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Leishmaniasis is considered as one of the 20 neglected tropical diseases. Current methods of leishmanial diagnosis depend on conventional laboratory-based techniques, which are time-consuming, costly and require special equipment and trained personnel. In this context, we aimed to provide an immuno field effect transistors (ImmunoFET) biosensor that matches the conventional standards for point-of-care (POC) monitoring and detection of Leishmania (L.) donovani/Leishmania major. Crude antigens prepared by repeated freeze thawing of L. donovani/L. major stationary phase promastigotes were used for ELISA and ImmunoFETs. Lesishmania-specific antigens were serially diluted in 1× PBS from a concentration of 10 6 -10 2 parasites/mL. A specific polyclonal antibody-based sandwich ELISA was established for the detection of Leishmania antigens. An immunoFET technology-based POC novel assay was constructed for the detection of Leishmania antigens. Interactions between antigen-antibody at the gate surface generate an electrical signal that can be measured by semiconductor field-effect principles. Sensitivity was considered and measured as the change in current divided by the initial current. The final L. donovani/L. major crude antigen protein concentrations were measured as 1.50 mg/mL. Sandwich ELISA against the Leishmania 40S ribosomal protein detected Leishmania antigens could detect as few as 100 L. donovani/L. major parasites. An immunoFET biosensor was constructed based on the optimization of aluminium gallium nitride/gallium nitride (AlGaN/GaN) surface oxidation methods. The device surface was composed by an AlGaN/GaN wafer with a 23 nm AlGaN barrier layer, a 2 μm GaN layer on the silicon carbide (SiC) substrate for Leishmania binding, and coated with a specific antibody against the Leishmania 40S ribosomal protein, which was successfully detected at concentrations from 10 6 to 10 2 parasites/mL in 1× PBS. At the concentration of 10 4 parasites, the immunoFETs device sensitivities were 13% and 0.052% in the sub-threshold regime and the saturation regime, respectively. Leishmania parasites were successfully detected by the ImmunoFET biosensor at a diluted concentration as low as 150 ng/mL. In this study, the developed ImmunoFET biosensor performed well. ImmunoFET biosensors can be used as an alternative diagnostic method to ELISA. Increasing the sensitivity and optimization of immuno-FET biosensors might allow earlier and faster detection of leishmaniasis., (© 2023 John Wiley & Sons Ltd.)

Background: New drugs are needed for leishmaniasis because current treatments such as pentavalent antimonials are toxic and require prolonged administration, leading to poor patient compliance. Ibrutinib is an anticancer drug known to modulate T-helper type 1 (Th1)/Th2 responses and has the potential to regulate immunity against infectious disease., Methods: In this study, we evaluated the efficacy of oral ibrutinib as a host-targeted treatment for visceral leishmaniasis (VL) caused by Leishmania donovani using an experimental mouse model., Results: We found that oral ibrutinib was significantly more effective than the pentavalent antimonial sodium stibogluconate (70 mg/kg) for the treatment of VL caused by L. donovani. Ibrutinib treatment increased the number of interleukin 4- and interferon γ-producing natural killer T cells in the liver and spleen and enhanced granuloma formation in the liver. Further, ibrutinib treatment reduced the influx of Ly6Chi inflammatory monocytes, which mediate susceptibility to L. donovani. Finally, ibrutinib treatment was associated with the increased production of the cytokines interferon γ, tumor necrosis factor α, interleukin 4, and interleukin 13 in the liver and spleen, which are associated with protection against L. donovani., Conclusions: Our findings show that oral ibrutinib is highly effective for the treatment of VL caused by L. donovani and mediates its antileishmanial activity by promoting host immunity. Therefore, ibrutinib could be a novel host-targeted drug for the treatment of VL.

The aim of this study was to evaluate mannose-anchored thiolated chitosan (MTC) based nanocarriers (NCs) for enhanced permeability, improved oral bioavailability and anti-parasitic potential of amphotericin B (AmB). Transgenic Leishmania donovani parasites expressing red fluorescent protein DsRed2 and imaging-flow cytometry was used to investigate parasitic burdens inside bone marrow-derived macrophages ex vivo. Cytokine estimation revealed that MTC nanocarriers activated the macrophages to impart an explicit immune response by higher production of TNF-α and IL-12 as compared to control. Cells treated with MTC NCs showed a significantly higher magnitude of nitrite and propidium iodide (PI) fluorescence intensity in contrast to cells treated with AmB. Concerning to apparent permeability coefficient (Papp) results, the MTC NCs formulation displayed more specific permeation across the Caco-2 cell monolayer as compared to AmB. The half-life of MTC NCs was about 3.3-fold persistent than oral AmB used as positive control. Also, t oral bioavailability of AmB was increased to 6.4-fold for MTC NCs compared to AmB for positive control. Acute oral evaluation indicated that MTC NCs were significantly less toxic compared to the AmB. Based on these findings, MTC NCs seems to be promising for significant oral absorption and improved oral bioavailability of AmB in leishmaniasis chemotherapy. [ABSTRACT FROM AUTHOR]