) and an increased transdermal absorption (ascosome components). The best permeability of the ASC10 ascosomes, led to select the formulation for skin irritation and corrosion tests in rats. Liver and dermal histological and pathological analyses demonstrated that hydroxyethyl cellulose hydrogels based on khellin loaded in the ASC10 ascosomes have no toxic effects.

An in vitro evaluation of antitumor activity of sirolimus-encapsulated liposomes in breast cancer cells

OBJECTIVES

Design and examine the effect of sirolimus-PEGylated (Stealth) liposomes for breast cancer treatment. In this study, we developed conventional and Stealth liposome nanoparticles comprising of distearoylphosphatidylcholine (DSPC) or dipalmitoyl-phosphatidylcholine (DPPC) and DSPE-MPEG-2000 lipids loaded with sirolimus as an anticancer agent. The effect of lipid grade, drug loading and incubation times were evaluated.

METHODS

Particle size distribution, encapsulation efficiency of conventional and Stealth liposomes were studied followed by cytotoxicity evaluation. The cellular uptake and internal localisation of liposome formulations were investigated using confocal microscopy.

KEY FINDINGS

The designed Stealth liposome formulations loaded with sirolimus demonstrated an effective in vitro anticancer therapy compared with conventional liposomes while the length of the acyl chain affected the cell viability. Anticancer activity was found to be related on the drug loading amounts and incubation times. Cell internalization was observed after 5 h while significant cellular uptake of liposome was detected after 24 h with liposome particles been located in the cytoplasm round the cell nucleus. Sirolimus Stealth liposomes induced cell apoptosis.

CONCLUSIONS

The design and evaluation of sirolimus-loaded PEGylated liposome nanoparticles demonstrated their capacity as drug delivery carrier for the treatment of breast cancer tumours.

Potent in vivo antimalarial activity of water-soluble artemisinin nano-preparations

Artemisinin is a remarkable compound whose derivatives and combinations with multiple drugs have been utilized at the forefront of malaria treatment. However, the inherent issues of the parent compound such as poor bioavailability, short serum half-life, and high first-pass metabolism partially limit further applications of this drug. In this study, we enhanced the aqueous phase solubility of artemisinin by encapsulating it in two nanocarriers based on the polymer polycaprolactone (ART-PCL) and lipid-based Large Unilamellar Vesicles (ART-LIPO) respectively. Both nanoformulations exhibit in vitro parasite killing activity against Plasmodium falciparum with the ART-LIPO performing at comparable efficacy to the control drug solubilized in ethanol. These water-soluble formulations showed potent in vivo antimalarial activity as well in the mouse model of malaria at equivalent doses of the parent drug. Additionally, the artemisinin-PCL nanoformulation used in combination with either pyrimethamine or chloroquine increased the survival of the Plasmodium berghei infected mice for more than 34 days and effectively cured the mice of the infection. We highlight the potential for polymer and liposome-based nanocarriers in improving not only the aqueous phase solubility of artemisinin but also concomitantly retaining its therapeutic efficacy in vivo as well.

Nanoparticles Formulations of Artemisinin and Derivatives as Potential Therapeutics for the Treatment of Cancer, Leishmaniasis and Malaria

Cancer, malaria, and leishmaniasis remain the deadly diseases around the world although several strategies of treatment have been developed. However, most of the drugs used to treat the aforementioned diseases suffer from several pharmacological limitations such as poor pharmacokinetics, toxicity, drug resistance, poor bioavailability and water solubility. Artemisinin and its derivatives are antimalarial drugs. However, they also exhibit anticancer and antileishmanial activity. They have been evaluated as potential anticancer and antileishmanial drugs but their use is also limited by their poor water solubility and poor bioavailability. To overcome the aforementioned limitations associated with artemisinin and its derivatives used for the treatment of these diseases, they have been incorporated into nanoparticles. Several researchers incorporated this class of drugs into nanoparticles resulting in enhanced therapeutic outcomes. Their potential efficacy for the treatment of parasitic infections such as malaria and leishmaniasis and chronic diseases such as cancer has been reported. This review article will be focused on the nanoparticles formulations of artemisinin and derivatives for the treatment of cancer, malaria, and leishmaniasis and the biological outcomes (in vitro and in vivo).

Hydroxypropyl methylcellulose hydrogel of berberine chloride-loaded escinosomes: Dermal absorption and biocompatibility

Aim of this work was to prepare and characterize new nanocarrier-loaded hydrogel formulations for topical application, using hydroxypropyl methylcellulose (HMPC) and special nanovesicles, the escinosomes. The combination of the two technological strategies, nanocarriers and hydrogels, was selected to circumvent some drawbacks of nanovesicles and develop stable and efficient skin-delivery platforms. HPMC is a derivative of cellulose with a wide range of physicochemical properties, forming suitable hydrogel for dermatological applications. Escinosomes, made of escin (ESN), a natural bioactive saponin, plus phosphatidylcholine, were loaded with berberine chloride (BRB), a bioactive natural product, and were entrapped in the polymeric matrix of HPMC. Release and permeation properties of aqueous ESN and BRB dispersions, escinosomes were compared with the corresponding hydrogels. Viscosity measurements evidenced their suitability for topical applications. In vitro permeation experiments showed a higher residence time of the HPMC-hydrogel. Thus, the new escinosome HPMC-hydrogel formulations combine the advantages of a modified release and increased transdermal permeability (escinosome components), with better viscosity properties (polysaccharide matrix). In addition, the developed HPMC-hydrogels also had a very good safety profile and skin biocompatibility studies showed no potentially hazardous skin irritation. Finally, the developed escinosome HMPC-hydrogel formulations were very stable with appropriate mechanical properties.

Combination Therapies of Artemisinin and its Derivatives as a Viable Approach for Future Cancer Treatment

BACKGROUND

Many anticancer drugs have been developed for clinical usage till now, but the major problem is the development of drug-resistance over a period of time in the treatment of cancer. Anticancer drugs produce huge adverse effects, ultimately leading to death of the patient. Researchers have been focusing on the development of novel molecules with higher efficacy and lower toxicity; the anti-malarial drug artemisinin and its derivatives have exhibited cytotoxic effects.

METHODS

We have done extensive literature search for artemisinin for its new role as anti-cancer agent for future treatment. Last two decades papers were referred for deep understanding to strengthen its role.

RESULT

Literature shows changes at 9, 10 position in the artemisinin structure produces anticancer activity. Artemisinin shows anticancer activity in leukemia, hepatocellular carcinoma, colorectal and breast cancer cell lines. Artemisinin and its derivatives have been studied as combination therapy with several synthetic compounds, RNA interfaces, recombinant proteins and antibodies etc., for synergizing the effect of these drugs. They produce an anticancer effect by causing cell cycle arrest, regulating signaling in apoptosis, angiogenesis and cytotoxicity activity on the steroid receptors. Many novel formulations of artemisinin are being developed in the form of carbon nanotubes, polymer-coated drug particles, etc., for delivering artemisinin, since it has poor water/ oil solubility and is chemically unstable.

CONCLUSION

We have summarize the combination therapies of artemisinin and its derivatives with other anticancer drugs and also focussed on recent developments of different drug delivery systems in the last 10 years. Various reports and clinical trials of artemisinin type drugs indicated selective cytotoxicity along with minimal toxicity thus projecting them as promising anti-cancer agents in future cancer therapies.

Development and Percutaneous Permeation Study of Escinosomes, Escin-Based Nanovesicles Loaded with Berberine Chloride

Escin is a natural saponin, clinically used for the anti-edematous and anti-inflammatory effects. The aim of the study was to explore the possibility of converting escin into vesicle bilayer-forming component. The hyaluronidase inhibition activity of escin was evaluated after its formulation in escinosomes. Berberine chloride, a natural quaternary isoquinoline alkaloid isolated from several medicinal plants that is traditionally used for various skin conditions was loaded in the vesicles. The developed nanovesicles were characterized in terms of diameter, polydispersity, ζ-potential, deformability, recovery, encapsulation efficiency, stability, and release kinetics. Nanovesicle permeation properties through artificial membranes and rabbit ear skin were investigated using skin-PAMPA^TM and Franz cells were also evaluated. Escinosomes, made of phosphatidylcholine and escin, were loaded with berberine chloride. These nanovesicles displayed the best characteristics for skin application, particularly optimal polydispersity (0.17) and deformability, high negative ζ-potential value, great encapsulation efficiency (about 67%), high stability, and the best release properties of berberine chloride (about 75% after 24 h). In conclusion, escinosomes seem to be new vesicular carriers, capable to maintain escin properties such as hyaluronidase inhibition activity, and able to load other active molecules such as berberine chloride, in order to enhance or expand the activity of the loaded drug.

Nanostructured lipid carriers for oral delivery of silymarin: Improving its absorption and in vivo efficacy in type 2 diabetes and metabolic syndrome model

Silymarin (SLM) is a mixture of flavonolignans extracted from the fruit of Silybum marianum L. Gaertn. which has been used for decades as a hepatoprotector. Silymarin has recently been proposed to be beneficial in type 2 diabetic patients. Constituents of SLM are poorly water-soluble and low permeable compounds, with consequently limited oral bioavailability. This study aimed to investigate the possibility of delivery of SLM via nanostructured lipid carriers (NLCs) to overcome these issues and for preparation of an oral dosage form. NLCs were prepared through an emulsion/evaporation/solidifying method. Cetyl palmitate:Lauroglycol 90 was selected as the lipid mixture and Brij S20 as surfactant. NLCs were chemically and physically characterized. Encapsulation efficiency was more than 92%. The storage stability of the NLC suspension was also investigated and the freeze-drying process was taken into consideration. After assessing the stability of the formulation in a simulated gastrointestinal environment, the release of SLM was monitored in different pH conditions. In vitro experiments with artificial membranes (PAMPA) and Caco-2 cells revealed that the NLCs enhanced the permeation of SLM. Active processes are involved in the internalization of NLCs, as evidenced by cellular uptake studies. After preliminary toxicological studies, the formulation was studied in vivo in a streptozotocin (STZ)-induced diabetic mouse model in the presence of metabolic syndrome. The formulation was also compared to an NLC containing stearic acid:Capryol 90, to evaluate the effect of the lipid matrix on the in vivo performance of nanocarriers. Finally, hepatic histopathological analyses were also conducted. Both SLM-loaded NLCs exhibited in vivo a significant down-regulation of blood glucose and triglyceride levels better than free SLM, with a liver-protective effect. Furthermore, both formulations showed a significant anti-hyperalgesic effect on STZ-induced neuropathy.

Nanocarriers: A Successful Tool to Increase Solubility, Stability and Optimise Bioefficacy of Natural Constituents

Natural products are fascinating molecules in drug discovery for their exciting structure variability and also for their interaction with various targets. Drugs multi-targeting effect represents a more realistic approach to develop successful medications for many diseases. However, besides a large number of successful in vitro and in vivo studies, most of the clinical trials fail. This is generally related to the scarce water solubility, low lipophilicity and inappropriate molecular size of natural compounds, which undergo structural instability in biological milieu, rapid clearance and high metabolic rate. Additionally, some molecules are destroyed in gastric juice or suffer to a massive pre-systemic metabolism in the liver, when administered orally, limiting their clinical use. A reduced bioavailability can also be linked to drug distribution/accumulation in non-targeted tissues and organs that increase the side effects lowering the therapeutic efficacy and patient compliance. Nanomedicine represents a favourable tool to increase bioavailability and activities of natural products. Generally, nanovectors provide a large surface area and can overcome anatomic barriers. Each nanovector has its own advantages, disadvantages, and characteristics. In this review, different nanocarriers made of compounds which are Generally Recognized As Safe (GRAS) for the delivery of natural products, marketed as food supplements and medicines are reported.

Encapsulation of Essential Oils for the Development of Biosourced Pesticides with Controlled Release: A Review

Essential oil (EO) encapsulation can be carried out via a multitude of techniques, depending on applications. Because of EOs’ biological activities, the development of biosourced pesticides with EO encapsulation is of great interest. A lot of methods have been developed; they are presented in this review, together with the properties of the final products. Encapsulation conserves and protects EOs from outside aggression, but also allows for controlled release, which is useful for applications in agronomy. The focus is on the matrices that are of interest for the controlled release of their content, namely: alginate, chitosan, and cyclodextrin. Those three matrices are used with several methods in order to create EO encapsulation with different structures, capacities, and release profiles.

Development Insights of Surface Modified Lipid Nanoemulsions of Dihydroartemisinin for Malaria Chemotherapy: Characterization, and in vivo Antimalarial Evaluation

BACKGROUND

The use of dihydroartemisinin (DHA) for effective malaria treatment is challenged by its poor aqueous solubility and inadequate bioavailability leading to treatment failures and emergence of resistant strains. A review of some novel drug delivery systems developed to address these challenges and their patents revealed that no study has reported the application of surface modified lipid nanoemulsions for improved antimalarial activity of DHA.

OBJECTIVE

The main thrust of this study is to develop oral dihydroartemisinin formulations solubilized in surface modified lipid nanoemulsions, characterize, and evaluate their activity against murine malaria.

METHOD

Lipid nanoemulsions containing dihydroartemisinin were formulated by high pressure homogenization using soybean oil, and polyethylene glycol 4000 was employed for surface modification. The formulations were characterized for droplet size, surface charge, pH, fouriertransform infrared spectroscopy, and surface morphology, viscosity and drug content efficiency. In vitro haemolytic study as a function of cytotoxicity using red blood cells as well as in vivo anti-malarial study using murine malaria model was also investigated.

RESULTS

Nanoemulsions recorded droplet sizes ranging from 26 - 56 nm, and zeta potential in the range of -28 to -35 mV. The formulations were slightly acidic (pH 4.4 - 5.8) with the drug molecularly dispersed as seen using infrared spectroscopy. The formulations showed non- Newtonian flow with significant drug content efficiency in the range of 77-96%. The formulations did not induce haemolysis of cells and showed good clearance of parasitaemia.

CONCLUSION

Surface-modified lipid nanoemulsion is a perfect carrier system for improving the anti-malarial activity of dihydroartemisinin.

Pain Relieving Effect of-NSAIDs-CAIs Hybrid Molecules: Systemic and Intra-Articular Treatments against Rheumatoid Arthritis

To study new target-oriented molecules that are active against rheumatoid arthritis-dependent pain, new dual inhibitors incorporating both a carbonic anhydrase (CA)-binding moiety and a cyclooxygenase inhibitor (NSAID) were tested in a rat model of rheumatoid arthritis induced by CFA intra-articular (i.a.) injection. A comparison between a repeated per os treatment and a single i.a. injection was performed. CFA (50 µL) was injected in the tibiotarsal joint, and the effect of per os repeated treatment (1 mg kg⁻¹) or single i.a injection (1 mg mL⁻¹, 50 µL) with NSAIDs-CAIs hybrid molecules, named 4 and 5, was evaluated. The molecules 4 and 5, which were administered daily for 14 days, significantly prevented CFA-induced hypersensitivity to mechanical noxious (Paw pressure test) and non-noxious stimuli (von Frey test), the postural unbalance related to spontaneous pain (Incapacitance test) and motor alterations (Beam balance test). Moreover, to study a possible localized activity, 4 and 5 were formulated in liposomes (lipo 4 and lipo 5, both 1 mg mL⁻¹) and directly administered by a single i.a. injection seven days after CFA injection. Lipo 5 decreased the mechanical hypersensitivity to noxious and non-noxious stimuli and improved motor coordination. Oral and i.a. treatments did not rescue the joint, as shown by the histological analysis. This new class of potent molecules, which is able to inhibit at the same time CA and cyclooxygenase, shows high activity in a preclinical condition of rheumatoid arthritis, strongly suggesting a novel attractive pharmacodynamic profile.

Stable, Monodisperse, and Highly Cell-Permeating Nanocochleates from Natural Soy Lecithin Liposomes

(1) Background: Andrographolide (AN), the main diterpenoid constituent of Andrographis paniculata, has a wide spectrum of biological activities. The aim of this study was the development of nanocochleates (NCs) loaded with AN and based on phosphatidylserine (PS) or phosphatidylcholine (PC), cholesterol and calcium ions in order to overcome AN low water solubility, its instability under alkaline conditions and its rapid metabolism in the intestine. (2) Methods: The AN-loaded NCs (AN⁻NCs) were physically and chemically characterised. The in vitro gastrointestinal stability and biocompatibility of AN⁻NCs in J77A.1 macrophage and 3T3 fibroblasts cell lines were also investigated. Finally, the uptake of nanocarriers in macrophage cells was studied. (3) Results: AN⁻NCs obtained from PC nanoliposomes were suitable nanocarriers in terms of size and homogeneity. They had an extraordinary stability after lyophilisation without the use of lyoprotectants and after storage at room temperature. The encapsulation efficiency was 71%, while approximately 95% of AN was released in PBS after 24 h, with kinetics according to the Hixson⁻Crowell model. The in vitro gastrointestinal stability and safety of NCs, both in macrophages and 3T3 fibroblasts, were also assessed. Additionally, NCs had extraordinary uptake properties in macrophages. (4) Conclusions: NCs developed in this study could be suitable for both AN oral and parental administration, amplifying its therapeutic value.

Stealth and Cationic Nanoliposomes as Drug Delivery Systems to Increase Andrographolide BBB Permeability

(1) Background: Andrographolide (AG) is a natural compound effective for the treatment of inflammation-mediated neurodegenerative disorders. The aim of this investigation was the preparation of liposomes to enhance the penetration into the brain of AG, by modifying the surface of the liposomes by adding Tween 80 (LPs-AG) alone or in combination with Didecyldimethylammonium bromide (DDAB) (CLPs-AG). (2) Methods: LPs-AG and CLPs-AG were physically and chemically characterized. The ability of liposomes to increase the permeability of AG was evaluated by artificial membranes (PAMPA) and hCMEC/D3 cells. (3) Results: Based on obtained results in terms of size, homogeneity, ζ-potential and EE%. both liposomes are suitable for parenteral administration. The systems showed excellent stability during a month of storage as suspensions or freeze-dried products. Glucose resulted the best cryoprotectant agent. PAMPA and hCMEC/D3 transport studies revealed that LPs-AG and CLPs-AG increased the permeability of AG, about an order of magnitude, compared to free AG without alterations in cell viability. The caveolae-mediated endocytosis resulted the main mechanism of up-take for both formulations. The presence of positive charge increased the cellular internalization of nanoparticles. (4) Conclusions: This study shows that developed liposomes might be ideal candidates for brain delivery of AG.

Nanostructured Lipid Carriers as Promising Delivery Systems for Plant Extracts: The Case of Silymarin

Background: Silymarin is the extract from seeds of Silybum marianum L. Gaertn. and it has been used for decades as hepatoprotectant. Recently, it has been proposed to be beneficial in type 2 diabetes patients. However, silymarin is a poorly water soluble drug with limited oral bioavailability. In this study, nanostructured lipid carriers were proposed to enhance its solubility and intestinal absorption. Methods: Nanostructured lipid carriers were made of Stearic acid:Capryol 90 as lipid mixtures and Brij S20 as surfactant. Formulations were physically and chemically characterized. Stability and in vitro release studies were also assessed. In vitro permeability and Caco-2 cellular uptake mechanism were investigated. Results: Obtained results were based on size, homogeneity, ζ-potential and EE%. Nanostructured lipid carriers could be orally administered. No degradation phenomena were observed in simulated gastrointestinal fluids. Storage stability of suspensions and lyophilized products was also tested. Glucose was selected as best cryoprotectant agent. About 60% of silymarin was released in 24 h in phosphate buffered saline. In vitro parallel artificial membrane permeability assay experiments revealed that the nanocarrier enhanced the permeation of Silymarin. Caco-2 study performed with fluorescent nanoparticles revealed the ability of carrier to enhance the permeation of a lipophilic probe. Cellular uptake studies indicated that active process is involved in the internalization of the formulation. Conclusions: The optimized nanostructured lipid carriers showed excellent chemical and physical stability and enhanced the absorption of silymarin.

Nanoemulsion for improving solubility and permeability of Vitex agnus-castus extract: formulation and in vitro evaluation using PAMPA and Caco-2 approaches

The purpose of this study was to develop new formulation for an improved oral delivery of Vitex agnus-castus (VAC) extract. After the optimization and validation of analytical method for quali-quantitative characterization of extract, nanoemulsion (NE) was selected as lipid-based nanocarrier. The composition of extract-loaded NE resulted in triacetin as oil phase, labrasol as surfactant, cremophor EL as co-surfactant and water. NE contains until 60 mg/mL of extract. It was characterized by DLS and TEM analyses and its droplets appear dark with an average diameter of 11.82 ± 0.125 nm and a polydispersity index (PdI) of 0.117 ± 0.019. The aqueous solubility of the extract was improved about 10 times: the extract is completely soluble in the NE at the concentration of 60 mg/mL, while its solubility in water results less than 6 mg. The passive intestinal permeation was tested by using parallel artificial membrane permeation assay (PAMPA) and the permeation across Caco-2 cells after preliminary cytotoxicity studies were also evaluated. NE shows a good solubilizing effect of the constituents of the extract, compared with aqueous solution. The total amount of constituents permeated from NE to acceptor compartment is greater than that permeated from saturated aqueous solution. Caco-2 test confirmed PAMPA results and they revealed that NE was successful in increasing the permeation of VAC extract. This formulation could improve oral bioavailability of extract due to enhanced solubility and permeability of phytocomplex.

Artemisinin as an anticancer drug: Recent advances in target profiling and mechanisms of action

Artemisinin and its derivatives (collectively termed as artemisinins) are among the most important and effective antimalarial drugs, with proven safety and efficacy in clinical use. Beyond their antimalarial effects, artemisinins have also been shown to possess selective anticancer properties, demonstrating cytotoxic effects against a wide range of cancer types both in vitro and in vivo. These effects appear to be mediated by artemisinin-induced changes in multiple signaling pathways, interfering simultaneously with multiple hallmarks of cancer. Great strides have been taken to characterize these pathways and to reveal their anticancer mechanisms of action of artemisinin. Moreover, encouraging data have also been obtained from a limited number of clinical trials to support their anticancer property. However, there are several key gaps in knowledge that continue to serve as significant barriers to the repurposing of artemisinins as effective anticancer agents. This review focuses on important and emerging aspects of this field, highlighting breakthroughs in unresolved questions as well as novel techniques and approaches that have been taken in recent studies. We discuss the mechanism of artemisinin activation in cancer, novel and significant findings with regards to artemisinin target proteins and pathways, new understandings in artemisinin-induced cell death mechanisms, as well as the practical issues of repurposing artemisinin. We believe these will be important topics in realizing the potential of artemisinin and its derivatives as safe and potent anticancer agents.

Design of Drug Delivery Systems Containing Artemisinin and Its Derivatives

Artemisinin and its derivatives have been reported to be experimentally effective for the treatment of highly aggressive cancers without developing drug resistance, they are useful for the treatment of malaria, other protozoal infections and they exhibit antiviral activity. However, they are limited pharmacologically by their poor bioavailability, short half-life in vivo, poor water solubility and long term usage results in toxicity. They are also expensive for the treatment of malaria when compared to other antimalarials. In order to enhance their therapeutic efficacy, they are incorporated onto different drug delivery systems, thus yielding improved biological outcomes. This review article is focused on the currently synthesized derivatives of artemisinin and different delivery systems used for the incorporation of artemisinin and its derivatives.

Self-nanoemulsifying drug delivery systems (SNEDDS) for oral delivery of arteether: pharmacokinetics, toxicity and antimalarial activity in mice

The nontoxic SNEDDS of arteether, improved arteether bioavailability and anti-malarial efficacy.