Encapsulamento simultâneo de nanopartículas magnéticas (NPMS) com ftalocianina de zinco (ZNPC) via polimerização em miniemulsão

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2012.Uma das alternativas mais promissoras para o tratamento do câncer é a Terapia Fotodinâmica (TFD). A Ftalocianina de Zinco (ZnPc) é um fotossensibilizante de segunda geração com caráter hidrofóbico e necessita ser incorporado em um sistema de liberação adequado para ser injetado sistemicamente. Nanopartículas magnéticas, NPMs, constituída principalmente de magnetita (Fe3O4) apresentam alto valor de magnetização com grande potencial de aplicação no tratamento do câncer por hipertermia. O encapsulamento simultâneo de fármacos com NPMs tem sido reconhecido como uma técnica promissora para o tratamento do câncer por possibilitar a ação sinergética dos diferentes tipos de tratamento. O objetivo deste trabalho foi a síntese, caracterização e avaliação da toxicidade e fototoxicidade das NPMs, do encapsulamento da NPMs e ZnPc e o encapsulamento simultâneo de ZnPc com NPMs via polimerização em miniemulsão. As NPMs com ácido oléico (AO) foram preparadas pelo método de co-precipitação em meio aquoso e a análise de DRX mostrou picos característicos da magnetita (Fe3O4) com diâmetro médio de nanopartículas de 13nm. As NPMs apresentaram um alto valor de magnetização de saturação (Ms) (64 emu/g óxido de ferro). O encapsulamento das NPMs foi realizado via polimerização em miniemulsão com metacrilato de metila (MMA). As NPMs encapsuladas apresentaram um diâmetro aproximado de 100nm com valor de Ms de 34 emu/g de óxido de ferro. Para o encapsulamento da ZnPc utilizou-se duas técnicas de encapsulamento. A primeira foi a técnica de miniemulsão com auxílio da técnica de nanoprecipitação (PMMA/ZnPc)(FA)) e a segunda utilizou-se apenas a técnica de miniemulsão direta (PMMA/ZnPc(FO)). O teor de ZnPc nas nanopartículas poliméricas foi um pouco superior na amostra PMMA/ZnPc(FA) (3,7µg/mg) do que na amostra de PMMA/ZnPc(FO) (3,0 µg/mg). Ambas as técnicas resultaram em um tamanho médio de aproximadamente 100nm. Ao encapsular a ZnPc simultaneamente com as NPMs (PMMA/ZnPc/NPMs) não alteração em relação ao tamanho das nanopartículas (100nm), concentração de ZnPc (3,6 µg/mg) e propriedades magnéticas (31 emu/g de óxido de ferro) em relação ao encapsulamento em separado da ZnPc e NPMs. A liberação da ZnPc das nanopartículas poliméricas foi sustentada e lenta. Nas primeiras 20 horas cerca de 5-10% do ZnPc contida nas nanopartículas poliméricas foi liberada em todas as amostras. No ensaio de toxicidade (ausência de luz), as nanopartículas encapsuladas mostraram baixa toxicidade. No ensaio de atividade fotobiológica, observou-se, que a luz isoladamente (sem nanopartículas contendo ZnPc) não foi capaz de induzir efeito citotóxico sobre a cultura de células. Ao utilizar nanopartículas contendo ZnPc observou-se uma redução acentuada da viabilidade celular para 22% (PMMA/ZnPc(FA)) e 30% (PMMA/ZnPc/NPMs).Abstract : Photodynamic therapy (TFD) is one of the most promising alternatives for the treatment of the cancer. Zinc phtalocyanine (ZnPc) is a second generation photosensitizer with hydrophobic character that should be incorporated in a suitable delivery system to be injected systemically. Magnetics nanoparticles (NPMs) consisting mainly of magnetite (Fe3O4) present high value of magnetization with great potential of application in the treatment of the cancer by hyperthermia. The simultaneous encapsulation of drugs with NPMs has been recognized as one promising technique for the treatment of the cancer making possible a synergetic action of the different types of treatment. The objective of this work was the synthesis, characterization and evaluation of the toxicity and phototoxicity of the NPMs, the encapsulation of the NPMs and ZnPc and the simultaneous encapsulation of ZnPc with NPMs by miniemulsion polymerization. The NPMs with oleic acid (AO) had been prepared by the co-precipitation method in aqueous solution. DRX analysis showed characteristic peaks of magnetite (Fe3O4) with average particle diameter of 13nm. The NPMs had presented high value of magnetization of saturation (Ms) (61 emu/g of iron oxide). The encapsulation of the NPMs was carried through methyl methacrylate (MMA) miniemulsion polymerization. The polymeric particles with NPMs encapsulated presented an average diameter of 100nm with value of Ms of 34 emu/g of iron oxide. Two techniques of encapsulation were employed for the encapsulation of ZnPc. The first one was the miniemulsion polymerization with the nanoprecipitation technique (PMMA/ZnPc) (FAN)) and second one used only the miniemulsion polymerization technique (PMMA/ZnPc (FO)). The amount of ZnPc in polymeric nanoparticles was higher in PMMA/ZnPc(FA) sample (3,7µg/mg) when compared to the sample of PMMA/ZnPc (FO) (3,0 µg/mg). Both techniques resulted in polymeric nanoparticles with an average diameter of approximately 100nm. The simultaneous encapsulation of ZnPc with NPMs (PMMA/ZnPc/NPMs) presented very similar values of average particle size (100nm), concentration of ZnPc (3,6 µg/mg) and magnetic properties (31 emu/g of iron oxide) when compared to the single encapsulation of ZnPc and NPMs. The release of the encapsulated ZnPc was supported and slow. In the first 20 hours approximately 5-10% of the encapsulated ZnPc was released in all samples. In the toxicity assay (light absence), the encapsulated nanoparticles had shown low toxicity. In the assay of phototoxicity activity, it was observed that the light (without polymeric nanoparticles containing ZnPc) was not able to induce cytotoxic effect on the culture of cells. When using polymeric nanoparticles with encapsulated ZnPc an accentuated reduction of the cellular viability of 22% (PMMA/ZnPc (FA)) and 30% (PMMA/ZnPc/NPMs) was observed

Superparamagnetic poly (methyl methacrylate) nanoparticles for biomedical applications

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2016.Abstract: Polymeric nanoparticles (NPs) with superparamagnetic properties and surface modified with folic acid (FA) can targeted drug delivery to tumors, which increase their cellular uptake (endocytosis) and therapeutic efficacy. Furthermore, NPs with superparamagnetic properties can induce cell death by hyperthermia (increasing cell temperature), and the combination of hyperthermia (HPT) with other methods like chemotherapy and radiotherapy turns these treatments much more effective. Having regard to the advantages and disadvantages of different therapeutic strategies, the idea of combining various treatments can be attractive for the next generation of cancer treatment. Thus the aim of this work was to synthesize by miniemulsion polymerization poly(methyl methacrylate) (PMMA) NPs with superparamagnetic properties for biomedical applications. In order to verify the effectiveness of NPs as drugs carrier systems, two antitumor compounds were used: zinc phthalocyanine (ZnPc), a second generation photosensitizer used in the treatment of cancer via photodynamic therapy (PDT) and lauryl gallate (G12), a derivative of gallic acid. With the aim to improve the drug delivery, the FA was used as a surface modifier of NPs. Finally, cytotoxicity and cellular uptake assay were performed in cells that express folate receptors (HeLa) to evaluate the entered mechanism of the prepared systems. The NPs obtained by minimeulsion polymerization presented a nanometric size, negative zeta potential and biocompatibility in tumor and non-tumor cells. From these excellent results of biocompatibility, ZnPc was encapsulated in PMMA NPs (PMMAZnPc). Cytotoxicity assays on leukemic cells (Jurkat and K562) showed a higher cytotoxic effect of PMMAZnPc than free ZnPc, suggesting that the death leukemic cells were by apoptosis. In another study, NPs with superparamagnetic properties (MNPs-PMMA) were obtained by miniemulsion polymerization. MNPs-PMMA NPs presented biocompatibility in tumor and non-tumor cells inducing the death of U87MG cells (~50%) by HPT. Simultaneous treatment by PDT and HPT in U87MG cells, with the simultaneous encapsulation of ZnPc and NPMs in PMMA NPs (PMMA-MNPsZnPc), showed a synergic effect when the treatments were combined. The in vitro results showed that the application of PDT and HPT together can be more effective than each of the two treatments applied separately. Finally, aiming toimprove the drug delivery efficacy, the surface of NPs were modified with folic acid (FA). The adsorption of the FA on PMMA NPs with superparamagnetic properties (FA-MNPsPMMA) increased internalization of NPs on cells that express folate receptors of type ß (K562). In another study, the G12 was encapsulated in superparamagnetic PMMA NPs (MNPsG12PMMA-FA). The simultaneous encapsulation presented a higher cytotoxic effect of FA-MNPsG12PMMA than NPs without FA, when incubated in HeLa cells. Cellular uptake assays and flow cytometry demonstrated a higher cellular uptake of FA-MNPsG12PMMA than NPs without FA, suggesting that these are internalized by folate receptor-mediated endocytosis mechanism. Furthermore, the encapsulation of G12 in PMMA NPs decreases possible cytotoxic effects of G12, in non-tumor cells and blood cells.O câncer é o nome dado a um conjunto de mais de 100 doenças que tem em comum, o crescimento desordenado de células (maligno), que invadem os tecidos e órgãos podendo espalhar-se (metástase) para outras regiões do corpo e o câncer benigno, que significa simplesmente uma massa localizada de células que se multiplicam vagarosamente e se assemelham ao seu tecido original e raramente constitui risco de vida, dependendo do tempo de diagnóstico. Dados da Organização Mundial de Saúde (OMS) mostram que o câncer é a segunda principal causa de mortes em todo o mundo. Estima se que no ano de 2030, o câncer poderá matar 17 milhões de pessoas contra os 7,6 milhões de óbitos que provocou em 2007. Um grande esforço na busca de novos tratamentos para o câncer, como um tratamento mais seletivo das células cancerígenas vem ganhando destaque na literatura. A busca de novas formulações farmacêutica utilizando como ferramenta a nanotecnologia pode melhorar a eficácia terapêutica de fármacos já existente no mercado e consequentemente diminuir seus inúmeros efeitos adversos. Nanopartículas poliméricas (NPs) com propriedades superparamagneticas e superfície modificada com ácido fólico (FA) podem direcionar o fármaco encapsulado a uma célula tumoral alvo, no qual, melhora sua internalização celular (endocitose) e eficácia terapêutica, diminuindo assim seus efeitos tóxicos. Outra vantagem destes sistemas com propriedades superparamagnéticas, é que estas podem induzir a morte das células por hipertermia (HPT) (aumento da temperatura), sendo este tratamento muito mais eficaz quando associado a terapias convencionais, como a quimioterapia e a radioterapia. Tendo em conta as vantagens e desvantagens de diferentes estratégias terapêuticas, a ideia de combinar vários tratamentos, pode ser um atrativo para a próxima geração do tratamento do câncer. Com isso, o objetivo deste trabalho foi a síntese, caracterização e estudos in vitro das NPs de poli (metacrilato de metila) (PMMA) com propriedades superparamagnéticas, obtidas via polimerização em miniemulsão. A fim de verificar a eficácia das NPs como sistemas carreadores de fármacos, dois compostos antitumorais foram utilizados: a ftalocianina de zinco (ZnPc), um fotossensibilizante de segunda geração utilizado no tratamento do câncer via Terapia Fotodinâmica (PDT) e o lauril galato (G12), um derivado do ácido gálico. Com o intuito de melhorar a vetorização das NPs de PMMA, o AF foi usado como modificador desuperfície. Por fim, ensaios de citotoxicidade e internalização celular foram realizados em células que expressam receptores folatos, com o objetivo de avaliar o mecanismo de entrada dos sistemas preparados. As NPs de PMMA obtidas via polimerização em miniemulsão apresentaram um tamanho nanométrico, com potencial zeta negativo e biocompatibilidade em células tumorais e não tumorais. A partir destes excelentes resultados de biocompatibilidade, a ZnPc foi incorporada nas NPs de PMMA (PMMAZnPc). Ensaios de citotoxicidade em células leucêmicas (K562 e Jurkat) mostraram um maior efeito citotóxico da ZnPc encapsulada em NPs que ZnPc livre, sugerindo que a morte das células leucêumicas foi mediada por apoptose. Em outro estudo, NPs de PMMA com propriedades superparamagnéticas (MNPs-PMMA) foram obtidas via polimerização em miniemulsão. MNPs-PMMA NPs apresentaram biocompatibilidade em células tumorais e não tumorais, e induziram a morte das células U87MG (~50%) por HPT. O tratamento simultâneo (PDT e HPT) sobre as mesmas células (U87MG) com o encapsulamento simultâneo da ZnPc e NPMs em NPs de PMMA (MNPsZnPc-PMMA), apresentaram um efeito sinérgico. Os resultados in vitro mostraram que a aplicação da PDT e HPT simultaneamente podem ser mais eficazes quando aplicados simultaneamente. Por fim, visando uma melhor vetorização das NPs de PMMA quando o FA foi usado como agente ligante (FA-MNPsPMMA). A adsorção do FA nas NPs de PMMA com propriedades superparamagnéticas aumentou a internalização das NPs nas células que expressam receptores folatos (células K562). Em outro estudo o G12 foi incorporado nas NPs de PMMA. O encapsulamento simultâneo do G12 e NPMs em NPs de PMMA com superfície modificada, apresentou um maior efeito citotóxico sobre as células HeLa, quando comparado com as NPs sem FA. Ensaios de captação celular e citometria de fluxo demostraram uma maior internalização das NPs de PMMA com superfície modificada, sugerindo que estas são internalizadas via receptor folato mediado pelo mecanismo de endocitose. Além disso, o encapsulamento do G12 em NPs de PMMA diminui possíveis efeitos citotóxicos do G12, em células não tumorais e células do sangue

Biocompatible superparamagnetic poly(thioether-ester) nanoparticles via miniemulsion technique

Biocompatible polymeric nanoparticles were obtained via thiol-ene polymerization of a biobased monomer in miniemulsion. The α,ω-diene-diester monomer was synthesized through esterification reaction of a glycerol derivative, namely 1,3-propanediol, with 10-undecenoic acid, a long-chain diene carboxylic acid. The biobased poly(thioether-ester), PTEE, nanoparticles were submitted to cytotoxicity and hemolysis analyses. High cell viability and no significant changes in cell morphology were observed. Lastly, hemolysis assays revealed blood compatibility and therefore PTEE nanoparticles have been shown to be a potential alternative drug delivery vector for intravenous administration. The poly(thioether-ester) was also employed to encapsulate magnetic nanoparticles (MNPs) by miniemulsification technique. Please click Additional Files below to see the full abstract

Synthesis and characterization of Supeparamagnetics Microspheres (PMMA) via suspension polymerization

Magnetics nanoparticles (NPMs) has found many applications in biomedical and technological areas. The objective of this work is the preparation and characterization of PMMA microspheres containing NPMs coated with oleic acid (NPMs-AO). For the preparation of MNPs-AO was used the coprecipitation method in an aqueous medium. For the preparation of the superparamagnetic microspheres used in suspension polymerization technique. The microspheres showed a size distribution particles of approximately 150um and a spherical morphology. From the analysis of gel permeation chromatography (GPC) determined the number average molecular weight (Mw) of the magnetics microspheres and there was a variation in the Mw depending on the concentration of MNPs-AO in this reaction. To analyze the magnetic properties used the vibrating sample magnetometer (MAV). The microspheres showed superparamagnetic properties and a value of saturation magnetization (Ms) of about 8 emu/g MNPs. Therefore you can conclude that it is possible to obtain superparamagnetics microspheres for a particular application, either, biomedical or technological

ZnO and quercetin encapsulated nanoparticles for sun protection obtained by miniemulsion polymerization using alternative co-stabilizers

The present work evaluated the encapsulation of ZnO and quercetin in PBMA-PMMA-PS using the miniemulsion polymerization technique, aiming to develop nanoparticles with sun protection factor (SPF) and antioxidant activity (AA) for application in photoprotective lotions. In both formulations, octocrylene and green coffee oil were tested as co-stabilizing agents of the miniemulsion, being also encapsulated in the NPs, contributing to the SPF and AA of the obtained latexes. Spherical nanoparticles of homogeneous size, from 169 to 346 nm, and regular surfaces were obtained, remaining stable for at least 30 days. The encapsulation efficiency on the formulations tested was from 59 to 87% for ZnO, 47 to 51% for quercetin, 80 to 92% for octocrylene and 90 to 92% for green coffee oil. The quercetin and green coffee oil presented high antioxidant activity when encapsulated in polymeric NPs. The values of in vitro SPF was very good for formulations containing NPs-ZnO, with the best result for the simultaneous nanoencapsulation of ZnO and octocrylene (SPF 29 ± 5). The application of the NPs of quercetin and green coffee oil may promote an increment on SPF in vivo , reducing the damage caused to the skin by UV radiation, beyond the ability to scavenge the free radicals generated by ZnO

Increased cellular uptake of lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles due to surface modification with folic acid

Lauryl gallate loaded in superparamagnetic poly (methyl methacrylate) nanoparticles surface modified with folic acid were synthesized by miniemulsion polymerization in just one step. In vitro biocompatibility and cytotoxicity assays on L929 (murine fibroblast), human red blood, and HeLa (uterine colon cancer) cells were performed. The effect of folic acid at the nanoparticles surface was evaluated through cellular uptake assays in HeLa cells. Resultsshowed that the presence of folic acid did not affect substantially the polymer particle size (~120 nm), the superparamagnetic behavior, the encapsulation efficiency of lauryl gallate (~87 %), the Zeta potential (~38 mV) of thepolymeric nanoparticles or the release profile of lauryl gallate. The release profile of lauryl gallate from superparamagnetic poly(methyl methacrylate) nanoparticles presented an initial burst effect (0?1 h) followed by a slow andsustained release, indicating a biphasic release system.Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles with folic acid did not present cytotoxicity effects on L929 and human red blood cells. However, free lauryl gallate presented significant cytotoxic effects on L929 and human red blood cells at all tested concentrations. The presence of folic acid increased the cytotoxicity of lauryl gallate loaded in nanoparticles on HeLa cells due to a higher cellular uptake when HeLa cells were incubated at 37 °C. On the other hand, when the nanoparticles were incubated at low temperature (4 °C) cellular uptake was not observed, suggesting that the uptake occurred by folate receptor mediated energy-dependent endocytosis. Based on presented results our work suggeststhat this carrier system can be an excellent alternative in targeted drug delivery by folate receptor.Fil: Feuser, Paulo Emilio. Universidade Federal de Santa Catarina; BrasilFil: Carpio Arévalo, Juan Marcelo. Universidade Federal do Paraná; BrasilFil: Lima, Enio Junior. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia de Física. Laboratorio de Resonancias Magnéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Rodrigues Rossi, Gustavo. Universidade Federal do Paraná; BrasilFil: Trindade, Edvaldo da Silva. Universidade Federal do Paraná; BrasilFil: Merlin Rocha, Maria Eliane. Universidade Federal do Paraná; BrasilFil: Virtuoso Jacques, Amanda. Universidade Federal de Santa Catarina; BrasilFil: Ricci Júnior, Eduardo. Universidade Federal do Rio de Janeiro; BrasilFil: Santos Silva, Maria Claudia. Universidade Federal de Santa Catarina; BrasilFil: Sayer, Claudia. Universidade Federal de Santa Catarina; BrasilFil: Hermes de Araújo, Pedro H.. Universidade Federal de Santa Catarina; Brasi

Green Synthesis of Gold Nanoparticles with Curcumin or Açai in the Tissue Repair of Palatal Wounds

This study aimed to evaluate and compare the effects of treatment with gold nanoparticles (GNPs) reduced with Curcumin (Curcuma longa L.) or Açai (Euterpe oleracea) to a standard commercial treatment of the pharmacological type (Omcilon®) and an electrophysical agent (photobiomodulation) in the palatal wounds of rats. As for the in vitro assay, a cell viability test was performed to assess the toxicity of the synthesized nanoparticles. In vivo assay: 60 Wistar rats were divided into five groups (n = 12): I. Palatal Wound (PW); II. PW + Photobiomodulation (PBM); III. PW + Omcilon®; IV. PW + GNPs-Cur (0.025 mg/mL); V. PW + GNPs-Açai (0.025 mg/mL). Animals were first anesthetized, and circular lesions in the palatine mucosa were induced using a 4 mm-diameter punch. The first treatment session started 24 h after the injury and occurred daily for 5 days. The animals were euthanized, and the palatal mucosa tissue was removed for histological, biochemical, and molecular analysis. GNPs-Açai were able to significantly reduce pro-inflammatory cytokines and increase anti-inflammatory ones, reduce oxidant markers, and reduce inflammatory infiltrate while increasing the collagen area and contraction rate of the wound, along with an improved visual qualification. The present study demonstrated that the proposed therapies of GNPs synthesized greenly, thus associating their effects with those of plants, favor the tissue repair process in palatal wounds

Preparation and characterization of 4-nitrochalcone-folic acid-poly(methyl methacrylate) nanocapsules and cytotoxic activity on HeLa and NIH3T3 cells

Chalcones of natural origin are plant metabolites which have been explored because of the cytotoxic effects towards tumor cells. In this study, the synthetic chalcone 4-nitrochalcone (4NC) and its encapsulated form in folic acid-poly(methyl methacrylate) (PMMA) nanocapsules (4NC-FA-PMMA) were investigated towards the cytotoxic effects on erytrocytes, mouse embryonic fibroblasts cells (NIH3T3), and tumor cells (HeLa cells). Characterization of 4NC-FA-PMMA presented spherical morphology with nanocapsule-type structure, a mean size of 170 ± 6 nm, a negative zeta potential of (−40 ± 4 mV), and an entrapment efficiency of ~80%. In HeLa cells, 4NC induced a dose-dependent reduction in cell viability, with an IC value of 46.7 μM. The cytotoxicity was confirmed by morphological alterations, cell death, and an increase in the population of hypodiploid cells. When 4NC-FA-PMMA nanocapsules were employed at concentrations of 15 and 30 μM the reduction in cell viability was higher than that of 4NC. In addition, 4NC and 4NC-FA-PMMA nanocapsules did not present any cytotoxic effect on the NIH3T3 cells and human erythrocytes up to 50 μM. These results demonstrated that the 4NC encapsulation in PMMA nanocapsules with folic acid-modified surface is a better system to promote selective cytotoxic effects to HeLa cells. Therefore, this formulation could be considered a promising preparation with potential chemotherapeutic action