Quantification of the actual composition of polymeric nanocapsules: a quality control analysis.

Nanocapsules (NCs) are drug delivery nanosystems that contain an oily core, stabilized by a surfactant, and surrounded by a polymeric shell. The assembling of the components is based on physical and physicochemical forces, and, hence, usually, only a fraction of each component is finally part of the NCs' structure, while the remaining amount might be solubilized or forming micelles in the NCs' suspending medium. Usually, reports on the characterization of nanostructures simply indicate the association efficiency of the loaded drugs instead of their complete final composition. In this work, we have developed a liquid chromatography (LC) mass spectrometry (MS) methodology that allows the quantification of all the components of a series of NCs prepared by different techniques, namely DL-α-tocopherol; D-α-tocopherol polyethylene glycol 1000 succinate; benzethonium; lecithin; hexadecyltrimethylammonium; 1,2-dioleoyl-3-trimethylammoniumpropane; caprylic/capric triglycerides; macrogol 15-hydroxystearate; polysorbate 80; polysialic acid; hyaluronic acid; and polyethylene glycol polyglutamic acid. The LC-MS method was validated in terms of linearity (0.9383 < r2 < 0.9997), quantification limits, and recoveries of the isolated NCs' and waste fractions. The final composition of the isolated NCs was found to strongly depend on their composition and preparation technique. In our view, the rigorous quantification of the exact composition of nanosystems is essential for the progress of nanotechnology. This quantitative analysis will allow researchers to draw more accurate conclusions about the influence of the nanosystems' composition on their biological performance.

Protamine Nanocapsules for the Development of Thermostable Adjuvanted Nanovaccines.

One of the main challenges in the development of vaccine has been to improve their stability at room temperature and eliminate the limitations associated with the cold chain storage. In this paper, we describe the development and optimization of thermostable nanocarriers consisting of an oily core with immunostimulating activity, containing squalene or α tocopherol surrounded by a protamine shell. The results showed that these nanocapsules can efficiently associate the recombinant hepatitis B surface antigen (rHBsAg) without compromising its antigenicity. Furthermore, the freeze-dried protamine nanocapsules were able to preserve the integrity and bioactivity of the associated antigen upon storage for at least 12 months at room temperature. In vitro studies evidenced the high internalization of the nanocapsules by immunocompetent cells, followed by cytokine secretion and complement activation. In vivo studies showed the capacity of rHBsAg-loaded nanocapsules to elicit protective levels upon intramuscular or intranasal administration to mice. Overall, our data indicate that protamine nanocapsules are an innovative thermostable nanovaccine platform for improved antigen delivery.

Bilayer polymeric nanocapsules: A formulation approach for a thermostable and adjuvanted E. coli antigen vaccine.

One of the strategies used to improve the immunogenicity of purified protein antigens has relied on their association with synthetic nanocarriers, which, in general, have functioned as simple antigen containers. Here, we present a more advanced strategy based on the design of an antigen nanocarrier at the molecular level. The nanocarrier is composed of a vitamin E oily core, surrounded by two layers: a first layer of chitosan and a second of dextran sulphate. The selected antigen, IutA protein from Escherichia coli, was harboured between the two polymeric layers. The final bilayer nanocapsules had a nanometric size (≈ 200 nm), a negative zeta potential (< -40 mV) and a good antigen association efficiency (≈ 70%). The bilayer architecture led to an improvement on the formulation stability and the controlled release of the associated antigen. Remarkably, after being administered to mice, bilayer nanocapsules elicited higher IgG levels than those obtained with antigen precipitated with Alum. Moreover, freeze-dried nanocapsules were stable at room temperature for, at least, 3 months. These promising data, in addition to their contribution to the development of an uropathogenic E. coli vaccine, has allowed us to validate these novel bilayer nanocapsules as adequate platforms for the delivery of protein antigens.

A comparative study of curcumin-loaded lipid-based nanocarriers in the treatment of inflammatory bowel disease.

Selective drug delivery to inflamed tissues is of widespread interest for the treatment of inflammatory bowel disease (IBD). Because a lack of physiological lipids has been described in patients suffering IBD, and some lipids present immunomodulatory properties, we hypothesize that the combination of lipids and anti-inflammatory drugs together within a nanocarrier may be a valuable strategy for overcoming IBD. In the present study, we investigated and compared the in vitro and in vivo efficacy of three lipid-based nanocarriers containing curcumin (CC) as an anti-inflammatory drug for treating IBD in a murine DSS-induced colitis model. These nanocarriers included self-nanoemulsifying drug delivery systems (SNEDDS), nanostructured lipid carriers (NLC) and lipid core-shell protamine nanocapsules (NC). In vitro, a 30-fold higher CC permeability across Caco-2 cell monolayers was obtained using NC compared to SNEDDS (NC>SNEDDS>NLC and CC suspension). The CC SNEDDS and CC NLC but not the CC NC or CC suspension significantly reduced TNF-α secretion by LPS-activated macrophages (J774 cells). In vivo, only CC NLC were able to significantly decrease neutrophil infiltration and TNF-α secretion and, thus, colonic inflammation. Our results show that a higher CC permeability does not correlate with a higher efficacy in IBD treatment, which suggests that lipidic nanocarriers exhibiting increased CC retention at the intestinal site, rather than increased CC permeability are efficient treatments of IBD.

Práctica y productos terapéuticos en medicinas complementarias y alternativas, ¿mercado regulado o mercado libre? / No disponible

No disponible

Selenium levels in related biological samples: human placenta, maternal and umbilical cord blood, hair and nails.

A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood.

[Medicinal plants useful in the cure of circulatory problems in legs]. / Plantas medicinales útiles en los trastornos circulatorios de las piernas.

Once the fundamentals of phyto-therapy in its western use are understood, this article presents concrete a application of medicinal plants: circulatory problems in legs, a problem which affects a growing sector of the population. According to epidemiological studies, close to 80% of adults suffer problems such as tired legs, swellings, edemas, cramps, or varicose veins during their lifetimes; these appear due to an insufficiency when veins can not conveniently transport blood to the heart.

Low molecular weight chitosan nanoparticles as new carriers for nasal vaccine delivery in mice.

High molecular weight (Mw) chitosan (CS) solutions have already been proposed as vehicles for nasal immunization. The aim of the present work was to investigate the potential utility of low Mw CS in the form of nanoparticles as new long-term nasal vaccine delivery vehicles. For this purpose, CS of low Mws (23 and 38 kDa) was obtained previously by a depolymerization process of the commercially available CS (70 kDa). Tetanus toxoid (TT), used as a model antigen, was entrapped within CS nanoparticles by an ionic cross-linking technique. TT-loaded nanoparticles were first characterized for their size, electrical charge, loading efficiency and in vitro release of antigenically active toxoid. The nanoparticles were then administered intranasally to conscious mice in order to study their feasibility as vaccine carriers. CS nanoparticles were also labeled with FITC-BSA and their interaction with the rat nasal mucosa examined by confocal laser scanning microcopy (CLSM). Irrespective of the CS Mw, the nanoparticles were in the 350 nm size range, and exhibited a positive electrical charge (+40 mV) and associated TT quite efficiently (loading efficiency: 50-60%). In vitro release studies showed an initial burst followed by an extended release of antigenically active toxoid. Following intranasal administration, TT-loaded nanoparticles elicited an increasing and long-lasting humoral immune response (IgG concentrations) as compared to the fluid vaccine. Similarly, the mucosal response (IgA levels) at 6 months post-administration of TT-loaded CS nanoparticles was significantly higher than that obtained for the fluid vaccine. The CLSM images indicated that CS nanoparticles can cross the nasal epithelia and, hence, transport the associated antigen. Interestingly, the ability of these nanoparticles to provide improved access to the associated antigen to the immune system was not significantly affected by the CS Mw. Indeed, high and long-lasting responses could be obtained using low Mw CS molecules. Furthermore, the response was not influenced by the CS dose (70-200 microg), achieving a significant response for a very low CS dose. In conclusion, nanoparticles made of low Mw CS are promising carriers for nasal vaccine delivery.

Importancia de las tisanas en el tratamiento de síndromes menores / The importance of tisanes, or medicinal herbal drinks, in the treatment of minor syndromes

Las tisanas, es decir, todas las extracciones "caseras" de plantas medicinales -ya sean infusiones, cocimientos o maceraciones-, siguen siendo de gran utilidad e importancia, ya sea en tratamiento único de síndromes menores o como coadyuvante de trastornos agudos o crónicos. En los preparados tipo tisana, los principios activos se encuentran en menor concentración, lo que determina una acción farmacológica más suave, pero también una menor incidencia en la aparición de efectos indeseables. En sucesivos artículos repasaremos aquellas plantas más frecuentemente utilizadas en patología menor que podemos manejar fácilmente, en forma de infusión, maceración o cocimiento, para beneficio de nuestros pacientes y para el nuestro propio. Las clasificaremos según su indicación y acción farmacológica (AU)

[Role of herbal teas in the treatment of minor syndromes]. / Importancia de las tisanas en el tratamiento de síndromes menores.

Tisanes, which include all the home remedies made from medicinal herbs, whether these are infusions, teas, decoctions or macerations, continue being of great importance and usefulness, both as a sole treatment for minor syndromes or as an additional aid to treat acute or chronic illnesses. In tisanes or infusion remedies, the principle active ingredients are found in lower concentrations which leads to a milder pharmaceutical action, but also provides a lesser degree of possible undesirable side effects. In upcoming articles, the author shall review the herbs most frequently used for treatment of minor pathology which one can easily handle, as an infusion, maceration or decoction, in order to provide beneficial effects in our patients and for ourselves. The author shall classify these according to their recommended use and pharmaceutical action.