FRACTIONATION OF THE PROTEINS OF HUMAN SYNOVIAL FLUID AND PLASMA

Recovery of human serum albumin by dual-mode chromatography from the waste stream of Cohn fraction V supernatant

Plasma fractionation industry is by far the largest protein pharmaceutical provider, but there are still some plasma components in its industrial waste liquid that have not been utilized. This study aimed to develop a simple and efficient method for plasma protein recovery from Cohn fraction V supernatant (FVS), an effluent containing about 40% ethanol. A new affinity chromatography medium was synthesized with a fatty acid ligand. When the medium was applied to recovery of human serum albumin (HSA) from FVS at physiological pH7.4, the process was unsuccessful due to substantial decrease in capacity in the presence of high ethanol concentration. Nevertheless, change of pH from 7.4 to 4.2 emerged an improved adsorption capacity. The carboxyl group of the ligand began to act as cationic ion exchange role. Both HSA and α2HS-glycoprotein were adsorbed by the column, but α2HS-glycoprotein could be eluted by increasing pH from 4.2 to 7.4, while HSA was retained by the column and could only be eluted by addition of fatty acid. Therefore, the adsorption of albumin under pH 4.2 is charge-induced affinity adsorption, not simple ion exchange. The so-called dual-mode adsorption depends not only on the chromatographic medium but also on the separated object and environment. HPSEC showed that the purity of recovered HSA was greater than 98%. Circular dichroism and fluorescence spectra were consistent with that of the commercial product. Furthermore, the measurement by isothermal titration calorimetry showed that the separated HSA still maintained the binding activities with the ligands of warfarin and naproxen. It is therefore possible to directly recover high-purity and high-quality human serum albumin from the effluent of plasma fractionation industry by one-step chromatography.

Micro- and nanodevices integrated with biomolecular probes

Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities.

Radial diffusion assay of tissue collagenase and its application in evaluation of collagenase inhibitors

A radial diffusion assay for tissue collagenase (EC 3.4.24.3) has been devised which is simple, sensitive and capable of application to large numbers of samples. The assay employs an agarose matrix containing solubilized lathyritic rat skin collagen as substrate. Fibril formation is induced for 2 h at 37 degrees C subsequent to 41 h digestion at 28 degrees C. The procedure results in sharply defined zones of lysis which may be measured directly or after photography. The characteristics of the procedure are otherwise similar to those reported for other radial diffusion assays. The new method was used to examine the action of 10 compounds which were known or potential inhibitors of tadpole collagenase. The concentration of inhibitor required to produce 50% inhibition is reported for the following compounds: alpha2-macroglobulin, 142 microng/ml; N-acetylcysteine, greater than or equal to 100 mM; cysteine, 8.7 mM; EDTA, 0.46 mM; histidine, greater than or equal to 100 mM; 2,3-dimercaptopropanol, 0.5 mM and mercaptoacetic acid, 70 mM. The procedure also has potential for clinical determinations (e.g. tears, synovial fluid) since assay dishes may be prepared in advance and only 15 micronl of sample is required.