**1. Introduction**

Despite the significant improvements in hemodialysis (HD) techniques over the past 40 years, patients on this therapy still suffer from the burden of HD-associated symptoms, vascular access-related issues, acute and chronic complications, poor quality of life, and the mortality rate remains unacceptably elevated [1, 2]. The European Renal Association (ERA) and the United States Renal Data System (USRDS) showed that the 5-year survival rate for patients on HD is close to only 50%, which is worse than patients with breast cancer, prostate cancer and almost like or worse than colon cancer [3–6].

The retention of large-size uremic toxins (e.g., proinflammatory cytokines, alpha 1-microglobulin, YKL-40, and kappa and lambda free light chains) has been associated with inflammation, atherosclerosis and vascular calcification, cardiovascular disease, and increased risk of mortality [7]. These uremic toxins have also been associated with poor quality of life, such as late recovery time post-HD session, impaired physical function, moderate-to-severe pruritus, and restless legs syndrome [8]. These drawbacks of HD treatment demonstrate the unmet needs in the current or conventional HD modalities.
