Honeybee wings hold antibiofouling and antimicrobial clues for improved applications in health care and industries

Abstract

Natural surfaces with remarkable properties and functionality have become the focus of intense research. Heretofore, the natural antimicrobial properties of insect wings have inspired research into their applications. The wings of cicadas, butterflies, dragonflies, and damselflies have evolved phenomenal anti-biofouling and antimicrobial properties. These wings are covered by periodic topography ranging from highly ordered hexagonal arrays of nanopillars to intricate "Christmas-tree" like structures with the ability to kill microbes by physically rupturing the cell membrane. In contrast, the topography of honeybee wings has received less attention. The role topography plays in antibiofouling, and antimicrobial activity of honeybee wings has never been investigated. Here, through antimicrobial and electron microscopy studies, we showed that pristine honeybee wings displayed no microbes on the wing surface. Also, the wings displayed antimicrobial properties that disrupt microbial cells and inhibit their growth. The antimicrobial activities of the wings were extremely effective at inhibiting the growth of Gram-negative bacterial cells when compared to Gram-positive bacterial cells. The fore wing was effective at inhibiting the growth of Gram-negative bacteria compared to Gram-positive samples. Electron microscopy revealed that the wings were studded with an array of rough, sharp, and pointed pillars that were distributed on both the dorsal and ventral sides, which enhanced anti-biofouling and antimicrobial effects. Our findings demonstrate the potential benefits of incorporating honeybee wings nanopatterns into the design of antibacterial nanomaterials which can be translated into countless applications in healthcare and industry.

Keywords: anti-biofouling; antimicrobial; bacteria; honeybee; wings; workers.

Figure 1.. Forewing and hindwing of a worker honeybee (Apis mellifera). Images of the forewing (A) and hindwing (B).

Figure 2.. Scanning electron microscopy (SEM) of dorsal surface of a worker honey bee (Apis mellifera) fore wing (A; B; C) and hind wing (D; E; F) surface topography at different magnifications: (A and D) at x 25; (B and E) at x 75 and (C and F) at x10000.

Figure 3.. Antimicrobial efficacy of a worker honeybee (Apis mellifera) wings against bacteria. (A) Klebsiella pneumoniae; (B) Escherichia coli; (C) Staphylococcus aureus, and (D) Micrococcus luteus.

Figure 4.. Viable cell number reduction of bacteria, expressed as log10 cfu/mL, after overnight exposure to honeybee worker wings.

Figure 5.. SEM images of forewings exposed to (A) E. coli and (B) S. aureus.