Journal of Cosmetics, Dermatological Sciences and Applications, 2013, 3, 124-128
http://dx.doi.org/10.4236/jcdsa.2013.31019 Published Online March 2013 (http://www.scirp.org/journal/jcdsa)
Hyaluronate Increases Polynucleotides Effect on Human
Cultured Fibroblasts
Stefano Guizzardi1, Jacopo Uggeri1, Silvana Belletti1, Giulia Cattarini2
1Department of Biomedical Biological and Tranlational Sciences (S.Bi.Bi.T.), University of Parma, Parma, Italy; 2Mastelli Research
Lab, Sanremo, Italy.
Received February 6th, 2013; revised March 1st, 2013; accepted March 8th, 2013
ABSTRACT
The HA is present in almost all vertebrates and plays a critical role in tissue development and cell proliferation, it has
been demonstrated to promote wound healing and involved in angiogenesis and inflammation. Also polynucleotydes
(PN) have proved to promote the “in vitro” growth and activity of human fibroblasts and osteoblasts, to increase repara-
tion on UVB damaged dermal fibroblasts and seems to promote proliferation of human pre-adipocytes. Several in vivo
studies have demonstrated the PN effect also in vivo, inducing an increase of angiogenesis and healing process. In this
paper we have evaluated the effect of a mixture of Polynucleotides (PN) and entire Hyaluronic Acid (HA) on cultured
human fibroblasts by analyzing cell growth. Different mixture have been tested and it has been demonstrated that the
presence of HA even at low concentration (1 mg/ml) determine an increase of PN activity up to 20%. Furthermore, the
addition of HA 1 mg/ml to PN 100 μg/ml induces a cell growth rate comparable to that exerted by PN concentration of
12 μg/ml.
Keywords: Polynucleotides; Fibroblasts; Hyaluronate; Dermal Regeneration
1. Introduction
Large body of evidence supports the concept of critical
role of microenvironment in cell behavior, in fact the
area around cells plays an important action in normal
tissues, regulating growth factor concentration, nutrients
supply and maintaining an intense cross-talk between
cells. During the tissue development, this carefully or-
ganized microenvironment changes its functions’ modi-
fying specifically. Microenvironment is a complex struc-
ture constituted by a milieu of molecules accounting pro-
teins as collagens, fibronectin, elastin, DNA fragments
and complex polysaccharides as proteoglycans and hya-
luronan (HA).
A source of DNA fragments may be considered Poly-
deoxyribonucleotide (PN). PN is a compound that, acting
through adenosine receptors, determines different effects
on mesenkymal derived cells. Thellung e coll and Sini e
coll [1,2] firstly have demonstrated that PN enhance
pro-liferation of human fibroblasts and the involvement
of purinergic A2 receptors. Some other authors have
studied the effect of PN both in in vitro and in vivo: PN
have been demonstrated to promote the growth of human
corneal fibroblasts [3] and osteoblasts [4], to increase
reparation on UVB damaged dermal fibroblasts [5] and
seems to promote proliferation of human pre-adipocytes
[6]. Numerous in vivo studies have demonstrated the
PDRN effect on patients undergoing skin explants [7] or
a fast corneal epithelisation after photorefractive kerato-
tomy [8]. PN have been also tested in osteorepair [9,10],
demonstrating an increase of healing process. Finally
polynucleotide has been demonstrated to stimulated wound
healing and angiogenesis inducing an increase of VEGF
production during pathologic conditions of low tissue
perfusion such as diabetes mellitus and thermal injury
[11-13].
PN is the active fraction of a preparation used in ther-
apy as an agent to stimulate tissue repair and is extracted
from the sperm of trout bred for human consumption.
The drug is obtained by an extraction process with pu-
rifying and high temperature sterilizing procedures to
obtain a 95% pure active principle without pharmaco-
logically active proteins and peptides. This compound
holds a mixture of deoxyribonucleotides polymers with
chain lengths ranging between 50 and 2000 bp and may
also represent the source of purine and pyrimidine de-
oxynucleosides/deoxyribonucleotides and bases.
HA is present in almost all vertebrates and plays a
critical role in tissue development and cell proliferation
[14]. HA is a non sulphated and non branched polysac-
charide, constituted by thousand of disaccharide units (it

Hyaluronate Increases Polynucleotides Effect on Human Cultured Fibroblasts 125
contains up to 25,000 disaccharide units of glucuronic
acid and N-Acetil-glucosamine), reaching million Dal-
tons in weight. Hyaluronan is important in tissue deve-
lopment and repair, it regulates water content and mo-
lecular trafficking forming a gel with specific viscoelas-
tic properties. The discovery of several HA cell receptors
and several interactions of this polymer with other ex-
tracellular molecules, including the role of hyaluronan
oligos in inflammation and angiogenesis, induced the
scientific community to reconsider the biological role of
this polysaccharide. HA is produced by cells throughout
the activity of three Hyaluronic Acid Synthases (HAS1, 2
and 3), membrane enzymes which produce the polymer
extruding the chain through the cell membranes. Extru-
sion of the growing HA chain extracellularly through the
plasma membrane permits unrestrained growth of the
polymer, so that it can reach 1000 - 10,000 kDa. Synthe-
sis of such an enormous polymer could not be possible
intracellularly.
The question why cell have three different enzymes
for the hyaluronan synthesis is still unknown. The three-
member HAS isoenzyme family, localized to three sepa-
rate chromosomes, was identified in human and mouse
genomes [15]. Sequence data indicate that there are se-
ven transmembrane regions, and that a central cytoplas-
mic domain contains consensus sequences that are sub-
strates for phosphorylation by protein kinase C [16].
HAS2 is also implicated in developmental and repair
processes involving tissue expansion and growth. HAS3
is the most active HAS enzyme, and drives the synthesis
of large amounts of lower MW HA chains. The products
of HAS3 may provide the pericellular glycocalyx and the
HA that interacts with cell surface receptors. Such short-
er HA chains may trigger cascades of signal transduction
events and major changes in cellular behaviour [17]. Our
studies suggested that the enzymes have different meta-
bolic regulation as well as produce polymers with dif-
ferent size (HAS2 produces HA of large size and HAS3
small size, HAS1 is active mainly in fetal stage). HAS2
and HAS3 are differently expressed in cancer cell lines,
and it was reported that HAS2 is more often related to
aggressive cancer and HAS3 to the less invasive form of
tumors [18]. Nevertheless the overexpression of HAS2
reduces the tumor growth maybe affecting the energy
availability of the cells [16]. HAS1-3 siRNA reduced the
cell motility in ovarian tumor cell lines altering cytos-
keleton framework.
Hyaluronan’s high capacity for holding water and high
viscoelasticity give it a unique profile among biological
materials and make it suitable for various medical and
pharmaceutical applications. We can find a variety of hy-
aluronan products in our daily life. For example, be-
cause it retains moisture, hyaluronan is used in some
cosmetics to keep skin young and freshlooking. Even
though hyaluronan is abundant in skin, as we age, the
waterholding ability of our skin’s hyaluronan is reduced
by depolymerization.
It is well recognized that there is an early accumula-
tion of HA in the wounded tissue [19,20] after wounding,
and also that the local concentration of HA in the wound
decreases within a few days, when instead there is an
increase in the concentration of sulphated glycosami-
noglycans. It is also recognized that the time pattern for
the increased HA concentration in the wound was sub-
stantially different in fetal and in adult wounds [21,22],
thus explaining the different behaviour of tissue repair in
adult and foetus [23].
Some authors reported that NaHA suppressed both the
production of free radicals and the reduction of pro-
teoglycan synthesis induced by IL-1beta in cultured bo-
vine articular chondrocytes [24], and it has been demon-
strated that NaHA of 900 × 103 average molecular weight
suppressed both the reduction of proteoglycan synthesis
induced by fibronectin fragments and subsequent carti-
lage degradation in vivo and in vitro [25]. HA moreover
determine a reduction of cartilage degradation, it has
been demonstrated that that expression of matrix metal-
loproteinase-3 (MMP-3) and IL-1beta were suppressed in
synovium but not in cartilage tissues of the rabbit ACLT
model by treatment with HA84, even though the sup-
pressive effect on the articular cartilage destruction was
still observed. This suggests that the suppression of the
destruction of articular cartilage is due in part to the sup-
pressive effect of NaHA on MMP-3 and IL-1beta ex-
pression in synovial tissue [26].
In this paper we have evaluated the possibility to sti-
mulate the growth of cultured dermal fibroblasts cre-
ating a synergic effect with the addiction of non frag-
mented HA to PDRN.
2. Material and Methods
We tested “in vitro” the effects of a mixture of short
chain polynucleotides (7.5 mg/ml) and a solution of hya-
luronic acid sodium salt (20 mg/ml).
Ha and PN were from Mastelli srl (Sanremo, Italy).
HA consists in pre filled syringe containing natural hya-
luronic acid of biotechnological origin, with a concentra-
tion of 20 mg/ml and molecular weight of 1000 Kda. PN
consists in pre filled syringe containing polynucleotides
7.5 mg/ml.
The compounds were tested onto culture of human der-
mal fibroblasts.
2.1. Cell Culture
Dermal fibroblast was obtained from skin biopsies of
young donor.
Cells was routinely grown in DMEM (Dulbecco Modi-

Hyaluronate Increases Polynucleotides Effect on Human Cultured Fibroblasts 126
fied Eagle Medium) (Lonza), with the addition of 10% of
FCS (Foetal Calf serum) (Lonza) and (Penicillin Strep-
tomycin, Sigma Aldrich) and maintained in modified at-
mosphere containing 5% of CO2 at 37˚C.
Cell for the experiment were from 4th to 9th passage in
vitro.
Twenty-four hours after seeding, cells were treated for
3 days with: PN alone, Hyaluronic acid alone or a mix-
ture of the 2 compounds at fixed doses and finally viabi-
lity/proliferation was tested using the MTT assay.
2.2. MTT Assay
The MTT assay was used to measure cell viability. Basi-
cally, the intact mitochondria reduce the yellow dye
tetrazolium salt (MTT) into blue formazan product. The
amount of formazan, produced by the mitochondrial de-
hydrogenase activity, was measured at 570 nm with a
microplate reader (Infinity F200, Tecan).
For these experiments dermal fibroblasts were seeded
(1 × 105 cells/well) onto 96-well plates and incubated for
3 days according with different experimental settings.
Assay was carried out according to Mosmann [27].
2.3. Images
Images of cell monolayer were collected with a Nikon
TMS phase contrast microscope equipped with a digital
camera (Digital sight DS-2Mv, Nikon). All shown im-
ages were acquired with a 20× objective.
3. Result and Conclusion
Proliferation and toxicity were evaluated with MTT as-
say.
Figure 1 shows the dose response effect (0 - 1600
µg/ml) of increasing doses of hyaluronic acid on prolif-
eration and viability of cultured dermal fibroblasts.
After 3 days of treatment, MTT assay shows a slight
increase of proliferation at the highest dose (1600 µg/ml)
Figure 1. Dose response effect (0 - 1600 µg/ml) of increasing
doses of hyaluronic acid on proliferation and viability of
cultured dermal fibroblasts. MTT assay was performed
after 3 days of treatment. Values represent the mean ± S.D.
of six wells.
and highlights the absolute absence of toxicity of this
compound at any proven dose.
Figure 2 shows the effect of increasing doses of a
compound containing a mixture of PN at same time (3
days of treatment). Proliferative activity of fibroblasts in-
creases in a dose-response manner with a maximal value
reached at the doses of 64 and 320 μg/ml (+14% above
control for both doses).
At the highest dose tested of 1600 µg/ml proliferation
seems to return to control level.
From these two experiment we concluded that the op-
timal doses to stimulate dermal fibroblast proliferation
was around 1 mg/ml for Hyaluronic acid while the opti-
mal range for PN in absence of any sign of cellular toxic-
ity was from 64 to 320 µg/ml.
On these bases we have tested a mixture of these
compound (PN and HA) to verify if the addition of Hya-
luronic acid can exert a favorable effect further improv-
ing proliferative activity of dermal fibroblast treated with
PN.
Figure 3 shows the results after 3 days of treatment.
The comparison between treatments with PN with or
without the addition of HA at the fixed dose of 1000
μg/ml indicates that the latter could further stimulate the
Figure 2. Dose response effect (0 - 1600 µg/ml) of increasing
doses of polynucleotides on proliferation and viability of
cultured dermal fibroblasts. MTT assay was performed
after 3 days of treatment. Values represent the mean ± S.D.
of six wells.
Figure 3. Dose response effect (0 - 1600 µg/ml) of increasing
doses of polynucleotides, in the presence or in the absence of
HA at the fixed dose of 1000 μg/ml. MTT assay was per-
formed after 3 days of treatment. Values represent the
mean ± S.D. of six wells.

Hyaluronate Increases Polynucleotides Effect on Human Cultured Fibroblasts 127
proliferation of dermal fibroblast and the best outcome is
reached with PN in the range from 37 µg/ml to 111 µg/
ml.
The representative images in Figure 4 are images with
phase-contrast microscopy of fibroblasts cultures collect-
ed with a camera in the same condition of treatment sum-
marized in the Figure 3 graph.
The column of images on the left shows PN only
treated cells, while the right column shows cell cultures
treated with the addition of HA 1 mg/ml. Photos suggest
the addition of hyaluronic acid appears to ameliorate the
overall culture conditions, with an highest density of the
cell culture obtained at the doses of PN mixture from 37
µg/ml to 111 µg/ml. In all tested conditions no changes
Figure 4. Representative images with phase-contrast mi-
croscopy of fibroblasts cultures collected with a camera in
the same condition of treatment summarized in the Figure 3
graph. Different PN concentration was indicated in central
colomn. Left column: only PN treated cells; right column:
PN + HA treated cells.
in cell morphology and signs of cellular toxicity were
detected.
In conclusion the collected data show a different sti-
mulating effect of PN in presence/absence of HA on cul-
tured dermal fibroblasts. Indeed the increased cell growth
obtained with 320 μg/ml of PN alone (14%) is similar to
those obtained at the dose of 64 µg/ml with the addiction
of HA 1000 µg/ml, thus indicating a sort of co-stimu-
lating effect of HA.
The reason of this effect is actually unclear, we can
argue a sort of clustering induced by HA comparable
with that observed for adhesion and spreading of cultured
cells.
Further investigations concerning HA derived PN co-sti-
mulation could be helpful on development of bioactive
fillers.
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