Facultad de Ciencias de la Salud

Chagas disease (CD) is a parasitic zoonosis endemic in Central and South America affecting nearly 10 million people, with 100 million people at high risk of contracting the disease. Treatment is only effective when received at the early stages of the disease and it involved two drugs (nifurtimox (NFX) and benznidazole (BNZ)). Both treatments require multiple daily administrations of high doses, suffer from variable efficacy and insufficient efficacy in chronic CD, many side effects, and a very long duration of treatment that results in poor compliance, while combined available therapies that lead to reduced duration of treatment are not available and polypharmacy reduces compliance and increases the cost further. Here we present self-nanoemulsified drug delivery systems (SNEDDS) able to produce easily scalable combined formulations of NFX and BNZ that can allow for tailoring of the dose and can be easily converted to oral solid dosage form by impregnation on mesoporous silica particles. SNEDDS demonstrated an enhanced solubilisation capacity for both drugs as demonstrated by flow-through studies and in vitro lipolysis studies. High loading of SNEDDS to Syloid 244 and 3050 silicas (2:1 w/w) allowed clinically translatable amounts of both NFX and BNZ to be loaded. Tablets prepared from NFX-BNZ combined SNEDDS loaded on Syloid 3050 silicas demonstration near complete dissolution in the flow through cell apparatus compared to NFX and BNZ commercial tablets respectively (Lampit® and Rochagan®). NFX-BNZ-SNEDDS demonstrated nanomolar efficacy in epimastigotes and amastigotes of T. cruzi with acceptable selectivity indexes and demonstrated enhanced survival and reduced parasitaemia in acute murine experimental models of CD. Thus, the results presented here illustrate the ability for an easily scalable and personalised combination oral therapy prepared from GRAS excipients, enabling treatment access worldwide for the treatment of CD.

Leishmaniasis a ects around 12 million people worldwide and is estimated to cause the ninth-largest disease burden. There are three main forms of the disease, visceral (VL), cutaneous (CL), and mucocutaneous (MCL), leading to more than one million new cases every year and several thousand deaths. Current treatments based on chemically synthesized molecules are far from ideal. In this study, we have tested the in vitro and in vivo e cacy of ursolic acid (UA), a multifunctional triterpenoid with well-known antitumoral, antioxidant, and antimicrobial e ects on di erent Leishmania strains. The in vitro antileishmanial activity against the intracellular forms was six and three-fold higher compared to extracellular forms of L. amazonensis and L. infantum, respectively. UA also showed to be a potent antileishmanial drug against both VL and CL manifestations of the disease in experimental models. UA parenterally administered at 5 mg/kg for seven days significantly reduced the parasite burden in liver and spleen not only in murine acute infection but also in a chronic-infection model against L. infantum. In addition, UA ointment (0.2%) topically administered for four weeks diminished (50%) lesion size progression in a chronic infection model of CL caused by L. amazonensis, which was much greater than the e ect of UA formulated as an O/W emulsion. UA played a key role in the immunological response modulating the Th1 response. The exposure of Leishmania-infected macrophages to UA led to a significant di erent production in the cytokine levels depending on the Leishmania strain causing the infection. In conclusion, UA can be a promising therapy against both CL and VL.

A stronger Th1 (cellular) immune response in canine leishmaniosis (CanL) leads to a better prognosis. Dietary nucleotides plus AHCC® have shown beneficial e ects in dogs with clinical leishmaniosis and in clinically healthy Leishmania-infected dogs. The potential leishmanicidal activity of nucleotides and AHCC was assessed by quantifying nitric oxide (NO) production and replication of parasites. Their e ects on lymphocyte proliferation were studied with and without soluble Leishmania infantum antigen (SLA) stimulation. Cytokine level variations were assessed using naïve and L. infantum-infected macrophages/lymphocytes cocultures. Promastigotes and amastigotes proliferation and NO macrophage production were not directly a ected. Lymphocyte proliferation was significantly enhanced by nucleotides, AHCC, and their combinations only after SLA stimulation. Nucleotides and AHCC significantly increased the production of IL-1 , IL-2, IL-5, IL-9, IL-10, and IL-12 by naïve immune cells. In naïve and L. infantum-infected macrophage/lymphocyte cocultures, nucleotides with or without AHCC led to significant increases in IFN- and TNF- . Given that these cytokines are involved in the e ective Th1 immune response against Leishmania parasites, these mechanisms of action could explain the previously reported in vivo clinical e cacy of such combination and further support the use of nucleotides with or without AHCC in the management of CanL patients.

Blended learning has risen in popularity over the last two decades as it has shown to be an effective approach for accommodating an increasingly diverse student population in Higher Education as well as enriching the learning environment through the incorporation of online teaching resources. The act of blending significant elements of the learning environment such as face-to-face, online and self-paced learning leads to better student experiences and outcomes, and more efficient teaching and course management practices if combined appropriately. For this reason, an appropriate systematic and dynamic approach of blended learning design is crucial for a positive outcome starting with planning for integrating blended elements into a course followed by creating blended activities and implementing them. Evaluating their effectiveness and knowing in which environments they work better and finally improving the blended activities designed from both the student’s and instructor’s perspective is critical for the next delivery of the course. This work aims to provide useful examples and increase awareness of Higher Education educators about how traditional face-to-face learning can be transformed into blended courses with the aim of increasing student engagement with both in-class and online approaches while being time effective for the instructor.

One of the main objectives of the WHO is controlling transmission of parasitic protozoa vector-borne diseases. A quick and precise diagnosis is critical in selecting the optimal therapeutic regime that avoids unnecessary treatments and the emergence of resistance. Molecular assays based on loopmediated isothermal amplification (LAMP) techniques are a good alternative to light microscopy and antigen-based rapid diagnostic tests in developing countries, since they allow for a large amount of genetic material generated from a few copies of DNA, and use primers that lead to high sensitivity and specificity, while the amplification process can be performed in isothermal conditions without the need of sophisticated equipment to interpret the results. In this review, the main advances in the development of LAMP assays for the diagnosis of malaria, leishmaniasis and Chagas' disease are discussed as well as the feasibility of their implementation in developing countries and use as point- of-care diagnostic tests.

Nano-enabled lipid based drug delivery systems offer a platform to overcome challenges encountered with current failed leads in the treatment of parasitic and infectious diseases. When prepared with FDA or EMA approved excipients, they can be readily translated without the need for further toxicological studies, while they remain affordable and amenable to scale-up. Buparvaquone (BPQ), a hydroxynapthoquinone with in vitro activity in the nanomolar range, failed to clinically translate as a viable treatment for visceral leishmaniasis due to its poor oral bioavailability limited by its poor aqueous solubility (BCS Class II drug). Here we describe a self-nanoemulsifying system (SNEDDS) with high loading and thermal stability up to 6 months in tropical conditions able to enhance the solubilisation capacity of BPQ in gastrointestinal media as demonstrated by flow-through cell and dynamic in vitro lipolysis studies. BPQ SNEDDS demonstrated an enhanced oral bioavailbility compared to aqueous BPQ dispersions (probe – sonicated) resulting in an increased plasma AUC0-24 by 55% that is four fold higher than any previous reported values for BPQ formulations. BPQ SNEDDS can be adsorbed on low molecular glycol chitosan polymers forming solid dispersions that when compressed into tablets allow the complete dissolution of BPQ in gastrointestinal media. BPQ SNEDDS and BPQ solid SNEDDS demonstrated potent in vitro efficacy in the nanomolar range (<37 nM) and were able to near completely inhibit parasite replication in the spleen and 48 ± 48 and 56 ± 23% inhibition of the parasite replication in the liver respectively compared to oral miltefosine after daily administration over 10 days. The proposed platform technology can be used to elicit a range of cost-effective and orally bioavailable non-invasive formulations for a range of antiparasitic and infectious disease drugs that are needed for closing the global health innovation gap.

Engineering of pharmaceutical cocrystals is an advantageous alternative to salt formation for improving the aqueous solubility of hydrophobic drugs. Although, spray drying is a well-established scale-up technique in the production of cocrystals, several issues can arise such as sublimation or stickiness due to low glass transition temperatures of some organic molecules, making the process very challenging. Even though, fluidised bed spray coating has been successfully employed in the production of amorphous drug-coated particles, to the best of our knowledge, it has never been employed in the production of cocrystals. The feasibility of this technique was proven using three model cocrystals: sulfadimidine (SDM)/4-aminosalicylic acid (4ASA), sulfadimidine/nicotinic acid (NA) and ibuprofen (IBU)/ nicotinamide (NAM). Design of experiments were performed to understand the critical formulation and process parameters that determine the formation of either cocrystal or coamorphous systems for SDM/4ASA. The amount and type of binder played a key role in the overall solid state and in vitro performance characteristics of the cocrystals. The optimal balance between high loading efficiencies and high degree of crystallinity was achieved only when a binder: cocrystal weight ratio of 5:95 or 10:90 was used. The cocrystal coated beads showed an improved in vitro-in vivo performance characterised by: (i) no tendency to aggregate in aqueous media compared to spray dried formulations, (ii) enhanced in vitro activity (1.8-fold greater) against S. aureus, (iii) larger oral absorption and bioavailability (2.2-fold higher Cmax), (iv) greater flow properties and (v) improved chemical stability than cocrystals produced by other methods derived from the morphology and solid nature of the starter cores.