Polymethylmethacrylate Membrane Dialyzer: Historic but Modern.

Polymethylmethacrylate (PMMA) hollow fiber membranes are one of the synthetic polymer hollow fiber membranes used to the hollow fiber artificial kidney. A PMMA hollow fiber membrane (PMMA membrane) has unique properties including the uniform structure and the adsorption property. Hemodialyzers using PMMA membranes, Filtryzer®, were approved in Japan in 1977 and have been used worldwide for over 40 years and so is a historical hemodialyzer.Various types in Filtryzer® having different pore sizes are developed and used in the clinical field. Filtryzer® B3 is a low-flux dialyzer. Filtryzer® BK has three types having different pore sizes, and above all, BK-F has the largest pores in the Filtryzer® series. Filtryzer® BG has a more uniform membrane structure by using weak anionic polymers compared with the earlier Filtryzer® series to remove β2-MG more. Filtryzer® NF is the latest Filtryzer® series and was developed as a dialyzer having improved antithrombogenicity compared with previous models and having protein adsorption property as the same with them. There have been many reports concerning Filtryzer® including improvement of patients' symptoms such as pruritus and nutrition on the advantages for dialysis patients. Although PMMA membranes are historic dialysis tools used for over 40 years, they are also modern dialysis membranes that have been updated to respond to dialysis therapy at those time.