We compared the ability of two enzymes to catalyze the formation of gels from solutions of gelatin and chitosan. A microbial transglutaminase, currently under investigation for food applications, was observed to catalyze the formation of strong and permanent gels from gelatin solutions. Chitosan was not required for transglutaminase-catalyzed gel formation, although gel formation was faster, an...

To study human neutrophil (polymorphonuclear leukocyte (PMN)) migration and killing of bacteria in an environment similar to that found in inflamed tissues in vivo, we have used fibrin gels. Fibrin gels (1500 microm thick) containing Staphylococcus epidermidis were formed in Boyden-type chemotaxis chambers. PMN migrated < 300 microm into these gels in 6 h and did not kill S. epidermidis when th...

In order to have access to chiral gels, a series of salts derived from (1R,3S)-(+)-camphoric acid and various secondary amines were prepared based on supramolecular synthon rationale. Out of seven salts prepared, two showed moderate gelation abilities. The gels were characterized by differential scanning calorimetry, table top rheology, scanning electron microscopy, single crystal and powder X-...

The conversion of mechanical to chemical energy is a natural phenomenon that few synthetic materials have been able to mimic robustly. The fi rst demonstration of mechanical triggering of Belousov–Zhabotinsky (BZ) oscillations is presented in N -isopropylacrylamideco -Ru(bpy) 3 gels for which the oscillatory nature of the BZ reaction can be visualized via periodic changes in color. It is demons...

Certain cellular responses to thyroid hormones appear to be mediated by non-histone chromatin protein receptors. Purification of these proteins is important for an investigation of the detailed mechanisms of their regulatory role. In the present studies, we report the development of an affinity chromatographic system that can be used to purify thyroid hormone receptors solubilized from nuclei. ...

Electrostatic interactions within a semiinterpenetrating network (semi-IPN) gel can control the postsynthesis loading, long-term retention, and subsequent release of small-molecule cationic antibiotics. Here, electrostatic charge is introduced into an otherwise neutral gel [poly(ethylene glycol) (PEG)] by physically entrapping high-molecularweight poly(acrylic acid) (PAA). The network structure...