Dialysis is one of the few options for detoxifying the blood of patients whose kidneys are failing. During the process, blood is cleansed of built-up toxins, notably creatinine, as it diffuses through a semipermeable membrane. But dialysis is lengthy and expensive, and the equipment is cumbersome. Mitsuhiro Ebara and colleagues at the National Institute for Materials Science, in Tsukuba, Japan, have now developed a zeolite-polymer material that selectively adsorbs creatinine from blood (Biomater. Sci. 2014, DOI: 10.1039/c3bm60263j). Drawing from advances in water purification, the team chose a zeolite that selectively adsorbs creatinine and paired it with a blood-compatible polymer, poly(ethylene-co-vinyl alcohol), via an electrospinning method. The resulting nanofiber material can be formed into a thin, watch-sized wafer that could be worn as part of a miniaturized purification system. Although the creatinine-adsorbing capacity is still not great enough for the material to be used clinically, the researchers suggest the surface area of the fibers could be increased to tune the material. The group is also exploring ways to further modify the material to capture other toxins involved in kidney failure.