RESUMO
Chagas disease, caused by the protozoan Trypanosoma cruzi, is an important public health problem in Latin America. Nanoencapsulation of anti-T. cruzi drugs has significantly improved their efficacy and reduced cardiotoxicity. Thus, we investigated the in vitro interaction of polyethylene glycol-block-poly(D,L-lactide) nanocapsules (PEG-PLA) with trypomastigotes and with intracellular amastigotes of the Y strain in cardiomyoblasts, which are the infective forms of T. cruzi, using fluorescence and confocal microscopy. Fluorescently labeled nanocapsules (NCs) were internalized by non-infected H9c2 cells toward the perinuclear region. The NCs did not induce significant cytotoxicity in the H9c2 cells, even at the highest concentrations and interacted equally with infected and non-infected cells. In infected cardiomyocytes, NCs were distributed in the cytoplasm and located near intracellular amastigote forms. PEG-PLA NCs and trypomastigote form interactions also occurred. Altogether, this study contributes to the development of engineered polymeric nanocarriers as a platform to encapsulate drugs and to improve their uptake by different intra- and extracellular forms of T. cruzi, paving the way to find new therapeutic strategies to fight the causative agent of Chagas disease.
Assuntos
Doença de Chagas , Nanocápsulas , Trypanosoma cruzi , Doença de Chagas/tratamento farmacológico , Humanos , Poliésteres , PolietilenoglicóisRESUMO
Standards of care for human visceral leishmaniasis (VL) are based on drugs used parenterally, and oral treatment options are urgently needed. In the present study, a repurposing strategy was used associating tamoxifen (TMX) with polyethylene glycol-block-polylactide nanocapsules (NC) and its anti-leishmanial efficacy was reported in vivo. Stable surface modified-NC (5 mg/mL of TMX) exhibited 200 nm in size, +42 mV of zeta potential, and 98% encapsulation efficiency. Atomic force microscopy evidenced core-shell-NC. Treatment with TMX-NC reduced parasite-DNA quantified in liver and spleen compared to free-TMX; and provided a similar reduction of parasite burden compared with meglumine antimoniate in mice and hamster models. Image-guided biodistribution showed accumulation of NC in liver and spleen after 30 min post-administration. TMX-NC reduced the number of liver granulomas and restored the aspect of capsules and trabeculae in the spleen of infected animals. TMX-NC was tested for the first time against VL models, indicating a promising formulation for oral treatment.
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Sclareol (SC) is arousing great interest due to its cytostatic and cytotoxic activities in several cancer cell lines. However, its hydrophobicity is a limiting factor for its in vivo administration. One way to solve this problem is through nanoencapsulation. Therefore, solid lipid nanoparticles (SLN-SC) and nanostructured lipid carriers (NLC-SC) loaded with SC were produced and compared regarding their physicochemical properties. NLC-SC showed better SC encapsulation than SLN-SC and was chosen to be compared with free SC in human cancer cell lines (MDA-MB-231 and HCT-116). Free SC had slightly higher cytotoxicity than NLC-SC and produced subdiploid DNA content in both cell lines. On the other hand, NLC-SC led to subdiploid content in MDA-MB-231 cells and G2/M checkpoint arrest in HCT-116 cells. These findings suggest that SC encapsulation in NLC is a way to allow the in vivo administration of SC and might alter its biological properties
Assuntos
Células/classificação , Neoplasias , Organização e Administração , Produtos Biológicos/efeitos adversos , DNA , Linhagem Celular , Células HCT116/classificação , Citostáticos/farmacologia , Interações Hidrofóbicas e HidrofílicasRESUMO
BACKGROUND: The co-encapsulation of paclitaxel (PTX) and doxorubicin (DXR) in liposomes has the potential to offer pharmacokinetic and pharmacodynamic advantages, providing delivery of both drugs to the tumor at the ratio required for synergism. OBJECTIVE: To prepare and characterize long-circulating and fusogenic liposomes co-encapsulating PTX and DXR in the 1:10 molar ratio (LCFL-PTX/DXR). METHODS: LCFL-PTX/DXR was prepared by the lipid film formation method. The release of PTX and DXR from liposomes was performed using a dialysis method. Studies of cytotoxicity, synergism, and cellular uptake were also carried out. RESULTS: The encapsulation percentage of PTX and DXR was 74.1 ± 1.8 % and 89.6 ± 12.3%, respectively, and the mean diameter of the liposomes was 244.4 ± 28.1 nm. The vesicles remained stable for 30 days after their preparation. The drugs were simultaneously released from vesicles during 36 hours, maintaining the drugs combination in the previously established ratio. Cytotoxicity studies using 4T1 breast cancer cells showed lower inhibitory concentration 50% (IC50) value for LCFL-PTX/DXR treatment (0.27 ± 0.11 µm) compared to the values of free drugs treatment. In addition, the combination index (CI) assessed for treatment with LCFL-PTX/DXR was equal to 0.11 ± 0.04, showing strong synergism between the drugs. Cell uptake studies have confirmed that the molar ratio between PTX and DXR is maintained when the drugs are administered in liposomes. CONCLUSION: It was possible to obtain LCFL-PTX/DXR suitable for intravenous administration, capable of releasing the drugs in a fixed synergistic molar ratio in the tumor region.
Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/administração & dosagem , Paclitaxel/administração & dosagem , Animais , Antibióticos Antineoplásicos/química , Antineoplásicos Fitogênicos/química , Protocolos de Quimioterapia Combinada Antineoplásica/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Liberação Controlada de Fármacos , Lipossomos , Camundongos , Paclitaxel/químicaRESUMO
The interaction of polymer nanocapsules (NC) prepared from four biodegradable polyesters with variable polymer hydrophobicity (PCL, PLA, PLGA and PLA-PEG) was investigated in the non-phagocytic Vero, Caco-2 and HepG2 cell lines. The NC, labeled with the highly lipophilic fluorescent indocarbocyanine dye DIL, had very similar sizes (approx. 140â¯nm) and negative zeta-potentials. Asymmetric flow field-flow fractionation evidenced NC colloidal stability and negligible transfer of the dye to serum proteins in the incubation medium. The cytotoxicity of the NC was evaluated via MTT assay over a large polymer concentration range (1-1000⯵g/mL) and time of exposure (2, 24 and 48â¯h). The NC were safe in vitro up to a concentration of approx. 100⯵g/mL or higher, depending on the cell line and nature of the polymer. Vero cells were more sensitive to the NC, in particular NC of the more hydrophobic polymer. The cells were exposed to endocytosis inhibitors, incubated with NC, and the cell-associated fluorescence was quantified by spectrofluorometry. HepG2 cells presented a 1.5-2-fold higher endocytic capacity than Caco-2 and Vero cells. The main mechanism of NC uptake was caveolin-mediated endocytosis in HepG2 and Vero cells, and macropinocytosis in Caco-2 cells. Polymer hydrophobicity had an effect on the level of NC associated to HepG2 cells and to a lesser extent on the endocytosis mechanisms in Vero and Caco-2 cells. The NC uptake levels and endocytosis mechanisms differed significantly between cell lines tested.
Assuntos
Nanocápsulas/administração & dosagem , Polímeros/administração & dosagem , Animais , Células CACO-2 , Chlorocebus aethiops , Endocitose , Células Hep G2 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Nanocápsulas/química , Polímeros/química , Células VeroRESUMO
Combination-based chemotherapies have been the standard treatment for multiple solid tumors since the 1960s. Combined therapies where both agents have toxicity results in dose-limiting effects. α- tocopherol succinate (TS) is an analogue of vitamin E that exhibits antitumor properties in the absence of toxicity. Hence, its combination with a frontline chemotherapy, doxorubicin (DOX) is an alternative to increase antitumor efficacy. Therefore, the aim of this work was to evaluate the antitumor activity of nanostructed lipid carriers (NLC) loaded with TS and DOX. The NLC-TS-DOX were prepared, characterized and radiolabeled with technetium-99m. Cytotoxicity studies were performed in vitro, using two breast cancer cell lines, MDA-MB-231 and 4T1. Biodistribution and antitumor activity were evaluated in 4T1 tumor-bearing mice. The results showed that NLC-TS-DOX had a small diameter (85â¯nm) and a long blood clearance (T1/2ßâ¯=â¯1107.71â¯min) that consequently resulted in a higher tumor uptake compared to contralateral muscle for up to 48â¯h. Drug combination studies in MDA-MB-231 and 4T1 cells showed a combination index below 0.8 at ED50-90 for both cell lines. Interestingly, a high synergism was found at ED90. Antitumor activity showed a better control of tumor growth for animals treated with NLC-ST-DOX. The small particle size, along with the EPR effect and the controlled release of DOX from the particle, associated with the synergic combination between TS and DOX led to an increase of the antitumor efficacy. Therefore, NLC-TS-DOX can be considered a plausible alternative to improve antitumor efficacy in DOX therapeutic regimens.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/uso terapêutico , Portadores de Fármacos/química , Lipídeos/química , Nanopartículas/química , alfa-Tocoferol/análogos & derivados , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Modelos Animais de Doenças , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Feminino , Humanos , Camundongos Endogâmicos BALB C , Microscopia de Força Atômica , Tamanho da Partícula , Eletricidade Estática , Distribuição Tecidual , alfa-Tocoferol/farmacologia , alfa-Tocoferol/uso terapêuticoRESUMO
This work aimed to optimise a new nanoemulsion (NE) formulation loaded with Amphotericin B (AmB) and to evaluate its in vivo antileishmanial activity and in vitro haemolytic toxicity. The influence of gradual increases in pressure, using a high-pressure homogeniser, was evaluated. The NE was characterised for droplet size, polydispersity index, zeta potential and encapsulation efficiency (EE). For antileishmanial activity studies, AmB-NE was administered intravenously in mice infected by Leishmania infantum chagasi, which causes Visceral Leishmaniasis (VL). When the NE was submitted to gradual increases in pressure, the PI values and droplet size decreased. The droplet size (â¼145 nm) was lower than that obtained in previous studies. The zeta potential was negative and the EE was almost 100%. The haemolytic toxicity, evaluated on human red blood cells, for AmB-loaded NE was lower than that observed for the conventional AmB (C-AmB). C-AmB at 2 mg/kg was very toxic. In contrast, administration of the AmB-loaded NE, at same dose, did not result in any sign of acute toxicity, promoting a significant reduction in parasite burden as compared to the C-AmB. These findings suggest that this new AmB-loaded NE constitutes an attractive alternative for the treatment of VL due to improved efficacy and lower toxicity.
Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Leishmaniose Visceral/tratamento farmacológico , Nanopartículas , Anfotericina B/farmacologia , Anfotericina B/toxicidade , Animais , Antiprotozoários/farmacologia , Antiprotozoários/toxicidade , Emulsões , Feminino , Hemólise/efeitos dos fármacos , Humanos , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da PartículaRESUMO
Lychnopholide, a lipophilic sesquiterpene lactone, is efficacious in mice at the acute and chronic phases of Chagas disease. Conventional poly-ε-caprolactone (PCL) and long-circulating poly(D,L-lactide)-block-polyethylene glycol (PLA-PEG) nanocapsules containing lychnopholide were developed and characterized. Lychnopholide presented high association efficiency (>90%) with the nanocapsules. A new, fast and simple HPLC-UV-based bioanalytical method was developed, validated in mouse plasma and applied to lychnopholide quantification in in vitro release kinetics and pharmacokinetics. The nanocapsules had mean hydrodynamic diameters in the range of 100-250 nm, negative zeta potentials (-30 mV to -57 mV), with good physical stability under storage. Atomic force microscopy morphological analysis revealed spherical monodispersed particles and the absence of lychnopholide crystallization or aggregation. Association of lychnopholide to PLA-PEG nanocapsules resulted in a 16-fold increase in body exposure, a 26-fold increase in plasma half-life and a dramatic reduction of the lychnopholide plasma clearance (17-fold) in comparison with free lychnopholide. The improved pharmacokinetic profile of lychnopholide in long-circulating nanocapsules is in agreement with the previously reported improved efficacy observed in Trypanosoma cruzi-infected mice. The present lychnopholide intravenous dosage form showed great potential for further pre-clinical and clinical studies in Chagas disease and cancer therapies.
Assuntos
Lactonas/administração & dosagem , Lactonas/farmacocinética , Nanoestruturas/química , Sesquiterpenos/administração & dosagem , Sesquiterpenos/farmacocinética , Tripanossomicidas/administração & dosagem , Tripanossomicidas/farmacocinética , Administração Intravenosa , Animais , Cromatografia Líquida de Alta Pressão , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Feminino , Lactonas/análise , Camundongos , Microscopia de Força Atômica , Nanoestruturas/administração & dosagem , Poliésteres/química , Polietilenoglicóis/química , Reprodutibilidade dos Testes , Sesquiterpenos/análise , Tripanossomicidas/análiseRESUMO
INTRODUCTION: The use of symptom-specific questionnaires on head and neck cancer (HNC), together with objective swallowing measures, can be sensitive to changes in quality of life (QoL) resulting from dysphagia, but this tool is not broadly used as a complement to clinical evaluations. PURPOSE: To analyze the correlation between the M. D. Anderson Dysphagia Inventory (MDADI) questionnaire and videofluoroscopy (VF) in patients treated for head and neck cancer. METHODS: This is a retrospective study with review of clinical data, VF and MDADI results. The study sample was composed of adult patients (>18 y.o.) treated for tumors at the oral cavity, oropharynx, hypopharynx, and larynx, regardless of treatment type. For the VF examination, swallowing of 5 and 20 ml of nectar-thick liquids were considered. The Mann-Whitney nonparametric test was applied to evaluate the correlations between the MDADI and VF. RESULTS: Thirty-nine patients, mostly men (87.18%), with mean age of 61 years participated in the study. Most patients (16) presented oral cavity tumors (41.03%). Twenty-two patients were in advanced clinical stage (IV). Surgery was the most prevalent treatment (41.03%). Approximately half of the participants (20) received oral feeding. The total mean (TM) on the MDADI was 63.36. Comparison between VF and MDADI data showed significant correlation between TM, emotional domain (ED), and physical domain (PD) with penetration during the swallowing of 5 ml. Penetration and aspiration with 20 ml determined worse QoL on the global (p=0.018 and p=0.0053), emotional (p=0.0012 and p=0.027) and physical (p=0.0002 and p=0.0051) domains, and TM (p=0.0023 and p=0.0299), respectively. The presence of stasis did not determine worse QoL. CONCLUSION: Patients treated for HNC who presented penetration/aspiration showed worse QoL on the emotional and physical domains of the MDADI.
Assuntos
Transtornos de Deglutição/psicologia , Neoplasias de Cabeça e Pescoço/terapia , Qualidade de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/etiologia , Feminino , Fluoroscopia , Neoplasias de Cabeça e Pescoço/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatísticas não Paramétricas , Inquéritos e Questionários , Adulto JovemRESUMO
RESUMO Introdução A utilização de questionários sintoma-específicos no câncer de cabeça e pescoço (CCP) em conjunto com avaliações objetivas da deglutição pode ser sensível às mudanças na qualidade de vida (QV) decorrentes da disfagia, porém é uma ferramenta pouco utilizada como complemento de avaliações clínicas. Objetivo analisar a associação entre o questionário de disfagia M. D. Anderson (MDADI) com a videofluoroscopia (VF) da deglutição em pacientes tratados do CCP. Método Estudo retrospectivo, com revisão de prontuários, dados da VF e do questionário de disfagia MDADI. Foram incluídos indivíduos maiores de 18 anos, tratados do câncer de cavidade oral, orofaringe, hipofaringe e laringe, independentemente do tratamento curativo. Para o exame de VF, foram consideradas as deglutições de 5 e 20 ml na consistência néctar. O teste não paramétrico de Mann-Whitney foi utilizado para avaliar a associação entre o questionário MDADI e a VF. Resultados Casuística de 39 indivíduos, predomínio de homens, 34 (87,18%), e média de idade de 61 anos. Prevalência de câncer de cavidade oral, 16 (41,03%). Vinte e dois (56,4%) possuíam estádio clínico IV. Cirurgia isolada foi o tratamento mais prevalente, 16 (41,03%). Vinte indivíduos (51,28%) se alimentavam por via oral. A média total (MT) do MDADI foi de 63,36. Na correlação da VF com o MDADI, observou-se associação significante entre MT, domínio emocional (DE) e domínio físico (DFis) com penetração para 5 ml. Penetração e aspiração com 20 ml determinou prejuízo para questão global (p=0,018 e p=0,0053), DE (p=0,0012 e p=0,027), DFis (p=0,0002 e p=0,0051) e MT (p=0,0023 e p=0,0299), respectivamente. A presença de estase não determinou piora da QV. Conclusão Pacientes tratados do CCP que apresentam penetração/aspiração demonstram impacto na qualidade de vida nos DE e DFis.
ABSTRACT Introduction The use of symptom-specific questionnaires on head and neck cancer (HNC), together with objective swallowing measures, can be sensitive to changes in quality of life (QoL) resulting from dysphagia, but this tool is not broadly used as a complement to clinical evaluations. Purpose To analyze the correlation between the M. D. Anderson Dysphagia Inventory (MDADI) questionnaire and videofluoroscopy (VF) in patients treated for head and neck cancer. Methods This is a retrospective study with review of clinical data, VF and MDADI results. The study sample was composed of adult patients (>18 y.o.) treated for tumors at the oral cavity, oropharynx, hypopharynx, and larynx, regardless of treatment type. For the VF examination, swallowing of 5 and 20 ml of nectar-thick liquids were considered. The Mann-Whitney nonparametric test was applied to evaluate the correlations between the MDADI and VF. Results Thirty-nine patients, mostly men (87.18%), with mean age of 61 years participated in the study. Most patients (16) presented oral cavity tumors (41.03%). Twenty-two patients were in advanced clinical stage (IV). Surgery was the most prevalent treatment (41.03%). Approximately half of the participants (20) received oral feeding. The total mean (TM) on the MDADI was 63.36. Comparison between VF and MDADI data showed significant correlation between TM, emotional domain (ED), and physical domain (PD) with penetration during the swallowing of 5 ml. Penetration and aspiration with 20 ml determined worse QoL on the global (p=0.018 and p=0.0053), emotional (p=0.0012 and p=0.027) and physical (p=0.0002 and p=0.0051) domains, and TM (p=0.0023 and p=0.0299), respectively. The presence of stasis did not determine worse QoL. Conclusion Patients treated for HNC who presented penetration/aspiration showed worse QoL on the emotional and physical domains of the MDADI.
Assuntos
Humanos , Masculino , Feminino , Adulto , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Qualidade de Vida , Transtornos de Deglutição/psicologia , Neoplasias de Cabeça e Pescoço/terapia , Fluoroscopia , Transtornos de Deglutição/etiologia , Inquéritos e Questionários , Estudos Retrospectivos , Estatísticas não Paramétricas , Neoplasias de Cabeça e Pescoço/complicações , Pessoa de Meia-IdadeRESUMO
There is a great need for orally active drugs for the treatment of the neglected tropical disease leishmaniasis. Amphiphilic Sb(V) complexes, such as 1:3 Sb-N-octanoyl-N-methylglucamide complex (SbL8), are promising drug candidates. It has been previously reported that SbL8 forms kinetically stabilized nanoassemblies in water and that this simple dispersion exhibits antileishmanial activity when given by oral route to a murine model of visceral leishmaniasis. The main objective of the present work was to interfere in the structural organization of these nanoassemblies so as to investigate their influence on the oral bioavailability of Sb, and ultimately, optimize an oral formulation of SbL8 for the treatment of cutaneous leishmaniasis. The structural organization of SbL8 nanoassemblies was manipulated through addition of propylene glycol (PG) to the aqueous dispersion of SbL8. The presence of 50% (v/v) PG resulted in the loss of hydrophobic microenvironment, as evidenced by fluorescence probing. However, nanostructures were still present, as demonstrated by dynamic light scattering, small-angle X-ray scattering, and atomic force microscopy (AFM). A remarkable property of these nanoassemblies, as revealed by AFM analysis, is the flexibility of their supramolecular organization, which showed changes as a function of the solvent and substrate polarities. The formulation of SbL8 in 1:1 water:PG given orally to mice promoted significantly higher and more sustained serum levels of Sb, when compared to SbL8 in water. The new formulation, when given as repeated doses (200 mg Sb/kg/day) to BALB/c mice infected with Leishmania amazonensis, was significantly more effective in reducing the lesion parasite burden, compared to SbL8 in water, and even, the conventional drug Glucantime(®) given intraperitoneally at the same dose. In conclusion, this work introduces a new concept of polarity-sensitive nanocarrier that was successfully applied to optimize an oral formulation of Sb(V) for treating cutaneous leishmaniasis.
Assuntos
Antimônio/uso terapêutico , Antiprotozoários/uso terapêutico , Portadores de Fármacos/química , Leishmaniose Cutânea/tratamento farmacológico , Nanopartículas/química , Administração Oral , Animais , Antimônio/sangue , Antimônio/farmacocinética , Antiprotozoários/química , Antiprotozoários/farmacocinética , Modelos Animais de Doenças , Feminino , Interações Hidrofóbicas e Hidrofílicas , Meglumina/uso terapêutico , Antimoniato de Meglumina , Camundongos Endogâmicos BALB C , Microscopia de Força Atômica , Nanopartículas/ultraestrutura , Compostos Organometálicos/uso terapêutico , Espalhamento a Baixo Ângulo , Solventes , Resultado do Tratamento , Difração de Raios XRESUMO
Paclitaxel (PTX) is widely used as a first-line treatment for patients with metastatic breast cancer; however, its poor water solubility represents a major challenge for parenteral administration. The encapsulation of the PTX in drug-delivery systems with high affinity for tumor sites could improve the uptake and increase its therapeutic efficacy. In this work, long-circulating and pH-sensitive PEG-coated (SpHL-PTX) and PEG-folate-coated liposomes containing PTX (SpHL-FT-PTX) were prepared, and the physicochemical properties and in vitro cytotoxic activity were evaluated. Both formulations presented adequate physicochemical properties, including a mean diameter smaller than 200 nm, zeta potential values near the neutral range, and an encapsulation percentage higher than 93%. Moreover, SpHL-FT-PTX showed a good stability after storage for 100 days at 4 °C. The viability studies on breast cancer cell lines (MDA-MB-231 and MCF-7) demonstrated cytotoxic activity more pronounced for SpHL-FT-PTX than for SpHL-PTX or free drug for both tumor cell lines. This activity was reduced to a rate comparable to SpHL-PTX when the cells were previously treated with folic acid in order to saturate the receptors. In contrast, in the normal cell line (L929), cell viability was decreased only by free or liposomal PTX in the highest concentrations. A significantly higher selectivity index was obtained after SpHL-FT-PTX treatment compared to SpHL-PTX and free PTX. Therefore, the results of the present work suggest that SpHL-FT-PTX can be a promising formulation for the treatment of metastatic breast cancer.
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Neoplasias da Mama/tratamento farmacológico , Lipídeos/administração & dosagem , Lipossomos , Paclitaxel/uso terapêutico , HumanosRESUMO
We report the in vitro release profile and comparative pharmacokinetics and biodistribution of a new peroxisome proliferator-activated receptor-γ agonist and cyclooxygenase inhibitor (Lyso-7) free or associated to poly(D,L-lactic acid) nanocapsules (NC) after intravenous administration in mice. Lyso-7 pertains to the class of insulin-sensitizing agents that shows potential beneficial effects in diabetes therapy. Monodispersed Lyso-7 NC with a mean diameter of 273 nm with high encapsulation efficiency (83%) were obtained. Lyso-7 dissolution rate was reduced (2.6-fold) upon loading in NC. The pharmacokinetic parameters were determined using a non-compartmental approach. In comparison with Lyso-7 in solution, the plasma-AUC increased 14-fold, the mean residence time 2.6-fold and the mean half-life (t1/2) 1.5-fold for Lyso-7-NC; the Lyso-7 plasma clearance, distribution volume and elimination rate were reduced 13, 10 and 1.4 fold, respectively, which indicates higher retention of encapsulated Lyso-7 in the blood compartment. Upon association with NC, organ exposure to Lyso-7 was higher in the heart (3.6-fold), lung (2.8-fold), spleen (2.3-fold), kidney (2-fold) and liver (1.8-fold) compared to Lyso-7 in solution. The analysis of whole data clearly indicates that body exposure to Lyso-7 was enhanced and the general toxicity reduced upon nanoencapsulation, allowing further evaluation of Lyso-7 in nonclinical and clinical studies.
Assuntos
Inibidores de Ciclo-Oxigenase/administração & dosagem , Inibidores de Ciclo-Oxigenase/farmacocinética , Indóis/administração & dosagem , Indóis/farmacocinética , Nanocápsulas/administração & dosagem , PPAR gama/agonistas , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/farmacocinética , Animais , Inibidores de Ciclo-Oxigenase/sangue , Inibidores de Ciclo-Oxigenase/química , Eritrócitos/efeitos dos fármacos , Feminino , Hemólise/efeitos dos fármacos , Indóis/sangue , Indóis/química , Rim/metabolismo , Fígado/metabolismo , Pulmão/metabolismo , Camundongos , Miocárdio/metabolismo , Nanocápsulas/química , Nanocápsulas/ultraestrutura , Tamanho da Partícula , Baço/metabolismo , Propriedades de Superfície , Tiazolidinedionas/sangue , Tiazolidinedionas/química , Distribuição TecidualRESUMO
BACKGROUND: Human T-lymphotropic virus 1 (HTLV-1) has been associated with leukemia/lymphoma (ATL) and myelopathy/tropical spastic paraparesis (HAM/TSP), in addition to other inflammatory diseases as well as infection complications. Therapeutic approaches for HTLV-1-related pathologies are limited. The labdane diterpene myriadenolide (AMY) is a natural product that exhibit biological activities, such as anti-inflammatory and antiviral activity as reported for HIV and herpesvirus. RESULTS: We demonstrated that this natural product was able to inhibit the expression of gag-pol mRNA and substantially reduced the expression of the structural proteins p19 and gp46. Comparison of treated and untreated cells shows that AMY alters both the morphology and the release of viral particles. The Atomic Force Microscopy assay showed that the AMY treatment reduced the number of particles on the cell surface by 47%. CONCLUSION: We demonstrated that the labdane diterpene myriadenolide reduced the expression of the structural proteins and the budding of viral particles, besides induces altered morphogenesis of HTLV-1, conferring on AMY a new antiviral activity that may be useful for the development of new compounds with specific anti-HTLV-1 activity.
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Antivirais/farmacologia , Diterpenos/farmacologia , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Morfogênese/efeitos dos fármacos , RNA Mensageiro/genética , Anti-Inflamatórios/farmacologia , Fatores Biológicos/farmacologia , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Humanos , Células JurkatRESUMO
Atomic force microscopy image analysis and energy dispersive X-ray diffraction experiments were used to investigate the structural organization of cationic nanoemulsion/oligonucleotide complexes. Oligonucleotides targeting topoisomerase II gene were adsorbed on cationic nanoemulsions obtained by means of spontaneous emulsification procedure. Topographical analysis by atomic force microscopy allowed the observation of the nanoemulsion/oligonucleotide complexes through three-dimensional high-resolution images. Flattening of the oil droplets was observed, which was reduced in the complexes obtained at high amount of adsorbed oligonucleotides. In such conditions, complexes exhibit droplet size in the 600nm range. The oligonucleotides molecules were detected on the surface of the droplets, preventing their fusion during aggregation. A lamellar structure organization was identified by energy dispersive X-ray diffraction experiments. The presence of the nucleic acid molecules led to a disorganization of the lipid arrangement and an expansion in the lattice spacing, which was proportional to the amount of oligonucleotides added.
Assuntos
Nanoestruturas/química , Oligonucleotídeos Antissenso/química , Cátions , DNA Topoisomerases Tipo II/genética , DNA de Protozoário/genética , Sistemas de Liberação de Medicamentos , Emulsões , Marcação de Genes , Microscopia de Força Atômica , Nanoestruturas/ultraestrutura , Oligonucleotídeos Antissenso/administração & dosagem , Oligonucleotídeos Antissenso/genética , Plasmodium falciparum/enzimologia , Plasmodium falciparum/genética , Difração de Raios XRESUMO
Nanoparticles of poly(d,l-lactide-co-glycolide), poly(d,l-lactide) and polyethylene glycol-block-poly(d,l-lactide) were developed to encapsulate chloroaluminium phthalocyanine (AlClPc), a new hydrophobic photosensitiser used in photodynamic therapy (PDT). The mean nanoparticle size varied from 115 to 274 nm, and the encapsulation efficiency ranged from 57% to 96% due to drug precipitation induced by different types of polymer. All nanoparticle formulations presented negative zeta potential values (-37 mV to -59 mV), explaining their colloidal stability. The characteristic photophysical parameters were analysed: the absorption spectrum profile, fluorescence quantum yield and transient absorbance decay, with similar values for free and nanoparticles of AlClPc. The time-resolved spectroscopy measurements for AlClPc triplet excited state lifetimes indicate that encapsulation in nanocapsules increases triplet lifetime, which is advantageous for PDT efficiency. A sustained release profile over 168 h was obtained using external sink method. An in vitro phototoxic effect higher than 80% was observed in human fibroblasts at low laser light doses (3 J/cm(2)) with 10 µM of AlClPc. The AlClPc loaded within polymeric nanocapsules presented suitable physical stability, improved photophysical properties, sustained released profile and suitable activity in vitro to be considered a promising formulation for PDT.
Assuntos
Indóis/química , Nanocápsulas/química , Nanosferas/química , Compostos Organometálicos/química , Fármacos Fotossensibilizantes/química , Polímeros/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fibroblastos/efeitos dos fármacos , Humanos , Indóis/administração & dosagem , Microscopia de Força Atômica , Nanocápsulas/administração & dosagem , Nanosferas/administração & dosagem , Compostos Organometálicos/administração & dosagem , Fármacos Fotossensibilizantes/administração & dosagem , Polímeros/administração & dosagem , SolubilidadeRESUMO
This study investigated the anti-viral effects of the polyphenolic compounds Quercetin and Kaempherol on the release of HTLV-1 from the surface of MT-2 cells. Atomic force microscopy (AFM) was used to scan the surface of the MT-2 cells. MT-2 cells were fixed with 100% methanol on round glass lamina or cleaved mica and dried under UV light and laminar flow. The images were captured on a Multimode equipment monitored by a NanoScope IIId controller from Veeco Instruments Inc operated in tapping mode and equipped with phase-imaging hardware. The images demonstrated viral budding structures 131 ± 57 nm in size, indicating profuse viral budding. Interestingly, cell-free viruses and budding structures visualized on the surface of cells were less common when MT-2 was incubated with Quercetin, and no particles were seen on the surface of cells incubated with Kaempherol. In summary, these data indicate that HTLV-1 is budding constantly from the MT-2 cell surface and that polyphenolic compounds were able to reduce this viral release. Biological samples were analyzed with crude cell preparations just after cultivation in the presence of Quercetin and Kaempherol, showing that the AFM technique is a rapid and powerful tool for analysis of antiviral activity of new biological compounds.
Assuntos
Antivirais/farmacologia , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Quempferóis/farmacologia , Quercetina/farmacologia , Linfócitos T/ultraestrutura , Linfócitos T/virologia , Liberação de Vírus/efeitos dos fármacos , Microscopia de Força AtômicaRESUMO
The present work describes the preparation, labeling, physicochemical characterization, and in vitro cytotoxic evaluation of long circulating pH-sensitive liposomes containing (159)Gd-DTPA-BMA. These liposomes were successfully obtained and submitted to neutron irradiation for gadolinium labeling. Their size, distribution, and homogeneity were determined by photon correlation spectroscopy, while their zeta potential was determined by laser Doppler anemometry. The morphology and structural organization were evaluated by atomic force microscopy. The stability and release profiles of Gd-DTPA-BMA in the liposomes were determined in vitro in Dubelco's Modified Eagle's Medium and rat serum at 70%. The results showed that liposomes remained physically stable after 8 h of irradiation and presented a low release profile of its content in two different biological mediums. The formulation of liposomes containing (159)Gd and its respective controls were evaluated by in vitro cytotoxicity against tumor cells RT2. The results showed increased cytotoxic activity of approximately 1170 fold in relation to free Gd-DTPA-BMA.
Assuntos
Gadolínio DTPA/química , Compostos Radiofarmacêuticos/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Físico-Química , Relação Dose-Resposta a Droga , Composição de Medicamentos , Estabilidade de Medicamentos , Gadolínio DTPA/administração & dosagem , Gadolínio DTPA/sangue , Gadolínio DTPA/farmacologia , Técnicas In Vitro , Lipossomos , Camundongos , Microscopia de Força Atômica , Estrutura Molecular , Tamanho da Partícula , Fótons , Radioisótopos , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/sangue , Compostos Radiofarmacêuticos/farmacologia , Ratos , Solubilidade , Propriedades de SuperfícieRESUMO
Complement activation is an important step in the acceleration of liposome clearance. The anaphylatoxins released following complement activation may motivate a wide variety of physiologic changes. We performed physicochemical characterization and in vitro studies of the interaction of complement system with both noncirculating and long-circulating pH-sensitive and nonpH-sensitive liposomes. The liposomes were characterized by diameter, zeta potential, and atomic force microscopy (AFM). The study of liposome interactions with complement system was conducted using hemolytic assay in rat serum. All liposomes presented a similar mean diameter (between 99.8 and 124.3 nm). The zeta potential was negative in all liposome preparations, except in liposomes modified with aminopoly (ethyleneglycol) 2000-distearoylphosphatidylethanolamine (aPEG(2000)-DSPE), which presented positive zeta potential. Atomic force microscopy images showed that non-long-circulating pH-sensitive liposomes are prone to vesicles aggregation. Non-pH-sensitive liposomes complement system activates, while pH-sensitive liposomes showed to be poor complement activators in rat serum.
Assuntos
Ativação do Complemento , Proteínas do Sistema Complemento/química , Lipossomos/química , Animais , Colesterol/química , Proteínas Inativadoras do Complemento/química , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Lipídeos/química , Masculino , Membranas/química , Microscopia de Força Atômica , Fosfatidilcolinas/química , Ratos , Ratos WistarRESUMO
Several classes of antifungal have been employed in candidiasis treatment, but patients with advanced immunodeficiency can present unsatisfactory results after therapy. In these cases, high doses of drugs or the use of multiple agents are sometimes used, and hence increasing the risk of serious side effects. Considering theses difficulties, the encapsulation of antifungal agents in nanoparticulate carriers has been used with the objective of modifying the pharmacokinetic of drugs resulting in more efficient treatments with less side effects. The purpose of this work was the preparation, characterization and the investigation of the release profiles of radiolabeled fluconazole nanocapsules. The size, homogeneity and zeta potential of NC preparations were determined with a Zetasizer 3000HS. The morphology and the structural organization were evaluated by atomic force microscopy (AFM). The release study in vitro of NC was evaluated in physiologic solution with or without 70% mouse plasma. The labeling yield of fluconazole with 99mTc was 94% and the radiolabeled drug was stable within 24h period. The encapsulation percentage of 99mTc-fluconazole in PLA-POLOX NC and PLA-PEG NC was approximately of 30%. The average diameter calculated by photon correlation spectroscopy (PCS) varied from 236 to 356 nm, while the average diameter determined by AFM varied from 238 to 411 nm. The diameter/height relation decreased significantly when 25% glutaraldehyde was used for NC fixation on mica. The zeta potential varied from -55 to -69 nm and surface-modified NC showed lower absolute values than conventional NC. The in vitro release of 99mTc-fluconazole in plasma medium of the conventional and surface-modified NC was greater than in saline. The drug release in plasma medium from conventional NC was faster than for surface-modified NC. The results obtained in this work suggest that the nanocapsules containing fluconazole could be used to identify infectious foci, due to the properties, such as size, zeta potential and controlled release of (99m)Tc-fluconazole. The surface-modified nanocapsules could constitute a long-circulating intravenous formulation of fluconazole for treating sepsis caused by disseminated form of candidiasis. However, in vivo studies should be considered and are under investigation.