Enantis (Czechia)

The newest trends in wound healing management and the development of the next generation of dressings are pointing toward natural polymeric materials with important beneficial properties such as antimicrobial effects, renewability, easier process of preparation, and biological activity. Here, we present the preparation and in vitro evaluation of a unique biopolymeric blend composed of natural polymers based on the positively charged polysaccharide chitosan and negatively charged gum karaya. A plate lysis assay of gum karaya and chitosan solution mixtures proved the synergistic antimicrobial effect against specific strains of both Gram-positive and Gram-negative bacteria and yeast. This polymeric mixture was used for hydrogel film preparation and determination of the composition effect on physical properties (swelling behavior in different solvents, pH, diffusion mechanism, hydrolytic stability, mechanical and optical properties). While the pure gum karaya with poly(vinyl alcohol) exhibited the highest hydrolytic degradation (68%), the mixture of poly(vinyl alcohol) and gum karaya with chitosan (in the 25:75 ratio) exhibited the lowest degradation value (41%) due to the strong physical interactions. Cytotoxicity tests performed with hydrogel extracts using two different in vitro models, adherent fibroblasts (NIH3T3) and non-adherent suspension B-lymphocytes (BaF3), exhibited excellent biocompatibility and no cytotoxicity. As expected, the antimicrobial activity of 3-day film extracts showed a significantly improved antimicrobial effect of mixtures involving a chitosan biopolymer. The physical and biological properties of prepared biopolymer-based hydrogels meet the requirements of modern wound dressings.

The NewProt protein engineering portal is a one-stop-shop for in silico protein engineering. It gives access to a large number of servers that compute a wide variety of protein structure characteristics supporting work on the modification of proteins through the introduction of (multiple) point mutations. The results can be inspected through multiple visualizers. The HOPE software is included to indicate mutations with possible undesired side effects. The Hotspot Wizard software is embedded for the design of mutations that modify a proteins' activity, specificity, or stability. The NewProt portal is freely accessible at http://newprot.cmbi.umcn.nl/ and http://newprot.fluidops.net/.

Biodegradation of organic compounds by natural attenuation or bioaugmentation is widely used for removal of unwanted chemicals from the environment. The essential component of remediation technologies is monitoring of a contaminant levels. Although the analytical methods of gas and liquid chromatography are available, they are time-, labour- and resource-demanding, placing limitations on the number of samples that can be analysed at a time. Furthermore, these methods cannot be easily adapted for in situ measurements. Biosensors can be used as an alternative or complement to these conventional techniques. Biosensors are based on a biological component coupled to a transducer, which translates the interaction between an analyte and a biocomponent into a signal that can be processed. Application of biosensors in monitoring of environmental contaminants is promising owing to their sensitivity, low costs, user-friendliness and adaptability for in situ measurements. In this contribution, we describe development of haloalkane dehalogenase-based biosensors and their application for detection of halogenated hydrocarbons in the environmental samples.