Synthesis and preliminary biological evaluation of a compound library of triazolylcyclitols

AbstractA small library of compounds was prepared by a combination of toluene dioxygenase (TDO)-catalyzed enzymatic dihydroxylation and copper(I)-catalyzed Hüisgen cycloaddition. Some compounds were obtained by coupling an alkyne and a conduritol derivative, while more complex structures were obtained by a double Hüisgen reaction of a dialkyne and two molecules of the cyclitol. The compounds were fully characterized and subjected to preliminary biological screening

Novel therapeutic mechanisms determine the effectiveness of lipid-core nanocapsules on melanoma models

Melanoma is a severe metastatic skin cancer with poor prognosis and no effective treatment. Therefore, novel therapeutic approaches using nanotechnology have been proposed to improve therapeutic effectiveness. Lipid-core nanocapsules (LNCs), prepared with poly(ε-caprolactone), capric/caprylic triglyceride, and sorbitan monostearate and stabilized by polysorbate 80, are efficient as drug delivery systems. Here, we investigated the effects of acetyleugenol-loaded LNC (AcE-LNC) on human SK-Mel-28 melanoma cells and its therapeutic efficacies on melanoma induced by B16F10 in C57B6 mice. LNC and AcE-LNC had z-average diameters and zeta potential close to 210 nm and -10.0 mV, respectively. CytoViva® microscopy images showed that LNC and AcE-LNC penetrated into SK-Mel-28 cells, and remained in the cytoplasm. AcE-LNC in vitro treatment (18–90×109 particles/mL; 1 hour) induced late apoptosis and necrosis; LNC and AcE-LNC (3–18×109 particles/mL; 48 hours) treatments reduced cell proliferation and delayed the cell cycle. Elevated levels of nitric oxide were found in supernatant of LNC and AcE-LNC, which were not dependent on nitric oxide synthase expressions. Daily intraperitoneal or oral treatment (days 3–10 after tumor injection) with LNC or AcE-LNC (1×1012 particles/day), but not with AcE (50 mg/kg/day, same dose as AcE-LNC), reduced the volume of the tumor; nevertheless, intraperitoneal treatment caused toxicity. Oral LNC treatment was more efficient than AcE-LNC treatment. Moreover, oral treatment with nonencapsulated capric/caprylic triglyceride did not inhibit tumor development, implying that nanocapsule supramolecular structure is important to the therapeutic effects. Together, data herein presented highlight the relevance of the supramolecular structure of LNCs to toxicity on SK-Mel-28 cells and to the therapeutic efficacy on melanoma development in mice, conferring novel therapeutic mechanisms to LNC further than a drug delivery system

Physicochemical characterisation of gold, silica and silver nanoparticles in water and in serum-containing cell culture media

This report presents the results from a study organised under the coordination of JRC as part of a project aiming at the adaptation of the in vitro micronucleus test (Test Guideline 487) for the assessment of manufactured NMs. The aim of the first step of the project was to evaluate the physicochemical characterisation of selected representative nanomaterials (5 nm gold, 30 nm gold, 22 nm silica, 30 nm citrate and 30 nm PVP stabilised silver nanoparticles) in pure water and in different complete culture media. The results of the study show that using a combination of different characterisation techniques is important to providing reliable information about the agglomeration behaviour of the tested nanoparticles in complete cell culture media (CCM). Most of the materials exhibited mild agglomeration in serum containing CCM. Only the PVP functionalised silver nanoparticles showed a size distribution change in all of the culture media that is so small that it could be attributed to solely protein adsorption without notable agglomeration. Silica nanoparticles were found to be the most sensitive to interaction with serum containing CCM, showing massive concentration and time dependent agglomeration strongly affected by the CCM composition. Extensive agglomeration might lead also to the accelerated sedimentation of the particles changing drastically the true, effective dose that the cells will receive under in vitro conditions1, 2. Thus, it has to be investigated in more detail and taken in account when designing in vitro experiments in the next phase of the project.JRC.F.2-Consumer Products Safet

Investigation of mechanisms of action of Amblyomin-X on in vivo on VEGF-induced angiogenesis

Amblyomin-X é um inibidor de serinoprotease do tipo kunitz obtido de uma biblioteca de cDNA das glândulas salivares do carrapato Amblyomma cajannense. Dados preliminares mostraram que a injeção in vivo de Amblyomin-X reduziu a formação de massa tumoral induzida por células de melanoma B16F10 em camundongos. Com base neste dado e na ação de inibidores de serinoproteases sobre a angiogênese, este projeto foi delineado para caracterizar as ações do Amblyomin-X sobre a angiogênese in vivo e sobre funções da célula endotelial in vitro na vigência do fator de crescimento VEGF-A. Os efeitos do Amblyomin-X sobre a cinética de formação de novos vasos na rede microcirculatória in vivo foram investigados no modelo de câmara dorsal em camundongos e na membrana corioalantóica. Empregando cultura de células endoteliais de linhagem de microcirculação (t-End), foram avaliados os efeitos do Amblyomin-X sobre viabilidade e citoproteção celular (anexina e iodeto de propídio - PI), proliferação celular (incorporação do fluoróforo diacetato de carboxi-fluoresceína succinimidil éster) e ciclo celular, além da expressão das moléculas de adesão PECAM-1, ICAM-1, VCAM-1, β1 e β3 integrinas em ensaios de citometria de fluxo. A aderência celular em Matrigel foi quantificada por espectrofotometria, a formação de tubos foi mensurada por microscopia óptica e a expressão gênica das moléculas de adesão PECAM-1, ICAM-1 e VCAM-1 por RT-PCR. Os dados obtidos mostraram que a aplicação tópica do Amblyomin-X (100ng/10µL) reduziu a formação de novos vasos no tecido subcutâneo dorsal de camundongos, quando o tratamento foi iniciado anterior ou concomitantemente, mas não posteriormente ao tratamento ao VEGF (10ng/10µL) e, reduziu a formação de novos vasos na membrana corioalantóica, quando administrado concomitantemente com o VEGF (0,25ng/10µL). O Amblyomin-X não alterou a viabilidade de células t-End (1000ng/mL, 72 horas); inibiu a apoptose e apoptose tardia causada por meio de cultura carenciado (100ng/mL); inibiu a proliferação (10, 100 ou 1000ng/mL de Amblyomin-X, 48 e 72 horas); induziu parada nas fases G1/G0 do ciclo celular; diminuiu a aderência e a formação de tubos das células endoteliais; não alterou a expressão basal de PECAM-1, VCAM-1, ICAM-1, β1 e β3 integrinas, mas reduziu a expressão de PECAM-1, VCAM-1, ICAM-1 induzida pelo VEGF-A. A redução da expressão protéica da PECAM-1 e ICAM-1 parece não ser dependente de ação do Amblyomin-X na expressão gênica, já que os níveis de RNAm não foram afetados pela ação do Amblyomin-X. Em conjunto, os dados obtidos neste trabalho mostram que o Amblyomin-X inibe a formação de novos vasos in vivo, por interferir, possivelmente, em mecanismos relacionados a sinalização da célula endotelial induzida pelo VEGF-A, em especial com a proliferação, adesão , tubulogênese e expressão de moléculas de adesão da família das imunoglobulinas.Amblyomin-X is a type-kunitz serineprotease inhibitor obtained from a cDNA library of the Amblyomma cajannense salivary glands. Preliminary data showed that in vivo injection of the protein reduced the formation of tumor-induced B16F10 melanoma cells in mice. Based on this data and on actions of serinorpoteases inhibitors on angiogenesis, this project aimed to characterize the actions of Amblyomin-X on angiogenesis in vivo and on in vitro endothelial cells functions in the presence of the growth factor VEGF. The effects of Amblyomin-X on the in vivo formation of microcirculatory new vessels were investigated in the dorsal chamber model in mice and in the chorioallantoic membrane assay. Mice microvascular endothelial cell lineage (t-End) was employed to evaluate the effects of Amblyomin-X on cytoprotection and cell viability (Annexin-V and propidium iodide-PI), cell proliferation (incorporation of the fluorophore fluorescein diacetate carboxy-succinimidil ester), cell cycle, membrane expression of PECAM-1, ICAM-1, VCAM-1, β1 and β3 integrins adhesion molecules using flow cytometry. Cell adhesion was assessed in matrigel by spectrophotometry, the formation of tubes was measured by optical microscopy and adhesion molecules PECAM-1, ICAM-1 and VCAM-1 gene expression was evaluated by RT-PCR. Data obtained showed that topical application of Amblyomin-X (100ng/10µL) reduced the formation of new vessels, only when Amblyomin-X treatment started before or simultaneously to VEGF-A stimulation (10ng/10µL). Amblyomin-X (100ng/10µL) also reduced the formation of new vessels in the chorioallantoic membrane assay, when coadministered with VEGF (0.25ng/10µL). The Amblyomin-X did not alter the viability of t-End (1000ng/mL, 72 hours), inhibited apoptosis and late apoptosis caused by deprivated serum (100ng/mL), inhibited proliferation (10, 100 or 1000ng/mL, 48 and 72 hours), induced G1/G0 arrest in cell cycle phases, decreased the cell adhesion and tube formation (100ng/mL), did not alter the basal expression of PECAM-1, VCAM-1, ICAM-1, β1 or β3 integrin, but reduced the PECAM-1, VCAM-1, ICAM-1 induced by VEGF-A. Impaired PECAM-1 and ICAM-1 expression seems not be dependent on gene expression, as, mRNA levels were not affected by the action of Amblyomin-X. Together, the data obtained shows that the Amblyomin-X inhibits new vessel formation in vivo, by interfering, possibly, with mechanisms related to VEGF-A induced endothelial cell signaling, especially with the proliferation, adhesion, tubulogenesis and expression of adhesion molecules

Effects of lipid-core nanocapsules with acetyleugenol in melanomas: in vivo and in vitro studies

O melanoma é uma neoplasia de pele invasivo, com maior taxa de morte, sem tratamento efetivo. Nanocápsulas poliméricas de núcleo lipídico (LNC) tem sido empregadas com sucesso como carreadores de fármacos hidrofóbicos. Como o eugenol é um composto hidrofóbico com atividades antiproliferativas e pró-apoptóticas em células cancerosas, visamos avaliar os efeitos dos tratamentos com acetileugenol (AC), LNC ou LNC contendo acetileugenol (LNC-AC) em modelo de melanoma in vivo em camundongos C57B6, e a citotoxicidade dos mesmos em células endoteliais (HUVEC) e de melanoma (SK-Mel-28) in vitro. Os resultados obtidos mostraram que: 1) tratamentos i.p. com as LNC ou com LNC-AC (50 mg/kg, 3-10 dia de indução do tumor) induziram toxicidade sistêmica e, somente o tratamento com LNC inibiu o desenvolvimento do melanoma. O tratamento com LNC, mas não com a mistura de triglicerídeos de cadeia média, por via oral, inibiu o desenvolvimento tumoral, sem toxicidade. Adicionalmente, os tratamentos com AC, LNC ou LNC-AC não foram eficazes quando administrados em fase tardia de evolução tumoral (50 mg/kg, 7-17 dia de indução do tumor, via oral); 2) os tratamentos agudos com AC, LNC ou LNC-AC (20 mg/kg, 200 µL, e.v.) não alteraram o número de leucócitos circulantes, mas os tratamentos com LNC ou com LNC-AC reduziram o comportamento de rolling dos leucócitos em vênulas póscapilares do músculo cremaster e causaram hemólise, sendo que este último efeito também foi observado após tratamento in vitro em hemácias murinas; 3) Os estudos in vitro mostraram que as LNC e LNC-AC foram captadas pelas células HUVEC e SK-Mel-28 após 1 hora de incubação; que a incubação com LNC-AC induziu apoptose tardia e necrose com maior eficácia em SK-Mel-28 do que em HUVEC; que as incubações com LNC ou LNC-AC exerceram efeitos antiproliferativos, induzindo parada na fase G2/M do ciclo celular das duas linhagens de células avaliadas; que somente a incubação com AC ou LNC-AC inibiu a adesão ao Matrigel® com maior eficácia na linhagem SK-Mel-28 do que HUVEC; que somente a incubação com as LNC reduziram a expressão de VCAM-1 em HUVEC e que as incubações com LNC ou LNC-AC reduziram a expressão de β3 integrina em SK-Mel- 28; que nenhum dos tratamentos alterou a migração celular das HUVEC ou SK-Mel- 28; que somente a incubação com LNC-AC reduziu os níveis de espécies reativas de oxigênio em HUVEC e SK-Mel-28; que a incubação com LNC ou LNC-AC aumentou a produção de óxido nítrico (NO) pelas duas linhagens de células avaliadas; que o tratamento com L-NAME reverteu os níveis de NO e a inibição sobre a proliferação celular induzida pela incubação com LNC ou LNC-AC e; que o tratamento de células de melanoma murino com LNC ou LNC-AC parece alterar a polarizar os neutrófilos para o fenótipo N1. Associados, os resultados obtidos mostram o tratamento oral com LNC inibe o crescimento do melanoma sem induzir efeitos tóxicos, e que este efeito benéfico pode ser dependente, pelo menos em parte, da nanoencapsulação dos triglicerídios de cadeia média e da supraestrutura da formulação, com toxicidade direta sobre as células de melanoma e possível modulação do microambiente tumoral.Melanoma is the most invasive skin cancer, with high rates of death without effective treatment. Polymeric lipid-core nanocapsules (LNC) has been successfully used as carriers of hydrophobic drugs. As eugenol is an hydrophobic compound with antiproliferative and pro-apoptotic activity in cancer cells, here we aimed to evaluate the effects of treatments with acetyleugenol (AC), LNC or LNC containing acetyleugenol (LNC-AC) in an in vivo melanoma model in C57BL6 mice and the cytotoxicity of the treatments in vitro, using endothelial (HUVEC) and melanoma (SK-Mel- 28) cells. The results obtained showed that: 1) i.p. treatments with LNC or LNCAC (50 mg/kg, 3-10 days of tumor injection) induced systemic toxicity and, only the treatment with LNC inhibited the melanoma development. Treatment with LNC, but not with mix of triglycerides of medium chain, by oral route, inhibited the tumor development, without toxicity. In addition, the treatments with AC, LNC or LNC-AC were not effective when administered in the late stage of tumor evolution (50 mg/kg, 10-20 days of tumor induction, oral route); 2) the acute treatments with AC, LNC or LNC-AC (20 mg/kg, 200 µL, intravenous route) did not altered the number of circulating leukocytes, but the treatments with LNC or LNC-AC reduced the rolling behavior of leukocytes in postcapillary venules of the cremaster muscle and induced hemolysis. The latter effect was also observed after in vitro treatment using murine erythrocytes; 3) In vitro studies showed that the LNC and LNC-AC suffered uptake by HUVEC and SK-Mel-28 cells after 1 hour of incubation; that the incubation with LNC-AC induced late apoptosis and necrosis more effectively in SK-Mel-28 than in HUVEC cells; that the incubation with LNC or LNC-AC presented antiproliferative effects, by inducing G2M arrest in cell cycle in both cells lines evaluated; that only the incubation with AC or LNC-AC inhibited the adhesion in Matrigel® with more efficaccy in SK-Mel-28 than in HUVEC cells; that only incubtion with LNC reduced the VCAM-1 expression in HUVEC and the incubation with LNC or LNC-AC reduced the β3 integrin expression in SK-Mel-28 cells; that any treatment affected the HUVEC or SK-Mel- 28 migration; that only the incubation with LNC-AC reduced the levels of reactive species of oxygen in HUVEC and SK-Mel-28 cells; that the incubation with LNC or LNC-AC increased the nitric oxide (NO) production by both cell lines used; that the treatment with L-NAME reversed the NO levels and the inhibition on cell proliferation induced by incubation with LNC or LNC-AC and; that the in vitro treatment of murine with LNC or LNC-AC altered the neutrophil polarization to N1 phenotype. Together, results obtained show that the oral treatment with LNC inhibit the melanoma growth without any toxic effect, and that the beneficial effect could be dependent, at least in part, of nanoencapsulation of medium chain triglycerides and the supraestrucuture of the formulation, with direct toxicity on melanoma cells and possible modulation of tumor microenvironment

Role of Translocator 18 KDa Ligands in the Activation of Leukotriene B4 Activated G-Protein Coupled Receptor and Toll Like Receptor-4 Pathways in Neutrophils

TSPO (Translocator 18 KDa; tryptophan-rich sensory protein oxygen sensor) is a constitutive outer mitochondrial membrane protein overexpressed in inflammatory cells during local or systemic processes. Despite its expression is characterized, role of TSPO in inflammation remains elusive. For this study, we investigated the role of TSPO ligands on neutrophil functions elicited by two different inflammatory pathways. Peritoneal neutrophils were isolated from male Balb-C mice, treated with TSPO ligand diazepam, Ro5-4864 or PK11195 (1,100 or 1000 nM; 2 h) and further stimulated with lipopolysaccharide from Escherichia coli (LPS), a binding for Toll-Like Receptor-4 (TLR4), or leukotriene B4 (LTB4), a G-protein coupled receptor (GPCR) ligand. LPS treatment did not lead to overexpression of TSPO on neutrophils, and pre-treatment with any TSPO ligand did not alter cytokine expression, adhesion molecule expression, or the production of reactive oxygen and nitrogen species caused by LPS stimulation. Conversely, all TSPO ligands impaired LTB4’s actions, as visualized by reductions in L-selectin shedding, β2 integrin overexpression, neutrophil chemotaxis, and actin filament assembly. TSPO ligands showed distinct intracellular effects on LTB4-induced neutrophil locomotion, with diazepam enhancing cofilin but not modifying Arp2/3 expression, and Ro5-4864 and PK11195 reducing both cofilin and Arp2/3 expression. Taken together, our data exclude a direct role of TSPO ligands in TLR4-elicited pathways, and indicate that TSPO activation inhibits GPCR inflammatory pathways in neutrophils, with a relevant role in neutrophil influx into inflammatory sites