SIMVASTATIN-LOADED NANOCAPSULES REDUCE TNF-Α EXPRESSION IN RAT PERITONEUM AFTER INFUSION OF PERITONEAL DIALYSIS SOLUTION

Objective: Obteinment and characterizing polymeric nanocapsules of simvastatin (SV), and investigating their action in an experimental model of peritoneal fibrosis induced in a rat by the infusion of peritoneal dialysis (PD) solution. Methods: Poly (ε-caprolactone) nanocapsules containing SV (NC-SV) were prepared by interfacial deposition of a preformed polymer. A suspension of nanoparticles with no drug was prepared as negative control. The average particle size and polydispersity index were measured by photon correlation spectroscopy. The morphological and surface evaluation of prepared nanocapsules was performed using field emission scanning electron microscopy. The ultra-high performance liquid chromatography with photodiode array detection method was used to evaluate the drug encapsulation efficiency. The release profiles of SV from polymeric nanocapsules were obtained by dialysis diffusion technique. The Animal Study was performed in a total of 48 male Wistar rats (Rattus norvegicus) divided in four groups: Sham, PD group, SV group, and Simvastatin-loaded nanocapsules group (NC-SV). After 28 days, tissue samples were surgically removed from the abdominal to perform histological and immunohistochemistry analysis. The statistical analysis was performed by one-way ANOVA followed by Bonferroni test, or by Kruskal–Wallis. Results: NC-SV presented suitable particle parameters with a mean particle size of 332 nm, and an encapsulation efficiency of 99.87±0.46%. The expression of tumor necrosis factor-alpha (TNF-α) was significantly different in NC-SV group. Conclusion: SV-loaded nanocapsules for controlled drug delivery were suitably prepared. This nanoformulation remarkable decreased the TNF-α tissue expression even at low SV dose in a chronic PD model

Co-loaded curcumin and methotrexate nanocapsules enhance cytotoxicity against non-small-cell lung cancer cells

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (−33 to −41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer

Applications of Calcium Oxalate Crystal Microscopy in the Characterization of Baccharis articulata

Abstract Baccharis articulata (Lam.) Pers., popularly known as carqueja, carquejinha or carqueja-doce, is a plant widely used in traditional medicine as a diuretic, digestive and antidiabetic. Due to its similar morphology with other species of the "carqueja group", especially Baccharis pentaptera (Less.) DC., it can be easily confused even by specialists. Thus, this study aimed to characterize micromorphology of the crystals present in B. articulata to show botanical markers that can help differentiate this species from other carquejas. Eleven crystalline morphotypes, including druses, styloids and various shapes of prismatic and sand crystals, were evidenced by scanning electron microscopy. In addition, the elemental chemical composition and the degree of hydration of the crystals were analyzed by EDS and Raman spectroscopy. The results of this study would aid in the authentication of B. articulata and serve as a basis for future studies of other species of Baccharis

Preparation, Characterization and Stability Study of Eugenol-Loaded Eudragit RS100 Nanocapsules for Dental Sensitivity Reduction

Abstract Eugenol is a phenolic compound with numerous biological activities. It is widely used in dentistry to treat toothache and pulpitis. In particular, eugenol may be used for tooth whitening procedures to minimize dental sensitivity in patients. However, eugenol has some disadvantages such as its volatility, its photosensitivity, and immediate effect, which can be avoided by using pharmaceutical nanotechnology. The aim of the present study was to obtain, characterize, quantify, and evaluate the physicochemical stability of eugenol-loaded Eudragit RS100 nanocapsules. The nanocapsules (NCs) were prepared by interfacial deposition of the preformed polymer method. The NCs were characterized through morphological and spectroscopic studies. The encapsulation efficiency was achieved by quantifying the non-encapsulated eugenol using a previously developed and validated analytical method. The physicochemical stability of NCs was assessed at predetermined time intervals for 90 days after preparation. The nanocapsules were successfully prepared by the chosen method and had a predominantly spherical shape with a smooth surface. The mean size, the polydispersion index, and the zeta potential were in agreement to literature data. Infrared spectra ensured that the nanoencapsulation process did not result in chemical reactions between the drug and the polymer. The formulations showed encapsulation efficiency higher than 90% and remained stable after 60 days of preparation. Thus, eugenol-loaded Eudragit RS100 nanocapsules may be further considered as an alternative formulation for dental sensitivity in order to provide a controlled release, a decreased toxicity, and a better dental sensitivity relief

Temperature profile and thermal piston component of photoacoustic response calculated by the fractional dual-phase-lag heat conduction theory

We present the temperature distribution predictions for photothermal systems by considering an extension of dual-phase lag. It is an extension of the GCE-II and GCE-III models with a fractional dual-phase lag from kinetic relaxation time. Solving the one-dimensional problem considering a planar and periodic excitation, we obtained the temperature distribution and the Photoacoustic (PA) signal for the transmission setup. We also analyze the effects of fractional order derivatives and kinetic relaxation time. It is shown that the derived models have promising results that could be used to explain the experimentally observed behavior of PA signals measured on thin films with an inhomogeneous internal structure

Anomalous thermal diffusion in two-layer system: The temperature profile and photoacoustic signal for rear light incidence

We analyze the influence of the generalizations of hyperbolic (Cattaneo) heat equations (GCE) on temperature profile and photoacoustic signal for the two-layer samples. The GCE extensions employ fractional-order derivatives related to the anomalous thermal diffusion in solid. We compare the superdiffusive (GCEII) and subdiffusive (GCEIII) generalizations with the classical and hyperbolic results. To show the fractional-order influence on results, we analyze opaque layers of aluminum with dye by considering only the last one with the anomalous characteristic. The promising results show that minor variations in fractional order and relaxation time can influence the photoacoustic signal

Investigating the real translucency of the endodontic fiber posts

Researchers have been investigating the light intensity scattered by a translucent fiber post with application in dentistry by different methods. In this work, we introduce a new system capable to record a light scattered profile, step-by-step, as a function of the length of the translucent fiber post. To support our studies, an extensive characterization of the system was carried out and this is presented and discussed here. The system was implemented using the phase sensitive detection. The equipment measures the light scattered without the need of any preparing parts and the fiber post is fixed directly in the fiber post holder becoming ready for measurement. Measures can be recorded with a spatial resolution smaller than 0.01 mm throughout the length of the fiber post being investigated. The system was implemented by using a photomultiplier tube that improves sensitivity for the optical detection. The recorded result is a signal directly proportional to the scattered light and it allows us to obtain a normalized profile that can be used as a map of the scattered light of the fiber post in study. Furthermore, we are able to demonstrate a low intensity of light in the tip region of the fiber post, along with the dependency of the light attenuation with the fiber post body volume and shape. This new system will certainly contribute to achieve better results in fiber post designing and in restoration of endodontic treated teeth because it provides a more well-founded choice of the fiber post to be used, and of the time of exposure to the curing light

DEVELOPMENT AND VALIDATION OF A FAST AND SENSITIVE UHPLC-PDA METHOD FOR THE QUANTIFICATION OF URSOLIC ACID IN POLY(L-LACTIC ACID) NANOCAPSULES

Objective: The aim of the present study is to develop and validation of a ultra-high performance liquid chromatography (UHPLC) method to determine the ursolic acid content and its encapsulation efficiency (EE) in lipid-core nanocapsules prepared from poly (L-lactic acid). Methods: A simple UHPLC-PDA method was developed and validated for the quantitative determination of ursolic acid in poly(L-lactic acid) nanocapsules. The chromatographic conditions used were: RP-C18 column, isocratic mobile phase containing acetonitrile:water (92:8, v/v), flow rate of 0.8 ml/min, column temperature of 50°C, and detection at 203 nm. The following parameters were evaluated: Specificity, linearity, limits of detection and quantification, precision, accuracy, and robustness. Results: The method was specific to the ursolic acid and linear (r=0.9998) in the range of 10–100 μg/ml. The limits of detection and quantification were 1.35 and 4.10 μg/ml, respectively. The precision was demonstrated by a relative standard deviation less than 2%. Adequate accuracy (98.35%±0.82) was obtained. Changes in flow rate, mobile phase, and column temperature did not significantly alter the peak area and the retention time of the ursolic acid. The mean EE was 99.89%. Conclusion: The method proved to be fast, sensitive, and simple for quantifying ursolic acid in nanocapsules and was successfully used for determining the EE