Drug delivery properties of macroporous polystyrene solid foams

Purpose. Polymeric porous foams have been evaluated as possible new pharmaceutical dosage forms. Methods. These materials were obtained by polymerization in the continuous phase of highly concentrated emulsions prepared by the phase inversion temperature method. Their porosity, specific surface and surface topography were characterized, and the incorporation and release of active principles was studied using ketoprofen as model lipophilic molecule. Results. Solid foams with very high pore volume, mainly inside macropores, were obtained by this method. The pore morphology of the materials was characterized, and very rough topography was observed, which contributed to their nearly superhydrophobic properties. These solid foams could be used as delivery systems for active principles with pharmaceutical interest, and in the present work ketoprofen was used as a model lipophilic molecule. Conclusions. Drug incorporation and release was studied from solid foam disks, using different concentrations of the loading solutions, achieving a delayed release with short lag-timePostprint (published version

Polyamide fabric coated with a DHA-loaded chitosan hydrogel for a cosmeto-textile application

Cosmeto-textiles, which allow the administration of molecules when in contact with the skin, are increasingly being developed by cosmetic industries. We have designed an innovative approach for cosmeto-textile products, based on the impregnation of textile fibers with chitosan hydrogels, which have been cross-linked with genipin and loaded with dihydroxyacetone, which is an active component that induces sunless tanning. Dihydroxyacetone-loaded chitosan hydrogels have been prepared and characterized by means of cryogenic scanning electron microscopy (cryo-SEM). The images showed that genipin cross-linking decreases the mesh distance of hydrogels. The release of dihydroxyacetone from these cross-linked genipin chitosan hydrogels has been studied by a dialysis membrane method. These dihydroxyacetone-loaded chitosan hydrogels have been incorporated to polyamide textiles by a simple padding technique. The presence of dihydroxyacetone on these textiles has been detected by hyperspectral imaging on a dark field high resolution optical microscope. Finally, the performance of fabrics as cosmeto-textiles, with a tanning effect, has been evaluated by skin-colorimetry measured with an evaluation panel of 10 people. The results have demonstrated that dihydroxyacetone-loaded textiles produce a tanning effect on skin, and incorporation of dihydroxyacetone-loaded chitosan hydrogels into polyamide fabrics represents a friendly and appropriate strategy to obtain a cosmeto-textile with tanning effect

Formation of nanoemulsion containing ibuprofen by PIC method for topical delivery

This study reports the formation of nanoemulsions from palm-kernel oil esters (PKOE)/Cremophor EL/water systems intended for topical administration of a non-steroidal anti-inflammatory drug, ibuprofen. Nanoemulsions containing 2% ibuprofen, various oil:surfactant ratios (10:90, 20:80 and 30:70) and 80% of water were selected from the ternary system of PKOE/Cremophor EL/water and prepared by the phase inversion composition (PIC) method. The characterization of the nanoemulsions such as droplet size, polydispersity index, zeta potential, stability and the permeation of ibuprofen from nanoemulsions were evaluated. The prepared nanoemulsions exhibited good stability without any phase separation, sedimentation or creaming for the period of tested experimental time (6 months). The permeation study of ibuprofen was performed on Franz type-diffusion cells through human abdominal skin. The median values of the fluxes obtained as well as the median of the percentage of permeated amount at 24h were not statistically different. The mean profiles of permeated ibuprofen versus time from PKOE was greater (p < 0.05) than those obtained from Miglyol 812

Adaptable photochromic switches with self-aggregating heterocyclic azo dyes

It is well-known that the thermal isomerization kinetics of photochromic azo dyes can be modulated by subtle changes in their chemical architecture. However, the availability of an orthogonal input to control the thermal relaxation of azo dyes is essential to enable access to multifunctional and adaptive photochromic switches based on these particular organic chromophores. In this work, we have designed and synthesized a new family of green-light-activated heterocyclic azo derivatives that modify their switching capabilities as a function of concentration. In this line, we have investigated their self-assembly and the nature of the supramolecular aggregates formed by means of dynamic light scattering, polarized optical microscopy, and X-ray diffraction. Indeed, imparting control over the self-assembly of these organic dyes allows to fine-tune their thermal relaxation time and produce adaptable photochromic switches. Specifically, swapping the azo dye concentration between values located above and below the corresponding critical aggregation concentration modifies significantly the relaxation time up to 250 times, i.e., from the millisecond to the microsecond timescale. Moreover, the optical density of the system can be switched back and forth hundreds of times, for both diluted and concentrated solutions, without any sign of fatigue.Financial support for this research was obtained from the Ministerio de Economia y Competitividad (Spain, PGC2018-095477-B-I00, CTQ2016-78454-C2-1-R, and CTQ2017-84998-P MINECO/FEDER). Thanks are also due to Fundacao para a Ciencia e Tecnologia (Portugal) for financial support to the Portuguese NMR network (PTNMR, Bruker Avance III 400-Univ. Minho), FCT, and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centre CQ/UM [ref UID/QUI/00686/2013 and UID/QUI/0686/2016], and a PhD grant to M.C.R.C. (SFRH/BD/78037/2011)

Formation and stabilization of multiple water-in-water-in-water (W/W/W) emulsions

Multiple Water-in-Water-in-Water (W/W/W) emulsions have been prepared, stabilized and characterized. The main objective has been to find a simple and low-cost method for the preparation of W/W/W emulsions. The system composed of gelatin, maltodextrin and water has been used, and two different methods have been studied for producing multiple emulsions in this system. In the first method, maltodextrin-in-gelatin (M/G) emulsions with small droplet size were formed by pH-induced nucleation of maltodextrin droplets, and afterwards, maltodextrinin-gelatin-in-maltodextrin (M/G/M) multiple emulsions were obtained by dispersing M/G droplets into maltodextrin solutions. The second method consisted in cooling down gelatin-inmaltodextrin (G/M) emulsions, leading to the spontaneous formation of inner maltodextrin droplets. The latter method allowed producing more homogenous M/G/M multiple emulsion droplets. The colloidal stability of such emulsions greatly improved with the addition of mucin particles, which is a glycoprotein that adsorbs on the G/M interface. Stable M/G/M multiple emulsions have been prepared and characterized by fluorescence optical microscopy, where contrast has been enhanced through covalently labelling the various components with fluorescent dyes. To our knowledge, this is the first report of a simple and cost-effective method for the production of multiple W/W/W emulsions, without using microfluidic techniques. Moreover, the present work also demonstrates that mucin microparticles can be effective stabilizers for protein-in-polysaccharide emulsions, and these dispersions can be easily prepared by phase transition methods

Interaction forces between particles stabilized by a hydrophobically modified inulin surfactant.

Submitted versio

Pelvic MRI findings in relapsed prostate cancer after radical prostatectomy

Little is known about the clinical impact of using multiparametric MRI to plan early salvage radiotherapy after radical prostatectomy. We aimed to evaluate the incidence and location of recurrence based on pelvic multiparametric MRI findings and to identify clinical variables predictive of positive imaging results. We defined radiological criteria of local and lymph node malignancy and reviewed records and MRI studies of 70 patients with PSA recurrence after radical prostatectomy. We performed univariate and multivariate analysis to identify any association between clinical, pathological and treatment-related variables and imaging results. Multiparametric MRI was positive in 33/70 patients. We found local and lymph node recurrence in 27 patients and 7 patients, respectively, with a median PSA value of 0.38 ng/ml. We found no statistically significant differences between patients with positive and negative multiparametric MRI for any variable. Shorter PSADT was associated with positive lymph nodes (median PSADT: 5.12 vs 12.70 months; p: 0.017). Nearly half the patients had visible disease in multiparametric MRI despite low PSA. Positive lymph nodes incidence should be considered when planning salvage radiotherapy, particularly in patients with a short PSADT

Bladder cancer index: cross-cultural adaptation into Spanish and psychometric evaluation

BACKGROUND: The Bladder Cancer Index (BCI) is so far the only instrument applicable across all bladder cancer patients, independent of tumor infiltration or treatment applied. We developed a Spanish version of the BCI, and assessed its acceptability and metric properties. METHODS: For the adaptation into Spanish we used the forward and back-translation method, expert panels, and cognitive debriefing patient interviews. For the assessment of metric properties we used data from 197 bladder cancer patients from a multi-center prospective study. The Spanish BCI and the SF-36 Health Survey were self-administered before and 12 months after treatment. Reliability was estimated by Cronbach's alpha. Construct validity was assessed through the multi-trait multi-method matrix. The magnitude of change was quantified by effect sizes to assess responsiveness. RESULTS: Reliability coefficients ranged 0.75-0.97. The validity analysis confirmed moderate associations between the BCI function and bother subscales for urinary (r = 0.61) and bowel (r = 0.53) domains; conceptual independence among all BCI domains (r ≤ 0.3); and low correlation coefficients with the SF-36 scores, ranging 0.14-0.48. Among patients reporting global improvement at follow-up, pre-post treatment changes were statistically significant for the urinary domain and urinary bother subscale, with effect sizes of 0.38 and 0.53. CONCLUSIONS: The Spanish BCI is well accepted, reliable, valid, responsive, and similar in performance compared to the original instrument. These findings support its use, both in Spanish and international studies, as a valuable and comprehensive tool for assessing quality of life across a wide range of bladder cancer patients

Recent advances on water-in-water emulsions in segregative systems of two water-soluble polymers

The present paper reviews the most recent knowledge on water-in-water (W/W) emulsions formed in aqueous two-phase systems based on incompatibility between two polymers. The interfaces of these systems are ill-defined, relatively thick, and interfacial tensions are extremely low. Consequently, small molecules do not adsorb in W/W interfaces and emulsions are inherently unstable and the main challenge is achieving a proper colloidal stability at long times. The most widely used strategy is the addition of particles and/or macromolecules able to adsorb at the W/W interfaces, but often the stability of these emulsions is still not satisfactory in the long term. More recently, stabilization of W/W emulsions has been improved by ionic complexation and/or autoaggregation, forming membranes at the interfaces. The proper colloidal stabilization of W/W is paving the way for novel applications, such as carriers of living cells or the development of new 3D cell cultures and cell organoids.J. Esquena thanks the Spanish Ministry of Science and Innovation and Agencia Estatal de Investigación (CTQ2017-84998-P project), and Generalitat de Catalunya (2017SGR1778 grant). He also thanks the European Regional Development Fund (FEDER) and the UB-CSIC Associated R&D Unit “Pharmaceutical Nanotechnology Group”, as well as C. Rodríguez-Abreu (Institute of Advanced Chemistry of Catalonia (IQAC)-Spanish National Research Council (CSIC)), M.J. Garcia-Celma (University of Barcelona), S. Vílchez, and J. Miras (IQAC-CSIC) for their support and many useful discussions.Peer reviewe