Hyaluronic acid (HA) is a linear non-sulphated glycosaminoglycan, used in dermatology as a
biomaterial for bioengineering purposes, temporary dermal filler, stimulation of wound healing
as well as drug vehicle in topical formulations. In addition to the well-characterized
structural properties, extensive research on HA has revealed a range of vastly immunemodulatory
effects, dependent on its size. In this in vitro study we investigated the ability of
HA-S3, a small fragment HA (MW, molecular weight: 68 kDa) with degree of sulphatation
of 3 and of HA fraction (MW:210 kDa) to reduce the bacterial induced inflammatory response
in spontaneous immortalized keratinocytes. To this purpose, HaCaT cells were treated for
24 hours with 25 µg/ml of E. Coli derived bacterial lipopolysaccharide (LPS) in absence or
presence of small fragment HA-S3 or HA. Cell viability was thereafter assessed using trypan
blue stain and interleukin (IL)-8, IL-1β and tumor necrosis factor alpha (TNF-α) concentrations
were determined in cell supernatants by single enzyme-linked immunoadsorbent assay
(ELISA). Our results showed that cell viability was not affected either by HA-S3 or HA which
in turn were able to reduce LPS-induced mortality. HA and especially HA-S3 were able to
significantly reduce LPS-induced pro-inflammatory cytokines. Our observation might suggest
new perspectives in the development of HA-S3 containing topical products able to modulate
cutaneous inflammatory response