María Adolfina Ruiz

Doxorubicin-Loaded Nanoparticles: New Advances in Breast Cancer Therapy

Doxorubicin, one of the most effective anticancer drugs currently known, is commonly used against breast cancer. However, its clinical use is restricted by dose-dependent toxicity (myelosuppression and cardiotoxicity), the emergence of multidrug resistance and its low specificity against cancer cells. Nanotechnology is a promising alternative to overcome these limitations in cancer therapy as it has been shown to reduce the systemic side-effects and increase the therapeutic effectiveness of drugs. Indeed, the numerous nanoparticle-based therapeutic systems developed in recent years have shown low toxicity, sustained drug release, molecular targeting, and additional therapeutic and imaging functions. Furthermore, the wide range of nanoparticle systems available may provide a solution to the different problems encountered during doxorubicin-based breast cancer treatment. Thus, a suitable nanoparticle system may transport active drugs to cancer cells using the pathophysiology of tumours, especially their enhanced permeability and retention effects, and the tumour microenvironment. In addition, active targeting strategies may allow doxorubicin to reach cancer cells using ligands or antibodies against selected tumour targets. Similarly, doxorubicin resistance may be overcome, or at least reduced, using nanoparticles that are not recognized by P-glycoprotein, one of the main mediators of multidrug resistance, thereby resulting in an increased intracellular concentration of drugs. This paper provides an overview of doxorubicin nanoplatform-based delivery systems and the principal advances obtained in breast cancer chemotherapy.

Chitosan nanoparticles as a new delivery system for the chemotherapy agent tegafur

Background: Despite the very efficient antitumor activity of conventional chemotherapy, generally high doses of anticancer molecules must be administered to obtain the required therapeutic action, simultaneously leading to severe side effects. This is frequently a consequence of the development of multidrug resistance by cancer cells and of the poor pharmacokinetic profile of these agents. Objective: In Order to improve the antitumor effect of tegafur and overcome their important drawbacks, we have investigated its incorporation into a drug nanoplatform based on the biodegradable polymer chitosan. Materials and Methods: Two tegafur loading methods were studied: (i) absorption into the polymeric network (entrapment procedure); and (ii) surface deposition (adsorption procedure) in already formed chitosan nanoparticles. Results: Tegafur entrapment into the polymeric matrix has yielded higher drug loading values and a slower drug release profile, compared to single surface adsorption. The main factores determining the drug loading to chitosan were identified. Discussion and Conclusion: Such polymeric colloid present very interesting properties for efficient tegafur delivery to cancer.

A novel double-layer mucoadhesive tablet containing probiotic strain for vaginal administration: Design, development and technological evaluation

ABSTRACT Vulvovaginal candidosis caused by Candida spp. is the most prevalent vaginal infection in Europe and the second one in EE.UU, so it has become a major female concern. Probiotics bacteria have been proposed as an alternative treatment with the aim of avoiding the adverse effects associated with conventional therapies including antibiotics and other aggressive drugs for the vaginal mucosa and microbiota. The purpose of this work was to design and develop a novel vaginal tablet that contained Lactobacillus spp. bacteria as a treatment against vulvovaginal infections. A total of 21 two‐layers vaginal tablets, which contained different polymeric ratios, were proposed. However, formulation F4 (20 mg Na‐CMC; 50 mg Carbopol® 934; 20 mg chitosan) was selected as optimal according to its swelling index and dissolution/erosion capability. F4 tablets showed suitable technological properties for vaginal administration as well as mucoadhesion time (24.36 ± 0.88 h) and force (0.0941 N). Disintegration assay in simulated vaginal fluid (SVF, pH 5.5) showed that effervescent layer disappeared in 27.48 ± 0.05 s whilst matrix layer was totally gelled in 1 h. Two different release profiles were achieved; on the one hand, a promptly release due to the dissolution of both effervescent layer and matrix layers surface (1.10 × 108 CFU/g), on the second hand, a prolonged released of the remaining bacteria until 24 h (5.48 × 107 CFU/g). For stability and storage study, it was found that bacteria viability was constant until 90 days in both ways of storage, in a desiccator and at room temperature, with a final dosage of 108 CFU/g which was considered appropriate for vaginal therapy (108–1010 CFU/g). &NA; Graphical abstract Figure. No Caption available.

Microorganismos probióticos y salud.

Objetivo: Mostrar los beneficios de los microorganismos probioticos sobre la salud y su aceptacion por parte del consumidor, asi como hacer una recopilacion de todos los productos probioticos disponibles en el mercado farmaceutico. Material y metodos: Se realizo un estudio del mercado farmaceutico en relacion a las formas farmaceuticas con microorganismos probioticos existentes y su evolucion en los ultimos anos. La clasificacion de todos los productos probioticos se llevo a cabo en funcion de la forma farmaceutica en la que se presentan;cada producto ira acompanado de la dosis de microorganismos probioticos que contiene, expresada como Unidades Formadoras de Colonias (UFC). Resultados: Es cada vez mayor el numero de cepas probioticas aisladas y los beneficios mostrados sobre la salud del hombre. Encontramos gran diversidad de productos probioticos disponibles en oficinas de farmacia como consecuencia de una demanda cada vez mayor por parte del consumidor; no obstante, cabe resaltar el hecho de que muchos de ellos carecen en envase de informacion necesaria, por ejemplo, la dosis contenida. Conclusiones: El interes por parte de la industria farmaceutica en lazar nuevas formas farmaceuticas contenidas en microorganismos probioticos sera cada vez mayor e ira ligado a la necesidad de una reglamentacion especifica para estos productos. Muchos de ellos no contienen la dosis minima requerida para obtener un efecto beneficioso en la salud lo que supone una publicidad enganosa para el consumidor, por tanto, deberian ser retirados del mercado, publicitando unicamente aquellos que contengan una dosis terapeutica y cuyos efectos esten avalados por diferentes ensayos clinicos.

Microencapsulation of probiotic cells: applications in nutraceutic and food industry

Manipulation of gut microbiota with probiotics has gained increasing interest, since they have demonstrated beneficial effects in the maintenance and promotion of health. Different approaches that increase the resistance of these sensitive microorganisms against adverse conditions have been studied. The most recent studies indicate that microencapsulation is one of the most efficient methods, and it has been under especial consideration and research. In this sense, some benefits of cells microencapsulation include the protection from bacteriophages and detrimental factors, thus increasing survival during freezing, freeze-drying, and storage and allowing researchers to obtain a probiotic powder that is easy to use and to incorporate into food or pharmaceutical matrices. Therefore, the aim of the present chapter is to describe the techniques for probiotics microencapsulation, the compounds used in the microencapsulation process, as well as applications in the food industry.