Pharmacokinetic study of intravenously administered artemisinin-loaded surface-decorated amphiphilic γ-cyclodextrin nanoparticles

Artemisinin and deoxyartemisinin isolated from Artemisia annua L. promote distinct antinociceptive and anti-inflammatory effects in an animal model

Artemisia annua L., known for antimalarial activity, has demonstrated evidence of anti-inflammatory potential. Previously our research group reported the anti-inflammatory and antinociceptive effect of a sesquiterpene lactone-enriched fraction (Lac-FR) obtained from plant, containing artemisinin and deoxyartemisinin. Both the isolated compounds and Lac-FR evaluated on experimental animal models, in the formalin test showed that deoxyartemisinin reduced both neurogenic pain (56.55 %) and inflammatory pain (45.43 %). These findings were superior to the effect of artemisinin (reduction of 28.66 % and 33.35 %, respectively). In the tail flick test, the antinociceptive effect reported as a percentage of the maximum possible effect (%MPE), deoxyartemisinin showed a lower antinociceptive effect (41.57 %) compared to morphine (75.94 %) in 0.5 h. After 1.5 h, the MPE of deoxyartemisinin (87.99 %) exceeded the effect of morphine (47.55 %), without reversal with naloxone. The MPE of artemisinin (23.3 %) observed after 2 h was lower than deoxiartemisinin, without reversal with the opioid antagonist. Lac-FR and artemisinin demonstrated reductions in ear edema of 43.37 % and 48.19 %, respectively, higher than the effect of deoxyartemisinin (33.64 %). Artemisinin reduced tumor necrosis factor alpha (TNF-α) (76.96 %) more selectively when compared to interleukin-1beta (IL-1β) (48.23 %) and interleukin-6 (IL-6) (44.49 %). Lac-FR showed greater selectivity in IL-6 reduction (56.49 %) in relationship to TNF-α (46.71 %) and IL-1β (45.12 %), whereas deoxyartemisinin selectively reduced TNF-α (37.37 %). The results of our study indicate that the lactones isolated did not have relationship with the opioid system. Deoxyartemisinin showed a higher antinociceptive potential than artemisinin. Whereas, artemisinin showed a higher reduction of inflammation and mediators, with a better anti-inflammatory activity outcome.

Plant-based nanoparticles targeting malaria management

Malaria is one of the most devastating diseases across the globe, particularly in low-income countries in Sub-Saharan Africa. The increasing incidence of malaria morbidity is mainly due to the shortcomings of preventative measures such as the lack of vaccines and inappropriate control over the parasite vector. Additionally, high mortality rates arise from therapeutic failures due to poor patient adherence and drug resistance development. Although the causative pathogen (Plasmodium spp.) is an intracellular parasite, the recommended antimalarial drugs show large volumes of distribution and low-to no-specificity towards the host cell. This leads to severe side effects that hamper patient compliance and promote the emergence of drug-resistant strains. Recent research efforts are promising to enable the discovery of new antimalarial agents; however, the lack of efficient means to achieve targeted delivery remains a concern, given the risk of further resistance development. New strategies based on green nanotechnologies are a promising avenue for malaria management due to their potential to eliminate malaria vectors (Anopheles sp.) and to encapsulate existing and emerging antimalarial agents and deliver them to different target sites. In this review we summarized studies on the use of plant-derived nanoparticles as cost-effective preventative measures against malaria parasites, starting from the vector stage. We also reviewed plant-based nanoengineering strategies to target malaria parasites, and further discussed the site-specific delivery of natural products using ligand-decorated nanoparticles that act through receptors on the host cells or malaria parasites. The exploration of traditionally established plant medicines, surface-engineered nanoparticles and the molecular targets of parasite/host cells may provide valuable insights for future discovery of antimalarial drugs and open new avenues for advancing science toward the goal of malaria eradication.

Green synthesis and characterization of an orally bioactive artemisinin-zinc nanoparticle with enhanced bactericidal activity

The occurrence of multidrug-resistant bacteria necessitates the development of new antibacterial agents. This study synthesized artemisinin-zinc nanoparticles (AZ NPs) using a simple green method and investigated their physicochemical properties, antibacterial activity, and oral biological activity. A spherical shape morphology of AZ NPs was observed by scanning and transmission electron microscopy, with a particle size of 73 ± 2.604 nm. Energy dispersive spectrometry analysis showed that the AZ NPs consisted mainly of Zn, C, N, and O elements. According to differential scanning calorimeter analysis, the AZ NPs were stable up to 450 °C. Fourier-transform infrared spectroscopy revealed that artemisinin successfully bound to zinc acetate. The AZ NPs showed antibacterial activity against Salmonella and Escherichia coli, with a minimum inhibitory concentration of 0.056 mg/mL for both and minimum bactericidal concentrations of 0.21 and 0.11 mg/mL, respectively. The mechanisms by which AZ NPs mediate membrane damage were revealed by the downregulation of gene expression, and potassium ion and protein leakage. In vivo safety trials of these drugs revealed low toxicity. After AZ NPs were administered to infected mice, the intestinal bacteria decreased significantly, liver and kidney function were restored, histopathological damage to the liver and spleen were reduced, and the expression of inflammatory cytokines decreased. Therefore, AZ NPs have the potential as an oral antibacterial agent and can be used in antibiotic development and in the pharmaceutical industry.

Evaluation of Pharmacokinetics, Biodistribution, and Antimalarial Efficacy of Artemether-Loaded Polymeric Nanorods

Artemether oily injection is recommended for the treatment of severe malaria by the intramuscular route. The major limitations of the artemisinin combination therapy are erratic absorption from the injection site and high dosing frequency due to a very short elimination half-life of the drug. Advanced drug delivery systems have shown significant improvement in the current malaria therapy; the desired drug concentration within infected erythrocytes is yet the major challenge. Recently, we have reported the fabrication of artemether-loaded polymeric nanorods for intravenous malaria therapy which was found to be biocompatible with THP-1 monocytes and rat erythrocytes. The objective of the present study was the evaluation of pharmacokinetics, biodistribution, and antimalarial efficacy of artemether-loaded polymeric nanorods. Scanning electron microscopy and confocal microscopy studies revealed that both nanospheres and nanorods were adsorbed onto the surface of rat erythrocytes after an incubation of 10 min. After intravenous administration to rats, artemether nanorods showed higher plasma concentration and lower elimination rate of artemether when compared with nanospheres. The biodistribution studies showed that, at 30 min, the liver concentration of DiR-loaded nanospheres was higher than that of DiR-loaded nanorods after intravenous administration to BALB/c mice. The in vitro schizont inhibition study showed that both nanorods and nanospheres exhibited concentration-dependent parasitic inhibition, wherein at lower concentrations (2 ppm), nanorods were more effective than nanospheres. However, at higher concentrations, nanospheres were found to be more effective. Nanorods showed higher chemosuppression on day 5 and day 7 than nanospheres and free artemether when studied with the Plasmodium berghei mouse model. Moreover, the survival rate of P. berghei infected mice was also found to be higher after treatment with artemether nanoformulations when compared with free artemether. In conclusion, polymeric nanorods could be a promising next-generation delivery system for the treatment of malaria.

Potential of nanoformulations in malaria treatment

Malaria is caused by the protozoan Plasmodium sp and affects millions of people worldwide. Its clinical form ranges from asymptomatic to potentially fatal and severe. Current treatments include single drugs such as chloroquine, lumefantrine, primaquine, or in combination with artemisinin or its derivatives. Resistance to antimalarial drugs has increased; therefore, there is an urgent need to diversify therapeutic approaches. The disease cycle is influenced by biological, social, and anthropological factors. This longevity and complexity contributes to the records of drug resistance, where further studies and proposals for new therapeutic formulations are needed for successful treatment of malaria. Nanotechnology is promising for drug development. Preclinical formulations with antimalarial agents have shown positive results, but only a few have progressed to clinical phase. Therefore, studies focusing on the development and evaluation of antimalarial formulations should be encouraged because of their enormous therapeutic potential.

Artemisinin hydroxypropyl-β-cyclodextrin inclusion complex loaded with porous starch for enhanced bioavailability

The current work aimed to enhance the oral bioavailability of water-insoluble drug Artemisinin (ART) by the inclusion of ART with hydroxypropyl-β-cyclodextrin (HP-β-CD) and then loaded with porous starch (PS). The preparation conditions of ART HP-β-CD inclusion complex loaded with PS (AHPS) were optimized according to drug loading (DL) and entrapment efficiency (EE). The properties of AHPS were characterized by optical and thermodynamic methods. ART was linked by hydrogen bond to HP-β-CD to form hydrophilic supramolecules, which are loaded into PS under the action of hydrogen bond. The maximum DL and EE of AHPS were about 16.51% and 67.26%, respectively. Then we investigated the physicochemical properties and antimalarial activity of AHPS. The solubility and bioavailability of AHPS at 48 h were higher than ART and market ART piperaquine tablets (APT), and showed better antimalarial activity in vitro and vivo. It provides a new idea for the development and application of fat-soluble drug.

Recent advances in targeting malaria with nanotechnology-based drug carriers

Malaria, as one of the most common human infectious diseases, remains the greatest global health concern, since approximately 3.5 billion people around the world, especially those in subtropical areas, are at the risk of being infected by malaria. Due to the emergence and spread of drug resistance to the current antimalarials, malaria-related mortality and incidence rates have recently increased. To overcome the aforementioned obstacles, nano-vehicles based on biodegradable, natural, and non-toxic polymers have been developed. Accordingly, these systems are considered as a potential drug vehicle, which due to their unique properties such as the excellent safety profile, good biocompatibility, tunable structure, diversity, and the presence of functional groups within the polymer structure, could facilitate covalent attachment of targeting moieties and antimalarials to the polymeric nano-vehicles. In this review, we highlighted some recent developments of liposomes as unique nanoscale drug delivery vehicles and several polymeric nanovehicles, including hydrogels, dendrimers, self-assembled micelles, and polymer-drug conjugates for the effective delivery of antimalarials.

Fabrication and evaluation of artemether loaded polymeric nanorods obtained by mechanical stretching of nanospheres

The objective of the present study was to prepare and evaluate artemether-loaded poly (lactic-co-glycolic acid) (PLGA) nanorods by mechanical stretching of nanospheres. Artemether-loaded PLGA nanospheres were prepared by the standard nanoprecipitation method. To prepare the nanorods, nanospheres (129 nm) were embedded in polyvinyl alcohol film. The film was stretched by using an in-house fabricated film stretching apparatus in one dimension at the rate of 10 mm/min in acetone or silicon oil. Nanorods were recovered by dissolving the film in Milli-Q-water after stretching. The effect of film thickness (100 µm vs 150 µm), the ratio of lactide to glycolide in PLGA (50:50 vs 75:25), extent of stretching (2x vs 4x), on the aspect ratio of the nanorods was studied. A sustained release of artemether was observed from both nanospheres and nanorods with almost 85% drug release at the end of 72 h. In cytotoxicity study, almost 90% cell viability was found when THP-1 cells were treated with artemether, nanospheres, and nanorods equivalent to 0.001 to 100 µg/mL of artemether. At all the concentrations of artemether, nanorods showed less haemolysis of RBCs than the nanospheres. Artemether-loaded PLGA nanorods could be successfully prepared by the film stretching method for intravenous delivery of antimalarial drugs.

Technological evolution of cyclodextrins in the pharmaceutical field

We herein disclose how global cyclodextrin-based pharmaceutical technologies have evolved since the early 80s through a 1998 patents dataset retrieved from Derwent Innovation Index. We used text-mining techniques based on the patents semantic content to extract the knowledge contained therein, to analyze technologies related to the principal attributes of CDs: solubility, stability, and taste-masking enhancement. The majority of CDs pharmaceutical technologies are directed toward parenteral aqueous solutions. The development of oral and ocular formulations is rapidly growing, while technologies for nasal and pulmonary routes are emerging and seem to be promising. Formulations for topical, transdermal, vaginal, and rectal routes do not account for a high number of patents, but they may be hiding a great potential, representing opportunity research areas. Certainly, the progress in materials sciences, supramolecular chemistry, and nanotechnology, will influence the trend of that, apparently neglected, research. The bottom line, CDs pharmaceutical technologies are still increasing, and this trend is expected to continue in the coming years.

Patent monitoring allows the identification of relevant technologies and trends to prioritize research, development, and investment in both, academia and industry. We expect the scope of this approach to be applied in the pharmaceutical field beyond CDs technological applications.

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).

Biocompatible Polymers Combined with Cyclodextrins: Fascinating Materials for Drug Delivery Applications

Cyclodextrins (CD) are a group of cyclic oligosaccharides with a cavity/specific structure that enables to form inclusion complexes (IC) with a variety of molecules through non-covalent host-guest interactions. By an elegant combination of CD with biocompatible, synthetic and natural polymers, different types of universal drug delivery systems with dynamic/reversible properties have been generated. This review presents the design of nano- and micro-carriers, hydrogels, and fibres based on the polymer/CD supramolecular systems highlighting their possible biomedical applications. Application of the most prominent hydrophobic aliphatic polyesters that exhibit biodegradability, represented by polylactide and polycaprolactone, is described first. Subsequently, particular attention is focused on materials obtained from hydrophilic polyethylene oxide. Moreover, examples are also presented for grafting of CD on polysaccharides. In summary, we show the application of host-guest interactions in multi-component functional biomaterials for controlled drug delivery.