High performance of a unique mesoporous polystyrene-based adsorbent for blood purification

Abstract

A multi-functional polystyrene based adsorbent (NKU-9) with a unique mesoporous and a high surface area was prepared by suspension polymerization for removal of therapeutic toxins in blood purification. The adsorbent produced had an almost equal amount of mesopore distribution in the range from 2 to 50 nm. The adsorption of serum toxins with different molecular weights were examined by in vitro adsorption assays and compared with some clinical currently used adsorbents such as HA-330, Cytosorb and BL-300 which are produced by China, America and Japan, respectively. Test results indicated that the adsorption rate for pentobarbital by NKU-9 was 81.24% which is nearly as high as HA-330 (81.44%). The latter adsorbent is currently used for acute detoxification treatment in China. To reach adsorption equilibrium, NKU-9 was faster than HA-330, which implies short treatment time. For the removal of middle molecular toxins such as β2-microglobulin (98.88%), NKU-9 performed better adsorptive selectivity than Cytosorb (92.80%). In addition, NKU-9 showed high performance for the removal of albumin-bound toxins (e.g., bilirubin), and its adsorption rate for total bilirubin (80.79%) in plasma was 8.4% higher than that of anion exchange resin BL-300 which is currently used to eliminate bilirubin in clinic. Therefore, our results indicate that the newly developed adsorbent with a wide distribution and almost equal amount of mesopores is a multifunctional adsorbent for high efficient removal of serum toxins with different molecular weights which might be an excellent blood purification adsorbent especially to treat diseases that conventional medical methods are low or not efficient.

Keywords: blood purification; mesoporous; polystyrene adsorbent; toxins removal.

Figure 1

SEM micrographs of adsorbent NKU-9.

Figure 2

Pore size distribution of adsorbents.

Figure 3

(a) Adsorption rates of pentobarbital in phosphate buffer solution. C_{Pentobarbital} =0.6 mg/ml; the adsorbent to solution ratio was 120 (v/v). (b) Adsorption rates of free cholic acid in phosphate buffer solution: C_CA=0.15 mg/ml; the adsorbent to solution ratio was 150 (v/v).

Figure 4

(a) Adsorption rates of lysozyme in phosphate buffer solution. C_lysozyme=0.6 mg/ml; the adsorbent to solution ratio was 120 (v/v). (b) Adsorption studies of plasma from dialysis patients. The adsorbent to solution ratio was 8 (v/v). (c) Adsorption studies of cytokines in spiked human plasma. The adsorbent to solution ratio was 7 (v/v).

Figure 5

(a) Adsorption rates of bilirubin in BSA solution. C_BIL=150 mg/l; the adsorbent to solution ratio was 36 (v/v). (b) Adsorption studies of bilirubin in human plasma. The adsorbent to solution ratio was 5; initial plasma: C_TBIL=182.2 μmol/l, C_DBIL=56.6 μmol/l, C_IBIL=125.6 μmol/l.

Figure 6

Adsorption studies of mixed solution. The adsorbent to solution ratio was 15 (v/v).