Immobilization of CD34 antibody on ferroferric oxide magnetic nanoparticles was achieved by the traditional carboxyl-amine conjugation reaction. Fourier transform infrared spectroscopy (FT-IR), nanoparticle size analysis (dynamic light scattering and transmission electron microscope), and other testing methods were used to detect the surface modified magnetic nanoparticles. The endothelial progenitor cells (EPCs) were cultured with the surface modified magnetic nanoparticles to evaluate cell compatibility and the combination effect of nanoparticles on EPCs in a short period of time. Directional guide of the surface modified magnetic nanoparticles to EPCs was evaluated under applied magnetic field and simulated dynamic flow condition. The results showed that the magnetic nanoparticles were successfully modified with CD34 antibody, which had good cell compatibility within a certain range of the nanoparticle concentrations. The surface modified nanoparticles can combine with EPCs effectively in a short time, and those nanoparticles combined EPCs can be directional guided under the magnetic field in the dynamic flow environment.
ObjectiveTo explore the effect of different doses of low molecular weight heparin (LMWH) on the patency rate of cuffed central venous catheter used by patients for hemodialysis therapy.MethodsFrom June 2012 to January 2018, patients who received long-term hemodialysis in 363 Hospital with cuffed central venous catheter were enrolled in this retrospective study. According to the dose of LMWH used in hemodialysis, they were divided into below 60 U/kg group and greater than or equal to 60 U/kg group. The general parameters, frequency of urokinase use, bleeding events, severe coagulation in dialysis line and occurrence of catheter dysfunction were collected and compared between two groups.ResultsA total of 48 cases were enrolled. Of these, the doses of LMWH of 31 cases were below 60 U/kg and 17 cases were greater than or equal to 60 U/kg. There was no significant difference between the two groups in terms of age, sex, diabetes, hemoglobin, platelets, albumin, low-density lipoprotein cholesterol, or hypersensitive C-reactive protein parameters (P>0.05). Between the below 60 U/kg group and the greater than or equal to 60 U/kg group, there was no statistically significant difference in the incidence of catheter dysfunction (16.1% vs. 29.4%; χ2=0.507, P=0.476) or the incidence of bleeding events (1.77 vs. 2.81 times per 1 000 catheter-days; χ2=1.500, P=0.221). The frequency of urokinase used in the two group were 27.89 and 36.18 times per 1 000 catheter-days, respectively (χ2=5.927, P=0.015) and the frequency of severe coagulation were 6.88 and 2.30 times per 1 000 catheter-days, respectively (χ2=5.140, P=0.023). The differences were statistically significant.ConclusionThe lower dose of LMWH used in hemodialysis for preventing extra-corporeal circuit thrombosis does not result in the decrease of the patency rate of cuffed central venous catheter.