Résumé
ZnO nanotubes were prepared via electrospinning the Zn ( AC ) 2-polyacrylonitrile-polyvinylpyrrolidone ( PAN-PVP) precursor, followed by thermal decomposition of the above polymers from the precursor fibers. SEM and XRD characterization confirmed that the as-prepared ZnO nanofibers presented the hollow nanotube form, which was composed of ZnO nanoparticles with the size of about 40 nm in wurtzite crystal structure. By mixing with graphene, the obtained ZnO-graphene composite modified glassy carbon electrode ( ZnO-RGO/GCE ) was successfully constructed by dip-coating, which was used for the determination of Pb2+in water. With the sensitive response of the ZnO-RGO/GC electrode to Pb2+in solution was demonstrated by square wave stripping voltammetry, the response pctential was at -0. 4V. Under the optimized conditions, a good linear relationship between peak current and Pb2+ concentration was obtained in the range of 2. 4×10-9-4. 8×10-7 mol/L (R=0. 9970) by 10 min preconcentration at -1. 0 V in 0. 1 mol/L HAc-NaAc buffer solution (pH=4. 6). The detection limit was 4. 8×10-10 mol/L (S/N>3). The ZnO-RGO/GC electrode had good stability. The practical analytical application of the ZnO-RGO modified electrode was assessed by the measurement of the actual water sample and the result was consistent with that obtained by ICP-MS.
Résumé
Objective: To prepare Danshensu loaded polycaprolactone (DSS-PCL) nanofiber scaffold by using electrospin technology. Methods: Using dichloromethane-N, N-dimethyl formamide (CH2Cl2-DMF) 8:2 as solvent, nanofibers containing danshensu was prepared by electrospinning, fiber morphology was observed by SEM, danshensu in vitro release rule from drug loaded nanofiber scaffold was investigated, and the security of nanofiber was assessed by MTT and hemolysis test. Results: By using CH2Cl2-DMF as solvent, drug and materials could be well dissolved and successfully electrospun into nanofiber, the average fiber diameters were 210 and 190 nm, the in vitro release experiment showed that the drug release after a quick release into the slow release. MTT test indicated that PCL and DSS-PCL nanofiber showed no influence to the cell viability, and hemolysis test showed hemolysis ratio of nanofiber was under 5%. Conclusion: DSS-PCL nanofibers is easy to prepare by electrospinning.
Résumé
ZnO nanoparticle-containing carbon composite nanofiber ( ZnO-CNF ) was prepared by the electrospinning of the ZnCl2-PAN precursor, followed by preoxidation and carbonization. The ZnO nanoparticles were uniformly distributed on the surface of the carbon nanofiber with the size of 20-30 nm, confirmed by scanning electron microscopy ( SEM ) . The wettability of the ZnO-CNF was studied by water contact angle test. With Nafion as an additive, the ZnO-CNF modified electrode was successfully constructed by dip-coating. The surface morphology and electrochemical properties of the modified electrode were investigated by SEM and cyclic voltammetry. There was a sensitive response of the ZnO-CNF modified electrode on Pb ions in solution, demonstrated by square wave stripping voltammetry. Under the optimized conditions, a good linear relationship between peak current and Pb2+concentration was obtained in the range of 2. 4×10-10-2. 4×10-7 mol/L (R=0. 998) by 10 min preconcentration at -1. 0 V in 0. 1 mol/L NaAc buffer solution (pH=4. 6). The detection limit was 4. 8×10-11 mol/L. The practical analytical application of the ZnO-CNF modified electrode was assessed by the measurement of the actual water sample and the result was consistent with that obtained by ICP-MS.
Résumé
Silica is known as a promising osteoconductive material, and polycaprolactone is a bioactive and degradable material. The purpose of this study was to monitor the differentiation of MC3T3-E1 cells cultured on the layer-built silica/poly caprolactone non-woven fabric produced by electrospinning. Non-woven fabric (silica, polycaprolactone, PSP, SPS) was made by electrospinning and they were inserted in the 48 well cell culture plate. MC3T3-E1 cells were prepared by subculture. Cells were seeded to each well 1x10(5) concentration per well. Dulbecco's modified eagle medium with 10% FBS and 1% antibiotic-antimycotic solution was used. Confocal laser scanning microscope was taken 4 hours after incubation (95% air, 5% CO2, 37degrees C). Cell proliferation was monitored by spectrophotometer on 1, 7, 14 days, and the morphology of the growing cells was observed by field emission scanning electron microscope. To monitor the differentiation of osteoblasts on the materials, MC3T3-E1 cells were incubated in 48 well culture plate after seeding with the density of 1x10(5) concentration. Then ELISA kit & EIA kit were used on to assess osteocalcin and osteopontin expression respectively. The other conditions were the same as above. MC3T3-E1 cells were proliferated well on all of the materials. There were no statistical differences among them. The osteopontin expression of silica, PSP, SPS was significantly higher than other groups on day 3 (p<0.05), but after that time, there were no statistically signigicant differences. The osteocalcin expression was significantly higher in silica and PSP than other groups on day 14. These findings show that PSP was as good as silica on the effect of osteoblast differentiation. The PSP non-woven fabric may have the possibility as bone graft materials.