Current advances in nanodrug delivery systems for malaria prevention and treatment

Evaluation of the transmission-blocking potential of Plasmodium vivax antigen Pvg37 using transgenic rodent parasites and clinical isolates

Background

Plasmodium vivax is a major cause of malaria, particularly outside Africa, necessitating effective strategies for public health management. Transmission-blocking vaccines (TBVs) have shown the potential to inhibit malaria transmission by targeting antigens expressed in sexual-stage parasites. Pbg37, a conserved protein expressed in sexual stages from gametocyte to ookinete in the rodent parasite P. berghei, is a viable target for TBV development.

Methods and findings

In this study, we constructed a transgenic strain, TrPvg37Pb, expressing Pvg37 using the P. berghei ΔPbg37 strain. Initial findings demonstrated that the replacement of Pbg37 with the exogenous Pvg37 did not impact parasite growth or development. Notably, Pvg37 was expressed during the gametocyte to ookinete development and was associated with the plasmic membrane, similar to Pbg37. To evaluate the potential of Pvg37 as a TBV candidate, we synthesized two Pvg37 polypeptides and immunized rabbits to generate antibodies. In vitro experiments demonstrated that anti-Pvg37-P2 antibodies significantly inhibited the formation of male gametes and ookinetes in the transgenic TrPvg37Pb parasite. Additionally, in mosquito feeding assays, mosquitos feeding on TrPvg37Pb-infected mice passively transferred with anti-Pvg37-P2 antibodies showed a significant 80.2% decrease in oocyst density compared to the control group. Furthermore, in direct membrane feeding experiments using four clinical P. vivax isolates, the anti-Pvg37 antibodies significantly reduced oocyst density by 28.6-50.4%.

Conclusion

Pvg37 is a promising candidate for P. vivax TBV development, deserving further research and optimization to enhance its immunogenicity and transmission-blocking activity.

Recent Advancement in Drug Development for Treating Malaria using Herbal Medicine and Nanotechnological Approach

More than two hundred million people around the world are infected with malaria, a blood-borne disease that poses a significant risk to human life. Single medications, such as lumefantrine, primaquine, and chloroquine, as well as combinations of these medications with artemisinin or its derivatives, are currently being used as therapies. In addition, due to rising antimalarial drug resistance, other therapeutic options are needed immediately. Furthermore, due to anti-malarial medication failures, a new drug is required. Medication discovery and development are costly and time-consuming. Many malaria treatments have been developed however, most treatments have low water solubility and bioavailability. They may also cause drugresistant parasites, which would increase malaria cases and fatalities. Nanotechnology may offer a safer, more effective malaria therapy and control option. Nanoparticles' high loading capacity, concentrated drug delivery, biocompatibility, and low toxicity make them an attractive alternative to traditional therapy. Nanotechnologybased anti-malarial chemotherapeutic medications outperform conventional therapies in therapeutic benefits, safety, and cost. This improves patient treatment compliance. The limitations of malaria treatments and the importance of nanotechnological approaches to the treatment of malaria were also topics that were covered in this review. The most recent advancements in nanomaterials and the advantages they offer in terms of medication delivery are discussed in this article. The prospective therapy for malaria is also discussed. Additionally, the limitations of malaria therapies and the importance of nanotechnology-based approaches to the treatment of malaria were explored.

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.

Improved Malaria Therapy with Cationic Nanocapsules Demonstrated in Plasmodium berghei-Infected Rodents Using Whole Blood Surrogate Population PK/PD Modeling

Objectives: Investigating how nanoparticle systems interact in whole blood (WB) is critical to evaluating the effectiveness of malaria therapy. Methods: We decided to establish a pharmacokinetic/pharmacodynamic (PK/PD) model of the quinine population in WB using Plasmodium berghei-infected mice, with a subsequent model comparison for nanocapsules coated with polysorbate (NCP80) or prepared with Eudragit® RS (NCEUD). The WB quinine population pharmacokinetic model in rats was developed using plasma and partition coefficients for rat erythrocytes. Mouse WB quinine population PK/PD modeling was developed using allometrically scaled literature-free mouse quinine pharmacokinetic data and covariate values to obtain a WB population pharmacokinetic model for quinine and nanocapsules in mice. This allowed for PK/PD modeling of the quinine population with the WB concentration and parasitemia data in mice. All models were built in NONMEN. Results: The WB quinine concentration profiles in rats were characterized using a two-compartment model. Nanoencapsulation reduced clearance and central compartment volume and increased peripherical compartimental volume. A maximum effect model described the PK/PD of the quinine WB population in mice, demonstrating that NCEUD enhances the antimalarial effect. Conclusions: Quinine WB is a good surrogate for describing the response to exposure in malaria. NCEUD outperformed NCP80 and free quinine, suggesting that cationic surfaces improve the potential for treating malaria.

Tailoring biomaterials for vaccine delivery

Biomaterials are substances that can be injected, implanted, or applied to the surface of tissues in biomedical applications and have the ability to interact with biological systems to initiate therapeutic responses. Biomaterial-based vaccine delivery systems possess robust packaging capabilities, enabling sustained and localized drug release at the target site. Throughout the vaccine delivery process, they can contribute to protecting, stabilizing, and guiding the immunogen while also serving as adjuvants to enhance vaccine efficacy. In this article, we provide a comprehensive review of the contributions of biomaterials to the advancement of vaccine development. We begin by categorizing biomaterial types and properties, detailing their reprocessing strategies, and exploring several common delivery systems, such as polymeric nanoparticles, lipid nanoparticles, hydrogels, and microneedles. Additionally, we investigated how the physicochemical properties and delivery routes of biomaterials influence immune responses. Notably, we delve into the design considerations of biomaterials as vaccine adjuvants, showcasing their application in vaccine development for cancer, acquired immunodeficiency syndrome, influenza, corona virus disease 2019 (COVID-19), tuberculosis, malaria, and hepatitis B. Throughout this review, we highlight successful instances where biomaterials have enhanced vaccine efficacy and discuss the limitations and future directions of biomaterials in vaccine delivery and immunotherapy. This review aims to offer researchers a comprehensive understanding of the application of biomaterials in vaccine development and stimulate further progress in related fields.

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.

Antimalarial Delivery with a Ferritin-Based Protein Cage: A Step toward Developing Smart Therapeutics against Malaria

Over the past two decades, the utilization of protein cages has witnessed exponential growth driven by their extensive applications in biotechnology and therapeutics. In the context of the recent Covid-19 pandemic, protein-cage-based scaffolds played a pivotal role in vaccine development. Beyond vaccines, these protein cages have proven valuable in diverse drug delivery applications thanks to their distinctive architecture and structural stability. Among the various types of protein cages, ferritin-based cages have taken the lead in drug delivery applications. This is primarily attributed to their ease of production, exceptional thermal stability, and nontoxic nature. While ferritin-based cages are commonly employed in anticancer drug delivery and contrast agent delivery, their efficacy in malarial drug delivery had not been explored until this study. In this investigation, several antimalarial drugs were encapsulated within horse spleen ferritin, and the binding and loading processes were validated through both experimental and computational techniques. The data unequivocally demonstrate the facile incorporation of antimalarial drugs into ferritin without disrupting its three-dimensional structure. Computational docking and molecular dynamics simulations were employed to pinpoint the precise location of the drug binding site within ferritin. Subsequent efficacy testing on Plasmodium revealed that the developed nanoconjugate, comprising the drug-ferritin conjugate, exhibited significant effectiveness in eradicating the parasite. In conclusion, the findings strongly indicate that ferritin-based carrier systems hold tremendous promise for the future of antimalarial drug delivery, offering high selectivity and limited side effects.

Biomolecular interactions between Plasmodium and human host: A basis of targeted antimalarial therapy

Malaria is one of the serious health concerns worldwide as it remains a clinical challenge due to the complex life cycle of the malaria parasite and the morphological changes it undergoes during infection. The malaria parasite multiplies rapidly and spreads in the population by changing its alternative hosts. These various morphological stages of the parasite in the human host cause clinical symptoms (anemia, fever, and coma). These symptoms arise due to the preprogrammed biology of the parasite in response to the human pathophysiological response. Thus, complete elimination becomes one of the major health challenges. Although malaria vaccine(s) are available in the market, they still contain to cause high morbidity and mortality. Therefore, an approach for eradication is needed through the exploration of novel molecular targets by tracking the epidemiological changes the parasite adopts. This review focuses on the various novel molecular targets.

Multifunctional Deep Eutectic Solvent-Based Microemulsion for Transdermal Delivery of Artemisinin

As a serious public health issue, malaria threatens the health of millions of people. Artemisinin, a gift from traditional Chinese medicine, has been used in the treatment of malaria and has shown good therapeutic efficiency. However, due to its low solubility, poor bioavailability, and short half-life time, some smart delivery strategies are still required. Herein, a multifunctional DES prepared from ibuprofen and menthol was prepared. This DES was shown to efficiently promote the solubility of artemisinin up to 400-fold. Then, it was further applied as the oil phase to construct an O/W microemulsion with the help of Tween-80 + Span-20 mixed surfactants. The prepared microemulsion displayed high efficiency in improving the permeability of artemisinin, which can be ascribed to the presence of the permeation enhancer menthol in DES and the microstructure of the O/W microemulsion. Moreover, the simultaneous permeation of artemisinin and ibuprofen further indicated the potential benefits of the presented formulation in the treatment of malaria. To sum up, the microemulsion based on multifunctional DES presented herein provided an effective method for transdermal delivery of artemisinin.