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Yang N.,Tianjin Polytechnic University | Chen L.,Tianjin Polytechnic University | Yang M.-K.,Tianjin Polytechnic University | Bi S.-X.,Tianjin Polytechnic University | And 3 more authors.
Carbohydrate Polymers | Year: 2012

The aim of this work is to explore the ability of poly(N- isopropylacrylamide) (NIPAAm) with galactosylated acrylate (GAC) hydrogels as cell scaffolds for HL-7702 cells to proliferate, keep function of albumin and urea synthesis and detach. The results indicate poly(NIPAAm-co-GAC) hydrogels with weight ratio of 0.2 could support cells to adhere, proliferate and maintain their liver functions for 7 days. An intact cells sheet could spontaneously detach from poly(NIPAAm-co-GAC) (r = 0.2) hydrogels without treating with any enzymes. And detached cells show more integrate morphology (H&E staining) and higher proliferation index (cell cycle analysis) than cells detached by trypsin treatment. The results also reveal excessive GAC introduced to PNIPAAm hydrogels could induce apoptotic cell death of adhered cells. © 2011 Elsevier Ltd. All rights reserved. Source

Bi S.-X.,Tianjin Polytechnic University | Yang N.,Tianjin Polytechnic University | Yang M.-K.,Tianjin Polytechnic University | He X.-L.,Tianjin Polytechnic University | And 5 more authors.
Acta Polymerica Sinica | Year: 2013

The galactosylated chitosan (GC) was synthesized by the reaction of the amino group of chitosan and carboxyl group of lactobionic acid under the activation of lethyl3-(3dimethyllaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide sodium salt (NHS). Subsequently, thermo-sensitive galactosylated chitosan-grqft-poly(N-isopropylacrylamide) (Gal-CS-g-PNIPAm) hydrogels were prepared via free radical polymerization method. The chemical composition and structure of the novel copolymer obtained were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. Thermo-sensitive feature of the hydrogel was studied by measuring its swelling ratio and contact angle. The results showed that Gal-CS-g-PNIPAm hydrogels exhibited good temperature response. HL-7702 cell behaviors such as proliferation, detachment and cell transfer were carefully investigated via cell culture on the surface of Gal-CS-g-PNIPAAm hydrogels in vitro. The results indicated that Gal-CS-g-PNIPAAm hydrogel exhibited a good biocompatibility. HL-7702 cells cultured on this hydrogel surface proliferated better than on the PNIPAAm hydrogel. Besides, HL-7702 cells could spontaneously detach from the surface of the Gal-CS-g-PNIPAAm hydrogel by lowering the temperature below the LCST (32. 5 °C),and the detached cells showed less damage than those detached by enzymes from TCPS. Meanwhile, cells detached from Gal-CS-g-PNIPAAm hydrogel showed higher viability than those from the PNIPAAm hydrogel, suggesting that introduction of GC monomer to PNIPAAm hydrogel evidently improved the activity of the detached cells. Source

Bi S.,Tianjin Polytechnic University | Yang N.,Tianjin Polytechnic University | Yang M.,Tianjin Polytechnic University | He X.,Tianjin Polytechnic University | And 4 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2014

A novel polystyrene (PS) substrate with microscale porous structure was facilely fabricated by crystalline-controlled casting method using mixed solvent [N,N-dimethylformamide and ethyl alcohol (v/v)] based on the nonsolvent induced phase separation process. The substrate surfaces exhibited a bi-continuous microscale porous morphology with high porosity, large pore size and pore-pore connection structure. Moreover, behaviors of the normal human liver cell line (HL-7702) seeded on this substrate surface were carefully investigated. The results indicated that the cell adhesion, spread and cell-cell connection on the surface with subcellular pore size (∼10 μm) were similar to the cells proliferated on the flat PS surface. However, the number of HL-7702 cells proliferated on the PS microscale porous surface was higher than cells on the conventional PS flat surface, suggesting that the pore-pore structure was conducive to HL-7702 cell proliferation. Furthermore, hematoxylin and eosin staining and micronucleus test were performed. The results showed that fewer damages for nuclear and cytoplasm and less cell genotoxicity were caused by the microscale porous structure within the scope of pore size (∼10 μm) than that of the flat surface. © 2013 Wiley Periodicals, Inc. Source

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