Em. Ehlers et al., Effects of hyaluronic acid on the morphology and proliferation of human chondrocytes in primary cell culture, ANN ANATOMY, 183(1), 2001, pp. 13-17
Hyaline articular cartilage is a specialised connective tissue with weight
bearing and adsorbing functions. Injury or loss of which often leads to imp
aired joint function and severe pain. Since the self-renewing abilities of
hyaline articular cartilage are limited, there is major interest in the dev
elopment of bioengineered cartilaginous implants. A cell-matrix-biocomposit
e composed of a collagen I/III scaffold seeded with autologous chondrocytes
is currently being used in clinical trials; however, in order to optimise
culture conditions, we cultured human condrocytes and seeded them on type I
/III collagen membranes and on Thermanox plastic coverslips with media cont
aining 0 to 500 mug/ml Hyaluronic Acid. After 4 days, the cells were either
fixed or BrdU incorporation procedures begun. HE staining clearly demonstr
ated that cells grown in HA form three dimensional clusters and produce sec
retory vesicles as opposed to the monolayer control cells with noticeably f
ewer secretory vesicles. BrdU incorporation revealed a noticeable increase
in cell proliferation in cells grown in 100 mug/ml; however, no comparable
increase in 500 mug/ml but rather a slight depression in proliferation. Imm
unohistochemistry for collagen II and aggrecan revealed an obvious increase
in deposition of these two substances with increased HA administration as
compared to the control: however, again, the higher concentration of HA, 50
0 mug/ml, did not result in a further increase in production. These results
suggest that HA at 100 mug/ml not only influences chondrocytes to differen
tiate and produce more Collagen II and aggrecan, but also increases prolife
ration. We, therefore, propose that the addition of HA at low to middle dos
ages in condrocyte culturing might help improve condrocyte redifferentation
and thus, the bioengineered cartilage.