**3.2.2 Results and discussion**

76 Progress in Hemodialysis – From Emergent Biotechnology to Clinical Practice

The platelet adhesion results were consistent with FBG adsorption. It is well known that FBG adsorption from plasma onto a material surface might promote the adhesion of the platelets because it had the ability to bind specifically to the platelet membrane glycoprotein, GP IIb-IIIa (Phillips et al., 1988). Thus, the observed decreasing amounts of platelet adhesion might be attributed to the increased hydrophilicity, and decreased FBG adsorption. These results indicated that the surface heparin-like PES membranes modified by SPES and P(AN-AA-VP) had good blood compatibility for using as blood contacting

The test solutions were prepared according to the international standard ISO 8637. The molar concentrations of urea, creatinine and phosphate in the simulation solution were 15mmol/l, 500mol/l and 1mmol/l, respectively. The test procedure was accordant to the procedure in ISO 8637. The ultrafiltration coefficient was calculated as the unit ml/mmHg.h. The clearance (K) of small molecules (urea, creatinine, phosphate) were established by sampling from the inlet and outlet segments of the extracorporeal circuit 1 h after the

*BI BO BO*

where CBI is the solute concentration in the blood (here is the simulation solution); I and O refer to the inlet and the outlet to the device, respectively; QBI is the blood flow rate at the

Urea was determined by a reagent Kit for Urea Determination (Diethyl-Monoxime, Beijing chemical regent factory, China); creatinine was quantified by the absorption at 235nm using an UV-VIS spectraphotometer U-200A (Hitachi Co., Ltd., Tokyo, Japan) through a standard

*BI BI CC C K QQ C C* 

*BI F*

initiation of the treatment, and was calculated using the following formula.

Fig. 7. The number of the adhering platelets on the membranes

**3.2 Ultrafiltration and solute clearances** 

dialyser inlet; QF is the filtration rate.

**3.2.1.1 Hemodialysis using a simulation solution** 

**3.2.1 Experimental** 

devices.

Table 1 summarizes the clearance data and the reduction ratio after the dialysis for small molecules in vitro. It was clearly that the clearances and the reduction ratios for all the solutes were larger using the simulated solution than that for blood. The removal of small molecules during dialysis is governed by hydrodynamic conditions within the dialyser rather than membrane structure since the major resistance to transport from the blood into the dialysis fluid lies not in the membrane but boundary layers adjacent to the membrane. Thus, the data of clearance and the reduction ratio (Table 1) for the simulated solution were higher than that for the blood due to the proteins in the blood, which may induce concentration polarization.

Hemolysis ratio was determined for the swine blood in vitro and for the goat blood in vivo. Data showed that there was only a slightly hemodialysis phenomena (about 1.7%) in vitro.


Data are expressed as the meansSD, n =3

Table 1. Small molecular clearance at a blood (or simulated solution) flow rate of 180 ml/min and dialysate flow rate of 500 ml/min
