Nanomedicine Approaches Against Parasitic Worm Infections

Role of Silver Nanoparticles for the Control of Anthelmintic Resistance in Small and Large Ruminants

Helminths are considered a significant threat to the livestock industry, as they cause substantial economic losses in small and large ruminant farming. Their morbidity and mortality rates are also increasing day by day as they have zoonotic importance. Anthelmintic drugs have been used for controlling these parasites; unfortunately, due to the development of resistance of these drugs in helminths (parasites), especially in three major classes like benzimidazoles, nicotinic agonists, and macrocyclic lactones, their use is becoming very low. Although new anthelmintics are being developed, the process is time-consuming and costly. As a result, nanoparticles are being explored as an alternative to anthelmintics. Nanoparticles enhance drug effectiveness, drug delivery, and target specificity and have no resistance against parasites. Different types of nanoparticles are used, such as organic (chitosan) and inorganic (gold, silver, zinc oxide, iron oxide, and nickel oxide). One of them, silver nanoparticles (AgNPs), has unique properties in various fields, especially parasitology. AgNPs are synthesized from three primary methods: physical, chemical, and biological. Their primary mechanism of action is causing stress through the production of ROS that destroys cells, organs, proteins, and DNA parasites. The present review is about AgNPs, their mode of action, and their role in controlling anthelmintic resistance against small and large ruminants.

Development of solid lipid nanoparticles-loaded drugs in parasitic diseases

Parasites cause illnesses with broad spectrum of symptoms from mild to severe, and are responsible for a significant number of outbreaks in the world. Current anti-parasitic drugs are toxic and have significant side effects. Nano-carriers are believed to obviate the limitations of conventional drugs via decreasing side effects and increasing target delivery and drug permeability with a controlled prolonged release of a drug. Solid lipid nanoparticles (SLNs) are lipid nanoparticles (LNPs), which have frequently been practiced. Suitable release rate, stability, and target delivery make SLNs a good alternative for colloidal carriers. SLNs are supposed to have great potential to deliver natural products with anti-parasitic properties. Nanoparticles have employed to improve stability and capacity loading of SLNs, during recent years. This review describes development of SLNs, the methods of preparation, characterization, and loaded drugs into SLNs in parasitic diseases. In addition, we summarize recent development in anti-parasitic SLNs-loaded drugs.

Nanotechnology: A promising strategy for the control of parasitic infections

Annually 3.5 billion people are affected by the parasitic infections that results around 200,000 deaths per annum. Major diseases occur due to the neglected tropical parasites. Variety of methods have been used to treat the parasitic infections but now these methods have become ineffective due to the development of resistance in the parasites and some other side effects of traditional treatment methods. Previous methods include use of chemotherapeutic agents and ethnobotanicals for the treatment of parasites. Parasites have developed resistance against the chemotherapeutic agents. A major problem related to Ethnobotanicals is the unequal availability of drug at the target site which is responsible for the low efficacy of drug. Nanotechnology technology involves the manipulation of matter on a nanoscale level and has the potential to enhance the efficacy and safety of existing drugs, develop new treatments, and improve diagnostic methods for parasitic infections. Nanoparticles can be designed to selectively target parasites while minimizing toxicity to the host, and they can also be used to improve drug delivery and increase drug stability. Some important nanotechnology-based tools for parasitic control include nanoparticle-based drug delivery, nanoparticle diagnostics, nanoparticle vaccines, nanoparticle insecticides. Nanotechnology has the potential to revolutionize the field of parasitic control by providing new methods for detection, prevention and treatment of parasitic infections. This review discusses the current state of nanotechnology-based approaches for controlling parasitic infections and highlights their potential to revolutionize the field of parasitology.

Nanoparticles: Synthesis and Their Role as Potential Drug Candidates for the Treatment of Parasitic Diseases

Protozoa, helminths and ectoparasites are the major groups of parasites distributed worldwide. Currently, these parasites are treated with chemotherapeutic antiprotozoal drugs, anti-helminthic and anti-ectoparasitic agents, but, with the passage of time, resistance to these drugs has developed due to overuse. In this scenario, nanoparticles are proving to be a major breakthrough in the treatment and control of parasitic diseases. In the last decade, there has been enormous development in the field of nanomedicine for parasitic control. Gold and silver nanoparticles have shown promising results in the treatments of various types of parasitic infections. These nanoparticles are synthesized through the use of various conventional and molecular technologies and have shown great efficacy. They work in different ways, that include damaging the parasite membrane, DNA (Deoxyribonucleic acid) disruption, protein synthesis inhibition and free-radical formation. These agents are effective against intracellular parasites as well. Other nanoparticles, such as iron, nickel, zinc and platinum, have also shown good results in the treatment and control of parasitic infections. It is hoped that this research subject will become the future of modern drug development. This review summarizes the methods that are used to synthesize nanoparticles and their possible mechanisms of action against parasites.

Anthelmintics for drug repurposing: Opportunities and challenges

Drug repositioning is defined as a process to identify a new application for drugs. This approach is critical as it takes advantage of well-known pharmacokinetics, pharmacodynamics, and toxicity profiles of the drugs; thus, the chance of their future failure decreases, and the cost of their development and the required time for their approval are reduced. Anthelmintics, which are antiparasitic drugs, have recently demonstrated promising anticancer effects in vitro and in vivo. This literature review focuses on the potential of anthelmintics for repositioning in the treatment of cancers. It also discusses their pharmacokinetics and pharmacodynamics as antiparasitic drugs, proposed anticancer mechanisms, present development conditions, challenges in cancer therapy, and strategies to overcome these challenges.

Single-cell deconstruction of stem-cell-driven schistosome development

Schistosomes cause one of the most devastating neglected tropical diseases, schistosomiasis. Their transmission is accomplished through a complex life cycle with two obligate hosts and requires multiple radically different body plans specialized for infecting and reproducing in each host. Recent single-cell transcriptomic studies on several schistosome body plans provide a comprehensive map of their cell types, which include stem cells and their differentiated progeny along an intricate developmental hierarchy. This progress not only extends our understanding of the basic biology of the schistosome life cycle but can also inform new therapeutic and preventive strategies against the disease, as blocking the development of specific cell types through genetic manipulations has shown promise in inhibiting parasite survival, growth, and reproduction.

Mentha villosa Hubs., M. x piperita and their bioactives against gastrointestinal nematodes of ruminants and the potential as drug enhancers

Parasitic diseases caused by gastrointestinal nematodes (GIN) are responsible for a major impact on ruminant welfare. Although the available anthelmintics have a safe margin of toxicity to the animals, their indiscriminate use has increased the selection of resistant parasite populations. In this scenario, essential oils (EO) stand out as a promising ecofriendly therapeutic alternative against GIN. The objective of this work was to determine the effect of the EO of Mentha villosa Hubs (MVEO) collected in 2017 and 2018, M. x piperita (MPEO) and their main components, carvone and limonene, against the third stage larvae (L3) of Haemonchus spp. and Trichostrongylus spp. The solutions, including in nanoemulsion preparations, were tested in a range of concentrations using the larval migration inhibition test (LMIT). The EO and carvone were also tested in combination with nitroxynil (NTX) to determine their effect as drug enhancers (additive or synergy). MVEO/2017, MVEO/2018, MPEO and carvone showed 70.6 (73.4 mg/mL), 86.3 (74.9 mL/mL), 95.5 (143.6 mg/mL), and 88.2 % (38.3 mg/mL) efficacy against L3, respectively. Carvone alone had approximately a 3-fold higher efficacy when compared to its concentration in each EO: 68.8 % in MVEO/2017 and 83.9 % in MVEO/2018. Limonene did not show any significant effect on inhibiting L3 migration. The combination of MPEO and NTX, and carvone and NTX showed a statistically significantly (P <  0.05) synergic and additive effect, respectively, when compared to the isolated treatment. The nanoemulsion of MVEO/2017 at 0.367 mg/mL, inhibited L3 migration by 83.1 %, demonstrating to be highly effective (concentration ratio of 1:0.004), when compared to the MVEO/2017 (70.6 % at 73.4 mg/mL) extraction. The in vitro data from the combination of MPEO or carvone plus NTX suggest that these products can be considered for in vivo experiments against the most important GIN of ruminants as drug enhancers, possibly reducing the final concentration of NTX`. The efficacy of carvone was higher (EC₅₀ = 1.96 mg/mL) than its expected efficacy, based on its concentrations on both EO. Therefore, this component does not need the entire EO composition to exert its L3 motility action. The remarkable efficacy demonstrated by the MVEO/2017/nanoemulsion (EC₅₀ = 0.10 mg/mL), supports its potential to be a candidate to the next-generation therapy to alleviate clinical parasite infections and combat GIN resistant populations.

Drug discovery technologies: Caenorhabditis elegans as a model for anthelmintic therapeutics

Helminthiasis is one of the gravest problems worldwide. There is a growing concern on less available anthelmintics and the emergence of resistance creating a major threat to human and livestock health resources. Novel and broad-spectrum anthelmintics are urgently needed. The free-living nematode Caenorhabditis elegans could address this issue through automated high-throughput technologies for the screening of large chemical libraries. This review discusses the strong advantages and limitations for using C elegans as a screening method for anthelmintic drug discovery. C elegans is the best model available for the validation of novel effective drugs in treating most, if not all, helminth infections, and for the elucidation the mode of action of anthelmintic candidates. This review also focuses on available technologies in the discovery of anthelmintics published over the last 15 years with particular attention to high-throughput technologies over conventional screens. On the other hand, this review highlights how combinatorial and nanomedicine strategies could prolong the use of anthelmintics and control resistance problems.

Integrating Biomaterials and Immunology to Improve Vaccines Against Infectious Diseases

Despite the success of vaccines in preventing many infectious diseases, effective vaccines against pathogens with ongoing challenges - such as HIV, malaria, and tuberculosis - remain unavailable. The emergence of new pathogen variants, the continued prevalence of existing pathogens, and the resurgence of yet other infectious agents motivate the need for new, interdisciplinary approaches to direct immune responses. Many current and candidate vaccines, for example, are poorly immunogenic, provide only transient protection, or create risks of regaining pathogenicity in certain immune-compromised conditions. Recent advances in biomaterials research are creating new potential to overcome these challenges through improved formulation, delivery, and control of immune signaling. At the same time, many of these materials systems - such as polymers, lipids, and self-assembly technologies - may achieve this goal while maintaining favorable safety profiles. This review highlights ways in which biomaterials can advance existing vaccines to safer, more efficacious technologies, and support new vaccines for pathogens that do not yet have vaccines. Biomaterials that have not yet been applied to vaccines for infectious disease are also discussed, and their potential in this area is highlighted.