Biocompatibility of chitosan carrier with rabbit corneal endothelium / 中华实验眼科杂志

Background There are a lot of studies about the carrier of corneal endothelial transplantation,but the best carrier has not been defined.Objective This study was to investigate the biocompatibility of chitosan carrier with rabbit corneal endothelium in vivo.Methods Fresh eye-balls were obtained from 10 New Zealand white rabbits.Rabbit corneal endothelial cells (CECs) were isolated and cultured on chitosan carrier in vitro.The morphology and density of rabbits CECs were observed every day,and the expressions of fibronectin (FN),collagen-1 (Coil-I) and Zonula occludens 1 (ZO-1) were detected by immunoinfluorescence.The morphology and ultrastructure of CECs were observed under the scanning and transmission electron microscope.Chitosan carrier with CECs was implanted into the anterior chamber of the left eyes in ten healthy New Zealand white rabbits,and only paracentesis of anterior chamber was performed in the right eyes as controls.The inflammation of ocular anterior segment was examined under the slit lamp microscope,and corneal thickness was measured 1 week,4 and 8 weeks after operation.Corneal endothelium cell density and morphology were examined under the corneal endothelial microscope at postoperative 2 weeks.Corneal samples were collected for the regular histopathological examination to observe the inflammatory reaction at postoperative 1 month and 3 months.Paired t test was used for statistical analyses between the control group (left eyes) and the experimental group (right eyes).The use and care of the animals followed the Statement of ARVO.Results CECs formed an intact monolayer of cells with the uniform shape and size on the chitosan membrane after incubated for 5 days.The cells reached confluence of 90％ 7 days after cultured with the 40％ hexagon cells.Under the scanning electron nicroscope,rabbit CECs showed the round or polygon in the shape with the microvillus on the cell surface.The cells connected closely by desmosome.The processes,pseudopodiums and microvillus on the cellular surface,vacuole in the cytoplasm,expanded endoplasmic reticulum with ribosome and abundant chromatin were exhibited under the transmission electron microscope.The immunofluorescence examination revealed the positive expressions of FN,Coll-Ⅰ and ZO-1 in the CECs on the chitosan carrier.In the in vivo experiment,the exudation in the anterior chamber and corneal edema were seen under the slit lamp microscope 3 days after implantation of chitosan carrier with CECs.However,the inflammation was gone 14 days after operation.The differences of the corneal thickness were no significant between the experimental group and the control group 1 week and 4,8 weeks after operation (t =1.377,P=0.265;t =1.795,P=0.165 ; t =0.390,P =0.760).In addition,no significant differences were found in the CECs density and the hexagon cells rate between the two groups(P =0.365,0.062).The histopathological examination showed that the inflammatory cells around the chitosan membrane were disappeared 3 months after operation and showed a good corneal structure.Conclusions Chitosan carrier has a good biocompatibility with rabbit CECs and anterior chamber,and it may be a potentially good carrier for CECs transplantation.

Antitumor activities of D-glucosamine and its derivatives / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The growth inhibitory effects of D-glucosamine hydrochloride (GlcNH(2).HCl), D-glucosamine (GlcNH(2)) and N-acetyl glucosamine (NAG) on human hepatoma SMMC-7721 cells in vitro were investigated. The results showed that GlcNH(2).HCl and GlcNH(2) resulted in a concentration-dependent reduction in hepatoma cell growth as measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. This effect was accompanied by a marked increase in the proportion of S cells as analyzed by flow cytometry. In addition, human hepatoma SMMC-7721 cells treated with GlcNH(2).HCl resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis. NAG could not inhibit the proliferation of SMMC-7721 cells. GlcNH(2).HCl exhibited antitumor activity against Sarcoma 180 in Kunming mice at dosage of 125-500 mg/kg, dose of 250 mg/kg being the best. GlcNH(2).HCl at dose of 250 mg/kg could enhance significantly the thymus index, and spleen index and could promote T lymphocyte proliferation induced by ConA. The antitumor effect of GlcNH(2).HCl is probably host-mediated and cytocidal.

Lead expelling effect of carboxymethyl chitosan calcium in lead poisoned mice / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the effects of carboxymethyl chitosan calcium (CCC) on concentration of lead, calcium and zinc, and the liver antioxidative capacity in lead poisoned mice.</p><p><b>METHODS</b>Mice were randomly divided into 7 groups, including normal group, calcium carbonate group, lead-model group, and three experimental groups treated with CCC in three different doses, and the CaNa2EDTA positive control group. The lead poisoned mice model was established by giving water contained with lead acetate. CCC was administrated to mice i.g. once a day. Thirty days later, mice were killed and the concentrations of lead, calcium and zinc in blood, liver, brain and femur were determined by atomic absorption spectrophotometer. Maleic dialdehyde (MDA), total antioxidative capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities in liver were measured by using assay kit.</p><p><b>RESULTS</b>CCC significantly reduced the concentration of lead in blood, brain, liver and femur from about 1.56 microg/g, 13.38 microg/g, 16.15 microg/g, 1011.62 microg/g to about 0.50 microg/g, 5.57microg/g, 5.64 microg/g, 457.86 microg/g, and markedly increased the concentration of calcium in femur in lead poisoned mice. CCC had no significant side-effects on concentration of zinc in lead poisoned mice. The antioxidative profile was favorably changed as manifested by decreasing the level of MDA, increasing the activities of SOD, GSH-Px and T-AOC in livers of the in lead poisoned mice.</p><p><b>CONCLUSION</b>CCC might significantly advance the excretion of lead, increase the concentration of calcium in femur and the antioxidative capacity in lead-loaded mice.</p>