Synthesis, characterization and cytocompatibility of a degradable polymer using ferric catalyst for esophageal tissue engineering.

This study focused on the synthesis, characterization and cytocompatibility of a biodegradable polymer by the cross-linking from poly(ethylene glycol-co-lactide) dimethacrylate (PLEGDMA), polyethylene glycol diacrylate (PEGDA) and N-isopropylacrylamide, where PLEGDMA was synthesized by ring-opening oligomerization of poly(ethylene glycol) with different molecular weights (Mn = 400, 600, 1000, 2000 Da) and L-lactide using low toxic iron(III) acetylacetonate (Fe(acac)3) as the catalyst and subsequently being terminated with dimethacrylate. The product, PLEGDMA, was analyzed to confirm its chemistry using FTIR spectroscopy, (1)H NMR spectra and gel permeation chromatography etc. The thermodynamic properties, mechanical behaviors, surface hydrophilicity, degradability and cytotoxicity of the cross-linked product were evaluated by differential scanning calorimetry, tensile tests, contact angle measurements and cell cultures. The effects of reaction variables such as PEGDA content and reactants ratio were optimized to achieve a material with low glass transition temperature (Tg), high wettability and preferable mechanical characteristics. Using a tubular mould which has been patented in our group, a tubular scaffold with predetermined dimension and pattern was fabricated, which aims at guiding the growth and phenotype regulation of esophageal primary cells like fibroblast and smooth muscle cell towards fabricating tissue engineered esophagus in future.

[Preparation and characteristics of a novel Cu(II)-imprinted epoxy resin-based monolithic polymer].

A novel Cu(II)-imprinted monolithic polymer was prepared by step-polymerization reaction of epoxy resin. A homogenous mixture of epoxy resin, diethylenetriamine as curing agent, copper ion as target molecule and polyethylene glycol as pore-forming reagent was poured into a glass-tube and polymerized under controlled reaction temperature and time. The PEG and copper ions were all removed from the solid product by deionized water and strong acid, respectively. The Cu(II)-imprinted epoxy resin-based monolithic porous polymer was successfully obtained, which was used as solid-phase extraction matrix for preconcentration and separation of trace copper ions in aqueous solution for determination by atomic adsorption spectrometry. The effect of pH on adsorption, maximum adsorption capacity, selectivity, analytical precision and availability was investigated in details by a series of experiments. Under the optimized enrichment conditions, i.e., pH 5.0-9.0 of medium and flow rate below 5.0 mL x min(-1), the recovery of Cu(II) ions in the aqueous solution could be over 95%. The maximum adsorption capacity is 126 mg Cu (II) x g(-1) dried resin. The selective recognition ability of Cu(II))-imprinted monolithic column is evidently preponderant over the non-imprinted materials. The up-loaded column could be completely eluted with 1.0 mol x L(-1) HNO3 and flow rate below 2.0 mL x min(-1). The proposed procedure was applied to the analysis of a mixed sample with satisfied result.