Efeito da terapia fotodinâmica antimicrobiana sobre culturas planctônicas e biofilmes de bactérias e fungos utilizando curcumina e cloro-alumínio ftalocianina veiculada por nanoemulsões

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento e caracterização físico-química e biofarmacêutica de nano e microemulsões lipídicas de uso intravenoso contendo metildiidrojasmonato

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antimicrobial and physical-mechanical properties of pectin/papaya puree/cinnamaldehyde nanoemulsion edible composite films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preparação de novos nanobiocompósitos comestíveis ativos contendo nanoemulsão de canela e pectina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Incorporação de nanoemulsões de óleos essenciais de melaleuca, copaíba e limão em filmes de alginato de sódio para utilização como curativo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Drug-targeting in combined cancer chemotherapy: tumor growth inhibition in mice by association of paclitaxel and etoposide with a cholesterol-rich nanoemulsion

Lipid nanoemulsions (LDE) may be used as carriers of paclitaxel (PTX) and etoposide (ETP) to decrease toxicity and increase the therapeutic action of those drugs. The current study investigates the combined chemotherapy with PTX and ETP associated with LDE. Four groups of 10-20 B16F10 melanoma-bearing mice were treated with LDE-PTX and LDE-ETP in combination (LDE-PTX + ETP), commercial PTX and ETP in combination (PTX + ETP), single LDE-PTX, and single LDE-ETP. PTX and ETX doses were 9 mu mol/kg administered in three intraperitoneal injections on three alternate days. In two control groups mice were treated with saline solution or LDE alone. Tumor growth, metastasis presence, cell-cycle distribution, blood cell counts and histological data were analyzed. Toxicity of all treatments was evaluated in mice without tumors. Tumor growth inhibition was similarly strong in all treatment groups. However, there was a greater reduction in the number of animals bearing metastases in the LDE-PTX + ETP group (30 %) in comparison to the PTX + ETP group (82 %, p < 0.05). Reduction of cellular density, blood vessels and increase of collagen fibers in tumor tissues were observed in the LDE-PTX + ETP group but not in the PTX + ETP group, and in both groups reduced melanoma-related anemia and thrombocytosis were observed. Flow cytometric analysis suggested that LDE-PTX + ETP exhibited greater selectivity to neoplastic cells than PTX-ETP, showing arrest (65 %) in the G(2)/M phase of the cell cycle (p < 0.001). Toxicity manifested by weight loss and myelosuppression was markedly milder in the LDE-PTX + ETP than in the PTX + ETP group. LDE-PTX + ETP combined drug-targeting therapy showed markedly superior anti-cancer properties and reduced toxicity compared to PTX + ETP.

The Use of Nanotechnology in Cosmetic Formulations: The Influence of Vehicle in the Vitamin A Skin Penetration

Despite the efficacy of topical retinoic acid, skin reactions have limited its acceptance by patients. Other retinoids, like Retinyl Palmitate (RP), are considerably less irritating, but they are also less effective. In order to enhance the performance of retinoids, in this work RP has been added to cosmetic formulations such as nanoemulsions, which can provide better penetration of this active substance. Because the vehicle can directly influence the skin penetration and the effectiveness of RP, two skin care products containing 5000 UI RP have been developed and investigated, namely a nanoemulsifying system and a classic gel cream. In vitro penetration tests were conducted by using Franz diffusion cells and placing porcine ear skin and iso-propanol in the receptor compartment. The RP concentration in the skin layers was analyzed by high performance liquid chromatography, and a Zeta-Sizer system was employed for measurement of the the particle size distribution. The penetration tests revealed a large difference between the vehicles in terms of the RP concentrations in each skin layer. The classic gel cream furnished better RP penetration in both the stratum corneum and the epidermis without stratum corneum + dermis, as compared to the self-nanoemulsifying system. The two vehicles displayed the same particle size (between 100 and 200 nm). Better understanding of RP skin delivery using different vehicles has been acquired, and the importance of evaluating the efficacy of nanocosmetics. Results from the present study should also contribute to the assessment of commercial self-nanoemulsifying systems with potential application in the facile production of nanoemulsions.

Lipid Transfer to HDL is Higher in Marathon Runners than in Sedentary Subjects, but is Acutely Inhibited During the Run

Although exercise increases HDL-cholesterol, exercise-induced changes in HDL metabolism have been little explored. Lipid transfer to HDL is essential for HDL's role in reverse cholesterol transport. We investigated the effects of acute exhaustive exercise on lipid transfer to HDL. We compared plasma lipid, apolipoprotein and cytokine levels and in vitro transfer of four lipids from a radioactively labeled lipid donor nanoemulsion to HDL in sedentary individuals (n = 28) and in marathon runners (n = 14) at baseline, immediately after and 72 h after a marathon. While HDL-cholesterol concentrations and apo A1 levels were higher in marathon runners, LDL-cholesterol, apo B and triacylglycerol levels were similar in both groups. Transfers of non-esterified cholesterol [6.8 (5.7-7.2) vs. 5.2 (4.5-6), p = 0.001], phospholipids [21.7 (20.4-22.2) vs. 8.2 (7.7-8.9), p = 0.0001] and triacylglycerol [3.7 (3.1-4) vs. 1.3 (0.8-1.7), p = 0.0001] were higher in marathon runners, but esterified-cholesterol transfer was similar. Immediately after the marathon, LDL- and HDL-cholesterol concentrations and apo A1 levels were unchanged, but apo B and triacylglycerol levels increased. Lipid transfer of non-esterified cholesterol [6.8 (5.7-7.2) vs. 5.8 (4.9-6.6), p = 0.0001], phospholipids [21.7 (20.4-22.2) vs. 19.1 (18.6-19.3), p = 0.0001], esterified-cholesterol [3.2 (2.2-3.8) vs. 2.3 (2-2.9), p = 0.02] and triacylglycerol [3.7 (3.1-4) vs. 2.6 (2.1-2.8), p = 0.0001] to HDL were all reduced immediately after the marathon but returned to baseline 72 h later. Running a marathon increased IL-6 and TNF-alpha levels, but after 72 h these values returned to baseline. Lipid transfer, except esterified-cholesterol transfer, was higher in marathon runners than in sedentary individuals, but the marathon itself acutely inhibited lipid transfer. In light of these novel observations, further study is required to clarify how these metabolic changes can influence HDL composition and anti-atherogenic function.

Effect of neoadjuvant chemotherapy on low-density lipoprotein (LDL) receptor and LDL receptor-related protein 1 (LRP-1) receptor in locally advanced breast cancer

Low-density lipoprotein (LDL) receptors are overexpressed in most neoplastic cell lines and provide a mechanism for the internalization and concentration of drug-laden nanoemulsions that bind to these receptors. The aim of the present study was to determine whether the administration of standard chemotherapeutic schemes can alter the expression of LDL and LDL receptor-related protein 1 (LRP-1) receptors in breast carcinoma. Fragments of tumoral and normal breast tissue from 16 consecutive volunteer women with breast cancer in stage II or III were obtained from biopsies before the beginning of neoadjuvant chemotherapy and after chemotherapy, from fragments excised during mastectomy. Tissues were analyzed by immunohistochemistry for both receptors. Because complete response to treatment was achieved in 4 patients, only the tumors from 12 were analyzed. Before chemotherapy, there was overexpression of LDL receptor in the tumoral tissue compared to normal breast tissue in 8 of these patients. LRP-1 receptor overexpression was observed in tumors of 4 patients. After chemotherapy, expression of both receptors decreased in the tumors of 6 patients, increased in 4 and was unchanged in 2. Nonetheless, even when chemotherapy reduced receptors expression, the expression was still above normal. The fact that chemotherapy does not impair LDL receptors expression supports the use of drug carrier systems that target neoplastic cells by the LDL receptor endocytic pathway in patients on conventional chemotherapy.

Amphotericin B nano-formulations : development, characterisation and suitability for oral administration

In der Form von Nanokapseln (AmB-HST), Nanoemulsion beziehungsweise multilamellaren Vesikeln (MLV) wurden drei Amphotericin-B-Formulierungen für die orale Applikation entwickelt, charakterisiert und verglichen. Die neuartige homogene Nanokapsel-Formulierung des hydrophoben Polyen-Antimykotikums Amphotericin B wurde in Analogie zu einem für Simvastatin und andere Arzneistoffe etablierten Prozess aus der Reinsubstanz, Lezithin und Gelatine mit Hilfe des HST-Verfahrens hergestellt. Photometrische Untersuchungen zeigten, dass das Endprodukt aus Monomeren aufgebaut ist. Mittels Mikroskopie ließen sich die Aggregate vor der Umhüllung mit Lezithin und Gelatine im Ausgangsmaterial als individuelle kugelförmige Arzneistoffpartikel darstellen. Strukturuntersuchungen mit dynamischer licht streuung (DLS) zeigten eine enge Größenverteilung der verkapselten Partikel von ca. 1 µm. Die Struktur der Hülle der HST-Partikel wurde erstmalig mit Neutronenstreuung unter Verwendung der Deuterium-basierten Lösungsmittel kontrastmethode aufgeklärt. Durch die teilweise Kontrastmaskierung des Partikelkerns bei der Neutronenstreuung konnte die Lezithin-Gelatine-Hülle als eine dünne, 5,64 ± 0.18 nm dicke Schicht aufgelöst werden, welche der biologischen Lipidmembran ähnlich, im Vergleich aber geringfügig größer ist. Dieses Resultat eröffnet Wege für die Optimierung der Formulierung von pharmazeutischen Nanopartikeln, z.B. durch Oberflächenmodifizierungen. Weitere Untersuchungen mittels Kleinwinkelneutronenstreuung unter Verwendung der D-Kontrastvariation deuten darauf hin, dass die Komponenten der Nanokapseln nicht den gleichen Masseschwerpunkt haben, sondern asymmetrisch aufgebaut sind und dass die stärker streuenden Domänen weiter außen liegen. Die Partikel sind im Vergleich zu Liposomen dichter. In-Vitro Freisetzungsstudien belegen das Solubilisierungsvermögen des HST-Systems, wonach die Freisetzung des Arzneistoffes aus der Formulierung zu allen gemessenen Zeitpunkten höher als diejenige der Reinsubstanz war. rnDie Nanoemulsion-Formulierung von Amphotericin B wurde mit einem Öl und Tensid system, jedoch mit unterschiedlichen Co-Solvenzien, erfolgreich entwickelt. Gemäß der Bestimmung der Löslichkeit in verschiedenen Hilfsstoffen erwies sich der Arzneistoff Amphotericin B als nicht-lipophil, gleichzeitig aber auch als nicht-hydrophil. Die zur Ermittlung der für die Emulsionsbildung notwendigen Hilfstoffkonzentrationen erstellten ternären Diagramme veranschaulichten, dass hohe Öl- und Tensidgehalte zu keiner Emulsionsbildung führten. Dementsprechend betrug der höchste Ölgehalt 10%. Die Tröpfchengröße wuchs mit zunehmender Tensidkonzentration, wobei die Co-Solventmenge der Propylenglykol-haltigen Nanoemulsion indirekt verringert wurde. Für die Transcutol®P-haltige Nanoemulsion hingegen wurde das Gegenteil beobachtet, nämlich eine Abnahme der Tröpfchengröße bei steigenden Tensidkonzentrationen. Durch den Einschluss des Arzneistoffes wurde nicht die Viskosität der Formulierung, sondern die Tröpfchengröße beeinflusst. Der Wirkstoffeinschluss führte zu höheren Tröpfchengrößen. Mit zunehmender Propylenglykolkonzentration wurde der Wirkstoffgehalt erhöht, mit zunehmender Transcutol®P-Konzentration dagegen vermindert. UV/VIS-spektroskopische Analysen deuten darauf hin, dass in beiden Formulierungen Amphotericin B als Monomer vorliegt. Allerdings erwiesen sich die Formulierungen Caco-2-Zellen und humanen roten Blutkörperchen gegenüber als toxisch. Da die Kontrollproben eine höhere Toxizität als die wirkstoffhaltigen Formulierungen zeigten, ist die Toxizität nicht nur auf Amphotericin, sondern auch auf die Hilfsstoffe zurückzuführen. Die solubilisierte Wirkstoffmenge ist in beiden Formulierungen nicht ausreichend im Hinblick auf die eingesetzte Menge an Hilfsstoff nach WHO-Kriterien. Gemäß diesen Untersuchungen erscheinen die Emulsions-Formulierungen für die orale Gabe nicht geeignet. Dennoch sind Tierstudien notwendig, um den Effekt bei Tieren sowie die systemisch verfügbare Wirkstoffmenge zu ermitteln. Dies wird bestandskräftige Schlussfolgerungen bezüglich der Formulierung und Aussagen über mögliche Perspektiven erlauben. Nichtsdestotrotz sind die Präkonzentrate sehr stabil und können bei Raumtemperatur gelagert werden.rnDie multilamellar-vesikulären Formulierungen von Amphotericin B mit ungesättigten und gesättigten neutralen Phospholipiden und Cholesterin wurden erfolgreich entwickelt und enthielten nicht nur Vesikel, sondern auch zusätzliche Strukturen bei zunehmender Cholesterinkonzentration. Mittels Partikelgrößenanalyse wurden bei den Formulierungen mit gesättigten Lipiden Mikropartikel detektiert, was abhängig von der Alkylkettenlänge war. Mit dem ungesättigten Lipid (DOPC) konnten hingegen Nanopartikel mit hinreichender Verkapselung und Partikelgrößenverteilung gebildet werden. Die Ergebnisse der thermischen und FTIR-spektroskopischen Analyse, welche den Einfluss des Arzneistoffes ausschließen ließen, liefern den Nachweis für die mögliche, bereits in der Literatur beschriebene Einlagerung des Wirkstoffs in lipid- und/oder cholesterinreiche Membranen. Mit Hilfe eines linearen Saccharosedichtegradienten konnte die Formulierung in Vesikel und Wirkstoff-Lipid-Komplexe nach bimodaler Verteilung aufgetrennt werden, wobei der Arzneistoff stärker mit den Komplexen als mit den Vesikeln assoziiert ist. Bei den Kleinwinkelneutronenstreu-Experimenten wurde die Methode der Kontrastvariation mit Erfolg angewendet. Dabei konnte gezeigt werden, dass Cholesterol in situ einen Komplex mit Amphotericin B bildet. Diesen Sachverhalt legt unter anderem die beobachtete Differenz in der äquivalenten Streulängendichte der Wirkstoff-Lipid- und Wirkstoff-Lipid-Cholesterin-haltigen kleinen unilamellaren Vesikeln nahe. Das Vorkommen von Bragg-Peaks im Streuprofil weist auf Domänen hin und systematische Untersuchungen zeigten, dass die Anzahl der Domänen mit steigendem Cholesteringehalt zunimmt, ab einem bestimmten Grenzwert jedoch wieder abnimmt. Die Domänen treten vor allem nahe der Außenfläche der Modellmembran auf und bestätigen, dass der Wirkstoff in den Cholesterinreichen Membranen vertikal eingelagert ist. Die Formulierung war sowohl Caco-2-Zellen als auch humanen roten Blutkörperchen gegenüber nicht toxisch und erwies sich unter Berücksichtigung der Aufnahme in Caco-2-Zellen als vielversprechend für die orale Applikation. Die Formulierung zeigt sich somit aussichtsreich und könnte in Tabletten weiterverarbeitet werden. Ein Filmüberzug würde den Wirkstoff gegen die saure Umgebung im Magen schützen. Für die Bestimmung der systemischen Verfügbarkeit der Formulierung sind Tierstudien notwendig. Die entwickelten multilamellaren Formulierungen einschließlich der Wirkstoff-Cholesterin-Komplexe bieten somit gute Aussichten auf die mögliche medizinische Anwendung. rnrn

Desenvolvimento e caracterização de nanoemulsões cosméticas contendo extrato de Opuntia ficus-indica L. Mill e avaliação in vivo da eficácia hidratante

Nanoemulsions are emulsified systems, characterized for reduced droplet size (50- 500nm), which the main characteristic are kinect stability and thermodynamic instability. These are promising systems on cosmetic area due to their droplet size that provide different advantages when compared to conventional systems, among others, larger surface area and better permeability. The Opuntia ficus-indica (L.) Mill is a plant cultivated on Caatinga Brazilian biome, which has great socioeconomic importance to region. This plant shows carbohydrates utilized for cosmetic industry as moisturizing active in their chemical composition. The aim of study was to develop, characterize, evaluate stability and moisturizing efficacy of cosmetic nanoemulsions added to Opuntia ficus-indica (L.) Mill extract. Nanoemulsions preparation was made using a low energy method. Different nanoemulsions were formulated varying the ratio of oil, water and surfactant phases beyond xanthan gum (0.5% e 1%) and Opuntia ficus-indica (L.) Mill hydroglycolic extract addition on 1% and 3%. Obtained nanoemulsions were submitted to preliminary and accelerated stability tests. The evaluated parameters monitored were: macroscopic aspect, pH value, droplet size, zeta potential and polydispersion index, during 60 days on different temperatures. Stable formulations were submitted to moisturizing efficacy assessment by capacitance and transepidermal water loss methodologies during 5 hours. Stable samples were white and showed homogeneous and fluid aspect, pH value was inside ideal range (4,5-6,0) to topical application and droplet size under 200nm characterizing these system as nanoemulsions. Developed nanoemulsions did not decrease transepidermal water loss, however increased the water content on stratum corneum, highlighting the nanoemulsions containing 0.5% of xanthan gum and 1% of hydroglycolic extract. This work presents cosmetic moisturizing nanoemulsions composed to vegetal raw material from Brazilian Caatinga with potential to be used on cosmetic area.

Aplicação de nanoemulsão ácida em acidificação de poços de petróleo

A constante busca da indústria de petróleo pelo aumento de produção à um baixo custo operacional faz necessário o desenvolvimento de tecnologias que una as duas necessidades. A Acidificação de matriz é um método de estimulação frequentemente empregado para aumentar produção de um poço de petróleo com um custo menor se comparado a um fraturamento. O objetivo deste trabalho é estudar a obtenção de nanoemulsões ácidas para aplicação em acidificação de matriz. As nanoemulsões são capazes de retardar reações, por diminuir a difusão do ácido no meio, possibilitando a acidificação em reservatórios com baixa permeabilidade. Os reagentes utilizados para formar os sistemas nanoemulsionados foram UNT L90/OMS e RNX 110 como tensoativos, Sec-butanol como cotensoativo, Xileno e Querosene como fase óleo e Solução de HCl como fase aquosa. As nanoemulsões foram obtidas a partir da diluição de microemulsões com água ou solução de HCl. Foi realizado estudo das tensões superficiais, estudo das cinéticas de reação, avaliação da injeção em rocha carbonática e remoção de borra asfáltica. As nanoemulsões apresentaram tensão superficial menor que suas microemulsões de origem. As nanoemulsões tiveram êxito em retardar a reação entre CaCO3 e HCl, onde o sistema mais eficiente é composto por UNT L90/OMS, Secbutanol, Querosene e solução de HCl. As nanoemulsões foram eficientes em formar wormholes em plugs de carbonato calcitico com baixa permeabilidade natural. As wormholes proporcionaram incremento de permeabilidade alcançando valores de até 390 mD. O sistema ácido apresentou bom resultado de remoção de borra asfáltica, mostrando o potencial das nanoemulsões em remover esse tipo de dano. Conclui-se que os sistemas nanoemulsionados têm grande potencial de aplicação em acidificação de matriz.

Produção de biossurfactantes e nanoemulsões a partir da microalga spirulina

As microalgas têm sido foco de muitos estudos tendo em vista sua grande aplicabilidade na indústria de alimentos e farmacêutica, como também nas áreas da biomedicina e ambiental. A Spirulina é uma microalga que possui alto valor nutricional, apresenta alto teor proteico e é rica em substâncias bioativas. Esta microalga apresenta em sua composição compostos como glicolípidios, fosfolipídios e lipídios neutros, que por sua vez possuem efeito biossurfactante. Assim, o objetivo deste estudo foi verificar a potencialidade de produção de biossurfactantes a partir de diferentes cepas de Spirulina. Para isso, foram realizados experimentos utilizando Delineamento Fatorial Completo 22 , visando avaliar a influência da concentração de fósforo e nitrogênio no cultivo das microalgas Spirulina platensis Paracas, Spirulina platensis LEB 52 e Spirulina sp. LEB 18, como também nos extratos oriundos das microalgas, através da medida da tensão superficial. Foi também avaliada a influência destes nutrientes em extratos de Spirulina platensis LEB 52 e Spirulina sp. LEB 18 a partir do índice de emulsificação e diâmetro médio das gotículas das emulsões preparadas a partir dos extratos. Para extrações de biossurfactantes foram testados os solventes metanol, etanol e hexano. Nas formulações das nanoemulsões utilizou-se homogeneizador de alta velocidade, como fase aquosa os extratos oriundos das microalgas e como fase oleosa, óleo de girassol. As formulações foram preparadas utilizando-se diferentes concentrações da fase aquosa e oleosa, bem como diferentes velocidades e tempos de agitação. De acordo com os cultivos de Spirulina platensis Paracas realizados foi verificado que o cultivo que atingiu maior valor de concentração máxima de biomassa e maior produtividade foi realizado com 114 mg.L-1 de fósforo e sem adição de nitrogênio. Porém em relação às microalgas Spirulina platensis LEB 52 e Spirulina sp. LEB 18, as variáveis fósforo e nitrogênio não apresentaram influência significativa na concentração máxima de biomassa e produtividade máxima. O extrato que apresentou a menor tensão superficial (26,75 mN.m-1 ) foi verificado quando foi utilizado etanol como solvente, sendo este obtido a partir de cultivo da microalga Spirulina sp. LEB 18 realizado sem adição de nitrogênio e de fósforo. Em relação ao índice de emulsificação foram atingidos valores superiores a 59%, porém as concentrações utilizadas de nitrogênio e fósforo não apresentaram influência significativa nesta resposta. Neste trabalho foi possível obter nanoemulsões estáveis por até 30 d e com diâmetro médio de gotículas de até 532 nm. Os resultados obtidos neste trabalho são favoráveis à pesquisa na aplicação tanto dos extratos microalgais como das nanoemulsões obtidas apresentando potencialidade de uso em diversos processos industriais, como nas áreas ambiental, farmacêutica, cosmética e alimentos.

Desenvolvimento de nanosistemas farmacêuticos para terapia gênica

Gene therapy is one of the major challenges of the post-genomic research and it is based on the transfer of genetic material into a cell, tissue or organ in order to cure or improve the patient s clinical status. In general, gene therapy consists in the insertion of functional genes aiming substitute, complement or inhibit defective genes. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, a key issue is to create systems, vectors, able to transfer and protect the DNA until it reaches the target. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easy to produce, present suitable stability and enable transfection. The aim of this work was to evaluate two different non-viral vectors, cationic liposomes and nanoemulsions, and the possibility of their use in gene therapy. For the two systems, cationic lipids and helper lipids were used. Nanoemulsions were prepared using sonication method and were composed of Captex® 355; Tween® 80; Spam® 80; cationic lipid, Stearylamine (SA) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) and water (Milli-Q®). These systems were characterized by average droplet size, Polidispersion Index (PI) and Zeta Potential. The stability of the systems; as well as the DNA compaction capacity; their cytotoxicity and the cytotoxicity of the isolated components; and their transfection capacity; were also evaluated. Liposomes were made by hydration film method and were composed of DOTAP; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), containing or not Rhodaminephosphatidylethanolamine (PE- Rhodamine) and the conjugate Hyaluronic Acid DOPE (HA-DOPE). These systems were also characterized as nanoemulsions. Stability of the systems and the influence of time, size of plasmid and presence or absence of endotoxin in the formation of lipoplexes were also analyzed. Besides, the ophthalmic biodistribution of PE-Rhodamine containing liposomes was studied after intravitreal injection. The obtained results show that these systems are promising non-viral vector for further utilization in gene therapy and that this field seems to be very important in the clinical practice in this century. However, from the possibility to the practice, there is still a long way