Poly(D,L-lactic-co-glycolic acid)-based artesunate nanoparticles: formulation, antimalarial and toxicity assessments

Nanotechnology based drug delivery systems for malaria

Malaria, caused by Plasmodium parasites transmitted through Anopheles mosquitoes, remains a global health burden, particularly in tropical regions. The most lethal species, Plasmodium falciparum and Plasmodium vivax, pose significant threats to human health. Despite various treatment strategies, malaria continues to claim lives, with Africa being disproportionately affected. This review explores the advancements in drug delivery systems for malaria treatment, focusing on polymeric and lipid-based nanoparticles. Traditional antimalarial drugs, while effective, face challenges such as toxicity and poor bio-distribution. To overcome these issues, nanocarrier systems have been developed, aiming to enhance drug efficacy, control release, and minimize side effects. Polymeric nanocapsules, dendrimers, micelles, liposomes, lipid nanoparticles, niosomes, and exosomes loaded with antimalarial drugs are examined, providing a comprehensive overview of recent developments in nanotechnology for malaria treatment. The current state of antimalarial treatment, including combination therapies and prophylactic drugs, is discussed, with a focus on the World Health Organization's recommendations. The importance of nanocarriers in malaria management is underscored, highlighting their role in targeted drug delivery, controlled release, and improved pharmacological properties. This review bridges the gap in the literature, consolidating the latest advancements in nanocarrier systems for malaria treatment and offering insights into potential future developments in the field.

Development, characterization, and evaluation of withaferin-A and artesunate-loaded pH-responsive acetal-dextran polymeric nanoparticles for the management of malaria

Artemisinin and its derivatives have been commonly used to treat malaria. However, the emergence of resistance against artemisinin derivatives has posed a critical challenge in malaria management. In the present study, we have proposed a combinatorial approach, utilizing pH-responsive acetal-dextran nanoparticles (Ac-Dex NPs) as carriers for the delivery of withaferin-A (WS-3) and artesunate (Art) to improve treatment efficacy of malaria. The optimized WS-3 and Art Ac-Dex NPs demonstrated enhanced pH-responsive release profiles under parasitophorous mimetic conditions (pH 5.5). Computational molecular modeling reveals that Ac-Dex's polymeric backbone strongly interacts with merozoite surface protein-1 (MSP-1), preventing erythrocyte invasion. In-vitro antimalarial activity of drug-loaded Ac-Dex NPs reveals a 1-1.5-fold reduction in IC50 values compared to pure drug against the 3D7 strain of Plasmodium falciparum. Treatment with WS-3 Ac-Dex NPs (100 mg/kg) and Art Ac-Dex NPs (30 mg/kg) to Plasmodium berghei-infected mice resulted in 78.11 % and 100 % inhibition of parasitemia. Notably, the combination therapy comprised of Art and WS-3 Ac-Dex NPs achieved complete inhibition of parasitemia even at a half dose of Art, indicating the synergistic potential of the combinations. However, further investigations are necessary to confirm the safety and effectiveness of WS-3 and Art Ac-Dex NPs for their successful clinical implications.

Surfactant Mediated Accelerated and Discriminatory In Vitro Drug Release Method for PLGA Nanoparticles of Poorly Water-Soluble Drug

In vitro drug release testing is an important quality control tool for formulation development. However, the literature has evidence that poly-lactide-co-glycolide (PLGA)-based formulations show a slower in vitro drug release than a real in vivo drug release. Much longer in vitro drug release profiles may not be reflective of real in vivo performances and may significantly affect the timeline for a formulation development. The objective of this study was to develop a surfactant mediated accelerated in vitro drug release method for the PLGA nanoparticles (NPs) of a novel chemotherapeutic agent AC1LPSZG, a model drug with a poor solubility. The Sotax USP apparatus 4 was used to test in vitro drug release in a phosphate buffer with a pH value of 6.8. The sink conditions were improved using surfactants in the order of sodium lauryl sulfate (SLS) < Tween 80 < cetyltrimethylammonium bromide (CTAB). The dissolution efficiency (DE) and area under the dissolution curve (AUC) were increased three-fold when increasing the CTAB concentration in the phosphate buffer (pH 6.8). Similar Weibull release kinetics and good linear correlations (R2~0.99) indicated a good correlation between the real-time in vitro release profile in the phosphate buffer (pH 6.8) and accelerated release profiles in the optimized medium. This newly developed accelerated and discriminatory in vitro test can be used as a quality control tool to identify critical formulation and process parameters to ensure a batch-to-batch uniformity. It may also serve as a surrogate for bioequivalence studies if a predictive in vitro in vivo correlation (IVIVC) is obtained. The results of this study are limited to AC1LPSZG NPs, but a similar consideration can be extended to other PLGA-based NPs of drugs with similar properties and solubility profiles.

Review of the Current Landscape of the Potential of Nanotechnology for Future Malaria Diagnosis, Treatment, and Vaccination Strategies

Malaria eradication has for decades been on the global health agenda, but the causative agents of the disease, several species of the protist parasite Plasmodium, have evolved mechanisms to evade vaccine-induced immunity and to rapidly acquire resistance against all drugs entering clinical use. Because classical antimalarial approaches have consistently failed, new strategies must be explored. One of these is nanomedicine, the application of manipulation and fabrication technology in the range of molecular dimensions between 1 and 100 nm, to the development of new medical solutions. Here we review the current state of the art in malaria diagnosis, prevention, and therapy and how nanotechnology is already having an incipient impact in improving them. In the second half of this review, the next generation of antimalarial drugs currently in the clinical pipeline is presented, with a definition of these drugs' target product profiles and an assessment of the potential role of nanotechnology in their development. Opinions extracted from interviews with experts in the fields of nanomedicine, clinical malaria, and the economic landscape of the disease are included to offer a wider scope of the current requirements to win the fight against malaria and of how nanoscience can contribute to achieve them.

Chondroitin sulfate derived theranostic and therapeutic nanocarriers for tumor-targeted drug delivery

The standard chemotherapy is facing the challenges of lack of cancer selectivity and development of drug resistance. Currently, with the application of nanotechnology, the rationally designed nanocarriers of chondroitin sulfate (CS) have been fabricated and their unique features of low toxicity, biocompatibility, and active and passive targeting made them drug delivery vehicles of the choice for cancer therapy. The hydrophilic and anionic CS could be incorporated as a building block into- or decorated on the surface of nanoformulations. Micellar nanoparticles (NPs) self-assembled from amphiphilic CS-drug conjugates and CS-polymer conjugates, polyelectrolyte complexes (PECs) and nanogels of CS have been widely implicated in cancer directed therapy. The surface modulation of organic, inorganic, lipid and metallic NPs with CS promotes the receptor-mediated internalization of NPs to the tumor cells. The potential contribution of CS and CS-proteoglycans (CSPGs) in the pathogenesis of various cancer types, and CS nanocarriers in immunotherapy, radiotherapy, sonodynamic therapy (SDT) and photodynamic therapy (PDT) of cancer are summarized in this review paper.

Effects of Surface Characteristics of Polymeric Nanocapsules on the Pharmacokinetics and Efficacy of Antimalarial Quinine

INTRODUCTION

The surface charge of nanoparticles, such as nanospheres (NS) and nanocapsules (NC), has been studied with the purpose of improving the in vivo performance of drugs. The aim of this study was to develop, characterize, and evaluate the in vitro antimalarial efficacy of NCP80 and NSP80 (polysorbate coated) or NCEUD and NSEUD (prepared with Eudragit RS 100) loading quinine (QN).

METHODS

Formulations were prepared by the nanoprecipitation method, followed by wide physicochemical characterization. Antimalarial activity in Plasmodium berghei-infected mice and populational pharmacokinetics (PopPK) in rats were evaluated.

RESULTS

The formulations showed a nanometric range (between 138 ± 3.8 to 201 ± 23.0 nm), zeta potential (mV) of -33.1 ± 0.7 (NCP80), -30.5 ± 1 (UNCP80), -25.5 ± 1 (NSP80), -20 ± 0.3 (UNSP80), 4.61 ± 1 (NCEUD), 14.1 ± 0.9 (UNCEUD), 2.86 ± 0.3 (NSEUD) and 2.84 ± 0.6 (UNSEUD), content close to 100%, and good QN protection against UVA light. There was a twofold increase in the penetration of QN into infected erythrocytes with NC compared to that with NS. There was a significant increase in t1/2 for all NC evaluated compared to that of Free-QN, due to changes in Vdss. PopPK analysis showed that NCP80 acted as a covariate to Q (intercompartmental clearance) and V2 (volume of distribution in the peripheral compartment). For NCEUD, V1 and Q were modified after QN nanoencapsulation. Regarding in vivo efficacy, NCEUD increased the survival of mice unlike Free-QN.

CONCLUSION

Cationic nanocapsules modified the pharmacology of QN, presenting a potential alternative for malaria treatment.

A systematic review on anti-malarial drug discovery and antiplasmodial potential of green synthesis mediated metal nanoparticles: overview, challenges and future perspectives

BACKGROUND

The recent emergence in Southeast Asia of artemisinin resistance poses major threats to malaria control and elimination globally. Green nanotechnologies can constitute interesting tools for discovering anti-malarial medicines. This systematic review focused on the green synthesis of metal nanoparticles as potential source of new antiplasmodial drugs.

METHODS

Seven electronic database were used following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 17 papers were included in the systematic review. 82.4% of the studies used plant leaves to produce nanoparticles (NPs) while three studies used microorganisms, including bacteria and fungi. Silver was the main metal precursor for the synthesis of NPs. The majority of studies obtained nanoparticles spherical in shape, with sizes ranging between 4 and 65 nm, and reported no or little cytotoxic effect of the NPs. Results based on 50% inhibitory concentration (IC50) varied between studies but, in general, could be divided into three NP categories; (i) those more effective than positive controls, (ii) those more effective than corresponding plant extracts and, (iii) those less effective than the positive controls or plant extracts.

CONCLUSIONS

This study highlights the high antiplasmodial potential of green-synthesized metal nanoparticles thereby underscoring the possibility to find and develop new anti-malarial drugs based on green synthesis approaches. However, the review also highlights the need for extensive in vitro and in vivo studies to confirm their safety in humans and the elucidation of the mechanism of action.

Molluscicidal Activities of Curcumin-Nisin Polylactic Acid Nanoparticle (PLA) on Adult Snail Intermediate Hosts of Schistosomes and Fasciola spp

Digenetic trematode infections including schistosomiasis and fascioliasis have highly neglected statuses but are a menace to people in the poorest countries of the tropics, causing high morbidity and mortality in humans as well as great global losses in livestock production. This has neccesitated the widespread search for better control options for the snail vectors of these diseases. Hence, a novel drug - curcumin and nisin poly lactic acid (PLA) entrapped nanoparticles (CurNisNp) was screened for molluscicidal activity against the adults (> 2 months old) of Biomphalaria pfeifferi, Bulinus globosus and Lymnaea natalensis vector snails. Mortality was determined after 96-h of exposure at varying concentrations. The snails of the species L. natalensis were found to be the most susceptible to the molluscicide (LC50 323.6 ppm). This finding further supports the desirability of curcumin-nisin polylactic acid (PLA) nanoparticles as a molluscicide and therefore shows that it could be a good alternative to conventional molluscicides with prospects in the selective control of fascioliasis. However, more optimization of the drug could ensure a greater molluscicidal potency.

Coating Dependent In Vitro Biocompatibility of New Fe-Si Nanoparticles

Magnetic nanoparticles offer multiple utilization possibilities in biomedicine. In this context, the interaction with cellular structures and their biological effects need to be understood and controlled for clinical safety. New magnetic nanoparticles containing metallic/carbidic iron and elemental silicon phases were synthesized by laser pyrolysis using Fe(CO)₅ vapors and SiH₄ gas as Fe and Si precursors, then passivated and coated with biocompatible agents, such as l-3,4-dihydroxyphenylalanine (l-DOPA) and sodium carboxymethyl cellulose (CMC-Na). The resulting magnetic nanoparticles were characterized by XRD, EDS, and TEM techniques. To evaluate their biocompatibility, doses ranging from 0⁻200 µg/mL hybrid Fe-Si nanoparticles were exposed to Caco2 cells for 24 and 72 h. Doses below 50 μg/mL of both l-DOPA and CMC-Na-coated Fe-Si nanoparticles induced no significant changes of cellular viability or membrane integrity. The cellular internalization of nanoparticles was dependent on their dispersion in culture medium and caused some changes of F-actin filaments organization after 72 h. However, reactive oxygen species were generated after exposure to 25 and 50 μg/mL of both Fe-Si nanoparticles types, inducing the increase of intracellular glutathione level and activation of transcription factor Nrf2. At nanoparticles doses below 50 μg/mL, Caco2 cells were able to counteract the oxidative stress by activating the cellular protection mechanisms. We concluded that in vitro biological responses to coated hybrid Fe-Si nanoparticles depended on particle synthesis conditions, surface coating, doses and incubation time.

Curcumin-Artesunate Based Polymeric Nanoparticle; Antiplasmodial and Toxicological Evaluation in Murine Model

Mainstay chemotherapy for malaria is often faced with the problem of instability and poor bio-distribution thus resulting in impaired pharmacokinetics. Nanomedicine has been acclaimed for its success in drug delivery and improved efficacy. The aim of the study was to assess the antiplasmodial efficacy and safety of curcumin-artesunate co-entrapped nanoparticle in mice model. Curcumin (C) and artesunate (A) were loaded in poly (d,l-lactic-co-glycolic acid) (PLGA) using solvent evaporation from oil-in-water single emulsion method. The nanoparticle formed was characterized for size, polydispersity index (PDI), zeta potential, and entrapment efficiency. The in vitro release of the drug was also determined. The in vivo antiplasmodial activity of CA-PLGA nanoparticle was tested on Plasmodium berghei at 5 and 10 mg/kg doses. The drug efficacy was determined at day 5 and 8. Hematological and hepatic toxicity assays were performed. The mean particle size of drug entrapped PLGA-nanoformulation was 251.1 ± 12.6 nm. The drug entrapment efficiency was 22.3 ± 0.4%. There was a sustained drug release from PLGA for 7 days. The percentage suppression of P. berghei was consistently significantly higher in CA-PLGA 5 mg/kg at day 5 (79.0%) and day 8 (72.5%) than the corresponding values 65.3 and 64.2% in the positive control group (p < 0.05). Aspartate aminotransferase (AST) was significantly lower in mice exposed to 5 mg/kg (42.0 ± 0.0 U/L) and 10 mg/kg (39.5 ± 3.5 U/L) nanotized CA-PLGA compared with the negative control (45.0 ± 4.0 U/L) (p < 0.05). Although alanine aminotransferase (ALT) was lower in nanotized CA-PLGA, the variation was not significant compared with the negative control (p > 0.05). No significant difference in the mean values of the different blood parameters in all exposed groups with the exception of platelets which were significantly higher in the positive control group. A simple method of dual entrapment of curcumin and artesunate with better antiplasmodial efficacy and low toxicity has been synthesized.

Intestinal Permeability of Artesunate-Loaded Solid Lipid Nanoparticles Using the Everted Gut Method

Background

Artesunate is one of the most potent, rapidly acting and therapeutically versatile antimalarial drugs. Its efficacy is hampered by poor aqueous solubility and stability resulting in low oral bioavailability. Recent efforts to nanoformulate artesunate have shown great potential of improving its dissolution profile and bioavailability. However, no study has yet been done to investigate the intestinal permeability of these nanoformulations, which is a critical determinant of systemic absorption.

Objective of the Study

The main aim of the study was to determine the intestinal permeability of artesunate-loaded solid lipid nanoparticles (SLN).

Method

The microemulsion dilution technique was used to fabricate artesunate-loaded solid lipid nanoparticles. In vitro drug release studies were performed at pH 1.2 and 6.8 using the dialysis membrane method. The everted gut sac method was used to assess the intestinal permeability of the prepared nanoparticles.

Results

The average particle size was 1109 nm and the polydispersity index (PDI) was 0.082. The zeta potential was found to be -20.7 mV. The encapsulation efficiency of the solid lipid nanoparticles obtained was 51.7%. At both pH 1.2 and 6.8, pure artesunate was rapidly released within the first 30 mins while the SLN showed a biphasic release pattern with an initial burst release during the first hour followed by a prolonged release over time. The rate of drug release increased with increasing pH. The apparent permeability (P_app) of SLN was found to be greater (0.169 mg/cm²) as compared to that of pure artesunate (0.117 mg/cm²) at the end of the experiment.

Conclusion

The results obtained in this study showed that the microemulsion dilution technique can be used to formulate artesunate solid lipid nanoparticles. The formulation exhibited a sustained drug release profile. The intestinal permeability of artesunate could be enhanced by the nanoformulation.

Molluscicidal activities of curcumin-nisin polylactic acid nanoparticle on Biomphalaria pfeifferi

BACKGROUND

Snail intermediate host control is a widely canvassed strategy for schistosomiasis control in endemic countries. While there have been increasing studies on the search for potent molluscicides in the past years, the use of nanoparticulate agents as molluscicides is yet to gain wide attention. The aim of this study was to assess the molluscicidal potential of curcumin-nisin poly lactic acid (PLA) entrapped nanoparticle (CurNisNp) against Biomphalaria pfeifferi, a snail intermediate host for Schistosoma mansoni.

METHODOLOGY/PRINCIPAL FINDINGS

CurNisNp formulated by double emulsion method was tested against the young adults, < 1 week, 1-2-week old juveniles, 1 day (blastula) and 7 day-old (hippo-stage) egg masses of B. pfeifferi. Mortality in the different stages was determined after 96-h of exposure at varying concentrations (350, 175, 87.5, 43.75 and 21.88 ppm). The sub-lethal effects of CurNisNp on the hatchability of the 7-day-old egg masses and egg laying capacity of the young adult snails were determined. The CurNisNp diameter, polydispersity index (PDI), zeta potential and drug entrapment efficiency were 284.0 ± 17.9 nm, 0.166 ± 0.03, -16.6 ± 2.45 mV and 35.0% respectively. The < 1 week old juveniles and the 1-day-old egg stage (blastula) of B. pfeifferi with LC50 277.9 ppm and 4279.5 ppm were the most susceptible and resistant stages to the drug respectively. CurNisNp was also observed to cause significant reductions (P<0.05) in egg hatchability and egg laying capacity with strong negative correlation between egg laying capacity and concentration (r = -0.928; P<0.05).

CONCLUSION/SIGNIFICANCE

This study showed that CurNisNp has molluscicidal activities on different developmental stages of B. pfeifferi. It is therefore recommended that the formulation be more optimised to give a nanoparticle with a narrow range monodispersed PDI for better drug distribution and eventual greater molluscicidal activities.