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- Acoustic cavitation (1)
- Albumin (1)
- Beständigkeit (1)
- Bewitterung (1)
- Carbamazepine (1)
- Degradation (1)
- ELISA (1)
- Hydrodynamic cavitation (1)
- Laser (1)
- Material, geosynthetisch (1)
Organisationseinheit der BAM
The antiepileptic drug carbamazepine is one of the most abundant pharmaceuticals in the German aquatic environment. The effect of low carbamazepine concentrations (1–50 µg L-1) is discussed controversially, but ecotoxicological studies revealed reproduction toxicity, decreased enzymatic activity and bioaccumulation in different test organisms. Therefore, as a preventive step, an efficient and cost-effective technique for wastewater treatment plants is needed to stop the entry of pharmaceuticals into the aquatic environment. Cavitation, the formation, growth, and subsequent collapse of gas- or vapor-filled bubbles in fluids, was applied to solve this problem. The technique of Hydrodynamic-Acoustic-Cavitation was used showing high synergistic effect. Under optimized conditions carbamazepine (5 µg L-1) was transformed by pseudo-first order kinetics to an extent of >96% within 15 min (27% by hydrodynamic cavitation, 33% by acoustic cavitation). A synergistic effect of 63% based on the sum of the single methods was calculated. Carbamazepine concentrations were monitored by a sensitive and selective immunoassay and after 60 min no known metabolites were detectable by LC-MS/MS.
Laser tissue soldering (LTS) based on indocyanine green (ICG)-mediated heat- denaturation of proteins might be a promising alternative technique for micro-suturing, but up to now the Problem of too weak shear strength of the solder welds in comparison to sutures is not solved. Earlier reports gave promising results showing that solder supported by carrier materials can enhance the cohesive strength of the liquid solder. In these studies, the solder was applied to the carriers by dip coating. Higher reliability of the connection between the solder and the carrier material is expected when the solder is bound covalently to the carrier material. In the present study a poly(ether imide) (PEI) membrane served as carrier material and ICG- supplemented albumin as solder substrate. The latter was covalently coupled to the carrier membrane under physiological conditions to prevent structural protein changes. As laser source a diode continuous-wave laser emitting at 808 nm with intensities between 250mW and 1500mW was utilized. The Albumin functionalized carrier membrane was placed onto the tunica media of explanted pig thoracic aortae forming an overlapping area of approximately 0.5×0.5 cm2. All tests were performed in a dry state to prevent laser light absorption by water. Infrared spectroscopy, spectro-photometrical determination of the secondary and Primary amine groups after acid orange II staining, contact angle measurements, and atomic force microscopy proved the successful functionalization of the PEI membrane with albumin. A laser power of 450mW LTS could generate a membrane-blood vessel connection which was characterized by a shear strength of 0.08±0.002MPa, corresponding to 15% of the tensile strength of the native blood vessel. Theoretically, an overlapping zone of 4.1mmaround the entire circumference of the blood vessel could have provided shear strength of the PEI membrane-blood vessel compound identical to the tensile strength of the native blood vessel. These in-vitro results confirmed the beneficial effects of solder reinforcement by carrier membranes, and suggest LTS with covalently bound solders on PEI substrates for further studies in animal models.