Diffusive Silicon Nanopore Membranes for Hemodialysis Applications

• Published in: PloS one Vol. 11; no. 7; p. e0159526
• Main Authors: Kim, Steven, Feinberg, Benjamin, Kant, Rishi, Chui, Benjamin, Goldman, Ken, Park, Jaehyun, Moses, Willieford, Blaha, Charles, Iqbal, Zohora, Chow, Clarence, Wright, Nathan, Fissell, William H, Zydney, Andrew, Roy, Shuvo
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.07.2016; Public Library of Science (PLoS)
• Subjects: Addition polymerization; Analysis; Animals; Biology and Life Sciences; Biomimetics; Blood platelets; Care and treatment; Chronic illnesses; Chronic kidney failure; Diagnosis; Dialysis; Diffusion; Fabrication; Feasibility studies; Geometry; Health aspects; Hemodialysis; Hollow fiber membranes; Humans; Illnesses; In vitro methods and tests; Innovations; Kidney Failure, Chronic - physiopathology; Kidney Failure, Chronic - therapy; Mathematical models; Mathematics; Medicine and Health Sciences; Membrane filters; Membrane permeability; Membranes; Membranes, Artificial; Microelectromechanical systems; Mortality; Nanopores; Nanostructured materials; Oxidative stress; Patient outcomes; Patients; Peritoneal dialysis; Permeability; Physical Sciences; Polymers; Polymers - chemistry; Polymers - therapeutic use; Porosity; Properties; Renal Dialysis - methods; Silicon; Silicon - chemistry; Silicon - therapeutic use; Size distribution; Solute transport; Solutions - chemistry; Swine; Transplants & implants; Transport; United States; San Francisco California; California; United States > US; Pennsylvania
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0159526

Hemodialysis using hollow-fiber membranes provides life-sustaining treatment for nearly 2 million patients worldwide with end stage renal disease (ESRD). However, patients on hemodialysis have worse long-term outcomes compared to kidney transplant or other chronic illnesses. Additionally, the underlying membrane technology of polymer hollow-fiber membranes has not fundamentally changed in over four decades. Therefore, we have proposed a fundamentally different approach using microelectromechanical systems (MEMS) fabrication techniques to create thin-flat sheets of silicon-based membranes for implantable or portable hemodialysis applications. The silicon nanopore membranes (SNM) have biomimetic slit-pore geometry and uniform pores size distribution that allow for exceptional permeability and selectivity. A quantitative diffusion model identified structural limits to diffusive solute transport and motivated a new microfabrication technique to create SNM with enhanced diffusive transport. We performed in vitro testing and extracorporeal testing in pigs on prototype membranes with an effective surface area of 2.52 cm2 and 2.02 cm2, respectively. The diffusive clearance was a two-fold improvement in with the new microfabrication technique and was consistent with our mathematical model. These results establish the feasibility of using SNM for hemodialysis applications with additional scale-up.