Leishmania amazonensis causes a clinical form called diffuse cutaneous leishmaniasis (DCL) with challenges to treatment, like low efficiency and drug toxicity. Therefore, it is necessary to investigate new therapies using less toxic leishmanicidal compounds, such as flavonoids like naringenin, and their combination with conventional drugs, such as miltefosine. Antileishmanial dose/response activity, isobologram, calculation of dose reduction index (DRI), and fractional inhibitory concentration index (FICI) tests were performed on in vitro assays using reference promastigote forms of L. amazonensis (IFLA/BR/67/PH8) to assess the combinatorial effect between naringenin and miltefosine. The in vitro results of isobologram, DRI, and FICI calculations showed that the combination of the compounds had an additive effect and was able to reduce the half maximal inhibitory concentration (IC₅₀) of miltefosine in the promastigote forms of the parasite compared to the treatment of the drug alone. This study demonstrated in vitro the viability of a combination action of the flavonoid with the treatment with miltefosine, opening space for further investigations on the association of natural compounds with the drugs used for the treatment of L. amazonensis.

The endothelial layer, formed by endothelial cells, performs crucial functions in maintaining homeostasis. The endothelial integrity and function might be compromised due to various causes, including infection by Toxoplasma gondii, leading to an endothelial dysfunction. Toxoplasma gondii is an Apicomplexa parasite that infects a broad range of animals, including humans. This parasite can invade all nucleated cells, as well as endothelial cells. The interaction between this protozoan and endothelial cells can be mediated by different molecules, such as extracellular vesicles (EVs), which may either favor or hinder the infectious process. To investigate this interaction, we evaluated the infection of T. gondii on human brain microvascular endothelial cells (HBMEC) and human umbilical vein endothelial cells (HUVEC), in addition to assessing transcriptional changes. We also featured the EVs secreted by T. gondii and by infected and non-infected HBMEC and HUVEC. Finally, we evaluated the infection of cells stimulated with EVs of parasitic or cellular origin. Our results demonstrated that HUVEC not only exhibit a higher infection rate than HBMEC but also display a more pro-inflammatory transcriptional profile, with increased expression of interleukin-6 (IL6), interleukin-8 (IL8), and monocyte chemotactic protein-1 (MCP1) following infection. Additionally, we observed few differences in the concentration, distribution, and morphology of EVs secreted by both cell types, although their properties in modulating infection varied significantly. When cells were EVs stimulated, EVs from T. gondii promoted an increase in the HBMEC infection, EVs from infected or uninfected HBMEC reduced the infection, whereas EVs from HUVEC had no effect on the infectious process. In conclusion, our data indicate that T. gondii infection induces distinct changes in different endothelial cell types, and EVs from these cells can contribute to the resolution of the infection.

The scaffolds and their interaction with mesenchymal stem cells are objects of study in bioengineering and tissue repair. Mechanisms such as surface adhesion, proliferation, viability, and cytotoxicity are essential for the development of therapies. The present study analyzed the influence of platelet-rich fibrin (PRF) in viability, cytotoxicity, and proliferation of stem cells from human exfoliated deciduous teeth (SHED) exposed to bovine biomaterial surfaces. The studied groups were divided and analyzed as follows: (S) only SHED as control Group; (SB) SHED + biomaterial; (SBP) SHED + biomaterial + PRF. Analyses of cells seeded in 24-well plates were performed after 24, 48 and 72 hours. Individual groups were subjected to viability, cytotoxicity and cell proliferation tests using neutral red, MTT and crystal violet, respectively; and in the 72-hour group, scanning electron microscopy (SEM) was performed to record cell ultra-morphology. Data were submitted to statistical analysis by two-factor ANOVA with a significance level of 5%. The results demonstrated a better performance in the viability/cytotoxicity and proliferation of stem cells for the group (SBP) in comparison to the group (SB) and the group (S). The applied statistical tests showed that the biomaterial factor, time, and interaction between them gave rise to results with statistical significance. SHED submitted to bovine biomaterial were more viable, proliferative and with lower toxicity when associated with PRF. PRF seemed to activate the metabolism of stem cells in culture, indicating that such an association can bring an effective benefit in clinical outcome.

A bichectomia é um procedimento que se constitui na remoção da porção anterior do corpo adiposo de Bichat (paCAB). O extrato celular obtido após o processamento por meio de digestão enzimática desse tecido é chamado de fração vascular estromal (FVE). A natureza das células que compõem a FVE qualifica esse produto para uma ampla gama de aplicações clínicas, especialmente em procedimentos de estímulo à renovação e à reparação tecidual, incluindo-se os fins estéticos de rejuvenescimento em face. Entretanto, o aproveitamento desse material biológico vivo está diretamente relacionado ao seu adequado manejo e transporte, desde sua coleta, processamento e envio para aplicação clínica. Este trabalho teve como objetivo caracterizar a FVE obtida a partir da paCAB, e também verificar se o plasma pobre em plaqueta (PPP) autólogo é eficiente na manutenção da viabilidade celular, podendo ser uma opção de meio para transporte até sua aplicação clínica mediata. Três pacientes com indicação da realização de bichectomia participaram da pesquisa. Antes da remoção da paCAB foi realizada a coleta sanguínea venosa para a obtenção do PPP. A paCAB bilateral coletada foi enviada para o Centro de Processamento Celular Curityba Biotech e submetida ao protocolo para desagregar as células da matriz extracelular. Ao final, a FVE foi fracionada em alíquotas que foram acondicionadas em seringas e em placas de cultivo, e impostas a ensaios para se avaliar a viabilidade celular nos tempos 0, 24 e 48 h. A viabilidade celular e a caracterização das células presentes na FVE foram avaliadas por microscopia de luz e imunofenotipagem por citometria de fluxo. Uma amostra foi mantida em garrafa de cultivo até atingir 7x106 células. Após, foram impostas a comprovação da presença de células-tronco mesenquimais (CTM) capazes de se manter em cultivo padrão. A amostra analisada por imunofenotipagem confirmou a existência das seguintes células: células-tronco mesenquimais e hematopoiéticas, células endoteliais e células T.