Here we describe a stoichiometric ion-complex of archaeal poly-γ-L-glutamate (L-PGA) and hexadecylpyridinium cation (HDP(+)), called PGAIC, which shows remarkable chemical resistance and potential as a novel functional thermoplastic. PGAIC films suppressed the proliferation of prokaryotic (Escherichia coli, Bacillus subtilis, Salmonella typhimurium, and Staphylococcus aureus) and eukaryotic (Saccharomyces cerevisiae) microorganisms. Moreover, its antifungal activity was demonstrated against a prevalent species of Candida (Candida albicans) and a filamentous fungus (Aspergillus niger). The minimal inhibitory concentrations were estimated as 0.25 mg mL(-1), and zones of growth inhibition appeared when PGAIC-coated polyethylene terephthalate (PET) films were placed in culture plates, whereas PET had very little effect on fungal growth. Soluble PGAIC thus shows promises as an antimicrobial and as a coating substrate. We also succeeded in synthesizing an L-PGA-based nanofiber using an ethanol solution of PGAIC.

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UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/, UMIN000001798.

The successful treatment of a very rare case of multiple carpal bone fractures in a child is described. Fractures of the scaphoid, the capitate, and the hamate were treated with wire fixation, leading to good clinical results twenty-nine months after surgery.