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Different carrier systems have been investigated for myocardial delivery of biopharmaceuticals for heart disease. Here, we aimed to evaluate the heart retention and tissue response of liposomes intended for cardiac drug delivery. Liposomes were produced by the lipid thin film hydration method followed by sonication. Cytocompatibility tests were performed in murine L929 fibroblasts and H2c9 cardiomyocytes using the Alamar Blue assay. In vivo experiments were assessed in a model of myocardial infarction induced by isoproterenol in mice. Cardiac delivery of fluorescent liposomes (rhodamine B-labeled) with different mean sizes (165 nm, 468 nm, 1551 nm and 1954 nm) was performed by ultrasound-guided transthoracic injection. After three days, mice were euthanized for histological evaluation using optical and fluorescence microscopy. No cytotoxic lipid concentrations were determined in the range 9.3 - 120 µM for fibroblasts and cardiomyocytes exposed to liposomes. In vivo, large liposomes induced significant inflammation in myocardium compared with the control group (p 0.0001). In contrast, heart mice injected with 468 nm-sized liposomes exhibited a lower number of inflammatory cells. Still, a greater tissue retention 72 h post-injection was found. Therefore, this study demonstrated the feasibility of the echocardiography-guided percutaneous injection to deliver liposomes successfully into the myocardium in a minimally invasive manner. In addition, these findings indicate the potential of liposomes as carriers of biopharmaceuticals for myocardial delivery, supporting the development of further research on these delivery systems for heart disease.

The present study describes the use of fucoidan, a negative sulfated polysaccharide, as a coating material for the development of liposomes targeted to macrophages infected with Mycobacterium tuberculosis. First, fucoidan was chemically modified to obtain a hydrophobized-fucoidan derivative (cholesteryl-fucoidan) using a two-step microwave-assisted (μW) method. The total reaction time was decreased from 14 hours to 1 hour while maintaining the overall yield. Cholesterylfucoidan was then used to prepare surface-modified liposomes containing usnic acid (UA-LipoFuc), an antimicrobial lichen derivative. UA-LipoFuc was evaluated for mean particle size, polydispersity index (PDI), surface charge (ζ), and UA encapsulation efficiency. In addition, a cytotoxicity study, competition assay and an evaluation of antimycobacterial activity against macrophages infected with M. tuberculosis (H37Ra) were performed. When the amount of fucoidan was increased (from 5 to 20 mg), vesicle size increased (from 168 ± 2.82 nm to 1.18 ± 0.01 μm). Changes in from +20 ± 0.41 mV for uncoated liposomes to −5.41 ± 0.23 mV for UA-LipoFuc suggested that the fucoidan was placed on the surface of the liposomes. UA-LipoFuc exhibited a lower IC50 (8.26 ± 1.11 μM) than uncoated liposomes (18.37 ± 3.34 μM), probably due to its higher uptake. UA-LipoFuc5 was internalized through the C-type carbohydrate recognition domain of the cell membrane. Finally, usnic acid, both in its free form and encapsulated in fucoidan-coated liposomes (UA-LipoFuc5), was effective against infected macrophages. Hence, this preliminary investigation suggests that encapsulated usnic acid will aid in further studies related to infected macrophages and may be a potential option for tuberculosis treatment.

Aedes aegypti is a species of mosquito with wide distribution worldwide, involved in the cycles of transmission of dengue, Zika and chikungunya. The lack of vaccines for most of these arboviruses highlights the importance of vector control as a measure to reduce the incidence of these diseases. Several researches have been carried out in order to find substances of plant origin that are candidates for the control of A. aegypti. In this sense, medicinal plants that also have an insecticidal action have shown promise for the development of new products, environmentally safer than traditional chemical insecticides. The objective of this work was to evaluate the larvicidal activity of the essential oil of the leaves of Croton rhamnifolioides and its formulation in nanocapsules for A. aegypti. The essential oil was extracted by hydrodistillation and analyzed by gas chromatography coupled to a mass spectrometer (CG/MS). Formulations were produced containing concentrations of pure oil, which ranged from 40 to 80 μg/mL and polycaprolactone nanocapsules with concentrations from 30 to 120 μg/mL. Larvicide tests were performed using varying concentrations of an aqueous suspension, in triplicates, containing 20 larvae / concentration, in addition to an untreated control. As a result, the essential oil had an average content that varied between 1.4% and 0.58%, depending on the time of collection and, as main constituents, eucalyptol (16.57%) and (E) -cariophylene (11, 32%). LC50 values ranged from 26.3 μg/mL to 52.2 μg/mL and CL90 from 37.8 μg/mL to 68.7 μg/mL for pure oil. In encapsulated oil, the LC50 = 63.4 μg/mL and the LC90 = 104.8 μg/mL. The pure oil of Croton rhamnifolioides was considered more active against the larvae of A. aegypti than the encapsulated one, although both have great potential for application as a larvicide.

The pandemic COVID-19 has worried everyone due to the high mortality rate and the high number of people hospitalized with severe acute respiratory syndrome caused by SARS-CoV-2. Given the seriousness of this disease, several companies and research institutions have sought alternative treatment and/or prevention methods for COVID-19. Due to its versatility, nanotechnology has allowed the development of protective equipment and vaccines to prevent the disease and reduce the number of severe COVID-19 cases. Thus, this article combined the main works and products developed in a nanotechnological field for COVID-19. We performed a literature search using the keywords "COVID-19," "SARS-CoV-2," "nanoparticles," "nanotechnology," and "liposomes" in the SciELO, Scifinder, PubMed, Sciencedirect, ClinicalTrials, and Nanotechnology Products databases Database. The data survey indicated 48 articles, 62 products, and 32 patents. The use of nanotechnology against COVID-19 has brought benefits in several parameters of this disease, helping develop rapid diagnostic tests that release the result in 10 min, as well as developing vaccines containing genetic material from SARS-CoV-2 (DNA, mRNA, and protein subunits). Nanotechnology is an exceptional ally against COVID-19, contributing to the most diverse areas, helping both prevent, diagnose, and treat COVID-19.

Oncocalyxone A (oncoA) is a quinone extracted from the Cordia oncocalyx plant. This compound has pharmacological properties, such as anti-inflammatory, analgesic, and cytotoxic activities, among others. OncoA presents a similar chemical structure to doxorubicin, a drug used in cancer treatment, which possesses an intrinsic fluorescence explored in various studies, including those using doxorubicin-loaded nanoparticles. Thus, due to the chemical structural similarity, the question arose whether oncoA could also show autofluorescence. Therefore, this study proposed to characterize the absorption and emission spectral profiles of oncoA and analyze if this compound could be used as a fluorescent probe.For this, fucoidan-coated polyisobutylcyanoacrylate (PIBCA) nanoparticles containing oncoA were prepared, and an uptake study was performed using a human metastatic breast cancer cell line (MDA-MB-231 cells).OncoA presented a maximum emission wavelength in the blue region, near 430 nm, at 350 nm excitation, compatible with standard microscope optics. Fluorescence microscopy analyses showed that oncoA-loaded PIBCA nanoparticles were internalized by MDA-MB-231 cells under incubation times as shorter as 15 min.According to these findings, oncoA-encapsulated nanoparticles are promising fluorescent probes and could be useful for cellular uptake studies.

Oncocalyxone A (onco A) isolated from heartwood of Cordia oncocalyx (Auxemma oncocalyx), exhibits antitumor, analgesic and anti-inflammatory activities. In order to produce drug delivery systems containing onco A, the objective of this study was to develop and validate an HPLC method for quantifying onco A in different media and nanocapsules. The validation method was performed according to ICH guidelines for pharmaceutical products. The solubility of onco A was determined in deionized water, simulated gastric and intestinal fluids, buffer solutions at pH 5.5, 7.0, 9.0 and oils: copaiba, soybean and medium-chain triglycerides. The partition coefficients of onco A between n-octanol, oils and aqueous phase were determined at 25 °C. Accuracy, intra- and inter-day precision values presented low random errors (less than or equal to 2.53, 2.21 and 3.12%, respectively). Onco A solubility was greater in water, buffer solutions, and simulated gastric and intestinal fluids (817 ± 54 μg mL−1) than in oils (434 ± 25 μg mL−1). Onco A showed hydrophilic characteristics (log P

Background: Target treatment using site-specific nanosystems is a hot topic for treating several diseases, especially cancer. Objective: The study was set out to develop site-specific liposomes using ConcanavalinA (ConA) to target β- lapachone(β-lap) to human breast cancer cells. Methods: Liposomes were prepared and characterized according to diameter size, zeta potential, ConA conjugation(%) and β-lap encapsulation efficiency (%). Isothermal Titration Calorimetry evaluated the binding energy between the biomolecules, which compose of the liposomes. ConA avidity was assessed before and after conjugation. Cytotoxicity was evaluated, and fluorescence microscopy was performed to investigate the influence of ConA influenced on MCF-7 uptake. Results: Uncoated and ConA-coated liposomes presented size, and zeta potential values from 97.46 ± 2.01 to 152.23 ± 2.73 nm, and -6.83 ± 0.28 to -17.23 ±0.64 mV, respectively. Both ConA conjugation and β-lap encapsulation efficiency were approximately 100%. The favorable and spontaneous process confirmed the binding between ConA and the lipid. Hemagglutination assay confirmed ConA avidity once Lipo-ConA and Lipo-PEG-ConA were able to hemagglutinate the red blood cells at 128-1 and 256-1, respectively. Lipo-ConA was not cytotoxic, and the site-specific liposomes presented the highest toxicity. ConA-coated liposomes were more internalized by MCF7 than uncoated-liposomes. Conclusion: Therefore, the presence of ConA on the surface of liposomes influenced MCF7 uptake, in that way could be used as a promising site-specific system to target β-lap to cancer cells.

The effect of microencapsulation of L. acidophilus La-05 (8 log CFU/mL) by external ionic gelation technique in alginate (30 g/L; AM) and alginate coated with a low molecular weight chitosan solution (5 g/L; AC5M) on the survival of the freeze-dried probiotic culture during storage (7 °C; 0, 7, 15, 30, 60, 90 and 120 days), and exposure to temperature (72, 85 and 90 °C), pH (2, 4, and 6), and NaCl (10, 15 and 20 g/L) were studied. Furthermore, vegan milks (soybean and rice milks) added with microencapsulated probiotic cultures were evaluated for the physicochemical characteristics and survival of the probiotic culture during refrigerated storage (7 °C; 7 days) and in vitro digestion. Free cells were used as control. AM and AC5M showed similar microencapsulation yield (>90%) with uniform and spherical microparticles dispersed without agglomeration. Scanning electron microscopy showed that chitosan was able to cover the porous structure of the alginate particles, resulting in a more stabilized microparticle. The microencapsulation provided higher probiotic protection to storage, thermal treatment, NaCl and pH (decreases of ~1 log CFU/mL) compared to the free cells (decreases of ~3, 4, 2 and 3 log CFU/mL, respectively), and increased probiotic survival during refrigerated storage and in vitro digestion of vegan milks compared to free cells (decreases of ~1 and 4 log CFU/mL, respectively). Only microencapsulated probiotic cultures (AM and AC5M) maintained suitable probiotic counts (>6 log CFU/mL) during storage, exposure to stress conditions and simulated gastrointestinal digestion. Chitosan coating increased the probiotic survival in the vegan milks during refrigerated storage. Microencapsulation by external ionic gelation in alginate proved to be a suitable microencapsulation technique to improve the probiotic survival to storage, stress conditions (temperature, pH and NaCl) and simulated gastrointestinal conditions. This was the first study that evaluated the addition of probiotic cultures to rice and soybean milks, proving that the vegan milks could be considered suitable carriers for microencapsulated probiotic cultures.

Background Oncocalyxone A (oncoA) is a natural benzoquinone isolated from Cordia oncocalyx, which exhibits many biological activities such as anti-tumor, anti-inflammatory, antioxidant, and hypoglycemic. However, it presents renal, cardiac, and pulmonary toxicity, which can be a limiting factor. The encapsulation of oncoA in polymeric nanoparticles can enhance its therapeutic effect, while reducing its toxicity. Objective Thus, this study aimed to develop nanoparticles of poly (isobutyl cyanoacrylate) containing oncoA, and to evaluate its activity against metastatic breast cancer cells. Methods The nanoparticles were obtained using the anionic emulsion polymerization technique and characterized by Fourier-transform Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), Differential Scanning Calorimetry (DSC), and Thermogravimetry (TG), in addition to studies of long-term stability, including different pH, and blood compatibility. Antiproliferative activity was assessed by MTT and cell migration assays. Results The nanoparticles were obtained with a particle size of 305 ± 6.49 nm and encapsulation rate of 101.5 ± 1.4%, and were stable at different pH over 7 months. The nanoparticles did not induce hemolysis. The encapsulation of oncoA in fucoidan-coated PIBCA nanoparticles increased its cytotoxicity on MDA-MB-231 cells, and inhibited cell migration. Conclusion In conclusion, fucoidan-coated PIBCA nanoparticles containing oncoA may be a promising alternative for further anticancer in vivo studies.

Purpose: To determine the release profile of moxifloxacin encapsulated in liposomes in the aqueous humor as a controlled release system for intracameral application. Methods: Liposomes containing moxifloxacin were obtained using the lipid film hydration method and were characterized by particle size and encapsulation efficiency. Female rabbits were used for the in vivo profile release study. Liposomes containing moxifloxacin was injected into the anterior chamber of the right eye of each animal. The rabbits were divided into five groups, and a sample of aqueous humor was collected 2, 4, 8, 24, and 48 h after administration of liposomes containing moxifloxacin administration. Moxifloxacin concentrations in the aqueous humor were analyzed using high-performance liquid chromatography. Results: The average size of the liposomes containing moxifloxacin was 60.5 ± 0.72 nm with a particle size distribution of 0.307. The encapsulation efficiency of moxifloxacin in liposomes was 92.24 ± 0.24%. The results of an in vivo release study of liposomes containing moxifloxacin, showed that the maximum moxifloxacin concentration was achieved within the first 2 h after administration (5.27 ± 1.09 mg/mL) and was followed by a decrease in intracameral concentration (0.35 ± 0.05 mg/mL) until the 24 h mark. Conclusions: The in vivo experiments resulted in liposomes containing moxifloxacin that were homogenous in size and exhibited high drug encapsulation efficiency. The results indicate that liposomes containing moxifloxacin offers a satisfactory aqueous humor release profile after intracameral application.

O ácido úsnico (AU) é um composto de origem liquênica e tem demonstrado importantes atividades biológicas, tais como: antitumoral, antimicrobiano, antiviral, antiproliferativo e antiinflamatório. Os lipossomas são vesículas lipídicas contendo espaço aquoso interno e têm sido utilizados como carreadores coloidais de fármacos, principalmente na terapêutica de câncer e infecções bacterianas e fúngicas. O objetivo desse trabalho foi desenvolver e validar um método espectrofotométrico UV para determinação de ácido úsnico em lipossomas. Os parâmetros de validação linearidade, precisão, exatidão, robustez, limites de detecção e quantificação foram determinados segundo diretrizes internacionais de padronização e Farmacopéia Americana. A faixa de linearidade foi de 3 a 15 µg.mL-1, a equação de regressão: absorbância = 0,070 x [AU] (µg.mL-1) + 0,013 e r = 0,9997. A repetibilidade (coeficiente de variação) do método foi 1,96% e a precisão intermediária indicou que a diferença entre as médias foi estatisticamente insignificante (P < 0,05). A exatidão revelou média percentual de recuperação de 100,4%. O método foi robusto apesar da variação de temperatura e solventes. Os limites de detecção e quantificação do ácido úsnico foram de 0,34 e 1,13 µg.mL-1, respectivamente. O doseamento do ácido úsnico nos lipossomas foi de 96,8% (± 0,2). O método proposto é exato, preciso e reprodutível sendo capaz de quantificar o ácido úsnico em matéria-prima e em preparações farmacêuticas.The secondary lichen metabolite usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzofuran] has demonstrated pharmacological potential activities such as antitumor, antimicrobial, antiviral, antiproliferative, and anti-inflammatory. Liposomes are vesicles composed of phospholipid bilayers surrounding aqueous compartments and they have been used as colloidal drug carriers. The aim of this study was to develop and validate a quantitative UV spectrophotometric method for determination of usnic acid in liposomal formulations. The validation parameters were assessed according to The International Conference on Harmonization (ICH) and American Pharmacopoeia guidelines. The linearity range was of 3-15 µg.mL-1, regression equation: absorbance = 0.070 x UA concentration (µg.mL-1) + 0.013, and r = 0.9997. The repeatability (relative standard deviation) of the method was 1.96% and intermediate precision indicated that the difference among mean was statistically insignificant (P < 0.05). The accuracy revealed a mean percentage recovery of 100.4% of usnic acid. The method was robust for the variation of temperature and solvent. The detection and quantization limits were found to be 0.34 and 1.13 µg.mL-1, respectively. The content of usnic acid in liposomes was of 96.8% (± 0.2). The proposed method is accurate, precise and reproducible for estimation of usnic acid as raw material and in pharmaceutical dosage forms such as liposomes.

Apesar do desenvolvimento tecnológico e científico, a malária permanece como um dos maiores problemas de saúde a serem combatidos. As estratégias modernas para o controle da doença prevêem ações conjuntas, como o combate do inseto vetor, diagnóstico rápido e preciso, garantia de terapêutica adequada, redução dos casos de resistência, além do desenvolvimento de novos agentes terapêuticos e vacina e através da otimização da ação de fármacos utilizados na atualidade. Os sistemas de liberação controlada de fármacos vêm recebendo atenção especial nesta área de pesquisa, com o desenvolvimento de estratégias para a veiculação de agentes bioativos e vacinas na forma de nanodispositivos tais como lipossomas, nanopartículas e micropartículas. Diversos nanossistemas já demonstraram eficácia na otimização de vacinas e quimioterápicos destinados ao controle da malária. Este artigo de revisão tem por objetivo avaliar o estado da arte na terapêutica da malária e demonstrar o potencial da nanotecnologia farmacêutica como ferramenta destinada ao combate da doença.In spite of living in a scientific and technological era, malaria continues to be one of the worldwide greatest health challenges. The state-of-the-art policy to keep malaria under control is expected to comprise joint-strategies, such as the vector control, fast diagnosis, therapeutic guarantee, resistance cutback, drug optimization and development of new therapeutic agents and vaccines. Nano and microcarrier systems have been receiving a special attention, including the development of strategies for carrying bioactive agents, vaccines through nanodevices, such as liposomes and nanoparticles, and microdevices, such as microparticles and microemulsions. Numerous nanosystems have already substantiated their effectiveness to optimize vaccines, insecticides, and chemotherapeutic agents applied to the control of malaria. This review is intended to explain the malaria scenario though the world, and to show the nanotechnology as a promising alternative for malaria control and treatment.

Lipossomas são vesículas constituídas de uma ou mais bicamadas fosfolipídicas orientadas concentricamente em torno de um compartimento aquoso e servem como carreadores de fármacos, biomoléculas ou agentes de diagnóstico. A estabilidade dos lipossomas pode ser afetada por fatores químicos, físicos e biológicos. Após administração intravenosa, lipossomas convencionais são rapidamente capturados pelo sistema fagocitário mononuclear. Para evitar essa captura, lipossomas furtivos foram desenvolvidos, os quais apresentam a superfície modificada com componentes hidrofílicos. Para permitir a liberação seletiva do fármaco nos sítios alvos, ligantes de reconhecimento específico são conjugados na superfície de lipossomas. Em geral, os métodos de preparação de lipossomas incluem hidratação de um filme lipídico seguida de sonicação ou extrusão para redução do tamanho das vesículas. Os lipossomas são caracterizados quanto ao tamanho e composição química das vesículas e conteúdo do material encapsulado. Nesta revisão, constata-se que os lipossomas oferecem maior eficácia e segurança com relação aos tratamentos convencionais. Apesar de algumas formulações lipossomais serem comercializadas desde os anos 1980 para tratamento de infecções fúngicas sistêmicas e do câncer, problemas de ordem tecnológica e biológica fazem com que os lipossomas sejam ainda extensivamente estudados para desenvolvimento de formulações estáveis no organismo visando à terapia de várias doenças, principalmente do câncer. Liposomes are vesicles that consist of one or more concentric phospholipidic bilayers organized around an aqueous inner compartment. They are carriers of drugs, biomolecules and diagnostic agents. The stability of liposomes can be influenced by chemical or physical factors. Once injected in the circulatory system, conventional liposomes suffer uptake by the mononuclear phagocytic system. To avoid such a capture, non-conventional or Stealth® liposomes were developed, which are coated by hydrophilic components. Specific ligand had been incorporated in their surface so as to control the drug release and selectivity, thereby originating the targeted liposomes. In general, all preparation methods of liposomes include the hydration of lipidic film followed by sonication or extrusion to reduce the mean size of vesicles. After preparation, the vesicles are characterized by size, chemical constitution, and amount of encapsulated material. In this review it is shown that the liposomes offer effectiveness and safety in comparison with many conventional treatments. In spite of the existence of a few liposomal formulations available since early 80's, which are used for the treatment of systemic fungal infections and cancer, many technological and biological issues remain as a challenge. In this scenario, liposomes have extensively been studied in order to improve their in vivo stability in the treatment of several diseases, including cancer.

Lipossomas são vesículas constituídas de uma ou mais bicamadas fosfolipídicas orientadas concentricamente em torno de um compartimento aquoso e servem como carreadores de fármacos, biomoléculas ou agentes de diagnóstico. A estabilidade dos lipossomas pode ser afetada por fatores químicos, físicos e biológicos. Após administração intravenosa, lipossomas convencionais são rapidamente capturados pelo sistema fagocitário mononuclear. Para evitar essa captura, lipossomas furtivos foram desenvolvidos, os quais apresentam a superfície modificada com componentes hidrofílicos. Para permitir a liberação seletiva do fármaco nos sítios alvos, ligantes de reconhecimento específico são conjugados na superfície de lipossomas. Em geral, os métodos de preparação de lipossomas incluem hidratação de um filme lipídico seguida de sonicação ou extrusão para redução do tamanho das vesículas. Os lipossomas são caracterizados quanto ao tamanho e composição química das vesículas e conteúdo do material encapsulado. Nesta revisão, constata-se que os lipossomas oferecem maior eficácia e segurança com relação aos tratamentos convencionais. Apesar de algumas formulações lipossomais serem comercializadas desde os anos 1980 para tratamento de infecções fúngicas sistêmicas e do câncer, problemas de ordem tecnológica e biológica fazem com que os lipossomas sejam ainda extensivamente estudados para desenvolvimento de formulações estáveis no organismo visando à terapia de várias doenças, principalmente do câncer.Liposomes are vesicles that consist of one or more concentric phospholipidic bilayers organized around an aqueous inner compartment. They are carriers of drugs, biomolecules and diagnostic agents. The stability of liposomes can be influenced by chemical or physical factors. Once injected in the circulatory system, conventional liposomes suffer uptake by the mononuclear phagocytic system. To avoid such a capture, non-conventional or Stealth® liposomes were developed, which are coated by hydrophilic components. Specific ligand had been incorporated in their surface so as to control the drug release and selectivity, thereby originating the targeted liposomes. In general, all preparation methods of liposomes include the hydration of lipidic film followed by sonication or extrusion to reduce the mean size of vesicles. After preparation, the vesicles are characterized by size, chemical constitution, and amount of encapsulated material. In this review it is shown that the liposomes offer effectiveness and safety in comparison with many conventional treatments. In spite of the existence of a few liposomal formulations available since early 80's, which are used for the treatment of systemic fungal infections and cancer, many technological and biological issues remain as a challenge. In this scenario, liposomes have extensively been studied in order to improve their in vivo stability in the treatment of several diseases, including cancer.

The present study investigated the potential of Concanavalin A lectin (Con A) conjugated to liposomes (Con A-liposomes) for targeting doxorubicin (DOX) to cells. The physicochemical properties and the cytotoxicity of DOX-loaded Con A-liposomes were evaluated. DOX-loaded Con A-liposomes were prepared by incubation of DOX-loaded liposomes with a Con A-SATA derivative. Lectin biological activity was monitored before and after conjugation by a hemagglutinating assay. The cytotoxicity of DOX-loaded Con A-liposomes was evaluated in terms of the inhibition of NCI-H299 and HEp-2 cell proliferation using the MTT method. The affinity of lectinized liposomes with these cells was thus assessed by evaluating the cytotoxic effect of the DOX released into cells. Stable DOX-loaded Con A-liposomes were obtained and their high affinity for cells was corroborated. The encapsulation of DOX into Con A-liposomes produced an inhibition of roughly 70% of Hep-2 cell proliferation and 50% of cell inhibition was verified on HCI-H292. DOX in solution was able to inhibit only 20% of cell proliferation for both cell lines. Unloaded Con A-liposomes were not cytotoxic. The encapsulation of DOX into Con A-liposomes improves drug penetration into cells, thereby enhancing its cytotoxicity, especially in Hep-2 cells. Drug Dev. Res. 67:430–437, 2006. © 2006 Wiley-Liss, Inc.

Este estudo se propõe a avaliar o perfil farmacocinético de comprimidos contendo lamivudina e zidovudina associados, produzidos pelo Laboratório Farmacêutico do Estado de Pernambuco - LAFEPE. O medicamento foi administrado em 10 voluntários sadios e foram observadas as concentrações plasmáticas dos dois anti-retrovirais durante 12 horas. A partir das concentrações plasmáticas foi possível encontrar os parâmetros farmacocinéticos de ambos os fármacos através de cálculos estatísticos. Os resultados obtidos foram comparados com aqueles resultantes de experimentos realizados por outros autores descritos neste trabalho, em que se verificou não haver diferenças significativas entre os valores encontrados e os descritos na literatura e que o fato dos anti-retrovirais estarem associados na mesma formulação não modificou o perfil cinético de nenhuma das substâncias. The purpose of this work was an evaluation of the pharmacokinetic profile from lamivudine and zidovudine combination tablets, produced by Laboratório Farmacêutico do Estado de Pernambuco - LAFEPE. The formulation was administered in 10 volunteers and the concentration-time serum profile was observed from both antiretroviral agents during 12 hours. From concentration-time serum profile the pharmacokinetic parameters for both drugs were calculated by statistical methods. The results were compared with those from experiments carried out by other authors referred in this paper. Differences between the results obtained herein and those from other authors were not significant. The kinetic profile for both substances was not modified by the anti-retroviral combination.

Este estudo se propõe a avaliar o perfil farmacocinético de comprimidos contendo lamivudina e zidovudina associados, produzidos pelo Laboratório Farmacêutico do Estado de Pernambuco - LAFEPE. O medicamento foi administrado em 10 voluntários sadios e foram observadas as concentrações plasmáticas dos dois anti-retrovirais durante 12 horas. A partir das concentrações plasmáticas foi possível encontrar os parâmetros farmacocinéticos de ambos os fármacos através de cálculos estatísticos. Os resultados obtidos foram comparados com aqueles resultantes de experimentos realizados por outros autores descritos neste trabalho, em que se verificou não haver diferenças significativas entre os valores encontrados e os descritos na literatura e que o fato dos anti-retrovirais estarem associados na mesma formulação não modificou o perfil cinético de nenhuma das substâncias.The purpose of this work was an evaluation of the pharmacokinetic profile from lamivudine and zidovudine combination tablets, produced by Laboratório Farmacêutico do Estado de Pernambuco - LAFEPE. The formulation was administered in 10 volunteers and the concentration-time serum profile was observed from both antiretroviral agents during 12 hours. From concentration-time serum profile the pharmacokinetic parameters for both drugs were calculated by statistical methods. The results were compared with those from experiments carried out by other authors referred in this paper. Differences between the results obtained herein and those from other authors were not significant. The kinetic profile for both substances was not modified by the anti-retroviral combination.

The aim of this study was to assess the efficacy of topical application of a liposomal formulation of itraconazole for the treatment of experimental keratitis with endophthalmitis caused by Aspergillus flavus. The liposomes were obtained by the lipid film hydration method followed by sonication. Adult female Wistar rats (weighing 200-220 g) were immunosuppressed by intraperitoneal injection of 150 mg/kg of cyclophosphamide 3 days before infection by exposure to the fungus A. flavus (10(7) spores/ml). Forty-eight hours later, the animals were treated with the liposomal formulation. For comparison, one group of animals (n = 6) was treated with the same drug not encapsulated. At the end of the experiment, the animals were evaluated for clinical signs and number of colony forming units (CFU/g), along with direct microscopic examination. The results indicated that the liposomal formulation of itraconazole has better antifungal activity than the unencapsulated drug in the treatment of fungal keratitis with endophthalmitis caused experimentally by A. flavus in Wistar rats.

A new agglomerative (bottom-up) hierarchical cluster technique referred to as the Adaptive Mean-Linkage algorithm is derived. Cluster algorithms are also offered as a tool to explore the descriptor space knowing the quantitative structure–activity relationship (QSAR). The substituents are clustered building a dendrogram (cluster tree) per site. Choosing appropriate pathways on such cluster trees according to the QSAR equation, an automated search for potentially active substituted compounds can be performed. Applications to a series of substituted phenylguanidines with anticancer activity are focused illustrating this approach.

Ab initio and semiempirical (AM1) molecular orbital calculations have been performed on O-(2,2,2-trichloro-1-hydroxyethyl)-benzamidoxime. The calculated values of the bond angles, bond lengths and dihedral angles have been compared witht hose obtained by X-ray crystallography. There is good agreement between the experimental geometry and the calculated structure at the ab initio and semiempirical levels. The hydrogen bonded dimers of two S enantiomers (SS dimer) and of RS enantiomer monomers have been studied with the AM1 method. The RS dimer calculated structure agrees quite well with the experimental X-ray data, having two hydrogen bonds between the OH group and the nitrogen atom of the C  NO group. However, the calculated hydrogen bond patterns in the SS dimer are different, with one H-bond between the OH and C  NO groups (OH⋯N) and another one between the NH2 and OH groups (HNH ⋯ OH).

Croton cajucara Beth (Euphorbiaceae) uma espécie medicinal nativa da região Amazônica do Brasil, onde é vulgarmente conhecida como 'sacaca', representa um recurso terapêutico eficaz no tratamento e cura de várias doenças. O metabólito majoritário trans-desidrocrotonina (DCTN), isolado das cascas do caule desta planta, encontra-se correlacionado com grande parte das propriedades medicinais da sacaca. Este artigo de revisão, descreve os resultados fitoquímicos e farmacológicos que foram realizados com o diterpeno do tipo clerodano DCTN, bem como seus derivados semi-sintéticos. Adicionalmente, apresenta perspectivas para a biodisponibilização deste protótipo de fármaco em nanosistemas. Croton cajucara Beth (Euphorbiaceae) is a plant found in the Amazonian Region of North Brazil, where it is popularly known as sacaca. The major secondary metabolite, trans-dehydrocrotonin (DCTN) a clerodane-type diterpene, isolated from the stem bark is a chief bioactive compound of Croton cajucara. This review describes results of extensive pharmacological studies of DCTN, as well as its semi-synthetic derivatives, and also presents insights into the use of DCTN as a therapeutic agent and some potential advantages of its incorporation in drug delivery systems.

A Terapia Fotodinâmica (TFD) é uma modalidade de tratamento de câncer relativamente nova e promissora. Baseia-se na utilização de uma substância fotossensibilizante e luz para provocar um dano seletivo ao tecido alvo, sendo que a seletividade ao órgão/tecido deve ser reconhecida como uma das vantagens no tratamento do câncer. Atualmente, o desenvolvimento de sistemas de liberação e promotores de absorção visando a otimização da liberação tópica de fotossensibilizadores, apresenta-se como um promissor e inexplorado campo de pesquisa na TFD do câncer de pele. Sistemas de liberação compostos por monoleína, um lipídeo polar biocompatível, e água são capazes de aumentar a permeação de fármacos na pele, além de serem capazes de controlar a liberação dos mesmos. No presente estudo foram desenvolvidas e caracterizadas nanodispersões de cristais líquidos como sistemas de liberação para os fotossensibilizadores Protoporfirina IX (PpIX) e Ftalocianinas de Zinco (ZnPc) e Cloro Alumínio (ClAlPc), objetivando otimizar a penetração cutânea destes na epiderme. As nanodispersões foram avaliadas em relação a sua eficiência de encapsulação, estabilidade física e química dos fotosensibilizadores veiculados, bem como a permeação e retenção cutânea in vitro e in vivo por microscopia de fluorescência. Estudos de pré-tratamento foram realizados, objetivando-se verificar o efeito promotor de absorção cutânea das nanodispersões desenvolvidas. Os experimentos de eficiência de encapsulação e estabilidade mostraram que as nanodispersões são um sistema de liberação adequado a aplicação tópica de fotosensibilizadores. Os experimentos in vitro mostraram que as nanodispersões aumentaram a penetração cutânea da PpIX e ClAlPc no estrato córneo em, respectivamente, 3,4 e 11,7 vezes, quando comparadas a formulação controle. Na epiderme mais derme sem estrato córneo, os aumentos promovidos pelas nanodispersões foram de 6,5 e 9,7 vezes para a PpIX e ClAlPc. No experimento in vivo as nanodispersões aumentaram a penetração cutânea da PpIX e ClAlPc no estrato córneo em, respectivamente, 13,7 e 7,0 vezes, quando comparadas ao controle, sendo que na epiderme mais derme sem estrato córneo somente as nanodispersões foram capazes de promover a penetração cutânea destes fotossensibilizadores nestas camadas da pele. A visualização da penetração cutânea dos fotosensibilizadores por microscopia de florescência confirmou os resultados obtidos nos experimentos in vivo de que as nanodispersões foram superiores ao controle em aumentar a penetração cutânea da PpIX e ClAlPc em camadas mais profundas da pele. Os resultados obtidos mostraram que as nanodispersões desenvolvidas são sistemas de liberação promissores para a PpIX e ClAlPc no tratamento do câncer de pele na TFD uma vez que aumentaram in vitro e in vivo a penetração cutânea destes na epiderme. Photodynamic therapy (PDT) is a relatively new and promising cancer treatment modality that involves the administration of a photosensitizing drug and its subsequent activation by light to produce activated oxygen species that selectively destroy target cells. Recently, PDT to treat skin cancer is focused on the development of drug delivery systems and penetration enhancers that aim to optimize the topical release of photosensitizers. Drug delivery systems based on monoolein, a biocompatible polar lipid, and water are able to enhance the cutaneous penetration of drugs and control their release. Liquid crystal nanodispersions were developed and characterized in this project as delivery systems for the photosensitizers Protoporphyrin IX (PpIX) and Zinc and Chloroaluminum phthalocyanines (ZnPc and ClAlPc), aiming to increase their topical penetration in the epidermis. The physical stability of the nanodispersions, their encapsulation efficiency and the chemical stability of the photosensitizers incorporated were tested. In vitro and in vivo skin penetration tests were performed to verify the efficacy of the nanodispersions in enhancing the topical delivery of the photosensitizers. In vitro pre-treatment tests were conducted to determine if the nanodispersions are able to increase the skin penetration of the photosensitizers by a penetration enhancing effect. Stability and encapsulation efficiency tests showed that nanodispersions are an adequate topical delivery system for photosensitizers. In vitro experiments showed increased PpIX and ClAlPc penetration in the stratum corneum, respectively, of 6.5- and 9.7-fold for the nanodispersions compared to the control. In the epidermis with dermis, without stratum corneum, the increase promoted by the nanodispersions for PpIX and ClAlPc were, respectively, of 6.5- and 9.7-fold. Experimental retention in vivo confirmed that when the nanodispersions were used as carrier, PpIX and ClAlPc concentrations in the stratum corneum were about 13.7- and 7.0-fold higher, respectively, than control. In the epidermis with dermis, without stratum corneum, only the nanodispersions were able to promote the skin penetration of these photosensitizers. Visualization of PpIX and ClAlPc skin penetration by fluorescence microscopy confirmed that the nanodispersions increased the skin penetration of these photosensitizers in deeper skin layers. The results showed that the nanodispersions are promising topical delivery systems in the PDT of skin cancer once they increased in vitro and in vivo the topical penetration of PpIX and ClAlPc in the epidermis.

A terapia gênica por interferência de RNA (RNAi) trata-se de um processo de silenciamento pós-transcricional capaz de suprimir a expressão de um determinado gene. A RNAi é uma proposta terapêutica promissora para o tratamento de muitas doenças severas que ainda não possuem cura ou terapias bem definidas. Porém, é necessário o desenvolvimento de sistemas de liberação clinicamente adequados, seguros e eficazes para se viabilizar essa nova terapêutica, uma vez que obstáculos na administração e distribuição in vivo comprometem o uso clínico dos siRNAs (small interfering RNA). Paralelamente, a liberação tópica de siRNAs surge como uma alternativa promissora para o tratamento de patologias cutâneas. Neste contexto, a presente pesquisa teve como objetivo o desenvolvimento de um sistema de liberação baseado em nanotecnologia para a liberação tópica de siRNAs, visando introduzir a terapia gênica como nova abordagem para o tratamento de patologias cutâneas. Como sistema de liberação, foram desenvolvidas nanodispersões líquido-cristalinas aquosas, compostas por monoleína (MO), um lipídeo polar biocompatível, associadas ou não com ácido oléico (AO). Foram incorporados a esses sistemas os adjuvantes catiônicos polietilenoimina (PEI) e oleilamina (OAM) para obtenção das nanodispersões. Dentre as nanodispersões aquosas desenvolvidas, foram escolhidas as preparações com as menores concentrações de adjuvantes catiônicos, a saber: MO e OAM a 0,4%, MO e PEI a 0,4%, MO, AO e OAM a 2,5% e MO, AO e PEI a 1,0%. Estas formulações apresentaram: reduzido tamanho médio das partículas, baixa polidispersividade, valores de potencial zeta positivos (característica interessante para interação com as moléculas de siRNA que apresentam carga negativa), baixa citotoxicidade in vitro e foram capazes de complexar o siRNA na concentração final de 2,5 ?M. A análise de difração de raios X caracterizou a fase líquido-cristalina desses sistemas como hexagonal, exceto a nanodispersão MO e PEI a 0,4% que foi caracterizada como uma mistura de fase hexagonal e cúbica. As nanodispersões obtidas foram capazes de aumentar a penetração cutânea de siRNA in vitro. Face aos resultados obtidos, podemos concluir que as formulações desenvolvidas são sistemas de liberação de base nanotecnológica promissores para administração tópica de siRNA para o tratamento de patologias cutâneas na terapia gênica. Gene therapy by RNA interference (RNAi) is a post-transcriptional silencing process that can suppress the expression of a particular gene. The RNAi is a promising therapeutic approach for the treatment of many severe diseases that have no cure or well-defined treatments. However, the development of clinically appropriate, safe and effective delivery systems is necessary to enable this new therapy, since obstacles in the in vivo administration and distribution committed the clinical use of siRNAs (small interfering RNA). In addition, the topical delivery of siRNAs appears as a promising alternative for the treatment of cutaneous pathologies. In this context, this research aimed to develop a delivery system based on Nanotechnology for the topical delivery of siRNAs, aiming to introduce gene therapy as a new approach for the treatment of skin disorders. As a delivery system, liquid-crystalline nanodispersions, composed by monoolein (MO), a polar biocompatible lipid, associated or not with oleic acid (OA) were developed. The cationic adjuvants polyethylenimine (PEI) and oleylamine (OAM) were incorporated into these systems to obtain the nanodispersions. Among the aqueous nanodispersions developed, preparations with lower concentration of cationic adjuvant were chosen, these consisting of: MO and OAM at 0.4%, MO and PEI at 0.4%, MO, OA and OAM at 2.5% and MO, OA and PEI at 1.0%. These formulations presented: reduced average particle size, low polydispersity, positive values of zeta potential (an interesting feature for interacting with the siRNA molecules that have a negative charge), low cytotoxicity in vitro and they were able to complex the siRNA at a final concentration of 2.5 ?M. The X-ray diffraction analysis characterized the liquid crystalline phase of these systems as hexagonal, except the nanodispersion MO and PEI at 0.4% which was characterized as a mixture of cubic and hexagonal phases. The nanodispersions obtained were able to increase the skin penetration of siRNA in vitro. With the results obtained, we can conclude that the formulations developed are delivery systems based on nanotechnology, promising for topical administration of siRNA for the treatment of cutaneous diseases in gene therapy.

A protoporfirina IX (PpIX) é uma substância fotodinâmicamente ativa, entretanto, devido a sua alta lipofilia apresenta dificuldades para penetrar nas camadas mais profundas da pele, não sendo administrada topicamente. Assim, o objetivo deste trabalho é estudar a influência de diferentes tipos de dendrímeros de poliamidoamina (PAMAM) na solubilidade, penetração cutânea e penetração celular da PpIX com o intuito de melhorar a terapia fotodinâmica tópica (TFD) com esta substância. Os estudos de solubilidade da PpIX na presença dos dendrímeros PAMAM G4, G4.5 e G4-OH mostraram que o dendrímero PAMAM G4.5, foi o que solubilizou a maior quantidade de PpIX seguido do PAMAM-OH G4> PAMAM G4 > tampão HEPES. A partir dos estudos de solubilidade foi possível identificar que a PpIX na presença dos dendrímeros PAMAM G-4.5 e G4-OH apresentam diagramas de solubilidade tipo BS, e BI quando na presença do PAMAM G4. Os estudos de varredura em espectroscopia UV-VIS e fluorescência indicaram a presença de agregados principalmente nos complexos PpIX-PAMAM G-4.5 obtidos. Os complexos solúveis PpIX-PAMAM G4-OH apresentaram tamanho médio de 13,2 nm, e potencial zeta de -3,41. Já os complexos com o dendrímero PAMAM G-4.5 apresentaram uma população bidispersa, com tamanhos de 31 e 391 nm e um potencial zeta de -17,3. A análise de DSC e espectroscopia de infravermelho com transformada de Fourrier mostraram alterações nas características da PpIX em solução e quando complexada com os dendrímeros. Nos estudos de permeação e retenção cutânea passiva com os complexos contendo 0,006 mg/mL de PpIX, estes não aumentaram a penetração cutânea do fármaco. No entanto, a complexação permitiu que maiores quantidades de PpIX ficassem disponíveis na solução doadora, e um aumento significativo na penetração da PpIX foi observado quando experimentos com 1 mg/mL de PpIX complexada foram conduzidos; ademais notou-se uma possível ação promotora do dendrímero PAMAM G4-OH. Nos estudos de iontoforese verificou-se que a corrente elétrica não aumentou a penetração da PpIX em relação aos experimentos passivos quando o complexo PpIX-PAMAM G4.5 foi estudado, provavelmente devido a maior liberação da PpIX do complexo na presença da corrente elétrica, aumentando os agregados que são grandes o suficientes para não penetrar na pele. Por outro lado, a iontoforese anódica aumentou a penetração do complexo PpIX-PAMAM G4-OH por eletrosmose até as camadas mais profundas da pele, levando a PpIX inclusive até a solução receptora. Os estudos de cultura de células tumorais confirmaram a capacidade dos dendrímeros em aumentar a penetração da PpIX através de membrana. A complexação melhorou a distribuição da PpIX no interior das células e aumentou significativamente a fotocitotoxicidade desta porfirina. Protoporphyrin IX (PpIX) is a photodynamic active drug that is not topically administered due to its high lipophilicity and consequent low penetration in deep skin layers. The aim of this work is to study the influence of different types of polyamidoamine dendrimers (PAMAM) in PpIX solubility, skin and cell penetration to enhance topical photodynamic therapy (PDT). The solubility studies of PpIX in the presence of PAMAM dendrimers G4, G4.5 and G4-OH demonstrated that the G4.5 solubilized the greatest amount of PpIX, followed by PAMAM G4-OH> PAMAM G4> HEPES buffer. Solubility studies showed that the PpIX in the presence of PAMAM dendrimers G-4.5 and G4-OH presented solubility diagrams of BS type, and BI type in the presence of PAMAM G4. Studies of scanning UV-VIS and fluorescence indicated the presence of aggregates mainly in PpIX-PAMAM G-4.5 solution. The PpIX-PAMAM G4-OH complexes showed a mean size of 13.2 nm and zeta potential of -3.41; the complexes with PAMAM dendrimer G-4.5 had a bi-dispersed population, with sizes of 31 and 391 nm and a zeta potential of -17.3. The analysis of DSC and Fourier transform infrared Fourier showed changes in the characteristics of PpIX when it was complexed with the dendrimers. Passive skin permeation and retention studies with the complexes containing 0.006 mg/ml PpIX had not increased PpIX penetration, however, the complexation allowed greater amounts of PpIX to become available in the donor solution, and experiments with 1 mg/mL of PpIX increased significantly the penetration of the drug. Moreover, dendrimer PAMAM G4-OH seemed to act as a penetration enhancer. Iontophoresis did not increase skin penetration of PpIX compared to passive studies when the PpIX-PAMAM G4.5 was studied, likely because the electric current increased PpIX release from the complexes, forming aggregates large enough to not penetrate through the skin. On the other hand, anodic iontophoresis increased significantly the penetration of the PpIX-PAMAM G4-OH by eletrosmosis, spreading the drug to deep skins layers, also reaching the receiver solution. Studies in cell culture confirmed the ability of dendrimers to increase the penetration of PpIX through the membrane. The complexation improved the distribution of PpIX within the cells and significantly increased photocytotoxic of the porphyrin.