Templating hydrogels

Templating processes for creating polymerized hydrogels are reviewed. The use of contact photonic crystals and of non-contact colloidal crystalline arrays as templates are described and applications to chemical sensing and device fabrication are illustrated. Emulsion templating is illustrated in the formation of microporous membranes, and templating on reverse emulsions and double emulsions is described. Templating in solutions of macromolecules and micelles is discussed and then various applications of hydrogel templating on surfactant liquid crystalline mesophases are illustrated, including a nanoscale analogue of colloidal crystalline array templating, except that the bead array in this case is a cubic array of nonionic micelles. The use of particles as templates in making core-shell and hollow microgel beads is described, as is the use of membrane pores as another illustration of confinement templating

Molecular Characterization of a Novel Intracellular ADP-Ribosyl Cyclase

Background. ADP-ribosyl cyclases are remarkable enzymes capable of catalyzing multiple reactions including the synthesis of the novel and potent intracellular calcium mobilizing messengers, cyclic ADP-ribose and NAADP. Not all ADP-ribosyl cyclases however have been characterized at the molecular level. Moreover, those that have are located predominately at the outer cell surface and thus away from their cytosolic substrates. Methodology/Principal Findings. Here we report the molecular cloning of a novel expanded family of ADP-ribosyl cyclases from the sea urchin, an extensively used model organism for the study of inositol trisphosphate-independent calcium mobilization. We provide evidence that one of the isoforms (SpARC1) is a soluble protein that is targeted exclusively to the endoplasmic reticulum lumen when heterologously expressed. Catalytic activity of the recombinant protein was readily demonstrable in crude cell homogenates, even under conditions where luminal continuity was maintained. Conclusions/Significance. Our data reveal a new intracellular location for ADP-ribosyl cyclases and suggest that production of calcium mobilizing messengers may be compartmentalized

Synthesis, characterization and applications of amphiphilic elastomeric polyurethane networks in drug delivery

Polyurethanes have a key role in the development of many different biomedical devices because of their exceptional biocompatibility, mechanical properties and versatility. Although linear segmented polyurethanes have been extensively studied, the investigation of cross-linked polyurethanes remains limited. In this work, three series of polyurethane networks were synthesized by reacting poly(ethylene glycol) and hexamethylene diisocyanate with either tetrafunctional poloxamer Tetronic 701 or poly(e-caprolactone)s triol with molecular weights of 1060 and 3130 Da. The hydrophilic/hydrophobic ratio was varied by selecting the appropriate amounts of monomers, and its effects on the swelling behavior and the thermal properties were analyzed. Studies concerning the release of a model drug were performed, the results of which indicate that these materials hold promise for use in controlled implantable drug-delivery devices and antimicrobial coatings.Fil: Caracciolo, Pablo Christian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina;Fil: Sanz Pita, Cristina. Universidad de Girona. Grupo Lepamap; España;Fil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina;Fil: Méndez, José Alberto. Universidad de Girona. Grupo Lepamap; España;Fil: Gironés Molera, Jordi. Consejo Superior de Investigaciones Cientificas. Instituto de Ciencia y Tecnologıa de Polimeros; España