Amphiphilic polyvinyl alcohol adsorbent for the removal of low-density lipoprotein.

Spacer can effectively reduce the steric hindrance and synergistic effect of the hydrophilic and hydrophobic ligands immobilized in adsorbents can improve the specific adsorption for low-density lipoprotein (LDL). In this paper, in order to improve the adsorption capacity for the Low-density lipoprotein-cholesterol (LDL-C), specifically, amphiphilic adsorbent based on polyvinyl alcohol (PVA) containing cholesterol ligand and sulfonic dextran ligands was synthesized. All kinds of factors affecting the synthesis yield and adsorption properties were studied in detail. Results showed that the amphiphilic PVA adsorbent has higher adsorption capacity for total cholesterol (TC), (LDL-C), triglyceride (TG), and lower adsorption capacity, and percentage for high-density lipoprotein-cholesterol (HDL-C), while the ligand ratio of cholesterol to sulfonic ligands is 1.57:1, the adsorption percentage and adsorption capacity for TC, LDL-C, TG, and HDL-C were 54.4%, 67.6%, 42.5%, 10.4% and 4.02, 3.612, 2.154, 0.168 mg/g, respectively.

Development of resin adsorbents for blood purification at Nankai University in China.

Various types of porous resin adsorbents based on polystyrene, agarose, and cellulose as matrixes coupling with DNA, amino acids and other biological active molecules as ligands were extensively studied in China. Molecular recognition between the ligand and pathogenic molecule was investigated. Several commercialized products are now widely used in hospitals all over China. Whole blood hemoperfusion is used to treat patients suffering from autoimmune diseases, uremia acute intoxication, and hyperbilirubinemia. Clinical performances of hundreds and thousands of patients treated by whole blood sorption therapy show that the therapy is safe, efficient, and cost-effective.

Extracorporeal whole blood immuno-adsorption of passively transferred myasthenia gravis rabbits by cellulose-tryptophan column.

The whole blood immuno-adsorption (WBIA) system, using an adsorbent to remove pathogenic antibodies of Myasthenia Gravis (MG), was studied. Cellulose-tryptophan adsorbent was synthesized and purified in our lab. Experimental autoimmune myasthenia gravis (EAMG) rabbits were passively transferred with immunoglobulin from patients with myasthenia gravis. The rabbits underwent extracorporeal whole blood adsorption for 2 hours. Results showed no significant damage to blood cells and no changes in the concentrations of electrolytes. Total protein decreased by 12.6% (P<0.05) and globulin protein decreased 21.9% (P<0.05). The overall removal of antibodies against nicotinic acetylcholine receptor (nAChR) was 49.85%. The percentage of decrement of compound muscle action potential in 3, 5, 10 Hz of EAMG rabbits all dropped down after the treatment. The quantity of neuromuscular junctions per unit area (25 mm(2)) increased significantly after treatment (P<0.05). In conclusion, the adsorbent was biocompatible, safe for whole blood immuno-adsorption. Whole blood immuno-adsorption improved clinical manifestation and neuromuscular function of the passively transferred EAMG rabbits.

1,25-Dihydroxyvitamin D3 stimulates bone neovascularization by enhancing the interactions of osteoblasts-like cells and endothelial cells.

The current work investigated whether 1,25-dihydroxyvitamin D(3)(1,25-(OH)(2)D(3)) can promote the neovascularization of tissue-engineered bone. Human osteoblast-like cells (HOB) and endothelial cells (EC) were isolated and cultured. HOB and EC were inoculated at the ratio of 2:1 onto the coral-derived hydroxyapatite (CHA) scaffolds coated with and without 1,25-(OH)(2)D(3). Tissue-engineered bones were cultured for 3 days before implantation into the backs of nude mice. Four and 8 weeks after the operation, the retrieved scaffolds and cells were examined histologically and by scanning electron microscope, and the vascular area was measured. The immature bone grew into the pores of CHA scaffolds in both groups. At each time interval, there was a conspicuous neovascularization in the 1,25-(OH)(2)D(3) treatment group, with a larger amount of new capillaries accompanying immature bone. In the 1,25-(OH)(2)D(3) group, scanning electron microscopy revealed luminal sprouting from the larger vessels. Maturation of the new bone was paralleled by the occurrence of the new capillaries. The vascular areas were 28.74% +/- 7.81% and 19.52% +/- 4.57% at 4-week intervals (p < 0.05) and 24.66% +/- 7.38% and 17.84% +/- 5.22% at 8-week intervals (p < 0.05) in test and control groups, respectively. These results imply that 1,25-dihydroxyvitamin D(3) may be useful as a cytokine for tissue engineering bone for neovascularization.

New method for preparing more stable microcapsules for the entrapment of genetically engineered cells.

In this paper, we studied a new preparation method of microcapsules for entrapment of genetically engineered cells. Polyvinyl alcohol microcapsules having well defined shape, high mechanical strength, good biochemical and permeability properties were prepared by using low temperature physical cross-linking method. Comparing with currently used alginate-polylysine-alginate microcapsules, polyvinyl alcohol microcapsules have much higher mechanical strength. The low temperature physical crosslinking procedure of polyvinyl alcohol is nontoxic to the genetically engineered E. coli DH5alpha cell, which attained high activity in decomposing and metabolizing urea in vitro studies.

Extracorporeal whole blood immunoadsorption of autoimmune myasthenia gravis by cellulose tryptophan adsorbent.

Whole blood immunoadsorption (WBIA) system, using an adsorbent to remove pathogenic antibodies of myasthenia gravis (MG), was studied. Cellulose-tryptophan adsorbent was synthesized and its adsorption capacity of binding with acetylcholine receptor in the plasma of MG patient was evaluated. Experimental autoimmune myasthenia gravis (EAMG) rabbits were induced by Ta183-200 peptide. The rabbits underwent extracorporeal whole blood adsorption for 2 h. Results showed no significant damages on blood cells and no changes in the concentration of electrolytes. Total protein decreased by 12.0% (P < 0.05), and globulin protein decreased 23.9 +/- 5.6% (P < 0.05). The mean overall removal of antibodies against Ta183-200 was 41.12%. The percentage of decrement of compound muscle action potential in 3, 5, 10Hz of EAMG rabbits all dropped down after the treatment. In conclusion, the adsorbent is biocompatible, was safe for whole blood immunoadsorption, and can remove antibodies in an MG patient effectively. Whole blood immunoadsorption improved clinical manifestation and neuromuscular function of the EAMG rabbits.

[The preparation of fructose-modified chitosan microcarrier and culture of primary rat hepatocyte].

Crosslinked chitosan microcarries were prepared by the reaction of glutaraldehyde with fructose-modified chitosan. Various factors that influence the preparation were studied and the reaction conditions were optimized. Morphology of rat hepatocyte cultured on chitosan microcarriers was observed using phase contrast microscopy and scanning electron microscope, the metabolic activity was measured. Rat hepatocytes cultured on chitosan microcarrier retained the spherical shape as they have in vivo and had high metabolic activity. Fructose can enhance the metabolic activity of hepatocytes and fructose-modified chitosan microcarrier is a promising scaffold for hepatocytes attachment, which can be used in bioartificial liver support system.