Encapsulation Of Cellswithin Electrospun Fibers And Its Applications

Successful microbial cells immobilization is of interest for a wide variety ofbiotechnological applications such as biological fuel cell, food engineering,environmental pollution improvement, fermentation engineering, and regenerativemedicine and so on. Comparing with the conventional immobilization methods,electrospinning is an effective processing method for fabrication of biohybridnanofibers. Biohybrid materials prepared by electrospinning technology have highspecific surface area, high porosity, continuous3D frameworks, high mechanical andchemical stability, and good biocompatibility compared with conventionalimmobilization technologies.Here we choose the synechococcus7942as immobilization object and PVPmodified PVA as immobilization matrix to investigate the method of fabrication ofbiohybrid fibers by electrospinning technology. Our method is achieved by theeffective immobilization of synechococcus cells through the modified polymer PVAPwhich provides a stable microenvironment for cell growth. Thus, this method couldenhance cells stability and activity to resist the abrupt environmental changes andprolong the life time of cells in complex environments.In this thesis, we first introduce the processes and features in electrospinningimmobilization of microbial cells, followed by elaborating the fabrication ofbiohybrid materials by electrospinning technology as well as the growth status of theimmobilized cells in different concentration ratio of synechococcus cells to modifiedpolymer. Though the measurement of field emission scanning electron microscope,the fluorescent electronic microscope and liquid oxygen electrode system, wedemonstrate that the spinning solution contained8-10%PVA can be well used tofabricate cell hybrid fibers with structural regularity as well as good dispersity of cell.We also find that the algae additives have a very limited influence on cell dispersityin the hybrid fibers. Finally, we one-step fabricate the biohybrid materials by coaxialspinning method without mixing of synechococcus cell and modified PVA in advance.The activity of the immobilized synechococcus cells (29days) has been obviouslyenhanced comparing with synechococuus cells in natural environment (2days) and cells in simple hybrid fibers (19days). The immobilized synechococcus cells exhibithigh activity (29days) in fiber.Moreover; the immobilized synechococcus cells couldstill maintain73%and62%activities in the solution of BG11after7h when the pHis4and10, respectively.