Di-block copolymers of poly(ethylene oxide) (PEO) and glycopolymers at three different pendant spacer lengths of glucose moiety were synthesized by deacetylation of pendant moieties of 2,3,4,6-tetra-O-acetyl-d-glucopyranosides which were prepared by reversible addition-fragmentation chain-transfer (RAFT) process. The water soluble deacetylated copolymers, PEO-b-poly(acryl-d-glucopyranoside) (PEO-b-PAG, 2a), PEO-b-poly[4′-(acryloxy)butyl-d-glucopyranoside] (PEO-b-PABG, 2b), and PEO-b-poly[6′-(acryloxy)hexyl-d-glucopyranoside] (PEO-b-PAHG, 2c) were characterized in comparison with acetylated copolymers by spectroscopic and gel permeation chromatography methods. In order to assess the biocompatibility of these three di-block copolymers, the adhesion (%), viability (%), and proliferation assays were carried out in MC3T3 cells in-vitro at different concentrations from 10 nM to 1000 μM. Qualitative analysis of cell cytoskeletal organization was obtained by immunostaining with talin and integrin α5. It was clearly indicative of well spreading of cells in the presence of all glycopolymers at lower concentrations but with an increase in the concentration (10 and 100 μM) showed significant change in the cell surface morphologies, despite having good cell adhesion and viability as compared to the control conditions. The use of di-block glycolpolymers at?≤?100 μM of the concentration showed very good osteoblast cells adhesion and viability response; however at higher concentrations (1000 μM) of glycopolymers > 80% of cells lost their viability. 相似文献
Polycrystalline powders of rare-earth doped La1?xGdxB3O6 (0?≤?x?≤?0.2) and La1?xSmxB3O6 (0.0?≤?x?≤?0.1) phosphors were successfully prepared by a B2O3 flux method. All the phosphor samples are well characterized by powder X-ray diffraction (XRD), infrared (IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) methods and fluorescence lifetime of Sm3+ ion. The XRD patterns show that La1?xMxB3O6 (M?=?Gd and Sm) adopt monoclinic with the I2/a space group. The SEM–EDS results confirmed the doping of Gd and Sm into LaB3O6 lattice. The IR and Raman spectra of these solid solutions gave distinctive bands corresponding to planar BO3 and tetrahedral BO4 groups. The photoluminescence (PL) spectra of La1?xGdxB3O6 gave a strong emission band, 6PJ?→?8S7/2, at 310 nm. The PL spectra of La1?xSmxB3O6 phosphor showed orange-red emission at 598 nm when excited using light of wavelength of 402 nm. The results were obtained by the transition 4G5/2?→?6H7/2 of Sm3+ ions. The influence of dopant concentration on the emission profiles was studied. The ESR spectra of La1?xGdxB3O6 (x?=?0.02) gave a typical U-spectrum and spin-Hamiltonian parameters are deduced.