Protein-engineered polymers functionalized with antimicrobial peptides for the development of active surfaces

Antibacterial resistance is a major worldwide threat due to the increasing number of infections caused by antibiotic-resistant bacteria with medical devices being a major source of these infections. This suggests the need for new antimicrobial biomaterial designs able to withstand the increasing pressure of antimicrobial resistance. Recombinant protein polymers (rPPs) are an emerging class of nature-inspired biopolymers with unique chemical, physical and biological properties. These polymers can be functionalized with antimicrobial molecules utilizing recombinant DNA technology and then produced in microbial cell factories. In this work, we report the functionalization of rPBPs based on elastin and silk-elastin with different antimicrobial peptides (AMPs). These polymers were produced in Escherichia coli , successfully purified by employing non-chromatographic processes, and used for the production of free-standing films. The antimicrobial activity of the materials was evaluated against Gram-positive and Gram-negative bacteria, and results showed that the polymers demonstrated antimicrobial activity, pointing out the potential of these biopolymers for the development of new advanced antimicrobial materials. This work was supported by the “Contrato-Programa” UIDB/04050/2020, project FunBioPlas (ERA-IB-2-6/0004/2014) and project FUN2CYT (POCI-01-0145-FEDER-030568) funded by Portugal national funds through the Fundação para a Ciência e a Tecnologia (FCT I.P.). A.M.P. acknowledges the Doctoral Programme in Applied and Environmental Microbiology (DP_AEM) and FCT I.P. for the PD/BD/113811/2015 grant. R.M. acknowledges FCT I.P. for funding in the scope of the Scientific Employment Stimulus instrument (CEECIND/00526/2018).