Improved efficacy and safety of low doses of benznidazole-loaded multiparticulate delivery systems in experimental Chagas disease therapy

Efficacy of benznidazole delivery during Chagas disease nanotherapy is dependent on the nanocarrier morphology

The causative agent of Chagas disease, the protozoan Trypanosoma cruzi, is an obligate intracellular parasite that is typically treated with daily oral administration of Benznidazole (BNZ), a parasiticidal pro-drug with considerable side effects. Previously, we effectively targeted intracellular parasites using ∼100 nm diameter BNZ-loaded poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-b-PPS) vesicular nanocarriers (a.k.a. polymersomes) in a T. cruzi-infected mouse model, without causing the typical side effects associated with standard BNZ treatment. Here, we exploit the structural versatility of the PEG-b-PPS system to investigate the impact of nanocarrier structure on the efficacy of BNZ nanotherapy. Despite sharing the same surface chemistry and oxidation-sensitive biodegradation, solid core ∼25 nm PEG-b-PPS micelles failed to produce in vivo trypanocidal effects. By applying the Förster Resonance Energy Transfer strategy, we demonstrated that PEG-b-PPS polymersomes promoted sustained intracellular drug release and enhanced tissue accumulation, offering a significant advantage for intracellular drug delivery compared to micelles with the same surface chemistry. Our studies further revealed that the lack of parasiticidal effect in PEG-b-PPS micelles is likely due to their slower rate of accumulation into solid tissues, consistent with the prolonged circulation time of intact micelles. Considering the cardiac damage typically induced by T. cruzi infection, this study also investigated the contributions of cardiac cellular biodistribution and payload release for both nanocarriers to the treatment outcomes of BNZ delivery. Our findings emphasize the crucial role of cardiac macrophages in the parasiticidal effect of BNZ formulations and highlight the critical importance of nanobiomaterial structure during therapeutic delivery.

Supramolecular eutectogel as new oral paediatric delivery system to enhance benznidazole bioavailability

Benznidazole (BNZ) serves as the primary drug for treating Chagas Disease and is listed in the WHO Model List of Essential Medicines for Children. Herein, a new child-friendly oral BNZ delivery platform is developed in the form of supramolecular eutectogels (EGs). EGs address BNZ's poor oral bioavailability and provide a flexible twice-daily dose in stick-pack format. This green and sustainable formulation strategy relies on the gelation of drug-loaded Natural Deep Eutectic Solvents (NaDES) with xanthan gum (XG) and water. Specifically, choline chloride-based NaDES form stable and biocompatible 5 mg/mL BNZ-loaded EGs. Rheological and Low-field NMR investigations indicate that EGs are viscoelastic materials comprised of two co-existing regions in the XG network generated by different crosslink distributions between the biopolymer, NaDES and water. Remarkably, the shear modulus and relaxation spectrum of EGs remain unaffected by temperature variations. Upon dilution with simulated gastrointestinal fluids, EGs results in BNZ supersaturation, serving as the primary driving force for its absorption. Interestingly, after oral administration of EGs to rats, drug bioavailability increases by 2.6-fold, with a similar increase detected in their cerebrospinal fluid. The noteworthy correlation between in vivo results and in vitro release profiles confirms the efficacy of EGs in enhancing both peripheral and central BNZ oral bioavailability.

Nonsteroidal Anti-Inflammatory Drugs and Experimental Chagas Disease: An Unsolved Question

Chagas disease is a parasitic disease caused by the protozoan Trypanosoma cruzi with an acute, detectable blood parasites phase and a chronic phase, in which the parasitemia is not observable, but cardiac and gastrointestinal consequences are possible. Mice are the principal host used in experimental Chagas disease but reproduce the human infection depending on the animal and parasite strain, besides dose and route of administration. Lipidic mediators are tremendously involved in the pathogenesis of T. cruzi infection, meaning the prostaglandins and thromboxane, which participate in the immunosuppression characteristic of the acute phase. Thus, the eicosanoids inhibition caused by the nonsteroidal anti-inflammatory drugs (NSAIDs) alters the dynamic of the disease in the experimental models, both in vitro and in vivo, which can explain the participation of the different mediators in infection. However, marked differences are founded in the various NSAIDs existing because of the varied routes blocked by the drugs. So, knowing the results in the experimental models of Chagas disease with or without the NSAIDs helps comprehend the pathogenesis of this infection, which still needs a better understanding.

New drug discovery strategies for the treatment of benznidazole-resistance in Trypanosoma cruzi, the causative agent of Chagas disease

INTRODUCTION

Benznidazole, the drug of choice for treating Chagas Disease (CD), has significant limitations, such as poor cure efficacy, mainly in the chronic phase of CD, association with side effects, and parasite resistance. Understanding parasite resistance to benznidazole is crucial for developing new drugs to treat CD.

AREAS COVERED

Here, the authors review the current understanding of the molecular basis of benznidazole resistance. Furthermore, they discuss the state-of-the-art methods and critical outcomes employed to evaluate the efficacy of potential drugs against T. cruzi, aiming to select better compounds likely to succeed in the clinic. Finally, the authors describe the different strategies employed to overcome resistance to benznidazole and find effective new treatments for CD.

EXPERT OPINION

Resistance to benznidazole is a complex phenomenon that occurs naturally among T. cruzi strains. The combination of compounds that inhibit different metabolic pathways of the parasite is an important strategy for developing a new chemotherapeutic protocol.

From Benznidazole to New Drugs: Nanotechnology Contribution in Chagas Disease

Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi. Benznidazole and nifurtimox are the two approved drugs for their treatment, but both drugs present side effects and efficacy problems, especially in the chronic phase of this disease. Therefore, new molecules have been tested with promising results aiming for strategic targeting action against T. cruzi. Several studies involve in vitro screening, but a considerable number of in vivo studies describe drug bioavailability increment, drug stability, toxicity assessment, and mainly the efficacy of new drugs and formulations. In this context, new drug delivery systems, such as nanotechnology systems, have been developed for these purposes. Some nanocarriers are able to interact with the immune system of the vertebrate host, modulating the immune response to the elimination of pathogenic microorganisms. In this overview of nanotechnology-based delivery strategies for established and new antichagasic agents, different strategies, and limitations of a wide class of nanocarriers are explored, as new perspectives in the treatment and monitoring of Chagas disease.

Leishmaniasis and Chagas disease: Is there hope in nanotechnology to fight neglected tropical diseases?

Nanotechnology is revolutionizing many sectors of science, from food preservation to healthcare to energy applications. Since 1995, when the first nanomedicines started being commercialized, drug developers have relied on nanotechnology to improve the pharmacokinetic properties of bioactive molecules. The development of advanced nanomaterials has greatly enhanced drug discovery through improved pharmacotherapeutic effects and reduction of toxicity and side effects. Therefore, highly toxic treatments such as cancer chemotherapy, have benefited from nanotechnology. Considering the toxicity of the few therapeutic options to treat neglected tropical diseases, such as leishmaniasis and Chagas disease, nanotechnology has also been explored as a potential innovation to treat these diseases. However, despite the significant research progress over the years, the benefits of nanotechnology for both diseases are still limited to preliminary animal studies, raising the question about the clinical utility of nanomedicines in this field. From this perspective, this review aims to discuss recent nanotechnological developments, the advantages of nanoformulations over current leishmanicidal and trypanocidal drugs, limitations of nano-based drugs, and research gaps that still must be filled to make these novel drug delivery systems a reality for leishmaniasis and Chagas disease treatment.

Combining network pharmacology with chromatographic fingerprinting and multi-component quantitative analysis for the quality evaluation of Astragali Radix

Nowadays, the cultivated variant and adulterant of Astragali Radix (AR) have flooded the market, causing the quality of AR to be challenging to distinguish. To address this issue, we combined network pharmacology with chromatographic fingerprinting and multi-component quantitative analysis for the quality evaluation of AR. Specifically, through network pharmacology, a complete understanding of the active components and pharmacological activities of AR was established. In addition, the establishment of the fingerprint profiles and multi-component quantitation by high-performance liquid chromatography (HPLC) is convenient and comprehensive, which can more fully reflect the overall situation of the distribution of various chemical components. To evaluate and differentiate AR from different origins, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were performed. The result showed that AR acts synergistically through multiple targets and pathways. And the content of chemical components in AR from different origins varied significantly. Combining network pharmacology and multi-component quantification results, astragaloside II, astragaloside IV and formononetin can be used as quality markers for quality control of AR. This study provides a comprehensive and reliable strategy for the quality evaluation of AR and identifies its quality markers to ensure the quality of the herb.