We developed a novel cultivating system for hollow-type spherical bacterial cellulose (HSBC) gel production without any molds or template. It consisted of floating aqueous medium droplet containing Gluconacetobacter xylinus (G. xylinus) at the boundary of two non-mixed silicone oil layers. The fibrils of bacterial cellulose (BC) were produced at the interface of water and oil phases. Fibril layers effectively thickened layer-by-layer and eventually formed a shell structure. The size of the HSBC gel can be controlled by the volume of dropped cell suspension. For cell suspensions of 50 μL and 10 μL, HSBC gels of approximately 4.0 mm and 2.5 mm were obtained, respectively. The shell of the HSBC gel is the gelatinous membrane formed by well-organized fibril networks; they comprised type-I crystal structure of cellulose. Additionally, we studied release profile of the fluorescein isothiocyanate-dextran (FITC-Dex) and observed that it released rapidly from the HSBC gels compared to from the BC gels obtained by the static culture method. The release behavior from HSBC gel agreed satisfactorily with Higuchi model. Therefore, the shell of HSBC gel is surely a thin gelatinous membrane of BC, and would be useful as a drug release device.

Neonatal mitochondrial disease is occasionally observed in patients with intraventricular cysts in the brain. Atypical morphology is rarely seen in these cysts. Here, we report a case of neonatal lethal mitochondrial disease with IBA57 gene mutation. We have, for the first time, described a subependymal pseudocyst (SEPC) with a fluctuating membrane. Our findings suggest that SEPCs with fluctuating membranes can be a potential diagnostic indicator of neonatal mitochondrial disease.