Bacterial Cellulose Films: Influence of bacterial strain and drying route on film properties from Muling Zeng, Anna Laromaine* and Anna Roig* accepted in Cellulose, DOI: 10.1007/s10570-014-0408-y
This paper reports the production of bacterial cellulose thin films from two bacterial strains, Gluconacetobacter xylinus (GX) and Gluconacetobacter europaeus (GE), and three methods of drying the films; at room temperature (RD), freeze drying (FD) and supercritical drying (SCD). The porosity, transparency, water absorption capacity and mechanical properties of the obtained films are further investigated. We conclude that materials with different properties can be fabricated by selecting the bacterial strain or the drying method.
Laura González has been awarded a full scholarship to attend the summer school “Integrative cellular and molecular biology. Fundaments and frontiers of the new biology”, which will be held from the 25th to the 28th of August 2014 at the Universidad Internacional Menéndez Pelayo, Santander.
Pol Sallés, undergraduate student of the Nanoscience and Nanotechnology degree at the Universitat Autònoma de Barcelona, has been awarded with a JAE-INTRO scholarship by the CSIC to spend a three-month internship in our group. He will work on a project related to “Heterostructures of layered inorganic nanoparticles on bacterial cellulose substrates” and will be supervised by Anna Laromaine and Anna Roig.
The N&N Group has been recognized as an Emerging Group (2014SGR213) accredited by the AGAUR (Agència de Gestió d’Ajuts Universitaris i de la Recerca) de la Generalitat de Catalunya. Our group has been also awarded with funding which is very much welcomed!
A novel solventless coating method to graft low molecular weight polyethyleneimine on silica
fine powders
Nerea Murillo-Cremaes, Pedro López-Aranguren, Lourdes F. Vega, Javier Saurina,
Anna Roig*, Concepción Domingo*
Journal of Polymer Science, Part A: Polymer Chemistry (2014), on-line July DOI:10.1002/pola.27297
A ring-opening polymerization process catalyzed by compressed CO2 at low pressure and temperature and in the absence of any organic solvent is presented. Fabrication of hybrid materials involving two types of silica nanoparticles (one of them with a magnetic core) coated with hyperbranched polyethyleneimine of low molecular weight was succesfully achieved. Properties of the obtained materials are identified as excellent for some biomedical applications
Compressed antisolvent process for polymer coating of drug-loaded aerogel nanoparticles
Nerea Murillo-Cremaes, Pascal Subra-Paternault*, Javier Saurina, Anna Roig*, Concepción Domingo*
Colloid and Polymer Science(2014) DOI 10.1007/s00396-014-3260-6, published on-line June 2014
The overall objective of the present work was to modulate the release behavior of drug-impregnated silica particles from almost instantaneous release to a more sustained delivery, prolonged during several hours. Triflusal was chosen as a model drug of the low biodisponibility type. The process is based in the coating with Eudragit® RL 100 polymer of aerogel-like silica particles. Materials were processed in compressed CO2 by using the batch and semicontinuous antisolvent coating methods. Triflusal release from Eudragit-coated aerogel particles was compared with the dissolution profiles recorded for pristine triflusal and for triflusal impregnated into polymer or non-coated aerogel particles. The release profiles were determined by high-performance liquid chromatography. Eudragit-coated materials presented an intermediate drug-release rate between this obtained for the infused polymer and that of the impregnated aerogel particles. Diffusion-governed mechanisms were found for the studied aerogel-like systems after fitting the release data to both Korsmeyer-Peppas and Baker-Lonsdale equations. The major advantage of the compressed CO2 antisolvent approach was the ability to physically coat very fine particles. Moreover, the stability of the studied drug in water increased after coating.
Rapid synthesis of water-dispersible superparamagnetic iron oxide nanoparticles by a microwave-assisted route for safe labeling of endothelial progenitor cells
Elisa Carenza, Verónica Barceló, Anna Morancho, Joan Montaner, Anna Rosell*, Anna Roig*
Acta-Biomaterialia10 (2014) pp. 3775-3785) DOI: 10.1016/j.actbio.2014.04.01
Highly crystalline citrate coated iron oxide superparamagnetic nanoparticles readily dispersible in water were fabricated by an extremely fast microwave-assisted route, the uptake of magnetic nanoparticles by endothelial cells is further investigated. Nanoparticles form large aggregates when added to complete endothelial cell media. The size of aggregates was controlled by adjusting the ionic strength of the media. The internalization of nanoparticles into endothelial cells was then investigated by transmission electron microscopy, magnetometry and chemical analysis together with cell viability assays. Interestingly, a seven-fold more efficient uptake was found for systems with larger nanoparticle aggregates which also showed significantly higher magnetic resonance imaging effectiveness without compromising cell viability and functionality. We are thus presenting an example of a straightforward microwave synthesis of citrate-coated iron oxide nanoparticles for safe endothelial progenitor cell labeling and good magnetic resonance cell imaging with potential application in magnetic cell guiding and in vivo cell tracking.