179Fig. 9.6 Primary culture
of macula flava with
MF-start primary culture
medium (Toyobo, Osaka,
Japan) (Phase-contrast
microscopy). Two types of
cells, cobblestone-like
squamous cells and
fibroblast-like spindle
cells, grow from the
macula flava fragments in
the primary culture
Fig. 9.5 Transmission electron micrograph of a vocal fold stellate cell in the human macula flava
(uranyl acetate and lead citrate stain). Vocal fold stellate cells are stellate in shape and possess
slender cytoplasmic processes. They possess vitamin A-storing lipid droplets and intracellular
organelles such as rough endoplasmic reticulum and Golgi apparatus
clearly delineated. Additionally, most of the cells in the maculae flavae express
CD44 (cell surface hyaluronan receptors) (Fig. 9.8). This indicates that the human
maculae flavae are hyaluronan-rich pericellular matrix (Sato et al. 2012b).
Since the cells in the human maculae flavae have cell surface hyaluronan recep-
tors and are surrounded by a high concentration of hyaluronan (Sato et al. 2012b),
9 The Macula Flava of the Human Vocal Fold as a Stem Cell Microenvironment