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1.
São Paulo; s.n; s.n; 2022. 97 p. graf, ilus.
Thesis in English | LILACS | ID: biblio-1416767

ABSTRACT

Cardiovascular diseases (CVDs) are the main cause of mortality worldwide, being the ischemic heart disease responsible for 85% of deaths. Atherosclerosis is a chronic inflammation of the arteries that underlies ischemic forms of CVD and involves the innate and adaptive immune systems, from initial fatty streak formation to atherosclerotic plaque ruptures, which defines the beginning and end stages of disease, respectively. Recent research on the reduction of systemic inflammation in order to treat CVD is controversial, since results show that this reduced inflammation can also increase patient susceptibility to general infection. Therefore, new tissue-targeting strategies are necessary. Docosahexaenoic fatty acid (DHA) is a natural bioactive precursor of pro-resolving oxylipins that can reduce inflammation. Based on these factors, the objective of this study was to develop a nanocapsule containing algae oil as a DHA source and apply anti-PECAM-1 on its surface to drive it to the inflamed endothelium. Initially, a surface-functionalized metal-complex multi-wall nanocapsule containing algae oil in its nucleus (MLNC-DHA-a1) was developed. This nanocapsules presented a mean diameter of 163 ± 5 nm, was spherical in shape, showed 94.80% conjugation efficiency using 200 µg/mL of anti-PECAM-1 on the surface, and did not show significant toxicity toward HUVECs at concentrations from 0.14 to 2.90x1011 nanocapsules/mL. The nanocapsules were also stable for 2 h, sufficient time to allow for clinical applications. In cell viability assays, concentrations of 0.14 to 1.40x1011 nanocapsules/mL did not significantly affect the viability of immortalized murine macrophages (RAW 264.7) and U-937 cells after 24, 48, and 72 h of treatment. Finally, macrophages were incubated with 0.75x1011 MLNC-DHA-a1 nanocapsules/mL for 4 h and showed a significant uptake, observed using dark-field hyperspectral microscopy (CytoViva®). Once inside murine macrophages (RAW 264.7), MLNC-DHA-a1 nanocapsules promoted a strong increase in M2 phenotype polarization compared to non-treated control cells. Our results suggest that DHA-enriched algae oil, as part of a lipid core nanocapsules, does not reduce cell viability and improves macrophage phenotype, making it a promising potential therapy for controlling chronic inflammation and healing or stabilizing atherosclerotic plaques


As doenças cardiovasculares (DCVs) são a principal causa de mortalidade no mundo, sendo os eventos isquêmicos responsáveis por 85% das mortes. A aterosclerose é uma inflamação crônica das artérias associada aos eventos isquêmicos das DCVs, na qual o sistema imunológico inato e adaptativo estão envolvidos desde a formação inicial das estrias gordurosas até a ruptura das placas ateroscleróticas. Pesquisas recentes direcionadas à redução da inflamação sistêmica têm mostrado resultados controversos, pois essa abordagem pode aumentar a susceptibilidade do paciente a infecções. Nesse sentido, novas estratégias direcionadas ao tecido lesionado são necessárias. No que se refere a medicamentos anti-inflamatórios ou suplementos alimentares, o ácido docosaexaenóico (DHA) tem sido relatado como um precursor natural de oxilipinas pró- resolutivas. Baseado nesse contexto, o objetivo deste estudo foi desenvolver nanocápsulas contendo óleo de alga como fonte de DHA e vetorizar essas nanopartículas com o anticorpo antiPECAM-1 em sua superfície, visando direcioná-las ao endotélio inflamado. Inicialmente, a nanocápsula multiparede metal-complexa funcionalizada contendo óleo de alga em seu núcleo (MLNC-DHA-a1) foi desenvolvida, apresentando um diâmetro médio de 163 ± 5 nm, formato esférico, onde a eficiência de conjugação do anti-PECAM-1 (200 µg/mL) foi de 94,80% sem toxicidade significativa em HUVECs nas concentrações de 1.14 a 2.9 x 1011 nanocápsulas/mL. As nanocápsulas apresentaram uma estabilidade de 2h, o que representa tempo suficiente para a sua aplicação clínica. A seguir, ensaios de viabilidade celular foram realizados em outras linhagens de células para avaliar a toxicidade das nanocápsulas. As concentrações de 0.14 a 1.40 x 1011 de nanocápsulas/mL não afetaram significativamente a viabilidade celular de macrófagos murinos imortalizados (RAW 264.7) e U-937 após 24, 48 e 72 h de tratamento. Por fim, os macrófagos (RAW 264.7) foram incubados com 0.75 x 1011 MLNC-DHA-a1/mL durante 4 h e apresentam uma captação significativa das nanocápsulas, observada por microscopia hiperespectral de campo escuro (CytoViva®). Uma vez captadas pelos macrófagos murinos imortalizados (RAW 264.7), as nanoformulações MLNC-DHA-a1 promoveram um forte aumento da polarização do fenótipo M2 em comparação com as células controle não tratadas. Nossos resultados sugerem que o óleo de alga rico em DHA presente no núcleo lipídico das nanocápsulas, não reduziu a viabilidade celular e estimulou uma maior polarização de macrófagos para o tipo M2, sendo assim uma terapia potencial para controlar a inflamação crônica e cicatrizar ou estabilizar placas ateroscleróticas


Subject(s)
Pharmaceutical Preparations/analysis , Cardiovascular Diseases/classification , Docosahexaenoic Acids/analysis , Atherosclerosis/pathology , Nanocapsules/analysis , Plaque, Atherosclerotic/metabolism , Arteries/abnormalities , Causality , Health Strategies , Platelet Endothelial Cell Adhesion Molecule-1 , Nanoparticles , Anti-Inflammatory Agents/administration & dosage
2.
Braz. J. Pharm. Sci. (Online) ; 55: e18736, 2019. tab, graf
Article in English | LILACS | ID: biblio-1011637

ABSTRACT

The major objective of this study was to investigate the effect of biodegradable polymer type and surfactant concentration on various characteristics viz. particle size, entrapment efficiency and drug release rate constant of aqueous core nanocapsules (ACNs) containing tenofovirdisoproxil fumarate. In this study, the nanocapsules were prepared by modified multiple emulsion technique with biodegradable polymers viz. poly(lactide-co-glycolide) of two different grades (PLGA RG502H and PLGA RG503H) and poly lactic acid (PLA R203H); and the surfactant employed was span 80. The experiments were designed under response surface methodology by employing the Design Expert software. Entrapment efficiency, particle size and drug release rate constant were taken as response variables. The prepared nanocapsules were subjected to characterization studies and the obtained results were statistically analyzed by Analysis of Variance (ANOVA) for response surface 2-Factorial Interaction model. ANOVA studies showed that the influence of both factors on all the response variables were significant at p<0.05. The optimized formulation was found to have the entrapment efficiency of 71.58%, particle size of 252.41 nm and the drug release rate constant of 0.045 h-1; thus, indicating that the ACNs were obtained with finest characteristics. SEM studies showed that the particles were spherical.


Subject(s)
Surface-Active Agents/adverse effects , Analysis of Variance , Nanocapsules/analysis , In Vitro Techniques/instrumentation , Pharmaceutical Preparations
3.
Braz. J. Pharm. Sci. (Online) ; 53(1): e16101, 2017. tab, graf
Article in English | LILACS | ID: biblio-839444

ABSTRACT

Abstract The purpose of this study was to prepare and characterize mupirocin-loaded polymeric nanocapsules using two different oils and to develop and validate an analytical method for quantitative determination by high performance liquid chromatography. The mean size of the nanoparticles was 233.05 nm and 275.03 nm for nanocapsules with a rosemary oil like oily core and caprylic/capric triglyceride, respectively, and a good polydispersity index below 0.25 for both formulations. The nanocapsules showed good stability when stored at 40 ºC and room temperature for 30 days. The quantitative method was performed with a mobile phase consisting of ammonium ammonium acetate (0.05 M adjusted to pH 5.0 with acetic acid) and acetonitrile 60:40 (v/v); the flow rate was 0.8 mL/min, UV detection at 230 nm. The analytical method was linear in the range of 5.0-15.0 µg/mL, specific for both oils, accurate, precise (intermediate precision RSD = 1.68% and repeatability RSD = 0.81%) and robust under the evaluated conditions. Therefore, this method can be performed for quantification of mupirocin in polymeric nanocapsules containing both oils.


Subject(s)
Oils, Volatile/therapeutic use , Mupirocin/pharmacology , Rosmarinus/classification , Chromatography, High Pressure Liquid/instrumentation , Nanocapsules/analysis
4.
São Paulo; s.n; s.n; mar. 2015. 101 p. tab, graf, ilus.
Thesis in Portuguese | LILACS | ID: biblio-836698

ABSTRACT

Jacaranda decurrens Cham., Jacaranda caroba (Vell.) DC. e Piper umbellatum L. são plantas nativas do Brasil, presentes no estado de São Paulo, com relatos de uso popular para atividade antiúlcera. Este trabalho teve como objetivo avaliar a atividade antiúlcera de J. caroba, J. decurrens e formulações de nanocápsulas contendo P. umbellatum. Também pretendeu-se caracterizar a fitoquímica de tais formulações e extratos. Adicionalmente, foi avaliada a toxicidade aguda e subaguda de J. caroba. Os extratos de Jacaranda apresentaram compostos fenólicos em seus perfis cromatográficos obtidos por CCD e CLAE, característicos para cada espécie. Os diferentes extratos de J. caroba variaram sua composição química conforme a procedência e idade da planta. As espécies J. decurrens e J. caroba de três diferentes regiões não apresentaram ação antiúlcera aguda em ratos em modelo de indução por etanol acidificado, embora o extrato e as frações de J. caroba apresentaram potencial atividade anti Helicobacter pylori, com CIM variando entre 125 e 1.000 µg/mL. O extrato de J. caroba não promoveu sintomas de toxicidade aguda e subaguda em ratos. A DL50 observada foi maior que 5.000 mg/kg. Não foram relatadas alterações significativas na aparência macroscópica e peso dos órgãos, porém houve indicação de atividade mutagênica em teste de Ames na linhagem TA98 de S. typhimurium, o qual apresentou uma tendência dose-resposta para concentrações entre 7,5 e 15,0 mg/placa após ativação metabólica (S9). A formulação de nanocápsulas de poli-ε- caprolactona com extrato de P. umbellatum apresentou partículas com diâmetro médio de 181,6 ± 0,9 nm e potencial zeta de -31 ± 4 mV. Através de análise por CLAE observou-se maior eficiência de encapsulamento para a porção mais apolar da fração, enquanto que os compostos mais polares ficaram dispersos no meio. As nanocápsulas poliméricas apresentaram atividade gastroprotetora mesmo sem a adição de ativos e tiveram sua atividade aumentada pela fração clorofórmica de P. umbellatum


Jacaranda decurrens Cham., Jacaranda caroba (Vell.) DC. and Piper umbellatum L. are native plants in Brazil, present in the state of São Paulo, with popular usage reports for anti-ulcer activity. This study aimed to evaluate the anti-ulcer activity of J. caroba, J. decurrens and nanocapsules formulations containing P. umbellatum. Also, we intended to characterize the phytochemistry of such formulations and extracts. Additionally, we evaluated the acute and subacute toxicity of J. caroba. Extracts from Jacaranda presented phenolic compounds in their chromatographic profiles obtained by TLC and HPLC, with variations between species. Samples of J. caroba extracts showed different chemical composition according to the origin and age of the plant. The species J. decurrens and J. caroba from three different regions showed no acute anti-ulcer action when tested in rats by acidified ethanol induction model. However, extract and fractions from J. caroba showed potential anti Helicobacter pylori activity, with MIC ranging from 125 and 1,000 ug/mL. J. caroba extract did not cause symptoms of acute and subacute toxicity in rats. The DL50 was determined above 5,000 mg/kg. Also, there were no significant changes to the macroscopic appearance of organs or changes in their weights. Meanwhile, an indication of mutagenic activity was observed in the Ames test. The TA98 strain of S. typhimurium, showed a tendency of dose-response for concentrations between 7.5 and 15.0 mg/plate after metabolic activation (S9). The nanocapsules formulation of poly-ε-caprolactone containing P. umbellatum extract had an average particle diameter of 181.6 ± 0.9 nm and zeta potential of -31 ± 4 mV. HPLC analysis showed better entrapping efficiency for the more apolar portion of the fraction, while the more polar compounds were dispersed in the medium. The polymeric nanocapsules showed gastroprotective activity even without the addition of active molecules and had their activity increased by chloroform fraction of P. umbellatum


Subject(s)
Rats , Photochemistry , Jacaranda caroba/pharmacology , Malvaceae/classification , Pharmacognosy/classification , Stomach Ulcer/pathology , Phenolic Compounds/classification , Nanocapsules/analysis , Phytochemicals
5.
Article in Portuguese | LILACS | ID: lil-737701

ABSTRACT

A simple, precise and accurate high-performance liquid chromatographic method has been developed for the determination of lupeol in polymeric nanocapsules. Chromatographic separation was performed on a Varian C8 column (250 mm x 4.6 mm x 5 mm) maintained at 35°C, with a mobile phase composed of acetonitrile and methanol (95:5 v/v) acidified with 0.1% acetic acid, flowing at 1.2 mL/min, with an injected sample volume of 20 µL, UV detection at 210 nm and a run time of 6.2 min. The proposed method was linear over the concentration range 10-250 µg/mL, with R2= 0.9996. Analyses of accuracy and precision showedlow values of relative standard deviation (<4.2%). The methodology was specific, linear, accurate, precise and robust and proved to be adequate for the quantitative analysis of lupeol in polymeric nanocapsules...


Um método de cromatografia líquida de alta performance simples, exato e preciso foi desenvolvido para a determinação do lupeol em nanocápsulas poliméricas. A separação cromatográfica foi realizada numa coluna Varian C8 (250 mm x 4,6 mm x 5 mm), mantida a 35°C, fase móvel constituída por acetonitrila e metanol acidificado com ácido acético a 0,1% (95:5 v/v), e taxa de fluxo de 1,2 mL/min, com um volume injeção de amostra de 20 µl e detecção UV a 210 nm, com o tempo de eluição de 6,2 min. O método proposto é linear para a faixa de concentração de 10 a 250 µg/mL com coeficiente de correlação de 0,9996. As análises de exatidão e precisão demonstraram baixos valores de desvio padrão relativo (< 4,2%). A metodologia foi específica, linear, precisa, exata e robusta, se mostrando capaz de ser aplicada para quantificação de lupeol em nanocápsulas poliméricas...


Subject(s)
Humans , Nanocapsules/analysis , Pentacyclic Triterpenes/isolation & purification , Chromatography, High Pressure Liquid
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