Biocomposites of Silk-Elastin and Essential Oil from Mentha piperita Display Antibacterial Activity

Diana S Gomes; André da Costa; Ana Margarida Pereira; Margarida Casal; Raul Machado

doi:10.1021/acsomega.1c05704

Biocomposites of Silk-Elastin and Essential Oil from Mentha piperita Display Antibacterial Activity

ACS Omega. 2022 Feb 15;7(8):6568-6578. doi: 10.1021/acsomega.1c05704. eCollection 2022 Mar 1.

Authors

Diana S Gomes^{1

2}, André da Costa^{1

2}, Ana Margarida Pereira^{1

2}, Margarida Casal^{1

2}, Raul Machado^{1

2}

Affiliations

¹ CBMA (Centre of Molecular and Environmental Biology), Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
² IB-S (Institute of Science and Innovation for Sustainability), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.

Abstract

In this study, novel antimicrobial biocomposite films comprising a genetically engineered silk-elastin protein polymer (SELP) and essential oil from Mentha piperita (MP_EO) have been fabricated and tested for the antibacterial performance. SELP/MP_EO biocomposite films were prepared by solvent casting using water as the solvent and aqueous emulsions of MP_EO at different concentrations. Emulsions of MP_EO were investigated, showing that the mixing method, relative amount of surfactant, and the presence of SELP influence particle size and homogeneity. The aqueous emulsions of SELP/MP_EO were characterized by a population of particles between 100 and 300 nm, depending on the MP_EO concentration. The emulsified oil droplets at the highest concentration showed to be homogeneously distributed into the SELP matrix and demonstrated antibacterial activity against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Moreover, the antibacterial activity of the biocomposite films was retained after a period of storage for 7 days at 4 °C. The formulation of composites comprising natural active fillers and recombinant protein polymers opens opportunities to develop new green, functional biocomposite materials, paving the way for a new generation of multifunctional materials.