Docosahexaenoic fatty acid nanoencapsulated with Anti-PECAM-1 as strategy to increase atherosclerotic plaque stability / Ácido graxo docosahexaenoico nanoencapsulado com anti-PECAM-1 como uma estratégia para aumentar a estabilidade de placas ateroscleróticas

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

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

Application of Design of Experiments® Approach-Driven Artificial Intelligence and Machine Learning for Systematic Optimization of Reverse Phase High Performance Liquid Chromatography Method to Analyze Simultaneously Two Drugs (Cyclosporin A and Etodolac) in Solution, Human Plasma, Nanocapsules, and Emulsions.

The objectives of current investigation are (1) to find out wavelength of maximum absorbance (λmax) for combined cyclosporin A and etodolac solution followed by selection of mobile phase suitable for the RP-HPLC method, (2) to define analytical target profile and critical analytical attributes (CAAs) for the analytical quality by design, (3) to screen critical method parameters with the help of full factorial design followed by optimization with face-centered central composite design (CCD) approach-driven artificial neural network (ANN)-linked with the Levenberg-Marquardt (LM) algorithm for finding the RP-HPLC conditions, (4) to perform validation of analytical procedures (trueness, linearity, precision, robustness, specificity and sensitivity) using combined drug solution, and (5) to determine drug entrapment efficiency value in dual drug-loaded nanocapsules/emulsions, percentage recovery value in human plasma spiked with two drugs and solution state stability analysis at different stress conditions for substantiating the double-stage systematically optimized RP-HPLC method conditions. Through isobestic point and scouting step, 205 nm and ACN:H2O mixture (74:26) were selected respectively as the λmax and mobile phase. The ANN topology (3:10:4) indicating the input, hidden and output layers were generated by taking the 20 trials produced from the face-centered CCD model. The ANN-linked LM model produced minimal differences between predicted and observed values of output parameters (or CAAs), low mean squared error and higher correlation coefficient values in comparison to the respective values produced by face-centered CCD model. The optimized RP-HPLC method could be applied to analyze two drugs concurrently in different formulations, human plasma and solution state stability checking.

Ultrasound-responsive nanobubbles for enhanced intravitreal drug migration: An ex vivo evaluation.

The intravitreal route faces many challenges in rapidly and effectively reaching posterior eye pathology, with administered therapeutics experiencing non-specific distribution around and premature clearance from ocular tissues. Nanobubbles and ultrasound may improve outcomes of intravitreally administered drugs by influencing the directionality of drug-containing particle migration. In this study, we assessed the impact of trans-scleral or corneal ultrasound application on the distribution of intravitreally-injected nanobubbles. Rhodamine-tagged gas entrapped nanobubble formulations were prepared and injected into ex vivo bovine and porcine eyes and subjected to ultrasound (1 MHz, 0-2.5 W/cm2, 50-100% duty, 60 s). Bovine eyes were partially dissected to visualize the vitreous humor and particle migration was evaluated via optical fluorescence spectroscopy. Directional migration in porcine eyes was evaluated using a snap freezing protocol complemented by quantification of regional fluorescence. The impact on nanobubble migration following pars-plana injection and sequential ultrasound cycle application from scleral or corneal-surface positions was also assessed. Administration of ultrasound significantly enhanced the directional migration of nanobubbles in both ex vivo models, with multiple corneal ultrasound cycles promoting greater migration of dye-filled nanobubbles to posterior regions of the vitreous. Moreover, particles moved in a directional manner away from the ultrasound wave source demonstrating an ability to effectively control the rate and path of nanobubble migration. These findings establish an encouraging new and safe modality enabling rapid distribution of intravitreally-injected therapeutics where expeditious therapeutic intervention is warranted.

Study on influence of polymer and surfactant on in vitro performance of biodegradable aqueous-core nanocapsules of tenofovirdisoproxil fumarate by response surface methodology

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

Direct quantitative 13 C-filtered 1 H magnetic resonance imaging of PEGylated biomacromolecules in vivo.

PURPOSE: 1 H MRI is an established diagnostic method that generally relies on detection of water. Imaging specific macromolecules is normally accomplished only indirectly through the use of paramagnetic tags, which alter the water signal in their vicinity. We demonstrate a new approach in which macromolecular constituents, such as proteins and drug delivery systems, are observed directly and quantitatively in vivo using 1 H MRI of 13 C-labeled poly(ethylene glycol) (13 C-PEG) tags. METHODS: Molecular imaging of 13 C-PEG-labeled species was accomplished by incorporating a modified heteronuclear multiple quantum coherence filter into a gradient echo imaging sequence. We demonstrate the approach by monitoring the real-time distribution of 13 C-PEG and 13 C-PEGylated albumin injected into the hind leg of a mouse. RESULTS: Filtering the 1 H PEG signal through the directly coupled 13 C nuclei largely eliminates background water and fat signals, thus enabling the imaging of molecules using 1 H MRI. CONCLUSION: PEGylation is widely employed to enhance the performance of a multitude of macromolecular therapeutics and drug delivery systems, and 13 C-filtered 1 H MRI of 13 C-PEG thus offers the possibility of imaging and quantitating their distribution in living systems in real time. Magn Reson Med 77:1553-1561, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Preparation of mupirocin-loaded polymeric nanocapsules using essential oil of rosemary

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

Farmacologia e fitoquímica de extratos e formulações de Jacaranda decurrens Cham., Jacaranda caroba (Vell.) DC. e Piper umbellatum L / Pharmacology and phytochemistry of extracts and formulations from Jacaranda decurrens Cham., Jacaranda caroba (Vell.) DC. and Piper umbellatum L

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

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

Desenvolvimento de método analítico de cromatografia líquida de alta eficiencia (CLAE) para quantificação de lupeol em nanocápsulas poliméricas / Development of analytical method for measurement of lupeol in polymeric nanocapsules by high-performance liquid chromatography (HPLC)

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

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

A display of pH-sensitive fusogenic GALA peptide facilitates endosomal escape from a Bio-nanocapsule via an endocytic uptake pathway.

BACKGROUND: An affibody-displaying bio-nanocapsule (ZHER2-BNC) with a hepatocyte specificity derived from hepatitis B virus (HBV) was converted into an affibody, ZHER2, that recognizes HER2 receptors. This affibody was previously reported to be the result of the endocytosis-dependent specific uptake of proteins and siRNA into target cancer cells. To assist the endosomal escape of inclusions, a helper lipid with pH-sensitive fusogenic ability (1,2-dioleoyl-sn-glycero-3-phos phoethanolamine; DOPE) was conjugated with a ZHER2-BNC. FINDINGS: In this study, we displayed a pH-sensitive fusogenic GALA peptide on the surface of a particle in order to confer the ability of endosomal escape to a ZHER2-BNC. A GALA-displaying ZHER2-BNC purified from yeast uneventfully formed a particle structure. Furthermore, endosomal escape of the particle was facilitated after endocytic uptake and release of the inclusions to the cytoplasm without the cell toxicity. CONCLUSION: The genetic fusion of a GALA peptide to the virus-like particle confers the ability of endosomal escape.

Poly(ethylene glycol)-poly(ε-caprolactone) iodinated nanocapsules as contrast agents for X-ray imaging.

PURPOSE: Synthesis and formulation of iodinated PCL-mPEG nanocapsules as new original blood pool contrast agents for computed tomography. METHODS: PCL-mPEG was synthesized and formulated following the emulsion-solvent diffusion process, in the form of iodinated nanocapsules. Physico-chemical characterization of such nano-materials was performed by DLS and transmission electron microscopy. A stability study of the nanocapsules suspension was followed-up to 3 month. Blood biocompatibility was performed. Finally, the nanocapsules suspension radiopacity was evaluated in vitro then in vivo in mice as micro-CT contrast agent. RESULTS: In this study, the iodine concentration in nanocapsules suspension was about 70 mgI/mL. Besides, these nanocarriers appeared non-toxic, and stable in suspension. In vivo, i.v. administration of 10 µL/g of mouse body weight of theses nano-particles induced a vascular contrast enhancement of 168 HU and a half-life in blood of 4.2 +/- 0.5 h. Elimination route of these particles appears mainly performed by the liver, without sequestration in spleen and lymph nodes confirming their stealth properties. CONCLUSIONS: This study proposes the first example of iodinated biodegradable polymeric blood pool contrast agent, able to induce an exploitable contrast enhancement. The main advantage of polymeric system compared to lipid ones, lies in their stability and handling, e.g. towards drying for storage.

Multimodal in vivo imaging exposes the voyage of nanoparticles in tumor microcirculation.

Tumors present numerous biobarriers to the successful delivery of nanoparticles. Decreased blood flow and high interstitial pressure in tumors dictate the degree of resistance to extravasation of nanoparticles. To understand how a nanoparticle can overcome these biobarriers, we developed a multimodal in vivo imaging methodology, which enabled the noninvasive measurement of microvascular parameters and deposition of nanoparticles at the microscopic scale. To monitor the spatiotemporal progression of tumor vasculature and its vascular permeability to nanoparticles at the microcapillary level, we developed a quantitative in vivo imaging method using an iodinated liposomal contrast agent and a micro-CT. Following perfusion CT for quantitative assessment of blood flow, small animal fluorescence molecular tomography was used to image the in vivo fate of cocktails containing liposomes of different sizes labeled with different NIR fluorophores. The animal studies showed that the deposition of liposomes depended on local blood flow. Considering tumor regions of different blood flow, the deposition of liposomes followed a size-dependent pattern. In general, the larger liposomes effectively extravasated in fast flow regions, while smaller liposomes performed better in slow flow regions. We also evaluated whether the tumor retention of nanoparticles is dictated by targeting them to a receptor overexpressed by the cancer cells. Targeting of 100 nm liposomes showed no benefits at any flow rate. However, active targeting of 30 nm liposomes substantially increased their deposition in slow flow tumor regions (∼12-fold increase), which suggested that targeting prevented the washout of the smaller nanoparticles from the tumor interstitium back to blood circulation.

Fluorescent magnetoliposomes as a platform technology for functional and molecular MR and optical imaging.

Here, we present a detailed characterisation of rhodamine B-containing magnetoliposomes (FLU-ML), emphasising the dependence of their fluorescence properties on the presence of iron oxide cores, and the molar fraction of the fluorophore. The magnetoliposome types used exist as colloidally stable, negatively charged clusters with an average hydrodynamic diameter of 95 nm. The molar rhodamine B fractions were 0.67 % and 1.97 %. Rhodamine B normalised fluorescence, quantum yields and fluorescence lifetimes were substantially reduced by inner filter effects as the magnetoliposome concentration is increased, by increasing molar rhodamine B fraction, and by quenching originating from the iron oxide cores. MR relaxometry at 3 T revealed extremely high r2 relaxivities (440 to 554 s-1mM-1) and moderately high r1 values (2.06 to 3.59 s-1mM-1). Upon incubating human prostate carcinoma (PC-3) cells with FLU-ML, a dose-dependent particle internalisation was found by MR relaxometry. In addition, the internalised FLU-ML were clearly visible by fluorescence microscopy. At the FLU-ML concentrations used (up to 3 × 10³ M Fe) cell viability was not substantially impaired. These results provide valuable insights on the fluorescence properties of bimodal magnetoliposomes and open promising perspectives for the use of these materials as a platform technology for advanced functional and molecular MR and optical imaging applications.

Remotely nano-rupturable yolk/shell capsules for magnetically-triggered drug release.

Yolk/shell capsules containing a volume/hydrophobicity transformable core and an ultra-thin silica shell have been prepared. When an external magnetic field induced the temperature, the cores exhibit a significant triggering size shrinkage and the diameter decreases more than 10 times, causing solid shells destruction and physical collapse, leading to drug burst release.

Encapsulation of curcumin in Pluronic block copolymer micelles for drug delivery applications.

We report here the potential of Pluronic tri-block copolymer micelles for the formulation of curcumin, a natural dietary compound having great therapeutic potential against many diseases including cancer. Two most commonly used Pluronic F127 and F68 were used for the formulation and analyzed for curcumin encapsulation efficiency and stability. The encapsulation of drug in micelle was highly dependent on drug-to-copolymer ratio. Pluronic F127 showed better encapsulation efficiency than Pluronic F68. In vitro release profile demonstrated slower and sustained release of curcumin from Pluronic micelles. The lyophilized form of the formulations exhibited good stability for long-term storage. The physical interaction of curcumin with Pluronic was evident by XRD analysis, UV-visible, fluorescence, and FT-IR spectroscopy. AFM study showed that the drug-encapsulated micelles were spherical in shape with diameters below 100 nm. The in vitro cytotoxicity of the drug formulations was investigated with HeLa cancer cells. Pluronic-encapsulated curcumin showed comparable anticancer activity with free curcumin.

Stabilization of a nutraceutical omega-3 fatty acid by encapsulation in ultrathin electrosprayed zein prolamine.

Docosahexaenoic acid (DHA) is a long chain polyunsaturated fatty acid of the omega-3 series (omega-3), which exerts strong positive influences on human health. The target of this study was the stabilization by encapsulation of this bioactive ingredient in zein ultrathin capsules produced by electrospraying. The zein ultrathin DHA encapsulation was observed by ATR-FTIR spectroscopy to be more efficient against degradation under both ambient conditions and in a confined space (so-called headspace experiment). In the latter case, that more closely simulates a sealed food packaging situation, the bioactive DHA was considerably more stable. By fitting the degradation data to a specific auto-decomposition food lipids kinetic model, it was seen that the encapsulated omega-3 fatty acid showed a 2.5-fold reduction in the degradation rate constant and also had much higher degradation induction time. Moreover, the ultrathin zein-DHA capsules resulted to be more stable across relative humidity and temperature. Finally, headspace analysis by gas chromatography coupled with mass spectrometry showed that the presence of 3 main flavor-influencing aldehydes in the headspace was much lower in the zein encapsulated DHA, suggesting that the encapsulated bioactive also releases much less off-flavors. Electrosprayed ultrathin capsules of zein are shown to exhibit potential in the design of novel functional foods or bioactive packaging strategies to enhance the stability of functional ingredients. Practical Application: This article presents a novel methodology for the stabilization by encapsulation of omega 3 nutraceuticals via electrospraying and has potential application in the development of functional foods.

The encapsulation of DNA molecules within biomimetic lipid nanocapsules.

Most of DNA synthetic complexes result from the self-assembly of DNA molecules with cationic lipids or polymers in an aqueous controlled medium. However, injection of such self-assembled complexes in medium like blood that differ from that of their formulation leads to strong instability. Therefore, DNA vectors that have physico-chemical properties and structural organisation that will not be sensitive to a completely different medium in terms of ionic and protein composition are actively sought. To this end, the goal here was to discover and optimize a nanostructured system where DNA molecules would be encapsulated in nanocapsules consisting in an oily core and a shell covered by PEG stretches obtained through a nanoemulsion process in the absence of organic solvent. This encapsulation form of DNA molecules would prevent interactions with external hostile biological fluid. The results show the entrapment of lipoplexes into lipid nanocapsules, leading to the formation of neutral 110 nm-DNA nanocapsules. They were weakly removed by the immune system, displaying an increased blood half-life, and improved carcinoma cell transfection, in comparison to the parent lipoplexes. Our results demonstrate that the fabrication of nanocapsules encapsulating hydrophilic DNA in an oily core that meet criteria for blood injection is possible.

Impact of microdialysis probes on vasculature and dopamine in the rat striatum: a combined fluorescence and voltammetric study.

Measuring extracellular dopamine in the brain of living animals by means of microdialysis and/or voltammetry is a route towards understanding both normal brain function and pathology. Previous reports, however, suggest that the tissue response to implantation of devices may affect the outcome of the measurements. To address the source of the tissue response and its impact on striatal dopamine systems microdialysis probes were placed in the striatum of anesthetized rats. Images obtained by dual-label fluorescence microscopy show signs of ischemia and opening of the blood-brain barrier near the probe tracks. Opening of the blood-brain barrier was further examined by determining dialysate concentrations of carbi-DOPA, a drug that normally does not penetrate the brain. Although carbi-DOPA was recovered in brain dialysate, it did not alter dialysate dopamine levels or evoked dopamine release as measured by voltammetry near the probes. Microdialysis probes also significantly diminished the effect of intrastriatal infusion of kynurenate on extracellular dopamine levels as measured by voltammetry near the probes.

Spray-dried microparticles containing polymeric nanocapsules: formulation aspects, liquid phase interactions and particles characteristics.

Up to now, the full potential of polymer-based nanoparticles is not yet exploited because of a lack of stability when conserved in aqueous medium. The present paper reports the water elimination from nanocapsules (NC) dispersions by means of the spray-drying technique with the aim to achieve dried solid forms of interest using colloidal silicon dioxide as drying auxiliary. The influence of formulation parameters on the suspension behaviour and on the powders characteristics was also evaluated. Our findings demonstrated that the mixing protocol, the concentrations of both NC and silica are crucial parameters that affect the feed behaviour and the spray-dried particles characteristics. Interactions occurring in the feed are directed by hydrogen bounds and were more sensitive to the silica concentration than that of NC as evidenced by rheological measurements. The NC are entrapped within solid dried matrixes following their interaction with silica particles in the feed. SEM analyses of the obtained powders showed spherical separated microparticles formed by the association of NC and silica when they are mixed at adequate concentrations in the feed before spray-drying. On the other hand, fused agglomerated particles presenting NC at their surface, characterised by irregular shapes and a strong adhesiveness were prepared when the silica concentration was not sufficient. The surface composition of the spray-dried powders was investigated using the ESCA technique and revealed the NC exclusion from the surface to obtain powders suitable for further handling.