Co-electrospinning of bacteria and viruses

Co-electrospinning provides a novel and highly versatile approach towards composite fibers with diameters ranging from a few hundred nm down to 30 nm with embedded elements. In the present work, co-electrospinning of poly(vinyl alcohol) (PVA) and viruses \textit{(T7, T4, $\lambda $}) or bacteria (\textit{Escherichia coli}, \textit{Staphylococcus albus}) was carried out. These preparations should have applications for tissue engineering, gene therapy, phage therapy and biosensing. The average diameter of the co-spun nanofibers was about \textit{300 nm}. We found that the encapsulated viruses and bacteria manage to survive the electrospinning process, its pressure buildup in the core of the fiber and the electrostatic field in the co-electrospinning process. Approximately 10{\%} of the \textit{Escherichia coli} and 20{\%} of \textit{Staphylococcus} \textit{albus }cells are viable after spinning. Approximately 5{\%} of the bacterial viruses were also viable after the electrospinning. It should be noted that the encapsulated cells and viruses remain stable for two months without a further decrease in number. These results demonstrate the potential of the co-electrospinning process for the encapsulation and immobilization of bio-objects and the possibility of adapting them to technical applications (e.g., bio-chips).