Immobilized enzyme reactors based on monoliths: Effect of pore size and enzyme loading on biocatalytic process.

Macroporous monolithic columns with different mean pore size (from 360 to 2020 nm) and appropriate flow-through properties were synthesized using free radical in situ copolymerization of glycidyl methacrylate, 2-hydroxyethyl methacrylate and ethylene dimethacrylate. In order to predict the composition of porogen mixture to generate the pores in the interested size interval, the Hildebrand theory was used. Ribonuclease A and its specific low- and macromolecular substrates cytidine-2',3'-cyclic monophosphate sodium salt and RNA were applied as model system. The effect of mean pore size of macroporous monoliths used for enzyme immobilization on molecular recognition and biocatalytic characteristics was examined. The monitoring of RNA degradation was performed using anion-exchange HPLC on monolithic CIM DEAE analytical column. The high efficiency of heterogeneous biocatalysts obtained comparatively to the catalytic reaction of RNA degradation in solution was demonstrated. Additionally, the series of six monolithic immobilized enzyme reactors with different amount of biocatalyst was prepared and studied regarding to the biocatalytic properties at recirculation mode at two experimental variants, e.g. (i) fixed range of concentrations of circulated substrate solutions, and (ii) fixed range of substrate/enzyme molar ratios.

Basophil mediated pro-allergic inflammation in vehicle-emitted particles exposure.

Despite of the fact that engine manufacturers develop a new technology to reduce exhaust emissions, insufficient attention given to particulate emissions. However, diesel exhaust particles are a major source of air-borne pollution, contain vast amount of polycyclic aromatic hydrocarbons (PAHs) and may have deleterious effects on the immune system, resulting in the induction and enhancement of pro-allergic processes. In the current study, vehicle emitted particles (VEP) from 2 different types of cars (diesel - D and gasoline - G) and locomotive (L) were collected. Overall, 129 four-week-old, male SPF-class Kunming mice were subcutaneously instilled with either low dose 100, 250 or high dose, 500mg/kg VEP and 15 mice were assigned as control group. The systemic toxicity was evaluated and alterations in the percentages of the CD3, CD4, CD8, CD16, CD25 expressing cells, basophils, eosinophils and neutrophils were determined. Basophil percentages were inversely associated with the PAH content of the VEPs, however basophil sensitization was more important than cell count in VEP exposure. Thus, the effects of VEP-PAHs emerge with the activation of basophils in an allergen independent fashion. Despite the increased percentage of CD4+ T cells, a sharp decrease in basophil counts at 500mg/kg of VEP indicates a decreased inhibitory effect of CD16+ monocytes on the proliferation of CD4+ T cell and suppressed polarization into a Th2 phenotype. Therefore, although the restrictions for vehicles emissions differ between countries, follow up studies and strict regulations are needed.