Random Peptide Mixtures Entrapped in Metals: New Nanocomposites to Fight Antibiotic Resistant Bacteria

Resistance to antibiotics is a serious worldwide crisis that possess the challenge of development new bacteriocide materials to tackle it. Antimicrobial random peptide mixtures designed in inspiration of natural antimicrobial peptides (AMPs) as they share characteristics of short chain length and presence of hydrophobic and cationic amino acids in binary ratio. A novel materials methodology, denoted dopant@metal, enables the incorporation and entrapment of small organic molecules within metals. The resulting material is of molecules entrapped within agglomerated nanocrystals that have synergistic activity, which was more than the sum of the individual properties of the two components. The aim of current study is to unite both concepts; i.e. entrapment of random peptide mixtures in copper, in order to generate new material that will have highly synergistic antimicrobial effect and shared potential for dealing with resistant bacteria strains in health and agriculture. Leucine-lysine peptide mixtures were entrapped in a copper by reduction with zinc for generating LK@Cu composite. The LK@Cu exhibited synergism in its antimicrobial effect, proving to be better than metallic copper (Cu⁰) or the leucine-lysine peptide mixture individually against the important pathogen methicillin resistant Staphylococcus aureus.