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Globally, approximately a billion patients are estimated to suffer from neurological disorders. Although there are many therapeutic candidates for the central nervous system, treatment of brain disorders is restricted by the blood-brain barrier (BBB), which is a highly selective membrane that protects the brain from exogenous substances. This study was undertaken to develop a novel strategy to overcome the BBB and improve the efficiency of drug delivery to the brain by mechanical load increase using hypergravity. Human cerebral microvascular endothelial cells were exposed three times to 20 min hypergravity (10g), with a 20-min rest period between each exposure. The applied hypergravity reversibly decreased the cellular metabolic activity and increased the permeation rate of fluorescein sodium salt, fluorescein isothiocyanate-labeled dextran (FD-4), and fluorescein-labeled jacalin. Following the exposure to hypergravity, we also observed structural changes of the cytoskeleton and tight junctions, and an alteration in the expression levels of related genes. These results indicate that increased mechanical load due to the applied hypergravity affects the cytoskeletal arrangement and tight junctions, thereby weakening the cell barrier function and enhancing the permeability of the paracellular pathway. Thus, the mechanical load increase by hypergravity has the potential of being used as a novel strategy to overcome the BBB for brain drug delivery.

Objectives/hypothesis This study was conducted to provide a vibrational culture model to investigate the effects of mechanical environments on cellular functions, and elucidate physiological characteristics of two different types of cells in vocal folds under static and vibrational conditions. Study design In vitro study of human vocal fold fibroblasts (hVFFs) and human macula flava stellate cells (hMF-SCs). Methods hVFFs and hMF-SCs were exposed to a 2-second-on/2-second-off, 205 Hz vibration regime for 4 hours by using a vibrational culture model. We compared cell morphology, cell viability, and gene expression in extracellular matrix-related components, growth factors, and differentiation markers under static and vibratory conditions. Results hVFFs and hMF-SCs differed in their morphologies and gene expression levels under static condition. The applied vibration did not induce changes in morphology and viability of either cell type. However, gene expression levels changed in both cell types in response to vibration; in particular, hMF-SCs exhibited a more sensitive response to vibration than that shown by hVFFs. Conclusions The vibrational culture model developed in this study enabled us to investigate the effects of the applied vibration on two types of vocal fold resident cells. As a result, we could demonstrate that hVFFs and hMF-SCs exhibited distinctively different characteristics under vibrational conditions. Level of evidence NA. Laryngoscope, 128:E258-E264, 2018.

Recombinant Escherichia coli was cultured up to OD600 90 with glycerol fed by the DO-STAT method to produce recombinant beta-lactamase. Optimum feeding and induction conditions were determined. When glycerol was maintained at a high concentration (40-50 g/L) after isopropyl thiogalactoside (IPTG) induction at OD600 75, a 2-fold increase in the amount of soluble beta-lactamase was obtained. Similarly, a 3-fold increase was obtained by the addition of NaCl (0.4 M) at low glycerol concentration (10 g/L).