Papers by Keyword: Cell Immobilization

Abstract: In this paper, an effective, simple and universal method for cell immobilization was developed. A self-polymerization nanofilm of poly (dopamine) was used to fix yeast cells in microfluidic channels. The surface morphology of the poly (dopamine) film was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Water contact angles (WCA) was also used to characterize the surface property of the poly (dopamine) nanofilm. The WCA on the PDMS substrates rapidly decreased from 105° to 59.8° with an increase in poly (dopamine) coating time. The interfacial process of dopamine self-polymerization and the cell immobilization were measured in a label-free and real-time mode by a surface plasmon resonance (SPR) instrument. Finally the immobilized yeast cells were observed by using a light microscope. From the experimental results, the yeast cells can be easily immobilized on the microfluidic channels modified with the nanofilm of poly (dopamine), which will hold great potential for the immobilization, detection and further analysis of other suspension cells, such as blood cells.

Abstract: A new-styled continuous stirred tank reactor (CSTR) seeded with activated sludge attached onto granular activated carbon (GAC) was developed for raised hydrogen production using diluted grenadine syrup. Emphasis was placed on the hydrogen producing performance and stability of the reactor. It was found that the temperature of (35 ± 1) °C, hydraulic retention time (HRT) of 4h, influent COD of 6000mg/L, the maximum hydrogen production was up 12.06L/d. In addition, though pH decreased to 3.42, the microbial growth still high and COD removal rate reached 50%, demonstrating that the reactor processed the ability of acid resistance.

Abstract: Surface plasmon resonance (SPR) biochemical analysis system began to be developed from the detection and analysis of molecular interactions to the ligand/cell interactions, cell/cell contacts, or cellular reactions. Cells needed be immobilized on the SPR chips based on the penetration depth of surface plasma waves. However it is not easily to fix suspension cells on the bare gold chips. In this paper, an effective method has been developed to immobilize yeast cells on the SPR chip based on a nanoSiO₂ film which was chemically modified. The sensitivity of the SPR chip with a nanoSiO₂ film is 6×10^-7 refractive index unit (RIU), which could meet different applications including cell detection. The whole procedure of cell immobilization has been measured in a lab-free and real-time mode by using our home-made SPR instrument. From the experimental results, the change of the SPR signal of the SPR chip with a modified nanoSiO₂ film is 2.83 times of the bare SPR chip. That means the cell immobilization capability of the modified SiO₂-coating SPR chip is much stronger than that of the bare gold SPR chip, which was also proved by using a microscope. Yeast cells can be effectively fixed on the SPR chip and their immobilization process could be monitored, which hold great potential for the immobilization, detection and further analysis of other suspension cells, such as blood cells.

Abstract: Fabrics provide an attractive alternative for cell immobilization carrier. In this study, the relationship of weave structure of fabrics and the effects of cell immobilization was investigated. Several kinds of fabrics with different weave structure were designed and produced acting as cell immobilization carrier. Adsorptive capacity of the textile carriers with different weave structure was measured and the biodegradation rate of TA by cells absorbed on textile carriers was also investigated. It is showed that adsorptive capacity and stability was significantly affected by weave structure of fabric carriers. The result also indicated that the ability to TA degradation was also improved by cell immobilization.

Abstract: The main purpose of the present work is the sol-gel synthesis, structure and application of hybrid inorganic–organic hybrids based on different silica precursors and addition of the organic compound sepharose (SP). The structural evolution of the hybrid materials containing different amounts of SP is examined. Formation of silica nanocomposites by self-assembling processes was studied by AFM and roughness analysis. The average size of nanoparticles on the sample surface is about 7 to 14 nm and the formation of their self-organized structures is observed. The hybrids are used for immobilization of bacterial cells, producers of thermostable nitrilase. The biocatalysts show good operational stability for a long period-18 days, as well as high thermostability. The degradation capability is greater for the encapsulated cells in the hybrid matrix with 5% SP.

Abstract: Alginate was shown to be a suitable support for entrapment and cultivation of chondrocytes and bone marrow stromal cells, which under appropriate in vitro conditions synthesized cartilaginous components. The main limitation in these cultures may be low rates of mass transport through the alginate matrix governed by diffusion. In this study, we have designed and utilized a bioreactor system based on a packed bed of alginate beads with immobilized chondrogenic cells. Continuous medium perfusion provided convective mass transport through the packed bed, while small diameters of beads (2.5 mm and down to 500 μm) ensured short diffusion distances to the immobilized cells. During up to 5 weeks of cultivation, the cells synthesized extracellular matrix components merging beads together and indicating potentials of this system for precise regulation of the cellular microenvironment in cartilage tissue engineering.