Induced death of Escherichia coli encapsulated in a hollow fiber membrane as observed in vitro or after subcutaneous implantation.

The encapsulation of bacteria may be used to harness them for longer period of time in order to make them viable, while antibiotic treatment would result in controlled release of therapeutic molecules. Encapsulated bacteria Escherichia coli GFP (green fluorescent protein) (E. coli GFP) were used here as a model for therapeutic substance - GFP fragments release (model of bioactive substances). Our aim was to evaluate the performance of bacteria encapsulated in hollow fibers (HF) treated with antibiotic for induction of cell death. The polypropylene surface modified HF was applied for E. coli encapsulation. The encapsulated bacteria were treated with tetracycline in vitro or in vivo during subcutaneous implantation into mice. The HF content was evaluated in flow cytometer, to assess the bacteria cell membrane permeability changes induced by tetracycline treatment. It was observed that applied membranes prevent release of bacteria through the HF wall. The encapsulated in HF E. coli GFP culture in vitro proves the tetracycline impact on bacteria viability and allows recognition sequence of events within process of bacteria death. Treatment with tetracycline of the SCID mice for 8 hours proves the tetracycline impact on bacteria viability in vivo, rising the necrotic bacteria releasing GFP fragments. It was concluded, that the bacteria may be safely enclosed within the HF at site of implantation, and when the animal is treated with antibiotic bacteria may act as a local source of bioactive factor.