Investigation on formulation parameters of donepezil HCl loaded solid lipid nanoparticles

Abstract Donepezil-HCl is a member of the acetylcholinesterase inhibitors that is indicated for the symptomatic treatment of Alzheimer's disease (AD) and has many side effects. In this study, to reduce the side effects of Donepezil-HCl and increase the penetration of the drug through the blood-brain barrier, we aimed to design a solid lipid nanoparticle (SLN) formulation. The effects of the different formulation parameters, such as homogenization speed, sonication time, lipid and drug concentration, surfactant type and concentration, and volume of the aqueous phase, were assessed for optimization. The particle size and PDI increased with increasing lipid concentration but decreased with increasing amounts of surfactant (Tween 80) and co-surfactant (lecithin). When the homogenization rate and sonication time increased, the particle size decreased and the encapsulation efficiency increased. The optimized formulation exhibited particle size, PDI, encapsulation efficiency, and zeta potential of 87.2±0.11 nm; 0.22±0.02; 93.84±0.01 %; -17.0±0.12 mV respectively. The in vitro release investigation revealed that approximately 70% of Donepezil-HCl was cumulatively released after 24 hours. TEM analysis proved that spherical and smooth particles were obtained and formulations had no toxic effect on cells. The final optimized formulation could be a candidate for Donepezil-HCl application in Alzheimer's treatment with reduced side effects and doses for patients

Nanocristais de besifloxacino para o tratamento de conjuntivite bacteriana: preparação, caracterização físico-química e toxicidade / Besifloxacin nanocrystals for treating bacterial conjunctivitis: preparation, physicochemical characterization, and toxicity

A conjuntivite bacteriana tem significante impacto na Saúde Pública. Essa infecção representa mais de um terço das doenças oculares relatadas em âmbito global. É uma doença altamente contagiosa causada por variedade de bactérias aeróbias e anaeróbias. Diferentes antibióticos empregados no tratamento dessa doença têm apresentado elevada incidência de resistência bacteriana. Dentre os antibióticos de última geração, destaca-se o besifloxacino, antibiótico de quarta geração da classe das fluoroquinolonas, indicado exclusivamente para uso oftálmico tópico. Entretanto, esse fármaco possui baixa solubilidade em água, diminuindo sua biodisponibilidade. Tendo em vista superar esse desafio, foi proposta abordagem nanotecnológica para o desenvolvimento de nanocristais desse fármaco. A preparação de nanocristais de besifloxacino empregando moagem via úmida em escala reduzida foi promissora empregando tensoativo Povacoat®. O Diâmetro hidrodinâmico médio (DHM) da partícula foi de aproximadamente 550 nm, com índice de polidispersão (IP) menor que 0,2. Esse resultado permitiu aumentar a solubilidade de saturação em aproximadamente duas vezes em relação a matéria-prima, possibilitando aumentar a velocidade de dissolução desse fármaco e melhorar sua biodisponibilidade e segurança. Além disso, foi validado o método para quantificação do besifloxacino por CLAE, apresentando especificidade, linearidade no intervalo de 20 a 80µg/mL (r= 0,9996), precisão por repetibilidade (DPR= 1,20%, 0,84% e 0,39%), precisão intermediária (DPR= 0,94%) e exatidão 99,03%. Estudo de estabilidade acelerado (90 dias) na condição 40°C±2°C/75%UR±5%UR e estudo de estabilidade de acompanhamento (150 dias) na condição: 25°C ± 2°C / 60% UR ± 5% UR evidenciaram a estabilidade do teor no período avaliado. Ainda, a nanossuspensão de besifloxacino 0,6% m/m (nanocristais) na dose máxima (500 mg/kg) e o estabilizante Povacoat® (750 mg/kg) não apresentaram toxicidade em larvas de G. mellonella. A concentração inibitória mínima (CIM) para a formulação inovadora foi de 0,0960 µg/mL e 1,60 µg/mL frente a Staphylococcus aureus e Pseudomonas aeruginosa, respectivamente, confirmando eficácia in vitro

Bacterial conjunctivitis greatly impacts the population's health, presenting more than a third of eye diseases reported worldwide. It is an infection caused by various aerobic and anaerobic bacteria and is highly contagious. Therefore, it presents a high incidence of bacterial resistance to the antibiotics commonly used for treatment. Among the most recent antibiotics, besifloxacin is a fourth-generation fluoroquinolone antibiotic indicated exclusively for topical ophthalmic use. Due to its importance in treating bacterial conjunctivitis and its low solubility in the water, a nanotechnological approach was proposed to develop besifloxacin nanocrystals. The preparation of besifloxacin nanocrystals using small-scale wet milling was promising using Povacoat® surfactant. The particle's average hydrodynamic diameter (DHM) was approximately 550 nm, with a polydispersity index (IP) of less than 0.2. This result increased the saturation solubility approximately two times concerning the raw material, making it possible to increase the dissolution rate of this drug and improve its bioavailability and safety. In addition, the method for quantification of besifloxacin by HPLC was validated, presenting specificity, linearity in the range of 20 to 80µg/mL (r= 0.9996), precision by repeatability (DPR= 1.20%, 0.84% and 0.39%), intermediate precision (DPR= 0.94%) and accuracy 99.03%. Accelerated stability study (90 days) at 40°C±2°C/75%RH±5%RH condition and follow-up stability study (150 days) at 25°C ± 2°C / 60% RH ± condition 5% RH showed the stability of content in the evaluated period. Furthermore, the 0.6% besifloxacin nanosuspension (nanocrystals) at the maximum dose (500 mg/kg) and the Povacoat® stabilizer (750 mg/kg) did not show toxicity in G. mellonella larvae. The minimum inhibitory concentration (MIC) to innovative formulation was 0.0960 µg/mL and e 1.60 µg/mL against Staphylococcus aureus and Pseudomonas aeruginosa, respectively, confirming in vitro efficacy

Development of diethylcarbamazine-loaded poly(caprolactone) nanoparticles for anti-inflammatory purpose: Preparation and characterization

Abstract Diethylcarbamazine-loaded nanoparticles were previously evaluated for their anti-inflammatory activity. However, little is known regarding their physicochemical properties. Thus, the purpose of this study was to physiochemically characterize diethylcarbamazine-loaded poly(caprolactone) nanoparticles and evaluate their in vitro cytotoxicity. All formulations were prepared using the double-emulsion method. The average particle size was in the ranged between 298 and 364 nm and the polydispersity indexes were below 0.3. The zeta potential values were marginally negative, which may be related to drug loading, as higher loading led to an increase in the modulus of the zeta potential values. Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) analysis did not reveal any chemical interactions between the chemicals used and the absence of drug in crystalline form on the nanoparticle surfaces. The in vitro drug release study revealed a concentration-dependent release from the nanoparticles into the medium. The in vitro cytotoxicity assay demonstrated the biocompatibility of the blank and loaded nanoparticles. Hence, all formulations presented good physicochemical and safety properties, corroborating the in vivo anti-inflammatory activity, previously reported by our group.

Calendula officinalis L. flower extract-mediated green synthesis of silver nanoparticles under LED light

Abstract Silver nanoparticles (AgNPs) are among the most known nanomaterials being used for several purposes, including medical applications. In this study, Calendula officinalis L. flower extract and silver nitrate were used for green synthesis of silver nanoparticles under red, green and blue light-emitting diodes. AgNPs were characterized by Ultraviolet-Visible Spectrophotometry, Field Emission Scanning Electron Microscopy, Dynamic Light Scattering, Electrophoretic Mobility, Fourier Transform Infrared Spectroscopy and X-ray Diffraction. Isotropic and anisotropic silver nanoparticles were obtained, presenting hydrodinamic diameters ranging 90 - 180 nm, polydispersity (PdI > 0.2) and moderate stability (zeta potential values around - 20 mV)

Formulation and Optimization of Diclofenac Sodium Loaded Ethylcellulose Nanoparticles

Abstract Design of experiment (DoE) is a useful time and cost-effective tool for analyzing the effect of independent variables on the formulation characteristics. The aim of this study is to evaluate the effect of the process variables on the characteristics involved in the preparation of Diclofenac Sodium (DC) loaded ethylcellulose (EC) nanoparticles (NP) using Central Composite Design (CCD). NP were prepared by W/O/W emulsion solvent evaporation method. Three factors were investigated (DC/EC mass ratio, PVA concentration, homogenization speed) in order to optimize the entrapment efficiency (EE) and the particle size of NP. The optimal formulation was characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), and in vitro release. Optimized formulation showed an EE of 49.09 % and an average particle size of 226.83 nm with a polydispersity index of 0.271. No drug-polymer interaction was observed in FTIR and DSC analysis. SEM images showed that the particles are spherical and uniform. The in vitro release study showed a sustained release nature, 53.98 % of the encapsulated drug has been released over 24hours period. This study demonstrated that statistical experimental design methodology can optimize the formulation and the process variables to achieve favorable responses.

TiO2 nanoparticles and salinity stress in relation to artemisinin production and ADS and DBR2 expression in Artemisia absinthium L / Nanopartículas de TiO2 e estresse de salinidade em relação à produção de artemisinina e expressão de ADS e DBR2 em Artemisia absinthium L

Artemisia absinthium L. is an important herb that is widely cultivated in different parts of the world for its medicinal properties. The present study evaluated the effects of four concentrations of nanoparticles treatment (0, 10, 20 and 30 mg L-¹) and NaCl salinity stress (0, 50, 100 and 150 mM NaCl) and their interactions with respect to the expression of two key genes, i.e. DBR2 and ADS, in the biosynthesis pathway of artemisinin in A. absinthium. Total RNA was extracted and a relative gene expression analysis was carried out using Real-Time PCR. The amount of artemisinin was also determined by HPLC. All the experiments were performed as factorial in a completely randomized design in three replications. The results revealed that salinity stress and nanoparticles treatment and their interaction affected the expressions of these genes significantly. The highest levels of ADS gene expression were observed in the 30 mg L-¹ nanoparticles–treated plants in the presence of 150 mM salinity stress and the lowest levels in the 10 mg L-¹ nanoparticles–treated plants under 50 mM salinity stress. The maximum DBR2 gene expression was recorded in the 10 mg L-¹ nanoparticles–treated plants in the absence of salinity stress and the minimum expression in the 100 mM salinity-stressed plants in the absence of nanoparticles treatment. Moreover, the smallest amounts of artemisinin were observed in the 150 mM salinity-stressed plants in the absence of nanoparticles and the highest amounts in the 30 mg L-¹ nanoparticles–treated plants. The maximum amounts of artemisinin and ADS gene expression were reported from the plants in the same nanoparticles treatment and salinity stress [...].

Artemisia absinthium L. é uma erva importante que é amplamente cultivada em diferentes partes do mundo por suas propriedades medicinais. O presente estudo avaliou os efeitos de quatro concentrações de tratamento com nanopartículas (0, 10, 20 e 30 mg L-¹) e estresse de salinidade com NaCl (0, 50, 100 e 150 mM NaCl) e suas interações com relação à expressão de dois genes-chave, isto é, DBR2 e ADS, na via de biossíntese da artemisinina em A. absinthium. O RNA total foi extraído, e uma análise de expressão gênica relativa foi realizada usando PCR em tempo real. A quantidade de artemisinina também foi determinada por HPLC. Todos os experimentos foram realizados como fatorial, em delineamento inteiramente casualizado, em três repetições. Os resultados revelaram que o estresse por salinidade e o tratamento com nanopartículas e sua interação afetaram significativamente as expressões desses genes. Os níveis mais altos de expressão do gene ADS foram observados nas plantas tratadas com nanopartículas de 30 mg L-¹ na presença de estresse de salinidade de 150 mM, e os níveis mais baixos, nas plantas tratadas com nanopartículas de 10 mg L-¹ com estresse de salinidade de 50 mM. A expressão máxima do gene DBR2 foi registrada nas plantas tratadas com nanopartículas de 10 mg L-¹ na ausência de estresse de salinidade, e a expressão mínima, nas plantas estressadas com salinidade de 100 mM na ausência de tratamento com nanopartículas. Além disso, as menores quantidades de artemisinina foram observadas nas plantas com estresse de salinidade de 150 mM na ausência de nanopartículas, e as maiores quantidades, nas plantas tratadas com nanopartículas de 30 mg L-¹. As quantidades máximas de expressão de genes de artemisinina e ADS foram relatadas a partir das plantas no mesmo tratamento com nanopartículas e condições de estresse de salinidade. A esse respeito, a quantidade de artemisinina diminuiu pela metade nas [...],

In vitro antibacterial activities of silver nanoparticles synthesised using the seed extracts of three varieties of Phoenix dactylifera / Atividades antibacterianas in vitro de nanopartículas de prata sintetizadas usando extratos de sementes de três variedades de Phoenix dactylifera

Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.

A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.

Preparation and characterization of liposomes loaded with silver nanoparticles obtained by green synthesis

The objective of this work was to develop and characterize liposomes loaded with silver nanoparticles (LAgNPs) to show improvement in stability characteristics. AgNPs were prepared by the green synthesis method with Aloe vera gel extract and exposure to sunlight. Liposomes were prepared by the modified reverse phase method. Particle size, polydispersity index, zeta potential, as well as the scanning electron microscopy (SEM) morphological aspects of AgNPs and LAgNPs were evaluated. In addition, was used flame atomic absorption spectroscopy to determine the amount of AgNP that was encapsulated in liposomes. The AgNPs presented as amorphous and polydisperse structures, with a mean diameter of 278.46 nm and zeta potential of -18.3 mV. LAgNPs had a mean diameter between 321 and 373 nm, the polydispersity index close to 0.2 and a zeta potential around -40 mV, which indicates greater stability to the AgNPs. The images obtained by SEM show semicircular structures for AgNPs and well-defined spherical shape for LAgNPs. The percentage of encapsulation was between 51.81 to 58.83%. These results showed that LAgNPs were obtained with adequate physicochemical characteristics as a release system.

Quality by design (Qbd) approach to develop stability indicating HPLC method for estimation of rutin in chitosan-sodium alginate nanoparticles

Rutin is a flavonoid glycoside, mainly consists of phenolic compounds, responsible for many biological activities. The objective of the present study was to develop and validate a precise, simple, robust, rapid and reliable reverse phase high -performance liquid chromatography (RP-HPLC) technique by using Qbd approach for evaluating the rutin in nanoparticles. Central composite design (CCD) was employed for optimizing the experimental conditions of RP-HPLC method. Buffer pH, methanol content in the mobile phase composition, flow rate, and wavelength were selected as independent variables whereas retention time, peak area, and asymmetry factor was selected as dependent variables. The retention time, peak area and asymmetric factor of rutin by using optimized independent variables were found to be 3.75 min, 1014.79 mV, and 1.26 respectively. The limit of detection and limit of quantitation values were found to be 0.005 µg/mL and 0.15 µg/mL respectively. For confirming linearity, accuracy, precision, and robustness, the optimized assay condition was validated as per ICH guidelines. The proposed method, which was optimized by QbD approach was found to be a suitable method for analyzing the rutin in chitosan-sodium alginate nanoparticles.

Development, in vitro biocompatibility, and antitumor efficacy of acetic acid-modified Cordyceps sinensis polysaccharide nanoparticle drug delivery system

Docetaxel-loaded acetic acid conjugated Cordyceps sinensis polysaccharide (DTX-AA-CSP) nanoparticles were prepared through dialysis and their release rates in vitro, particle sizes, zeta potentials, drug loading capacities, and encapsulation efficiencies were characterized for the synthesis of AA-modified CSPs from traditional Chinese medicine Cordyceps sinensis (Berk.) Sacc. Then, the AA-modified CSPs were characterized by 1H-NMR and FT-IR. Furthermore, the biocompatibility of the delivery carrier (AA-CSP nanoparticles) was assessed on human umbilical vein endothelial cells. In vitro antitumor activity studies on DTX-AA-CSP nanoparticles were conducted on the human liver (HepG2) and colon cancer cells (SW480). The DTX-AA-CSP nanoparticles were spherical and had an average size of 98.91±0.29 nm and zeta potential within the −19.75±1.13 mV. The encapsulation efficiency and loading capacity were 80.95%±0.43% and 8.09%±0.04%, respectively. In vitro, DTX from the DTX-AA-CSP nanoparticles exhibited a sustained release, and the anticancer activities of DTX-AA-CSP nanoparticles against SW480 and HepG2 were significantly higher than those of marketed docetaxel injection (Taxotere®) in nearly all the tested concentrations. The AA-CSP nanoparticles showed good biocompatibility. This study provided a promising biocompatible delivery system for carrying antitumor drugs for cancer therapy

Novel Eudragit® -based polymeric nanoparticles for sustained release of simvastatin

This paper reports on the development of nanoparticles aiming at the in vitro controlled release of simvastatin (SVT). The nanoparticles were prepared by the nanoprecipitation method with polymers Eudragit® FS30D (EDGFS) or Eudragit® NE30D (EDGNE). EDGFS+SVT nanoparticles showed mean size of 148.8 nm and entrapment efficiency of 76.4%, whereas EDGNE+SVT nanoparticles showed mean size of 105.0 nm and entrapment efficiency of 103.2%. Infrared absorption spectra demonstrated that SVT incorporated into the polymer matrix, especially EDGNE. Similarly, the differential scanning calorimeter (DSC) curve presented no endothermic peak of fusion, indicating that the system is amorphous and the drug is not in the crystalline state. The maintenance of SVT in the amorphous state may favors its solubilization in the target release sites. In the in vitro dissolution assay, the SVT incorporated into the EDGFS+SVT nanoparticles showed a rapid initial release, which may be related to the pH of the dissolution medium used. Regarding the EDGNE+SVT nanoparticles, the in vitro release occurred in a bimodal behavior, i.e., an initial "burst" followed by a sustained delivery, with the kinetics of drug release following Baker-Lonsdale's mathematical model. All these features suggest the nanoparticulate system's potential to modulate SVT delivery and enhance its bioavailability.

Preparation and characterization of novel, mucoadhesive ofloxacin nanoparticles for ocular drug delivery

The efficacy of conventional ocular formulations is limited by poor corneal retention and permeation, resulting in low ocular bioavailability. Mucoadhesive chitosan (CS)/ tripolyphosphatesodium (TPP) and chitosan (CS)/ tripolyphosphatesodium (TPP)-alginate (ALG) nanoparticles were investigated for the prolonged topical ophthalmic delivery of ofloxacin. A modified ionotropic gelation method was used to produce ofloxacin-loaded nanoreservoir systems. The ofloxacin-loaded CS/TPP and CS/TPP-ALG nanoparticles were characterized for particle size, morphology, zeta potential, encapsulation efficiency, subsequent release and corneal penetration study. The designed nanoparticles have a particle size from 113.8 nm to 509 nm and zeta potential from 16.2 mV to 40.3 mV and encapsulation efficiency values ranging from 19.7% to 33.1%. Nanoparticles revealed a release during the first hours, followed by a more gradual drug release. The ofloxacin-loading CS/TPP or CS/TPP-ALG NPs developed are pronounced penetration enhancing effect as compared to OFX solution (5-6.5 times). Thus, these nanoparticles have a strong potential for ocular drug delivery.

Titanium Dioxide Nanoparticles and Sodium Nitroprusside Alleviate the Adverse Effects of Cadmium Stress on Germination and Seedling Growth of Wheat (Triticum aestivum L) / Nanopartículas de dióxido de titanio y nitroprusiato de sodio alivian los efectos adversos del estrés por cadmio en la germinación y el crecimiento de as plántulas de trigo (Triticum aestivum L) / Nanopartículas de dióxido de titânio e nitroprussiato de sódio aliviam os efeitos adversos do estresse por cádmio na germinação e no crescimento do trigo (Triticum aestivum L)

Abstract Effect of titanium dioxide nanoparticles (TiO2 NPs) (0, 500, 1 000 and 2 000 mg/L) and sodium nitroprusside (SNP) (0 and 100 μM) as nitric oxide (NO) donor, on wheat seed germination and seedling growth were investigated under cadmium (Cd) stress (0, 50 and 100 mM CdCl2). Concentration-dependent declining trends were observed in wheat germination indices upon seed exposure to CdCl2 suspensions which were more obvious under higher Cd stress. Exogenous sodium nitroprusside (SNP) and TiO2 nanoparticles (NPs) positively affected most germination indices under normal and stress conditions. In most cases, combined application of TiO2 NPs and SNP suspensions boosted stimulatory function of both compounds and moderated adverse effects of Cd treatments on wheat seed germination and seedling growth. 2 000 mg/L TiO2 + SNP (100 μM) treatment recorded the best results regarding most germination indices under lower and higher (50 and 100 mM CdCl2) Cd stress. Overall, it could be concluded that application of TiO2 NPs in combination with SNP might be a promising approach in counteracting the adverse effects of Cd stress on wheat seed germination and early growth.

Resumen Se investigó el efecto de nanopartículas de dióxido de titanio (TiO2 NPs) (0, 500, 1 000 and 2 000 mg/L) y nitroprusiato de sodio (SNP) (0 and 100 μM) como donador de óxido nítrico (NO), en la germinación de las semillas y el crecimiento de las plántulas de trigo bajo estrés por Cadmio (Cd) (0, 50 and 100 mM CdCl2). Se observaron tendencias decrecientes en los índices de germinación de las semillas de trigo expuestas a suspensiones de CdCl2. Estas tendencias fueron dependientes de la concentración, y más obvias ante alto estrés por Cd. El Nitroprusiato de Sodio exógeno (SNP) y las nanopartículas de TiO2 (NPs) afectaron positivamente la mayoría de los índices de germinación bajo condiciones normales y de estrés. En la mayoría de los casos, la aplicación combinada de suspensiones de TiO2 NPs y SNP incrementó la función estimulante de ambos componentes y moderó los efectos adversos de los tratamientos de Cd en la geminación de las semillas de trigo y el crecimiento de las plántulas. Con el tratamiento de 2000 mg/L TiO2 + SNP (100 μM) se registraron los mejores resultados en cuanto a los índices de germinación sometidos a bajo y alto estrés por Cd (50 and 100 mM CdCl2). En general, podría concluirse que la aplicación de TiO2 NPs en combinación con SNP podría ser una aproximación promisoria para contrarrestar los efectos adversos del estrés por Cd en la germinación de las semillas de trigo y en su crecimiento temprano.

Resumo Foram investigados os efeitos de nanopartículas de dióxido de titânio (TiO2 NPs) (0, 500, 1000 e 2000 mg/L) e nitroprussiato de sódio (SNP) (0 e 100 pM) como donadoras de óxido nítrico (NO) na germinação de sementes e no crescimento de plántulas de trigo sob estresse por cádmio (Cd) (0, 50 e 100 mM CdCl2). Se observaram tendências decrescentes nos índices de germinação de sementes de trigo expostas a suspensões de CdCl2. Essas tendências foram dependentes da concentração, sendo mais evidentes frente ao alto estresse por Cd. O nitroprussiato de sódio (SNP) e as nanopartículas de TiO2 (NPs) afetaram positivamente a maioria dos índices de germinação sob condições normais e de estresse. Na maioria dos casos, a aplicação combinada de suspensões de TiO2 NPs e SNP aumentou a função estimulante de ambos componentes e moderou os efeitos adversos dos tratamentos de Cd na germinação de semestres de trigo e no crescimento das plántulas. Com o tratamento de 2 000 mg/L TiO2 + SNP (100 μM) se registraram os melhores resultados em quanto aos índices de germinação submetidos a baixo e alto estresse por Cd (50 e 100 mM CdCl2). De modo geral, se pode concluir que a aplicação de TiO2 NPs em combinação com SNP poderia ser uma aproximação promissora para combater os efeitos adversos do estresse por Cd na germinação de sementes de trigo e no seu crescimento inicial.

Antibacterial, anti fungal and E. coli DNA cleavage of Euphorbia prostrata and Pelargonium graveolens extract and their combination with novel nanoparticles

As there are a lot of antibacterial and anti-fungal resistant pathogens, researchers attempt to substitute antimicrobial drugs with various medical plants and novel nanoparticles. The present study was conducted to characterize antimicrobial activities of Euphorbia prostrata and Pelargonium graveolens extract alone and in combination with Mn-Ni@Fe3O4-NPs & Mn: Fe (OH)3-NPs on the DNA cleavage of E. coli and also Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Aspergillus oryzae, and Candida albicans. The effects of antimicrobial activities on above scenarios were evaluated using disc diffusion, MIC, MBC, and E. coli DNA electrophoresis methods. The results showed that the effects of antibacterial assay values of Euphorbia prostrata & Mn: Fe(OH)3 was 21.00 mm for E. coli and while it was 19.5 mm for Euphorbia prostrata & Mn-Ni@Fe3O4 against Pseudomonas aeruginosa at a concentration of 100mg/mL. The highest level of DNA cleavage was seen in mixed of Euphorbia prostrata & Mn: Fe(OH)3 nanoparticles. In conclusion, the combination of Euphorbia prostrata and Pelargonium graveolens extracts with nanostructures showed synergic effects on eliminating the bacteria via DNA destruction and others mechanisms. Moreover, the synergistic effect of nanoparticles with plant extracts seems to bring about new choices for the treatment of infectious diseases

Developed and validated stability indicating HPLC method for the determination of epirubicin in bulk drug, marketed injection and polymeric nanoparticles

Present work is aimed to develop a simple, sensitive, robust and reliable HPLC method for routine quality control of epirubicin (EPI) in bulk drug, marketed injections and polymeric nanoparticles. Separation was carried out by C18 column. Isocratic elution was carried out using mobile phase A: 0.16% o-phosphoric acid solution, B: acetonitrile and methanol mixture (80:20, v/v) in the ratio of 60:40 (A: B) while the flow rate was maintained at 1mL/min. Analyses were performed at 233.5 nm using PDA detector. Excellent linear relationship was observed between peak-area versus drug concentration in the range of 1.0-100.0 µg/mL (r2, 0.999). Developed method was found to be sensitive (Limits of detection and quantification were found to be ~8 ng/mL and ~25 ng/mL, respectively), precise (RSD <1.0%, for repeatability and <2.0% for intermediate precision, within acceptable ranges of precision), accurate (recovery in different dosage form, 94.65 -100.26%, within acceptable range, 80-120%), specific and robust (% RSD <2, for system suitability parameters). Stress-induced degradation studies demonstrated that method can suitability be applied in the presence of degradants. Developed method has been successfully applied for the determination of entrapment efficiency, drug loading, in vitro release profile, in vitro permeation studies as well as stability assessment of polymeric nanoparticles

Nanopartículas de óxidos de ferro e nióbio com diferentes recobrimentos: síntese, caracterização e avaliação do potencial biológico / Iron oxide nanoparticles with different coatings and niobium oxide nanoparticles: synthesis, characterization and assessment of biological potential

Nanopartículas (NPs) tem ganhado notoriedade crescente em aplicações biomédicas. Podendo ser constituídas de diversos materiais, NPs tem sido empregadas como agentes de contraste, na liberação direcionada e controlada de fármacos, em terapia para tratamento de câncer, em catálise heterogênea, entre outras aplicações. As nanopartículas magnéticas de óxido de ferro (MNP) destacam-se pela multiplicidade de aplicações, apesar de serem pouco caracterizadas quanto à toxicidade celular. Outras nanopartículas com excelente potencial são as constituídas de óxido de nióbio (NbONPs), as quais merecem atenção especial, pois o Brasil é detentor de 98% das reservas comercialmente viáveis deste elemento. Neste trabalho NPs destes dois metais de transição (ferro e nióbio) foram sintetizadas, almejando entender suas interações com materiais, biomoléculas e meios biológicos. Diversas metodologias foram desenvolvidas e testadas com intuito de otimizar a morfologia e o rendimento da preparação, resultando na escolha de decomposição térmica para MNP e, para NbONPs, escolheu-se a impregnação do óxido de nióbio sobre uma matriz de MNPs recobertas com sílica. No caso das MNPs, procedeu-se ao recobrimento das mesmas com lipídeos zwitteriônicos (Dioleilfosfatidilcolina (DOPC)) e carregados positivamente (Brometo de dioctadecildimetilamônio (DODAB)). Foram inicialmente caracterizadas as suas propriedades em diversos ambientes biológicos para posteriormente realizarmos ensaios de citoxicidade em queratinócitos humanos (HaCaT). Avaliamos também a degradação das NPs em diferentes pH, bem como, a interação das mesmas com membranas miméticas de vesículas gigantes unilamelares (GUVs - Giant Unilamellar Vesicles), com visualização microscópica. As MNPs recobertas com DODAB mostraram-se mais tóxicas para os queratinócitos em cultura e também causaram lise das GUVs. No caso das NbONPs, avaliou-se a acidez proveniente do Nb2O5 e o seu potencial em catálise heterogênea, bem como a avaliação da citotoxicidade em HaCaT revelou um potencial uso biomédico

Nanoparticles (NPs) have received increasing attention in biomedical applications. NPs can be constituted by different materials and have been used as contrast agents, in drug delivery, in cancer therapy, in heterogeneous catalysis, among other applications. Magnetic iron oxide nanoparticles (MNP) are notable for their multiplicity of applications, although they are poorly characterized for cellular toxicity. Other nanoparticles with excellent potential are made of niobium oxide (NbONPs), which deserve special attention, since Brazil holds 98% of the commercially viable reserves of this element. In this Thesis, NPs of these two transition metals (iron and niobium) were synthesized, aiming to understand their interactions with materials, biomolecules and media biological. Several methodologies were developed and tested to optimize the morphology and yield of the preparation, resulting in the choice of thermal decomposition for MNPs and, for NbONPs, the impregnation of niobium oxide on a matrix of silica-coated MNPs. In the case of MNPs, they were also coated with lipid zwitterionics (Dioleoyl phosphocholine (DOPC)) and positively charged (Dimethyldioctadecylammonium bromide (DODAB)) lipids. Its properties were initially characterized in several biological environments for later cytotoxicity assays in human keratinocytes (HaCaT). It evaluated the degradation of the NPs in different pH, as well as their interaction with giant unilamellar vesicle (GUVs) mimetic membranes, with microscopic visualization. MNPs coated with DODAB were more toxic to keratinocytes in culture and caused lysis of GUVs. In the case of NbONPs, acidity from Nb2O5 was evaluated in heterogeneous catalysis, as well as the evaluation of HaCaT cytotoxicity revealed a potential biomedical use

Nanocristais de hidroximetilnitrofural: preparação, caracterização fí­sico-quí­mica, avaliação da atividade in vitro antileishmania / Hydroxymethylnitrofurazone nanocrystals: optimization, characterization, leishmanicidal activity evaluation

De acordo com a Organização Mundial de Saúde, existem atualmente 17 doenças tropicais negligenciadas prevalentes em 149 países, afetando aproximadamente um bilhão de pessoas, a nível global. A leishmaniose, problema de saúde prevalente nos países em desenvolvimento, é endêmica em aproximadamente 98 países e territórios, com 350 milhões de pessoas em risco e 12 milhões de casos de infecção no mundo. A transmissão da doença ocorre pela picada de flebotomíneos fêmeas infectadas. Essa doença apresenta três formas principais: leishmaniose cutânea (LC), leishmaniose mucocutânea (LMC) e leishmaniose visceral (LV). Enquanto a leishmaniose cutânea é a forma mais comum da doença, a leishmaniose visceral é a mais grave e pode ser fatal se não for tratada. Em 2016, o Brasil reportou 3.626 e 12.690 casos de LC e LV, respectivamente. O candidato a fármaco hidroximetilnitrofural (NFOH) mostrou atividade contra o parasita da doença de chagas e da leishmaniose. Embora o NFOH seja promissor para o tratamento da leishmaniose, esse possui baixa solubilidade em água. A nanotecnologia tem sido empregada como plataforma para o desenvolvimento de formas farmacêuticas inovadoras com maior eficácia e segurança. A redução do tamanho de partículas em escala nanométrica permite aumentar a biodisponibilidade oral de fármacos pouco solúveis em água. Os nanocristais apresentam vantagens, tais como, o aumento da solubilidade de saturação e da velocidade de dissolução, decorrentes do aumento da área superficial da partícula. Além disso, esses apresentam maior adesividade às membranas biológicas, membrana celular e superfície do trato gastrointestinal. No presente trabalho utilizou-se a moagem por via úmida em escala reduzida para a obtenção dos nanocristais de NFOH. Diferentes tensoativos foram avaliados empregando o método selecionado, os tensoativos poloxamer 188 e poloxamer 407 foram os que favoreceram a redução do tamanho das partículas. Tal característica foi observada na caracterização físico-química das nanosuspensões de NFOH. A utilização desse método permitiu a obtenção de nanocristais de NFOH, com diâmetro hidrodinâmico médio (DHM) de 184,8 ± 0,5 a 325,9 ± 2,2 nm, índice de polidispersão (IP) de 0,21 ± 0,01 a 0,57 ± 0,01 e DHM de 191,3 ± 2,1 a 326,8 ± 4,6 nm e IP de 0,21 ± 0,01 a 0,50 ± 0,01, respectivamente para o poloxamer 188 e 407. O uso de ambos os tensoativos resultaram em distribuição monomodal de tamanho das partículas. As formulações foram obtidas por meio de planejamento fatorial completo e experimentos por superfície de resposta tendo como variáreis independentes as concentrações de NFOH, dos tensoativos e o tempo de moagem. A resposta, DHM, foi determinada utilizando espalhamento de luz dinâmica (DLS). Adicionalmente, as avaliações empregando calorimetria exploratória diferencial (DSC) e difração de raio X (DRX) revelaram que não houve interação entre o fármaco e os excipientes, assim como, não foi observada alteração na estrutura cristalina do NFOH. A microscopia eletrônica de varredura demonstrou a morfologia característica do estado cristalino. Além disso, a preparação liofilizada apresentou instabilidade após armazenamento por três meses a temperatura de 25 e 4 °C

According to the World Health Organization, there are currently 17 neglected tropical diseases prevalent in 149 countries, affecting approximately one billion people globally. Leishmaniasis, a health problem prevalent in developing countries, is endemic in approximately 98 countries and territories, with 350 million people at risk and 12 million cases of infection worldwide. The transmission of the disease occurs by the bite of infected female sandflies. This disease has three main forms: cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL) and visceral leishmaniasis (VL). While cutaneous leishmaniasis is the most usual form of the disease, visceral leishmaniasis is the most serious and can be fatal if left untreated. In 2016, Brazil reported 3.626 and 12.690 cases of LC and LV, respectively. The drug candidate for hydroxymethylnitrofurazone (NFOH) showed activity against the parasite of chagas disease and leishmaniasis. Although NFOH is promising for the treatment of leishmaniasis, it has low solubility in water. Nanotechnology has been used as a platform for the development of innovative pharmaceutical forms with greater effectiveness and safety. Particle size reduction on the nanoscale enables the oral bioavailability of poorly water-soluble drugs to be increased. Nanotechnology has been used as a platform for the development of innovative pharmaceutical forms, improving effectiveness and safety. Particle size reduction on the nanoscale enables the oral bioavailability of poorly water-soluble drugs to be increased. Nanocrystals have advantages such as increased saturation solubility and dissolution rate due to the increase in the surface area of the particle. In addition, this present greater adhesiveness to the biological membranes, cell membrane and surface of the gastrointestinal tract. In the present work, wet scale milling was used to obtain NFOH nanocrystals. Different surfactants were evaluated using the selected method, poloxamer 188 and poloxamer 407 surfactants favored the reduction of particle size. This characteristic was observed in the physical-chemical characterization of NFOH nanosuspensions. The use of NFOH nanocrystals with a mean hydrodynamic diameter (DHM) of 184.8 ± 0.5 to 325.9 ± 2.2 nm, polydispersity index (IP) of 0.21 ± 0, 01 to 0.57 ± 0.01 for poloxamer 188 and DHM of 191.3 ± 2.1 at 326.8 ± 4.6 nm and IP of 0.21 ± 0.01 at 0.50 ± 0.01 for poloxamer 407, both with monomodal size distribution. The formulations were obtained by means of complete factorial planning and surface response experiments having as independent variables the concentrations of NFOH, surfactants and milling time. The response, DHM, was determined using dynamic light scattering (DLS). In addition, evaluations using differential scanning calorimetry (DSC) and X-ray diffraction (DRX) revealed that there was no change in the crystal structure of NFOH and interaction between the drug and the excipients. Scanning electron microscopy demonstrated the characteristic morphology of the crystalline state. In addition, the lyophilized preparation was instable after storage for three months at 25 and 4 ° C

Evaluation of polymeric PLGA nanoparticles conjugated to curcumin for use in aPDT

ABSTRACT Antimicrobial photodynamic therapy (aPDT) involves the association of a photosensitizing agent with a light source with the goal of causing apoptosis or microbial lysing. The use of compounds with natural active principles is gaining prominence throughout the world. Several studies from groups that are linked to the development of innovations in the pharmaceutical market have used natural dyes, such as curcumin, the efficacy of which has been demonstrated in aPDT trials. Difficulties related to physicochemical stability, solubility and cell penetration are some of the challenges associated with this field. The present work aimed to prepare, investigate the characteristics and improve the photodynamic activity of PLGA-based nanoparticles loaded with curcumin for use in aPDT therapy. Using the simple technique of emulsion during the evaporation of a solvent, the particles were built, characterized and tested against microorganisms with importance for medicine and dentistry. The results revealed that the particles were able to protect the curcumin against degradation and eliminate some microorganism species at nanomolar concentrations.

Desenvolvimento e caracterização de nanopartículas de poli (n-butil cianoacrilato) contendo a associação lamivudina e zidovudina / Development and characterization of poly (n- butyl cyanoacrylate) nanoparticles containing the combination of lamivudine and zidovudine

A zidovudina (AZT), fármaco antirretroviral utilizado no tratamento da AIDS, apresenta biodisponibilidade oral em torno de 60% e seu uso prolongado pode ocasionar efeitos tóxicos e tolerância ao tratamento. A lamivudina (3TC), apesar de demonstrar menor citotoxicidade e menor resistência viral, é considerada também menos potente. A associação entre os dois fármacos é recomendável em função da boa resposta terapêutica e maior adesão ao tratamento. As nanopartículas são uma alternativa para melhorar a biodisponibilidade e o transporte de fármacos sobretudo através da BHE. Nesse sentido, as nanopartículas poliméricas de poli (n-butil cianoacrilato) (PBCA) apresentam grande potencial para melhoria das características farmacêuticas, além de possibilitar resultados terapêuticos mais eficazes por meio da modificação de sua superfície, direcionando o fármaco ao sítio alvo. Diante do exposto, foram desenvolvidas nanopartículas de PBCA contendo a associação lamivudina e zidovudina (3TC/AZT) revestidas com polissorbato 80 (Ps80). As nanopartículas obtidas foram caracterizadas e apresentaram resultados coerentes aos encontrados na literatura. Após a encapsulação dos fármacos e o revestimento com Ps80, notou-se um aumento no diâmetro médio e o potencial Zeta foi próximo de zero. Esses resultados juntamente com a análise de SAXS comprovam o revestimento das nanopartículas de PBCA. Os dados de DSC e TG/DTG mostram que a encapsulação foi eficiente para a estabilização térmica dos fármacos. Foi desenvolvido e validado o método analítico por CLAE, a fim de determinar a eficiência de encapsulação. A validação do método analítico para quantificação simultânea do 3TC e AZT, tanto nas nanopartículas de PBCA quanto nas nanopartículas revestidas, apresentou linearidade, especificidade, precisão e exatidão adequadas de acordo com as normativas. A porcentagem de encapsulação dos fármacos foi igual a 44,45% e 30,44%. As nanopartículas de PBCA e PBCAPs80, em concentrações abaixo de 100 µg/mL, apresentaram viabilidade celular superior a 70% em células Caco-2, comprovando que o sistema apresenta baixa citotoxicidade, o que representa uma alternativa promissora para a encapsulação de fármacos antirretrovirais e consequente progresso no tratamento da AIDS

Zidovudine (AZT), which is an anti-retroviral drug used in the treatment of AIDS, has oral bioavailability around 60% and its prolonged use can cause toxic effects and tolerance to the treatment. Lamivudine (3TC), although it has lower cytotoxicity and lower viral resistance, is also considered less potent. The association between these two drugs is recommended based on the good therapeutic response and greater adherence to treatment. Nanoparticles are an alternative to improve the bioavailability and the transport of drugs, particularly through the BBB. Thus, the polymeric nanoparticles of poly (n-butyl cyanoacrylate) (PBCA) have great potential for improving the pharmaceutical characteristics, besides enabling more effective therapeutic results through the modification of its surface, directing the drug to the target site. That being said, PBCA nanoparticles were developed containing the association of lamivudine and zidovudine (3TC/AZT) coated with polysorbate 80 (Ps80). Nanoparticles obtained were characterized and presented coherent results when compared to those found in the literature. After the encapsulation of pharmaceuticals and Ps80 coating, it was noted an increase in the average diameter and Zeta potential was close to zero. These results along with the SAXS analysis proved the coating of the PBCA nanoparticles. The data of DSC and TG/DTG show that encapsulation was efficient for thermal stabilization of pharmaceuticals. An analytical method by HPLC was developed and validated to determine the efficiency of encapsulation. The validation of the analytical method for simultaneous quantification of 3TC and AZT, in both the PBCA nanoparticles and coated nanoparticles, presented as in linearity, specificity, precision and accuracy according to the regulations. The percentage of drug encapsulation was equal to 44.45% and 30.44%. The nanoparticles of PBCA and PBCA-Ps80, at concentrations below 100 µg/ml, presented cell viability greater than 70% in Caco-2 cells, proving that the system has low cytotoxicity, which represents a promising alternative for the encapsulation of antiretroviral drugs and consequent progress in AIDS treatment

Estudio exploratorio II: identificación de nanopartículas en procesos industriales de soldadura y de minería / Exploratory study II: identification of nanoparticles in industrial processes welding and mining

Se realizó un estudio exploratorio sobre la exposición laboral a nanopartículas en procesos de empresas del sector minero, fundición y soldadura. Para evaluar la exposición se utilizó un método cualitativo simplificado y un método semi-cuantitativo basado en las técnicas tradicionales de higiene ocupacional y de espectroscopía y microscopía electrónica para caracterizar las nanopartículas en cuanto a composición elemental, morfología y tamaños. Se evaluó cualitativamente el riesgo de exposición a nanopartículas de sílice y hierro, encontrándose una mayor criticidad en los procesos de preparación de muestras de minerales y de vaciado de colada en moldes de fundición. El análisis de muestras personales y ambientales evidenció la exposición de trabajadores a nanopartículas de sílice, hierro, magnesio, aluminio, manganeso, entre otras. La toxicidad de estas depende de la morfología y vía de ingreso (la principal vía es por inhalación). Se identificaron morfologías esféricas e irregulares, así como nanoalambres, aglomerados, estructuras cristalinas y amorfas, con tamaños bajo 100 nm. El trabajo realizado entrega la composición elemental y morfológica de las nanopartículas a los cuales se exponen los trabajadores en los procesos evaluados, junto con el alcance de los métodos de evaluación y la necesidad futura de realizar estudios cuantitativos para determinar niveles de exposición y concentraciones.

An exploratory study on occupational exposure to nanoparticles in processes of mining companies, casting and welding was performed. To assess exposure it was used a simplified qualitative and semiquantitative method based on traditional techniques of occupational hygiene and spectroscopy and electron microscopy to characterize nanoparticles in terms of elemental composition, morphology and size. The risk of exposure to silica nanoparticles and iron was qualitatively assessed, finding a bigger criticality in the process of sample preparation and emptying mineral casting molds. Analysis of personal and environmental samples showed workers exposure to nanoparticles of silica, iron, magnesium, aluminum, manganese, among others. The toxicity of these depends on the morphology and route of entry (the main way is by inhalation). Spherical and irregular morphologies were identified, as well as nanowires, crystalline and amorphous structures with sizes below 100 nm. The work performed gives the elemental composition and morphology of nanoparticles to which workers are exposed in the processes evaluated, along with the scope of the evaluation methods and the future need for quantitative studies to determine exposure levels and concentrations.