Seoul, South Korea
Seoul, South Korea

Time filter

Source Type

Lee K.,AnC Bio Inc. | Lee K.,Seoul National University | Mun C.H.,Seoul National University | Min B.G.,Seoul National University | Won Y.S.,Soonchunhyang University
Artificial Organs | Year: 2012

Convective clearance during hemodialysis (HD) improves dialysis outcomes in kidney failure patients, and, thus, trials have been undertaken to increase convective mass transfer, which is directly related to internal filtration rates. The authors designed a new hemodialyzer to increase the internal filtration rates, and here describe the hemodialytic efficacy of the devised unit. The developed dual-chambered hemodialyzer (DCH) contains two separate chambers for dialysate flow within a single housing. By placing a flow restrictor on the dialysate stream between these two chambers, dialysate pressures are regulated independently. Dialysate is maintained at a higher pressure than blood pressure in one chamber, and at a lower pressure in the other chamber. The dialysis performance of the DCH was investigated using an acute canine renal failure model. Urea and creatinine reductions and albumin loss were monitored, and forward and backward filtration rates were measured. No procedurally related malfunction was encountered, and animals remained stable without any complications. Urea and creatinine reductions after 4-h dialysis treatments were 75.2±6.5% and 67.7±8.9%, respectively. Post-treatment total protein and albumin levels remained at pretreatment values. Total filtration volume was 4.98±0.5L over 4h, whereas the corresponding backfiltration (BF) volume was 4.77±0.6L. The developed dual-chamber dialyzer has the benefit of providing independent control of forward filtration and BF rates. HD using this dialyzer provides a straightforward means of increasing the internal filtration and convective dose. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.


Lee K.,AnC Bio Inc. | Lee K.,University of Michigan | Mun C.H.,Interdisciplinary Program in Bioengineering and | Min B.G.,Seoul National University
Blood Purification | Year: 2013

Background/Aims: Extracorporeal blood detoxification strategies aimed at supporting impaired liver function have been explored because of the imbalance between donor organs and waiting patients. A limited number of artificial devices are now available clinically, and these are characterized by the use of multistage adsorption procedures in conjunction with hemodialysis, but these features simultaneously increase system complexity and treatment costs. Methods: The authors developed a simpler strategy for liver dialysis based on the use of a multifunctional filter, which enables plasma separation and perfusion in a single unit. Results: Liver dialysis treatments were successfully performed using the devised unit when bovine blood containing uremic and hepatic toxins was circulated. Removal of the solutes under investigation was significant, and reduction ratios of 78% for urea, 98% for creatinine and 91% for bilirubin were achieved. Plasma free hemoglobin levels were reasonably maintained despite prolonged blood recirculation for 5 h, and platelet, hematocrit and hemoglobin levels remained uniform throughout liver dialysis sessions. Conclusion: The devised liver support unit may offer a straightforward and efficient means of cleansing blood for patients with hepatic failure. Copyright © 2012 S. Karger AG, Basel.


Lee K.,AnC Bio Inc. | Lee K.,Seoul National University | Min B.G.,Seoul National University | Lee K.K.,Jeju National University | And 2 more authors.
ASAIO Journal | Year: 2012

The repetition of forward and backward filtration during hemodialysis (HD) increases convective mass transfer, and thus, the authors devised a method of achieving cyclic repletion of ultrafiltration and backfiltration. Hemodialytic efficiencies of the developed unit are described. The devised method, named pulse push/pull hemodialysis (PPPHD), is based on the utilization of dual pulsation in a dialysate stream. Clearances of solutes with different molecular weights were determined, and in vivo hemodialytic performance was investigated in a canine renal failure model. Urea and creatinine reduction and albumin (ALB) loss were monitored, and the results obtained were compared with those of a conventional high-flux hemodialysis (CHD). Dialysis sessions were repeated eight times for PPPHD and six times for CHD by alternating PPPHD and CHD sessions in a single animal, which remained stable throughout the experiments. Urea and creatinine reductions for the PPPHD unit were 49.2 ± 2% and 44.3 ± 3.3%, respectively, which were slightly higher than those obtained for the CHD. Total protein and ALB levels were preserved by both methods. However, in vitro results revealed that PPPHD achieved significantly greater inulin clearance than CHD. The developed PPPHD unit facilitates repetitive filtration and improves convective mass transfer during HD, without the need for external replacement infusion. Copyright © 2012 by the American Society for Artificial Internal.


Lee K.,AnC Bio Inc. | Wook Lee D.,AnC Bio Inc. | Goo Min B.,Seoul National University | Kap Lee K.,Jeju National University | Min Yun Y.,Jeju National University
Journal of Medical Devices, Transactions of the ASME | Year: 2011

Although hemodiafiltration is presumed to be a gold standard for higher convective therapy for kidney failure patients, the repetition of forward and backward filtration during hemodialysis increases the total filtration volume and convective clearance. Hence, the authors describe a new method of enhancing forward filtration and backfiltration. The devised method, named pulse push/pull hemodialysis (PPPHD), is based on the utilization of dual pulsation in a dialysate stream; namely, pulsatile devices in the dialysate stream both upstream (a dialysate pump) and downstream (an effluent pump) of the dialyzer. Fluid management accuracy of the unit was assessed using fresh bovine blood, and its hemodialytic performance was investigated in a canine renal failure model. Forward filtration rates during PPPHD were maintained at the levels of dialysate flow rates. Fluid balancing error was less than ±0.84% of total dialysate volume, when 97.4 ± 1.66L of pure dialysate was circulated for 4 hs. The animal remained stable without any complication. Urea and creatinine reductions were 56.9 ± 1.6 and 52.8 ± 2.3%, respectively, and albumin levels remained uniform throughout treatment. The devised PPPHD unit offers a simple, but efficient strategy of combined simultaneous diffusive and convective solute transport for ESRD patients, without the need for external replacement infusion. © 2011 American Society of Mechanical Engineers.


PubMed | AnC Bio Inc.
Type: Comparative Study | Journal: ASAIO journal (American Society for Artificial Internal Organs : 1992) | Year: 2012

The repetition of forward and backward filtration during hemodialysis (HD) increases convective mass transfer, and thus, the authors devised a method of achieving cyclic repletion of ultrafiltration and backfiltration. Hemodialytic efficiencies of the developed unit are described. The devised method, named pulse push/pull hemodialysis (PPPHD), is based on the utilization of dual pulsation in a dialysate stream. Clearances of solutes with different molecular weights were determined, and in vivo hemodialytic performance was investigated in a canine renal failure model. Urea and creatinine reduction and albumin (ALB) loss were monitored, and the results obtained were compared with those of a conventional high-flux hemodialysis (CHD). Dialysis sessions were repeated eight times for PPPHD and six times for CHD by alternating PPPHD and CHD sessions in a single animal, which remained stable throughout the experiments. Urea and creatinine reductions for the PPPHD unit were 49.2 2% and 44.3 3.3%, respectively, which were slightly higher than those obtained for the CHD. Total protein and ALB levels were preserved by both methods. However, in vitro results revealed that PPPHD achieved significantly greater inulin clearance than CHD. The developed PPPHD unit facilitates repetitive filtration and improves convective mass transfer during HD, without the need for external replacement infusion.


PubMed | AnC Bio Inc.
Type: Journal Article | Journal: Artificial organs | Year: 2012

Convective clearance during hemodialysis (HD) improves dialysis outcomes in kidney failure patients, and, thus, trials have been undertaken to increase convective mass transfer, which is directly related to internal filtration rates. The authors designed a new hemodialyzer to increase the internal filtration rates, and here describe the hemodialytic efficacy of the devised unit. The developed dual-chambered hemodialyzer (DCH) contains two separate chambers for dialysate flow within a single housing. By placing a flow restrictor on the dialysate stream between these two chambers, dialysate pressures are regulated independently. Dialysate is maintained at a higher pressure than blood pressure in one chamber, and at a lower pressure in the other chamber. The dialysis performance of the DCH was investigated using an acute canine renal failure model. Urea and creatinine reductions and albumin loss were monitored, and forward and backward filtration rates were measured. No procedurally related malfunction was encountered, and animals remained stable without any complications. Urea and creatinine reductions after 4-h dialysis treatments were 75.26.5% and 67.78.9%, respectively. Post-treatment total protein and albumin levels remained at pretreatment values. Total filtration volume was 4.980.5L over 4h, whereas the corresponding backfiltration (BF) volume was 4.770.6L. The developed dual-chamber dialyzer has the benefit of providing independent control of forward filtration and BF rates. HD using this dialyzer provides a straightforward means of increasing the internal filtration and convective dose.

Loading AnC Bio Inc. collaborators
Loading AnC Bio Inc. collaborators