A novel chitosan based antimalarial drug delivery against Plasmodium berghei infection

The efficacy of cercarial antigen loaded on nanoparticles as a potential vaccine candidate in Schistosoma mansoni-infected mice

Schistosomiasis is one of the most common causes of morbidity and mortality from parasitic diseases. Mass treatment has proven to be insufficient because of repeated infection after treatment and the appearance of strains resistant to drug therapy. Hence, immunization is a new approach to control the disease and limit the pathological consequences of schistosomiasis. To evaluate the prophylactic effect of Cercarial antigen (CAP) loaded on chitosan nanoparticles (CSNPs) as a potential vaccine against Schistosoma mansoni-infected mice. 130 mice divided into 2 groups were used: Group I: Control groups (50 mice) subdivided into subgroup Ia (10 mice): Non-infected mice (normal control), subgroup Ib (20 mice): Schistosoma infected mice (infected control) and subgroup Ic (20 mice): Non-infected mice receiving NPs only. Group II: Vaccinated group (80 mice) subdivided equally into subgroup IIa (CAP): Received cercarial antigen and subgroup IIb (CAP + CSNP): Received cercarial antigen loaded on chitosan NPs then both vaccinated groups were infected with S. mansoni 3 weeks following the initial vaccination dose. CAP + CSNP and CAP groups showed significant reduction in adult worms count, hepatic egg count, hepatic granulomas number and size in comparison to the infected control group. Elevation of serum IgG and IgM levels, CD4+ and CD8+ T cell frequencies, IL-4, IL-10 and INF-γ levels was more significant in CAP + CSNP group than CAP group. CAP + CSNP is a promising new preparation of Schistosomal antigens that gave better results than immunization with CAP alone. CSNPs enhanced the immune and protective effect of CAP as validated by parasitological, histopathological and immunohistochemical studies.

Antiplasmodial Effect of Nano Dendrimer G2 Loaded with Chloroquine in Mice Infected with Plasmodium berghei

BACKGROUND

Malaria is a parasitic lethal disease caused by Plasmodium protozoa. The resistance and drugs' side effects have led to numerous researches for alternative suitable drugs with better efficiency and lower toxicity PURPOSE: In the present study, we investigated in vivo antimalarial effects of G2 linear dendrimer-based nano-chloroquine.

METHODS

After the preparation of nano dendrimer G2, chloroquine loading was done. Determine the characterization of particles were specified by DLS, SLS and SEM. The LC-MS and FTIR were used for verifying the nano dendrimer G2 and the loading of chloroquine into the compound. The Solubility N-chloroquine and measurement of drug release rate were done. Antiplasmodial activity of N-chloroquine on BALB/c mice was performed by the microscope and enzymatic methods. At the end, In vivo toxicity of N-chloroquine on tissues was assayed. The RBC morphology and enzyme levels were identified.

RESULTS

The results showed the synthesized N-chloroquine had suitable size and solubility. Highest inhibitory effect on Plasmodium parasitic growth was observed at 16 mg/kg dose of N-chloroquine, which eliminated 95% of the parasites (p > 0.05). ED₅₀ is observed at 7.7 mg/kg of N-chloroquine dose. Biochemical findings showed the synthesized N-chloroquine was safer than chloroquine. The N-chloroquine no adverse effects were observed in examined tissues.

CONCLUSION

Due to the better effect of the synthesized N-chloroquine on Plasmodium berghei in mice compared to chloroquine, this nanoparticle can be considered as an effective anti-plasmodium compound while more comprehensive research is recommended.

Interaction between Chitosan and Chloroquine against Plasmodium berghei and P. falciparum Using In-Vivo and In-Vitro Tests

Background:

The use of antimalarial drugs with number of compounds in combination form may potentiate each other’s activity.

Methods:

This study was conducted in the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran in 2018. It was based on two methods including in vivo and in vitro tests with aim of considering interaction between chitosan and chloroquine against Plasmodium berghei and P. falciparum parasites using different ratios of the agents with ED50^s and IC50^s baselines.

Results:

Administrating 10 and 20 mg/kg (mouse body weight) of chitosan alone to the P. berghei –infected mice up to 4 successive days resulted in 37% and 45% inhibition of P. berghei respectively, while employing the compound with chloroquine in combination form with ratios of 90/10 and 70/30 (chloroquine/chitosan) had a considerable potentiation including 71.58% and 83.85% inhibition effectiveness against P. berghei. Moreover, 20 mg/L (CCM) concentration of chitosan alone could eliminate 69.55% of P. falciparum in culture medium while in combination with chloroquine in ratios of 90/10 (chloroquine/chitosan) had considerable potentiation including 79.14% inhibition effectiveness. Mean survival time of those mice received combination therapy in ratios of 90/10 and 70/30 (chloroquine/chitosan) was longer than those took up mono therapy of either chloroquine or chitosan based on their ED50^s doses.

Conclusion:

Interaction between chloroquine and chitosan showed considerable potentiation in combination form against either P. berghei or P. falciparum using in vivo and in vitro tests respectively. Meanwhile, interaction between the above mentioned agents resulted in a notable survival time for those P. berghei-infected mice treated with the combination.

Intranasal immunization with chitosan microparticles enhances lack-dna vaccine protection and induces specific long-lasting immunity against visceral leishmaniasis

Development of a protective vaccine against Leishmania depends on antigen formulation and adjuvants that induce specific immunity and long-lasting immune responses. We previously demonstrated that BALB/c mice intranasally vaccinated with a plasmid DNA encoding the p36/LACK leishmanial antigen (LACK-DNA) develop a protective immunity for up to 3 months after vaccination, which was linked with the systemic expression of vaccine mRNA in peripheral organs. In this study, LACK-DNA vaccine was associated with biocompatible chitosan microparticles cross-linked with glyceraldehyde (CMC) to boost the long-lasting immunity against the late L. infantum challenge. Infection at 7 days, 3 or 6 months after vaccination resulted in significantly lower parasite loads when compared with non-vaccinated controls. Besides, LACK-DNA-chitosan vaccinated mice showed long-time protection observed after the late time point challenge. The achieved protection was correlated with an enhanced spleen cell responsiveness to parasite antigens, marked by increased proliferation and IFN-γ as well as decreased IL-10 production. Moreover, we found diminished systemic levels of TNF-α that was compatible with the better health condition observed in LACK-DNA/CMC vaccinated-infected mice. Together, our data indicate the feasibility of chitosan microparticles as a delivery system tool to extend the protective immunity conferred by LACK-DNA vaccine, which may be explored in vaccine formulations against Leishmania parasite infections.

In Vitro Antiprotozoal Effects of Nano-chitosan on Plasmodium falciparum, Giardia lamblia and Trichomonas vaginalis

BACKGROUND

Treatment of parasitic infections with conventional drugs is associated with high toxicity, and undesirable side effects require cogent substitutions. Nanotechnology has provided novel approaches to synthesize nano-drugs to improve efficient antipathetic treatment.

PURPOSE

Nano-chitosan as a nontoxic antimicrobial agent was examined against three most prevalent protozoa in humans, Plasmodium falciparum, Giardia lamblia and Trichomonas vaginalis.

METHODS

Chitosan extracted from Penicillium fungi was converted to nanoparticles to maximize its therapeutic properties. Safety of nano-chitosan was examined by determining its hemolytic property and toxicity on PC12 cells. The studied parasites were identified with RFLP-PCR and cultivation in relevant media. Characteristics of nano-chitosan as an useful and valuable curative compound was evaluated by FTIR, DLS and SEM. Dose dependent anti-parasitic effect of nano-chitosan was evaluated.

RESULTS

The highest anti-parasitic activity of the nano-chitosan was observed at 50 μg/mL by which growth rates of cultivated P. falciparum, T. vaginalis and G. lamblia were inhibited by 59.5%, 99.4%, and 31.3%, respectively. The study demonstrated that nano-chitosan with the least toxicity, low side effects, and substantial efficacy deserved to be considered as an anti-parasitic nano-compound.

CONCLUSION

Nano-chitosan significantly inhibited protozoan growth in vitro promising to explore its use to combat parasitic infections. Further investigations covering extended sample size, in vivo experiments and optimizing the concentration used may lead to efficient treatment of protozoan diseases.

Nanomedicine Reformulation of Chloroquine and Hydroxychloroquine

The chloroquine family of antimalarials has a long history of use, spanning many decades. Despite this extensive clinical experience, novel applications, including use in autoimmune disorders, infectious disease, and cancer, have only recently been identified. While short term use of chloroquine or hydroxychloroquine is safe at traditional therapeutic doses in patients without predisposing conditions, administration of higher doses and for longer durations are associated with toxicity, including retinotoxicity. Additional liabilities of these medications include pharmacokinetic profiles that require extended dosing to achieve therapeutic tissue concentrations. To improve chloroquine therapy, researchers have turned toward nanomedicine reformulation of chloroquine and hydroxychloroquine to increase exposure of target tissues relative to off-target tissues, thereby improving the therapeutic index. This review highlights these reformulation efforts to date, identifying issues in experimental designs leading to ambiguity regarding the nanoformulation improvements and lack of thorough pharmacokinetics and safety evaluation. Gaps in our current understanding of these formulations, as well as recommendations for future formulation efforts, are presented.

Highlighting the impact of chitosan on the development of gastroretentive drug delivery systems

The development of gastroretentive systems have been growing lately due to the high demand for carriers that increase drug bioavailability and therapeutic effectiveness after oral administration. Most of systems reported up to now are based on chitosan (CS) due to its peculiar properties, such as cationic nature, biodegradability, biocompatibility and important mucoadhesiveness, which make CS a promising biopolymer to design effective gastroretentive systems. In light of this, we reported in this review the CS versatility to fabricate different types of nano- and microstructured gastroretentive systems. For a better understanding of the gastric retention mechanisms, we highlighted expandable, density-based, magnetic, mucoadhesive and superporous systems. The biological and chemical properties of CS, anatomophysiological aspects related to gastrointestinal tract (GIT) and some applications of these systems are also described here. Overall, this review may assist researchers to explore new strategies to design safe and efficient gastroretentive systems in order to popularize them in the treatment of diseases and clinical practices.

Promising In Vitro Anti-Toxoplasma gondii Effects of Commercial Chitosan

CDATA[Background: Toxoplasmosis is a disease that results from infection with an obligate intracellular T. gondii parasite, one of the world's most common parasites. Considering the complications of chemical drugs and the need for an appropriate drug combination for treatment of toxoplasmosis and considering the antimicrobial potential of chitosan, as a natural source, this study was aimed to evaluate in vitro activity of commercial chitosan (CC) on T. gondii.

METHODS

In this experimental study, the tachyzoites of T. gondii were collected from the peritoneal exudates from infected Balb/c mice. The tachyzoites were diluted in phosphate buffer saline (PBS) solution. Chitosan with low molecular weight was commercially purchased. Then, at concentrations of 10, 50, 100, and 200 μg/mL and after 30, 60, 120, and 180 minutes, the viability of tachyzoites was determined by using trypan blue 0.1%. Anti-T.gondii activity of CC in all concentrations was significantly higher than pyrimethamine as the control group (P=0.05).

RESULTS

The concentration of 200 μg/mL of CC had the highest effects and killed 30.5, 52, 59, and 81.5% of tachyzoites after 30, 60, 120, and 180 minutes. Moreover, IC50 values of CC were 515, 171, 12.5, and <10 μg/mL in comparison with pyrimethamine as 58.82 μg/mL for 30, 60, 120, and 180 min of exposure time.

CONCLUSION

Our results indicate that chitosan in low molecular weight had potent activity against T. gondii tachyzoites and could be an appropriate candidate for the treatment of at least acute toxoplasmosis, certainly, after complementary in vivo experiments.

Nanoparticles for antiparasitic drug delivery

As an emerging novel drug carrier, nanoparticles provide a promising way for effective treatment of parasitic diseases by overcoming the shortcomings of low bioavailability, poor cellular permeability, nonspecific distribution and rapid elimination of antiparasitic drugs from the body. In recent years, some kinds of ideal nanocarriers have been developed for antiparasitic drug delivery. In this review, the progress of the enhanced antiparasitic effects of different nanoparticles payload and their influencing factors were firstly summarized. Secondly, the transport and disposition process in the body were reviewed. Finally, the challenges and prospects of nanoparticles for antiparasitic drug delivery were proposed. This review will help scholars to understand the development trend of nanoparticles in the treatment of parasitic diseases and explore strategies in the development of more efficient nanocarriers to overcome the difficulty in the treatment of parasite infections in the future.

A new effective antiplasmodial compound: Nanoformulated pyrimethamine

OBJECTIVES

The aim of this study was to evaluate the efficacy of pyrimethamine-loaded poloxamer 407 nanomicelles on Plasmodium berghei strain NICD in vivo.

METHODS

Pyrimethamine-loaded nanomicelles were prepared and their zeta potential, particle size and polydispersity index were measured. For antiplasmodial assessment, 54 mice were randomly divided into six groups. Four groups were infected intraperitoneally with P. berghei, whereas the two remaining groups did not receive the parasite (negative controls). Three of the P. berghei-infected groups received treatment with either pyrimethamine-loaded nanomicelles (2 mg/kg), pyrimethamine (2 mg/kg) or empty nanomicelles (2 mg/kg); the fourth group remained untreated (positive control). The parasitaemia rate, survival rate and histopathological changes in the liver, spleen and kidneys were examined and were compared with the negative and positive control groups.

RESULTS

The mean parasitaemia rate differed significantly between the nanoformulated pyrimethamine group and each of the other groups (P<0.05). Moreover, the survival rate of mice in the nanoformulated pyrimethamine group (7/9; 78%) was significantly higher compared with each of the other groups (P<0.01). The main histopathological changes, including hepatic necrosis in the liver, lymphoid hypoplasia in the spleen, and tubular nephrosis and perivascular and interstitial lymphocytic infiltration in the kidneys, were considerably lower in the nanoformulated pyrimethamine group than in the pyrimethamine and positive control groups.

CONCLUSION

Pyrimethamine-loaded nanomicelles showed potent antimalarial activity and can be considered as a potential candidate for further examination of their suitability as an antimalarial drug.

Nano-facilitated drug delivery strategies in the treatment of plasmodium infection

Malaria, one of the major infectious disease-causing sizeable morbidity, mortality and economic loss worldwide. The main drawback for the failure to eradicate malaria is the spread of multiple drug resistance to the majority of currently available chemotherapy. At present nanotechnology offers an advanced opportunity in the delivery of drugs and vaccines to the desired targeted site in the body following oral and systemic administration. It confers the major advantages like improving drug pharmacokinetic profiles, reduce dose frequency and reduction in drug toxicity. Hence, Nano-based drug delivery system can provide a promising prospect in the way of malaria treatment. This paper is a review of recent researches highlighting includes nanocarriers loaded antimalarial drugs for better therapeutic efficacy and future perspective in the treatment of malaria.

Scolicidal Effects of Chitosan-Curcumin Nanoparticles on the Hydatid Cyst Protoscolices

PURPOSE

In the current era, cystic echinococcosis (CE), as larval stage of Echinococcus granulosus, is considered as a threat to human health. Scolicidal agents used in the surgery of cysts have different side effects. Therefore, the present study aimed to assess the effects of chitosan nanoparticles containing curcumin (Ch-Cu NPs) on the protoscolices of the hydatid cyst in vitro.

METHODS

Ch-Cu NPs were synthesized using a simple co-precipitation method and their structural and morphological properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta analyzer, and Fourier transform infrared (FT-IR) spectroscopy. Then, the effects of different concentrations of Ch-Cu NPs (0.25, 0.05, 1, 2, and 4 mg/mL) on the fatality rate, and the length and width of protoscolices in different times (5, 10, 20, 30, and 60 min) were investigated. In addition, the SEM technique was used to evaluate the structure of the protoscolices after treatment.

RESULTS

Based on the results, the presence of curcumin on the chitosan nanoparticles was confirmed by FT-IR analysis. Further, XRD analysis approved the crystal structure of chitosan NPs. Furthermore, the highest fatality rate was 68% in 4 mg/mL concentration of Ch-Cu NPs. The length and width of protoscolices decreased based on the high concentrations of Ch-Cu NPs, compared to the control group.

CONCLUSION

Finally, Ch-Cu NPs expressed good scolicidal activities, which made them suitable to be considered as an anti-protoscolex agent.

Allosteric Site Inhibitor Disrupting Auto-Processing of Malarial Cysteine Proteases

Falcipains are major haemoglobinases of Plasmodium falciparum required for parasite growth and development. They consist of pro- and mature domains that interact via 'hot-spot' interactions and maintain the structural integrity of enzyme in zymogen state. Upon sensing the acidic environment, these interactions dissociate and active enzyme is released. For inhibiting falcipains, several active site inhibitors exist, however, compounds that target via allosteric mechanism remains uncharacterized. Therefore, we designed and synthesized six azapeptide compounds, among which, NA-01 & NA-03 arrested parasite growth by specifically blocking the auto-processing of falcipains. Inhibitors showed high affinity for enzymes in presence of the prodomain without affecting the secondary structure. Binding of NA-03 at the interface induced rigidity in the prodomain preventing structural reorganization. We further reported a histidine-dependent activation of falcipain. Collectively, for the first time we provide a framework for blocking the allosteric site of crucial haemoglobinases of the human malaria parasite. Targeting the allosteric site could provide high selectivity and less vulnerable to drug resistance.

Nanomedicines for Malaria Chemotherapy: Encapsulation vs. Polymer Therapeutics

Malaria is one of the oldest infectious diseases that afflict humans and its history extends back for millennia. It was once prevalent throughout the globe but today it is mainly endemic to tropical regions like sub-Saharan Africa and South-east Asia. Ironically, treatment for malaria has existed for centuries yet it still exerts an enormous death toll. This contradiction is attributed in part to the rapid development of resistance by the malaria parasite to chemotherapeutic drugs. In turn, resistance has been fuelled by poor patient compliance to the relatively toxic antimalarial drugs. While drug toxicity and poor pharmacological potentials have been addressed or ameliorated with various nanomedicine drug delivery systems in diseases like cancer, no clinically significant success story has been reported for malaria. There have been several reviews on the application of nanomedicine technologies, especially drug encapsulation, to malaria treatment. Here we extend the scope of the collation of the nanomedicine research literature to polymer therapeutics technology. We first discuss the history of the disease and how a flurry of scientific breakthroughs in the latter part of the nineteenth century provided scientific understanding of the disease. This is followed by a review of the disease biology and the major antimalarial chemotherapy. The achievements of nanomedicine in cancer and other infectious diseases are discussed to draw parallels with malaria. A review of the current state of the research into malaria nanomedicines, both encapsulation and polymer therapeutics polymer-drug conjugation technologies, is covered and we conclude with a consideration of the opportunities and challenges offered by both technologies.

Antibacterial Effects of Chitosan/Cationic Peptide Nanoparticles

This study attempted to develop chitosan-based nanoparticles with increased stability and antibacterial activity. The chitosan/protamine hybrid nanoparticles were formed based on an ionic gelation method by mixing chitosan with protamine and subsequently cross-linking the mixtures with sodium tripolyphosphate (TPP). The effects of protamine on the chemical structures, physical properties, and antibacterial activities of the hybrid nanoparticles were investigated. The antibacterial experiments demonstrated that the addition of protamine (125 µg/mL) in the hybrid nanoparticles (500 µg/mL chitosan and 166.67 µg/mL TPP) improved the antimicrobial specificity with the minimum inhibitory concentration (MIC) value of 31.25 µg/mL towards Escherichia coli (E. coli), while the MIC value was higher than 250 µg/mL towards Bacillus cereus. The chitosan/protamine hybrid nanoparticles induced the formation of biofilm-like structure in B. cereus and non-motile-like structure in E. coli. The detection of bacterial cell ruptures showed that the inclusion of protamine in the hybrid nanoparticles caused different membrane permeability compared to chitosan nanoparticles and chitosan alone. The chitosan/protamine nanoparticles also exhibited lower binding affinity towards B. cereus than E. coli. The results suggested that the hybridization of chitosan with protamine improved the antibacterial activity of chitosan nanoparticles towards pathogenic E. coli, but the inhibitory effect against probiotic B. cereus was significantly reduced.

Nanopharmaceuticals as a solution to neglected diseases: Is it possible?

The study of neglected diseases has not received much attention, especially from public and private institutions over the last years, in terms of strong support for developing treatment for these diseases. Support in the form of substantial amounts of private and public investment is greatly needed in this area. Due to the lack of novel drugs for these diseases, nanobiotechnology has appeared as an important new breakthrough for the treatment of neglected diseases. Recently, very few reviews focusing on filiarasis, leishmaniasis, leprosy, malaria, onchocerciasis, schistosomiasis, trypanosomiasis, and tuberculosis, and dengue virus have been published. New developments in nanocarriers have made promising advances in the treatment of several kinds of diseases with less toxicity, high efficacy and improved bioavailability of drugs with extended release and fewer applications. This review deals with the current status of nanobiotechnology in the treatment of neglected diseases and highlights how it provides key tools for exploring new perspectives in the treatment of a wide range of diseases.

Chitosan nanoparticles in drug therapy of infectious and inflammatory diseases

INTRODUCTION

Chitosan, a polymer from the chitin family has diverse pharmaceutical and bio-medical utility because of its easy widespread availability, non-toxicity, biocompatibility, biodegradability, rich functionalities and high drug-loading capacity. Recent pharmaceutical research has examined the use of chitosan-based systems for drug delivery applications in various diseases. The availability of functional groups permits the conjugation of specific ligands and thus helps to target loaded drugs to the site of infection/inflammation. Slow biodegradation of chitosan permits controlled and sustained release of loaded moieties; reduces the dosing frequency and is useful for improving patient compliance in infectious drug therapy. The muco-adhesion offered by chitosan makes it an attractive candidate for anti-inflammatory drug delivery, where rapid clearance of the active moiety due to the increased tissue permeability is the major problem. The pH-dependent swelling and drug release properties of chitosan present a means of passive targeting of active drug moieties to inflammatory sites.

AREAS COVERED

Development of chitosan-based nanoparticulate systems for drug delivery applications is reviewed. The current state of chitosan-based nanosystems; with particular emphasis on drug therapy in inflammatory and infectious diseases is also covered.

EXPERT OPINION

The authors believe that chitosan-based nanosystems, due to the special and specific advantages, will have a promising role in the management of infectious and inflammatory diseases.

A ZnO decorated chitosan–graphene oxide nanocomposite shows significantly enhanced antimicrobial activity with ROS generation

The rise in antimicrobial resistance requires the development of new antibacterial agents.