Irene Esparza

Nanomedicine: Novel approaches in human and veterinary therapeutics

Nanomedicine can be defined as the application of nanotechnology to the prevention and treatment of diseases as well as for diagnosis purposes. In this context, the development of various types of drug-carrier nanodevices offers new strategies for targeted drug delivery, minimising the secondary effects and the toxicity associated to drug widespread to healthy organs or cells. This review is divided in two different parts. The first one summarizes the main types of nanomedicines developed in the past few decades, including drug nanocrystals, polymer therapeutics, lipid-nanosized and polymeric-nanosized drug delivery systems. The second part of our review is devoted, more specifically, to the presentation of polymeric nanoparticles. Here, we discuss various aspects of nanoparticle formulation, characterization, behaviour in the body and some of their potential applications. More particularly we present some approaches for the treatment of cancer, treatment of infectious diseases and the potential of these nanoparticles as adjuvants for vaccination purposes.

Nanoparticulate adjuvants and delivery systems for allergen immunotherapy

In the last decades, significant progress in research and clinics has been made to offer possible innovative therapeutics for the management of allergic diseases. However, current allergen immunotherapy shows limitations concerning the long-term efficacy and safety due to local side effects and risk of anaphylaxis. Thus, effective and safe vaccines with reduced dose of allergen have been developed using adjuvants. Nevertheless, the use of adjuvants still has several disadvantages, which limits its use in human vaccines. In this context, several novel adjuvants for allergen immunotherapy are currently being investigated and developed. Currently, nanoparticles-based allergen-delivery systems have received much interest as potential adjuvants for allergen immunotherapy. It has been demonstrated that the incorporation of allergens into a delivery system plays an important role in the efficacy of allergy vaccines. Several nanoparticles-based delivery systems have been described, including biodegradable and nondegradable polymeric carriers. Therefore, this paper provides an overview of the current adjuvants used for allergen immunotherapy. Furthermore, nanoparticles-based allergen-delivery systems are focused as a novel and promising strategy for allergy vaccines.

Zein based-nanoparticles improve the oral bioavailability of resveratrol and its anti-inflammatory effects in a mouse model of endotoxic shock

Resveratrol offers pleiotropic health benefits including a reported ability to inhibit lipopolysaccharide (LPS)-induced cytokine production. The aim of this work was to prepare, characterize, and evaluate a resveratrol nanoparticulate formulation based on zein. For this purpose, the oral bioavailability of the encapsulated polyphenol as well as its anti-inflammatory effects in a mouse model of endotoxic shock was studied. The resveratrol-loaded nanoparticles displayed a mean size of 307 ± 3 nm, with a negative zeta potential (-51.1 ± 1.55 mV), and a polyphenol loading of 80.2 ± 3.26 μg/mg. In vitro, the release of resveratrol from the nanoparticles was found to be pH independent and adjusted well to the Peppas-Sahlin kinetic model, suggesting a mechanism based on the combination of diffusion and erosion of the nanoparticle matrix. Pharmacokinetic studies demonstrated that zein-based nanoparticles provided high and prolonged plasma levels of the polyphenol for at least 48 h. The oral bioavailability of resveratrol when administered in these nanoparticles increased up to 50% (19.2-fold higher than for the control solution of the polyphenol). Furthermore, nanoparticles administered daily for 7 days at 15 mg/kg were able to diminish the endotoxic symptoms induced in mice by the intraperitoneal administration of LPS (i.e., hypothermia, piloerection, and stillness). In addition, serum tumor necrosis factor-alpha (TNF-α) levels were slightly lower (approximately 15%) than those observed in the control.

Pru p 3 acts as a strong sensitizer for peanut allergy in Spain

Pru p 3 has been suggested to be the primary sensitizing allergen in patients with peanut allergy in the Mediterranean area. We aimed to confirm this hypothesis, studying 79 subjects.

Cyclodextrin-poly(anhydride) nanoparticles as new vehicles for oral drug delivery.

Introduction: The oral administration of drugs belonging to Class IV of the Biopharmaceutical Classification System (BCS) represents a major challenge. These drugs display poor aqueous solubility and specific permeability characteristics. Most of these compounds are substrates of the P-glycoprotein and/or the cytochrome P450. Among other types of drug, various anti-cancer drugs also suffer from these drawbacks (i.e., paclitaxel), which limits the possibilities for developing oral treatments. Areas covered: This review discusses the factors that influence the bioavailability of drugs when administered by the oral route, as well as the capabilities of cyclodextrins when associated with nanoparticles. In particular, evidence is given regarding the synergistic effect between cyclodextrins and bioadhesive nanoparticles, on the oral delivery of pharmaceuticals. Expert opinion: This article aims to provide an overview of the multiple gains in incorporating cyclodextrins in poly(anhydride) nanoparticles, including improvement of their bioadhesive capability, the loading of lipophilic drugs and the effect on efflux membrane proteins and cytochrome P450. The combination between bioadhesive nanoparticles and P-gp inhibitors without pharmacological activity (i.e., cyclodextrins) may be useful to promote the oral bioavailability of drugs ascribed to Class IV of the BCS.

Development of poly(anhydride) nanoparticles loaded with peanut proteins: the influence of preparation method on the immunogenic properties.

Allergen-specific immunotherapy is based on the administration of allergens with the main disadvantage of inducing an allergic reaction. Within this context, we report the generation of an adjuvant and allergen-delivery system for peanut allergen immunotherapy with reduced IgE induction. Therefore, we prepared and characterized poly(anhydride) nanoparticles loaded with peanut proteins using the solvent displacement method, with some modifications in the manufacturing process. The precipitation of polymer was performed with either a mixture of ethanol and water or water. The resultant nanoparticles were dried by either freeze-drying or spray-drying, respectively. Poly(anhydride) nanoparticles loaded with peanut proteins were successfully developed, achieving both high encapsulation efficiency (70-80%) and manufacturing yield (60-80%). After intradermal immunization of mice (C57Bl/6) with peanut proteins incorporated into poly(anhydride) nanoparticles, a strong mixed T(H)1/T(H)2-type immune response was observed. Furthermore, we also provide, to our knowledge for the first time, clear evidence of the influence of formulation design on the immunostimulatory properties of nanoparticles. Taken together, our findings indicate that poly(anhydride) nanoparticles are efficient stimulators of immune responses and promising adjuvants and allergen-delivery systems applied for immunotherapy.

Significance of CIELAB parameters in the routine analysis of red wines

Correlations have been sought among different parameters (total polyphenols, anthocyanins and flavonoids, monomeric anthocyanins, Zn, Cu, Mn, and Fe) analyzed in two consecutive vintages of a Tempranillo wine. A comparative study of those parameters with color characteristics (both CIELAB and Glories parameters) is presented for these wines. Principal Component Analysis (PCA) has showed the existence of a close relationship between CIELAB parameters and polyphenol concentrations, whereas no correlation could be found with classic color parameters but in the expected case of Color Intensity (CI). An equation is proposed that allows the concentration of total polyphenols to be estimated as a function of total anthocyanins, cyanidin-3-glucoside (Cy-3-gluc), and petunidin-3-glucoside (Pt-3-gluc) concentrations. Chromatographic fractioning of wine samples evidenced the specific interaction of both Pt-3-gluc and Cy-3-gluc with Fe, Zn, and Cu.

Zein nanoparticles for oral delivery of quercetin: Pharmacokinetic studies and preventive anti-inflammatory effects in a mouse model of endotoxemia

Zein nanoparticles were evaluated as nanocarriers to promote the oral bioavailability of quercetin and, thus, improve its anti-inflammatory effect on a mouse model of induced endotoxemia. For this purpose, the flavonoid and 2-hydroxypropyl-β-cyclodextrin were encapsulated in zein nanoparticles. The resulting nanoparticles displayed a mean size of about 300nm and the payload was calculated to be close to 70μg/mg nanoparticle. The release of quercetin from zein nanoparticles followed a zero-order kinetic. After oral administration, nanoparticles provided high and sustained levels of quercetin in plasma and the relative oral bioavailability was calculated to be approx. 60%. Animals treated with quercetin-loaded nanoparticles (1 dose every two days; 1week) presented endotoxic symptoms less severe than those observed in animals treated with the oral solution of the flavonoid (1 dose every day; 1week). This was further corroborated by the significantly low circulating TNF-alpha in the quercetin-loaded nanoparticles treated mice.