Preparation And Investigation On Bacteria-loaded Electrospun Fiber

Using bacteria for the treatment of tumor has been an effective way of anti-tumor treatment since traditional methods are difficult to overcome shortcomings of cancer therapy, such as severe adverse reaction, high cost and incomplete anti-tumor effect. However, the use of bacteria to treat cancer often causes undesirable and unpredictable side effects because most existing antitumor bacteria itself are toxic. Even using probiotics, such as Escherichia coli Nissle 1917, also has a lot of shortcomings since some of the bacteria are not colonize in tumor tissues but in other normal organs of the body which can aggravate the aseptic burden of other organs and cause adverse effects by using antibiotics to kill excess bacteria. This study aims to immobilize bacteria in electrospun fiber membrane to avoid the harm and burden caused by free bacteria to the body during using bacteria for tumor treatment. Therefore, this study examines the influence of different immobilizing ways on the bacteria growth and function.It is difficult to investigate the effects of electrospinning process on bacteria entrapped in fibers of water-insoluble polymers since bacteria is hard to move out of the confined space for detection. In this study we added sodium chloride particles in the outer solution of coaxial electrostatic spinning to produce pores within the fibers. After immersing the fibers in water, bacteria were available to be detected by Alamar Blue. This study, for the first time, evaluated the viabilities of bacteria immobilized in water-insoluble electrospun fibers. The results show that bacteria could maintain 48% viability in electrospun fiber still have the ability to reproduce and express protein. But the reproducing ability and protein expression ability of bacteria decreased with the increase of incubation time due to the limited space within fibers.This study investigated the bacteria immobilization on fibers through covalent grafting and affinity adsorption. The results shows that the covalent grafting process and affinity adsorption process did not affect the activity of bacteria; Bacteria proliferation and protein expression were not affected obviously by the two methods. The reproduce ability of bacteria returned to normal level after five reproducing batches.