Résumé
<p><b>OBJECTIVE</b>To prepare a platinum microcoil coated with polymers and vascular endothelial growth factor (VEGF), and evaluate its surface characteristics and property of sustained VEGF release.</p><p><b>METHODS</b>The surface of the platinum microcoils (GDC) were modified by coating P(DLLA-co-TMC) copolymer and immobilizing heparin on the surface of GDC. VEGF was then loaded onto the surface of GDC and the controlled release of VEGF within GDC was achieved. The morphology was observed by scanning electron microscope, and the sustained release of VEGF was evaluated by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>Platinum coils were prepared by successive deposition of P(DLLA-co-TMC) copolymer and anionic heparin, and VEGF was immobilized through affinity interaction with heparin. The accumulative release of VEGF increased obviously during the entire testing period without burst release.</p><p><b>CONCLUSION</b>The use of P(DLLA-co-TMC) copolymer allows immobilization of VEGF on the platinum coils for controlled VEGF release, and improves the biological property of the coils.</p>
Sujets)
Matériaux revêtus, biocompatibles , Chimie , Préparations à action retardée , Pharmacologie , Platine , Chimie , Polymères , Chimie , Facteur de croissance endothéliale vasculaire de type A , PharmacologieRésumé
<p><b>OBJECTIVE</b>This article reports a population genetic study on six short tandem repeat(STR) loci, D7S820, D19S253, D12S391, D5S818, D16S539 and D8S1179, in a sample of unrelated Chinese Han individuals(n=122-173) living in Hebei province.</p><p><b>METHODS</b>DNA extraction from blood samples (200 in number) and multiplex amplification of the above six loci were carried out. Using denaturing polyacrylamide gel electrophoresis and silver stain, the authors investigated the distribution of allele frequencies of the six loci in Han population in Hebei province.</p><p><b>RESULTS</b>The STR polymorphisms at all of the six loci were observed in Chinese Han population in Hebei province. The observed heterozygosities of D7S820, D19S253, D12S391, D5S818, D16S539 and D8S1179 were 0.828, 0.757, 0.769, 0.837, 0.785 and 0.852, respectively. The measured values of the power of discrimination (PD) were 0.914, 0.919, 0.940, 0.909, 0.917, 0.944; of the mean exclusion chance(MEC) 0.618, 0.740, 0.801, 0.557, 0.655, 0.696 and of the polymorphism information content (PIC) in Chinese 0.771, 0.760, 0.762, 0.708, 0.776 and 0.794, respectively.</p><p><b>CONCLUSION</b>The genotype distributions of the six STR were in accordance with Hardy-Weinberg equilibrium. The numerical values of the PD and MEC are relatively high in Hebei province, and thus can be of significant application in population genetics and forensic medicine.</p>
Sujets)
Femelle , Humains , Mâle , Asiatiques , Génétique , Chine , Ethnologie , ADN , Fréquence d'allèle , Génétique des populations , Répétitions microsatellites , Génétique , Polymorphisme génétique , Groupes de population , Séquences répétées en tandem , Génétique , PhysiologieRésumé
The chitosan/PHEA-blended hydrogels were prepared from PHEA and chitosan in various blend ratios. The water contents of the hydrogels were in the range of 50%-80% (wt). The attachment and growth of fibroblast cells(L929) on the hydrogels were studied. The results indicated the PHEA content in hydrogels has great effect on cell attachment but has little effect on the growth of L929 cells.