The increase in infections derived from biofilms from Staphylococcal spp. prompted us to develop novel strategies to inhibit biofilm development. Nanoscale protrusion structures (nanopillars) observed on the wings of dragonflies and cicadas have recently gained notable attention owing to their physical, antimicrobial, and bactericidal properties. Thus, they are not only expected to reduce the damage caused by chemical antimicrobial agents to human health and the environment, but also to serve as a potential countermeasure against the emergence of antimicrobial-resistant bacteria (ARB). In this study, we evaluated the anti-biofilm effects of cyclo-olefin polymer (COP) nanopillars by changing the wettability of surfaces ranging in height from 100 to 500 nm against Staphylococcus spp., such as Staphylococcus aureus NBRC 100910 (MSSA), Staphylococcus aureus JCM 8702 methicillin-resistant S. aureus (MRSA), and Staphylococcus epidermidis ATCC 35984. The results clearly show that the fabricated nanopillar structures exhibited particularly strong biofilm inhibition against MRSA, with inhibition rates ranging from 51.2% to 62.5%. For MSSA, anti-biofilm effects were observed only at nanopillar heights of 100–300 nm, with relatively low hydrophobicity, with inhibition rates ranging from 23.9% to 40.8%. Conversely, no significant anti-biofilm effect was observed for S. epidermidis in any of the nanopillar structures. These findings suggest that the anti-biofilm properties of nanopillars vary among bacteria of the same species. In other words, by adjusting the height of the nanopillars, selective anti-biofilm effects against specific bacterial strains can be achieved.

Cutibacterium acnes is abundant and commonly exists as a superficial bacteria on human skin. Recently, the resistance of C. acnes to antimicrobial agents has become a serious concern, necessitating the development of alternative pharmaceutical products with antimicrobial activity against C. acnes. To address this need, we evaluated the antimicrobial activity of CKR-13—a mutant oligopeptide of FK-13 with increased net charge and theoretical α-helical content—against C. acnes in modified Gifu Anaerobic Medium broth by determining the minimum inhibitory concentration (MIC). CKR-13 exerted greater antimicrobial activity against C. acnes than FK-13 in the broth at pH 7.0. The antimicrobial activity of CKR-13 with RXM against C. albicans was pH-dependent. The ionization of CKR-13 and pH-dependent growth delay of C. albicans was suggested to be associated with the increase in CKR-13 antimicrobial activity.

Various methods have been proposed to memorize the structures of hexoses and pentoses, but none have been widely accepted. Hexoses are classified into four types based on two factors: (1) the combination of hydroxyl group orientations at positions C-2 and C-5, and (2) the symmetry of hydroxyl group orientations from C-2 to C-5. These four types were visualized in a four-part matrix referred to as the "Kiryu Hexose Matrix." This matrix enables the easy and comprehensive identification of the epimeric relationships among aldohexoses and ketohexoses. Furthermore, the matrix can identify hexoses with multiple epimerized hydroxyl groups. This matrix facilitates the derivation of all aldohexose structures based on differences from d- and l-allose, whose C-2 to C-5 hydroxyl groups face right or left, respectively. Ketohexose structures can also be derived. Aldose derivatives with identical functional groups at both ends, such as sugar alcohols, form a synonym pair, which can also be systematically identified using the matrix. Similarly, a corresponding matrix, the "Kiryu Pentose Matrix," can be constructed. By combining Izumoring, a comprehensive diagram of hexose transformations, with the hexose matrix, we were able to incorporate an epimerization-induced model. This model is called the "Izumori-Kiryu matrix." Additionally, we propose a new representation for saccharides using matrices, called the δ/λ-representation. The method easily represents complex saccharide structures with multiple synonyms and comprehensively identifies all synonyms without omission.