Dye decolorisation by laccase immobilised in lens-shaped poly(vinyl alcohol) hydrogel capsules

In this study, laccase (from Trametes versicolor, 8.3 U mg _enz ^?1 ) was used for the decolorisation of Saturn Blue L4G (10 mg L^?1). The efficiency of the decolorisation (ratio between the amount of decolorised dye and initial amount of dye) by a free enzyme was 48 % and the decolorisation rate was determined at 2.11 × 10^?3 mg_dye mg _enz ^?1 min^?1. After immobilisation in lens-shaped poly(vinyl alcohol) hydrogel capsules LentiKats® Biocatalyst (LB) (concentration of immobilised enzyme: 4 mg per g of particles; volume-loading rate of LB: 10 g per 100 mL of medium), the enzyme retained 16.1 % of its original activity (1.34 U mg _enz ^?1 ). Immobilised laccase was used for the dye decolorisation in 130 repeated batch tests with 71 % efficiency (LB activity: 7 × 10^?3 mgdye min^?1 g _LB ^?1 ). In continuous mode (after 716.5 h), the efficiency of the dye decolorisation was 48 % (LB activity: 3.3 × 10^?4 mg_dye min^/?1 g _LB ^?1 ).     

Crystal structure, spectroscopic and magnetic properties, and antimicrobial activities of cobalt(II) 2-methylthionicotinate complexes with N-heterocyclic ligands

Synthesis and characterization of 10 new 2-methylthionicotinate (2-MeSnic) Co(II) complexes, namely, [Co(2-MeSnic)₂L₂(H₂O)₂] · nH₂O (L is N,N-diethylnicotinamide—Et₂nia, ethylnicotinate—Etnic, nicotinamide—nia, isonicotinamide—isonia, N-methylnicotinamide—N-Menia, furo[3,2-c]pyridine—fpy, 2,3-dimethylfuro[3,2-c]pyridine—Me₂fpy or benzo[4,5]furo[3,2-c]pyridine—Bfp; n is 0, 1 or 2) as well as [Co(2-MeSnic)₂L₂] (L is ronicol—ron or 2-methylfuro[3,2-c]pyridine—Mefpy), are reported. The characterizations were based on physico-chemical and spectroscopic methods. The crystal structure of one of the complexes has been determined. In the molecular complex [Co(2-MeSnic)₂(Me₂fpy)₂(H₂O)₂], the Co(II) central atom, located at a symmetry centre, is octahedrally coordinated by an oxygen atom of the unidentate 2-MeSnic carboxyl group, the nitrogen atom of the pyridine ring of Me₂fpy, a water molecule and the corresponding centrosymmetrically located atoms. Also, biological activity of the complexes against various strains of bacteria and filamentous fungi has been investigated. It is concluded that by complexation of these nicotinate derivatives their biological activities are elevated. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Protein-resistant surfaces through mild dopamine surface functionalization

The synthesis and evaluation of new dopamine-based catechol anchors coupled to poly(ethylene glycol) (PEG) for surface modification of TiO(2) are reported. Dopamine is modified by dimethylamine-methylene (7) or trimethylammonium-methylene (8) groups, and the preparation of mPEG-Glu didopamine polymer 11 is presented. All these PEG polymers allow stable adlayers on TiO(2) to be generated through mild dip-and-rinse procedures, as evaluated both by variable angle spectroscopic ellipsometry and X-ray photoelectron spectroscopy. The resulting surfaces substantially reduced protein adsorption upon exposure to full human serum.     

Interaction of cells with polymers

This paper summarizes the results of our experiments studying the effect of functional chemical groups of synthetic hydrophilic polymers on the recognition of these materials by macrophages in in vivo experiments. The interaction of keratinocytes with synthetic hydrophilic polymers in vitro is also demonstrated. The implants containing anionic groups (carboxylates) were shown to be better tolerated by nonspecific immunity. The keratinocytes are able to grow on hydrophilic polymer supports and migrate to surfaces with improved adhesivity (in vitro). The clinical applications of these experiments are demonstrated.     

Hydrogels for encapsulation of mammalian cells

In our attempt to prepare new hydrogels for cell encapsulation, we decided to use synthetic copolymers presuming that chemical bonds should bring better mechanical stability of capsules than electrostatic forces between polyanions and polycations in the so far predominantly used materials based on polyelectrolyte complexes. Two series of copolymers of 2‐hydroxyethyl methacrylate (HEMA) with alkyl acrylates (methacrylates) or N‐alkylacrylamides (methacrylamides) were prepared. The copolymers, prepared by solution copolymerization in ethanol, were characterized by swelling in water and PBS solution, viscometric molecular weight, and NMR analysis, and their encapsulation processability was tested. Their characteristics and the first biological tests are the subject of this paper.