STM Article Repository

The capacity to load bacteriophages into electrospun nanofibers of two representative biocompatible
polymers has been evaluated, paying special attention to the possibility of preserving their
antibacterial activity. Specifically, the work involves the following steps: (a) Evaluation of the effect of
the applied electrical field on the phage activity; (b) evaluation of the activity when a lyophilization
process could be avoided by using water soluble polymers (e.g., poly(ethylene glycol); (c) evaluation
of the activity when dissolution of the polymer requires an organic solvent and lyophilization is
theoretically necessary. In this case, a poly(ester urea) (PEU) derived from the natural L-leucine
amino acid has been considered. Adsorption of commercial bacteriophage preparations into calcium
carbonate particles was demonstrated to be a promising methodology to avoid lyophilization and keep
the initial bactericide activity at a maximum. Phagestaph and Fersis bacteriophage commercial
preparations have been selected for this study due to their specific activity against Staphylococci
(e.g., S. aureus) and Streptococci (e.g., S. pyogenes) bacteria. Adhesion and proliferation assays
using epithelial cells demonstrated the biocompatibility of both unloaded and bacteriophage-loaded
PEU scaffolds, although some slight differences were observed depending on the type of
bacteriophage and the selected preparation methodology.