The search for advanced materials, especially for those bioinspired, has recently been the focus of
great research in many fields of application. Due to recent advances in materials characterization and
fabrication technologies, and especially through the use of synthetic biology approaches, it is now
possible to reengineer novel functionalities and structures of protein-based materials, taking advantage
of their extreme versatility and applicability.
Antimicrobial peptides (AMPs) are small molecules that occur as part of the innate defense mechanism
in many organisms, even in microbes and virus. The combination of AMPs with recombinant protein-based polymers can be explored for the development of advanced medical devices, to overcome
infections and biofilm formation. In this work, we describe the design, biolog ical production and
processing of a protein-based-polymer comprising a functional domain based on a synthetic cationic
AMP, fused in frame with an elastin-like-polymer consisting of 200 repeats of VPAVG (A200), as
structural unit. The functionalized protein-based-polymer was produced in Escherichia coli and further
purified by exploring the thermoresponsiveness property of poly-VPAVG.
Free standing films, especially thinking in downstream processing for application as thin film coating of
medical devices, were obtained by solvent-cast. The antibacterial and antifungal activities of cast films
were tested against different bacterial and fungal species, both in vitro and ex vivo. The recombinant
AMP:A200 biopolymer showed high growth inhibition against a wide range of bacterial species, both
gram positive and negative, and yeast species. The antimicrobial activity was time dependent of
exposition and remarkably, in some bacterial species, almost 100% of cell death was detected after 30
minutes of cell suspension in contact with cast films.This work was financially supported Portuguese funding from FEDER through POFC – COMPETE and PEst project C-BIA-UI4050-2011 (Portugal). AC and RM acknowledge FCT for SFRH-BD-75882-2011 and SFRH-BPD-86470-2012 grants, respectively
