Biochemical Assessment and Clinical Evaluation of a Non-Ionic Adsorbent Resin in Patients with Intractable Jaundice

We investigated in vitro and in vivo the ability of a non-ionic adsorbing resin (styrenedivinylbenzene copolymer) to remove bilirubin and bile acids from human plasma. In preliminary experiments, human plasma from healthy donors, enriched in conjugated bile acids and bilirubin, and pooled plasma from jaundiced patients were recirculated through the resin column. The removal of bilirubin and bile acids was evaluated at two different flow rates (200 ml/min and 40 ml/min), and compared to an activated charcoal column. Four patients with severe jaundice were subsequently treated by 4-hour plasmaperfusion through the resin. The in vitro studies showed that after 1 hour the removal of bile acids was almost complete and bilirubin level decreased significantly, reaching a plateau after 4 hours. In the in vivo study, all treatments were well tolerated. After plasmaperfusion, serum bile acid levels decreased by 64.9–94.6% and total bilirubin by 35.3–57.7%. No clinical or biochemical side effects were observed. Our data suggest that plasmaperfusion through this resin is safe and efficient for removal of bilirubin and bile acids in jaundiced patients. Thus, it may serve as a method of artificial liver support in the treatment of cholestatic syndromes.

Isolation of plasma from whole blood using planar microfilters for lab-on-a-chip applications

Researchers are actively developing devices for the microanalysis of complex fluids, such as blood. These devices have the potential to revolutionize biological analysis in a manner parallel to the computer chip by providing very high throughput screening of complex samples and massively parallel bioanalytical capabilities. A necessary step performed in clinical chemistry is the isolation of plasma from whole blood, and effective sample preparation techniques are needed for the development of miniaturized clinical diagnostic devices. This study demonstrates the use of passive, operating entirely on capillary action, transverse-flow microfilter devices for the microfluidic isolation of plasma from whole blood. Using these planar microfilters, blood can be controllably fractionated with minimal cell lysis. A characterization of the device performance reveals that plasma filter flux is dependent upon the wall shear rate of blood in the filtration channel, and this result is consistent with macroscale blood filtration using microporous membranes. Also, an innovative microfluidic layout is demonstrated that extends device operation time via capillary action from seconds to minutes. Efficiency of these microfilters is approximately three times higher than the separation efficiencies predicted for microporous membranes under similar conditions. As such, the application of the microscale blood filtration designs used in this study may have broad implications in the design of lab-on-a-chip devices, as well as the field of separation science.