J. Biomedical Science and Engineering, 2011, 4, 1-9
doi:10.4236/jbise.2011.41001 Published Online January 2011 (http://www.SciRP.org/journal/jbise/
JBiSE
).
Published Online January 2011 in SciRes. http://www.scirp.org/jour nal/JBiSE
Material properties and characterizations of cross-linked
electro-spinning raspberry ketone incorporated polyvinyl
alcohol/gelatin fibrous scaffolds
Trinh Quang Bao, Rose Ann Franco, Byong Taek Lee
Department of Biomedical Engineering and Materials, College of Medicine, Soonchunhyang University, Cheonan, Chungnam, Ko-
rea.
Received 20 October 2010; revised 26 October 2010; accepted 29 October 2010.
ABSTRACT
The properties of polyvinyl alcohol/gelatin (PVA/GE)
nanofibers have been previously investigated as a
function of the processing parameters such as the ra-
tios of PVA and GE, electrical field and tip-to-collector
distance during the electro-spinning process, in this
study, the properties of the electro-spinning PVA/GE
nanofibers were examined when different solution
feed rates were used to create the fibrous scaffold.
The optimal conditions for the PVA/GE fibrous scaf-
fold were determined to be a PVA/GE blend ratio of
8/2, electrical field of 24 kV, tip-to-collector distance
of 10 cm and speed rate of 1 ml.h-1. Using these con-
ditions, Raspberry ketone (RK) was incorporated
into PVA/GE fibrous scaffolds and their microstruc-
ture and material properties were characterized by
SEM, DSC and XRD techniques. When the incorpo-
rated RK and PVA/GE fibrous scaffolds were cross-
linked, the tensile strength and water-resistant ability
increased at increasing cross-linking time. However,
in the in vitro analysis, a longer cross-linking time
was shown to increase its cytotoxicity. The cytotoxic-
ity of RKPVA/GE-8 fibrous scaffold was evaluated
based on a cell proliferation study by culturing L-929
fibroblast cell on the fibrous scaffold for 1, 3 and 5
days. In these experiments, cell expansion was ob-
served and the cells spread during the entire cell cul-
ture time.
Keywords: Electro-Spinning; PVA/GE Fibrous Scaffold;
Raspberry Ketone; Nanofibers
1. INTRODUCTION
The electro-spinning (ES) method is the simplest method
for manufacturing nanoscale fibrous scaffolds [1]. This
process can be used to produce continuous fibers since
this approach allows the scaffold to decrease the diame-
ter of the pore size from micrometer to nanometer range
[2]. Therefore, ES can be used to fabricate natural poly-
mers, synthetic polymers, and polymer loaded with nano-
particles as well as metals and ceramics to enhance cell
attachment and proliferation [3-6]. Furthermore, this tech-
nique is suitable for biomedical applications, such as the
development of tissue engineering scaffolds, drug deliv-
ery systems, wound healing and wound dressing [7-10].
It is well known that GE derived from denatured col-
lagen is suitable for cell adhesion. GE can form direct
molecular interactions with cells to promote attachment
and growth [11,12]. Hence, it has been widely used in
the biomedical field as a sealant for vascular prostheses,
dressings for wound healing and carriers for drug release
[13]. However, GE is much less effective in fiber proc-
essing; thus, fabrication of practical microfibers con-
taining GE through conventional ES is not common
[14].
PVA is a non-toxic, biocompatible, and biodegradable
synthetic polymer that has been broadly used in the
biomedical field. Moreover, it has been extensively em-
ployed as a drug and protein carrier for the treatment of
injuries and the regeneration of tissue because of its ex-
cellent properties and simple incorporation of drugs or
proteins inside the fibers [15-17]. Furthermore, it is fre-
quently combined with natural molecules that are recog-
nized by cells favoring preliminary adhesion [18,19].
RK is a compound found in red raspberries and has
been used in medicine. Recently, some studies have re-
ported that RK has anti-inflammatory activity when ap-
plied to the skin [20,21]. Due to these promising charac-
teristics, RK was incorporated in a PVA/GE fibrous scaf-
fold, which offers a unique combination of the inherent
properties of electro-spun scaffolds and the anti-in-
flammatory activity for pain relief and healing.
In recent years, some studies have examined blends of

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
2
PVA and GE in the form of PVA/GE films or PVA/GE
sponges for industrial and tissue engineering applica-
tions [18,22]. In addition, Yang et al reported that the
PVA/GE nanofibers have potential application in the
controlled release of RK, which depended on the cross-
linking time [21]. More recently, we studied the proper-
ties of PVA/GE nanofibers. In this previous study, the
effect of different ratios of PVA/GE on the tensile strength
of nano membranes was examined in detail [23]. How-
ever, no study has examined the effect of cross-linking
time on the tensile strength and biocompatibility of PVA/
GE fibrous scaffold for the applications in a wound
dressing device. There have been some reports that at-
tempted to improve the tensile strength of GE nanofibers
[11], PVA/GE nanofibers [21] by the cross-linking with
glutaraldehyde (GTA). Thus, here, GTA was used to
cross-link PVA/GE fibrous scaffold for different cross-
linking times and biocompatibility of the cross-linked
PVA/GE fibrous scaffold were investigated.
In this study, the effects of different solution feed rates
on the morphology of the PVA/GE fibrous scaffolds
were investigated by SEM. Based on these morphologic
evaluations, the best conditions to fabricate RK incorpo-
rated PVA/GE fibrous scaffolds were determined. In
addition, a GTA solution was used to cross-link the fi-
brous scaffolds and the properties of the cross-linked
scaffolds were characterized. After the fibrous scaffolds
were cross-linked, the mechanical properties, water-resistant
ability and biocompatibility were examined as a function
of the cross-linking time.
2. MATERIALS AND METHODS
2.1. Materials
PVA was obtained from Aldrich Chemical Co (USA).
GE Type A (Approx. 300 Bloom, Sigma, St. Louis, MO)
was obtained in powder form. RK was purchased from
Sigma Co.; GTA was obtained from DeaJung Co.; Fetal
bovine serum (FBS), P.S. (penicillin/streptomycin (anti-
biotics)), Dulbecco’s phosphate buffered saline (D-PBS)
without calcium or magnesiumand and MTT solution
and trypsin-EDTA were purchased from GIBCO (Carls-
bad, CA). The L-929 cell line was obtained from the
ATCC Cell Line (CCL-1TM, NCTC clone 929 [L cell,
L-929, derivative of Strain L], Korea). All other chemi-
cals and solvents were in the analytical reagent grade.
2.2. Preparation of Polymer Solutions, ES
Setting and Cross-Linking Process
Aqueous PVA solutions (10% m/v) were prepared by
dissolving PVA in deionized water at 80°C with constant
stirring for 2 hours. The GE solution (10% m/v) was also
prepared by dissolving GE in an acetic acid solution at
room temperature.
The GE solution was added into the PVA solution
with specific volumes to obtain the PVA/GE (8/2) solu-
tion. Then, RK was added and the blend was mixed to
obtain a homogenous solution. This solution was placed
into a 10 ml syringe fitted to a needle with a tip diameter
of 21 GA, a syringe pump (lure-lock type, Korea) for
controlling feed rates, and a grounded cylindrical stainless
steel that was used to collect the fibers. The ES voltage
was applied directly using a high DC voltage power
supply (NNC-30 kilovolts-2 mA portable type, Korea).
The PVA/GE fibrous scaffolds were hung on the edge
of the beaker. GTA (2%) was added into the beaker and
covered with aluminum foil for cross-linking through the
evaporation of GTA. At predetermined intervals, the
sample was taken out and dried for future studies.
2.3. Characteristic Morphology and Analysis of
Material Properties
The morphology of the fibrous scaffolds was examined
by scanning electron microscopy (SEM, JSM-7401F
Japan). Differential Scanning Calorimetry (DSC) meas-
urements (METTLER TOLEDO KOREA—DSC822e)
were acquired with a sample weight of 3 mg under ni-
trogen atmosphere. The fibrous scaffolds were subjected
to X-ray Diffraction (XRD) (Rigaku, D/MAX-2500 V
Japan) with CuKa radiation of 40 kV and 200 mA. The
mechanical properties of the electrospun scaffolds were
determined by using a universal testing machine (R&B
UNITECH-T) [4]. For water resistant ability test, the
cross-linked PVA/GE scaffolds were cut into dimensions
of 2 × 2 cm2 then immersed into deionized water (37°C)
in incubator for a certain period of time before being
dried to observe the morphology by SEM.
2.4. In Vitro Study
The cellular viability of fibroblast cells on samples was
determined by using the MTT assay. The L-929 mouse
fibroblast cells were seeded in 96-well tissue culture
plates at 1,000 cells/well in 100 µl RPMI. All media
contained 10% of FBS and cell lines were incubated
overnight. Diluted extract solutions of every fibrous
scaffold at various concentrations (0, 12.5, 25, 50 and
100%) were then added. The cells were treated for 1, 2,
and 3 days and then 20 µl of filtered MTT solution was
added. After incubation at 37°C for 3 h, the medium was
removed from the well and 150 µl of DMSO was added
to dissolve any insoluble formazan crystals. The ab-
sorbance was measured at 560 nm using an ELISA
reader. The cell viability was calculated as a percentage
relative to the untreated control cells.
To examine the proliferation and spreading behavior
of the cells, samples 20 mm × 20mm in size were steril-

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
3
tween the different samples. For example, at an applied
feed rate of 0.05 ml.h-1 (Figure 1(a)), the fibers were
very thin and some of fibers gathered at the bead posi-
tions and were far from each other. In contrast, when the
applied feed rate was 0.5 ml.h-1 (Figure 1(b)), the fibers
were cylindrical, thicker, strained, non-woven and had a
close distribution. On the other hand, when the applied
feed rate was increased to 1 ml.h-1, the fibers were very
stretched, had a wide distribution and many small pore
size were formed (Figure 1(c)). Beside the diameter of
resulting fibers ranged from 40 to 170 µm.
ized with 70% of EtOH for 30 minutes, then washed
with PBS and suspended in conditioning medium (15
min). The fibroblast cells (L-929) were cultured on TCPs
(Tissue Culture Polystyrene), control-like and samples.
The cells were seeded at a cell density of 104 cells/cm2
in RPMI and cultured for 1, 3 and 5 days s at 37°C in a
humidified air atmosphere with 5% of CO2.
3. RESULTS
3.1. Morphology of Fibrous Scaffold from
Electro-Spun Figure 2 shows the effect of incorporating RK on the
morphology of the PVA/GE fibrous scaffold. The con-
tinuous fibers were successfully electro-spun from the
PVA/GE solution. They possessed the common features
of being round-shaped, randomly arrayed and highly
porous. Both RK-free and RK incorporated PVA/GE
fibers appeared smooth and no RK crystals were de-
tected on the polymer surface. Figure 2(a) shows SEM
photographs of the electro-spinning fiber without the
incorporation of RK. Under these conditions the fibers
were cylindrical, smooth and separated from each other.
Figure 1 shows SEM images of the PVA/GE nanofibers
prepared from electro-spinning at various feed rates. The
applied PVA/GE blend ratio, electric field and tip-to-
collector were fixed at 8/2, 24 kV and 10 cm, respec-
tively. The diameter distributions and density distribu-
tions of the fibers at each different feed rate are shown in
Figures 1(a), (b) and (c). Based on the analysis of the
SEM images, the nanofibers were homogenous and uni-
form over a large area. However, there were differences
in the fibers diameter and fibers density distribution be-
(a) (b) (c)
Figure 1. SEM images of PVA/GE fibers at a PVA/GE blend ratio of 8/2, electric field of 24
kV and tip-to collector distance of 10 cm at feed rate of 0.05 ml.h-1 (a), 0.5 ml.h-1 (b) and 1
ml.h-1 (c).
(a) (b)
Figure 2. SEM images of PVA/GE fibrous scaffolds before (a) and after (b) RK incorporation.
JBiSE

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
4
However, the morphology and average diameter of elec-
tro-spun nanofibers change significantly after RK was
incorporated. Figure 2(b) shows that the fibers were
attached and had melted into each other. In the case of
RK incorporated PVA/GE, some of the stump-like
structures were observed in the white circles. The aver-
age diameter of the RK-incorporated and RK-free fibers
was 200 ± 105, 160 ± 91 nm, respectively. These results
demonstrate that incorporation of RK significantly al-
tered the diameter of the nanofiber.
3.2. X-Ray Diff ra ct io n
Figure 3 shows the XRD patterns of RK, PVA/GE fi-
brous scaffold and RK incorporated PVA/GE fibrous
scaffold. Several distinct peaks were observed for RK at
diffraction angles of 2θ = 14.4˚, 15.6˚, 20.4˚, 23.7˚, 23.9˚,
28.6˚ and 34.8˚. The diffraction of RK incorporated
PVA/GE fibrous scaffold exhibited several peaks at 2θ =
14.5˚, 15.7˚, 19.4˚, 20.2˚, 20.4˚, 23.7˚, 24.1˚, 26.4˚, 28.3˚,
and 27.9˚. While the PVA/GE fibrous scaffold had a
broad peak at 2θ = 20.9˚. In addition, some peaks such
as 2θ = 34.8˚ of RK and 2θ = 20.9˚ of PVA/GE fibrous
scaffold were not observed in the XRD pattern of the RK
incorporated PVA/GE fibrous scaffold. These results
indicate that the fibrous scaffold structure of RK incor-
porated PVA/GE changes relative the structure of RK
and the PVA/GE fibrous scaffold alone.
3.3. Differential Scanning Calorimetry (DSC)
DSC thermograms of the RK and RK incorporated PVA/
GE fibrous scaffold are shown in Figure 4. The pure RK
showed a relatively sharp endothermic curve with a peak
at 67˚C. However, two peaks were observed in the DSC
scan of RK incorporated PVA/GE fibrous scaffold, which
corresponded to the melting of the crystal structure of
RK at 105˚C and PVA/GE matrix at 225˚C. The ob-
served melting peaks of RK incorporated PVA/GE fi-
brous scaffold were much different from that of pure RK
(67˚C) and PVA/GE fibrous scaffold (100˚C) [23],
which implies that particular interactions were present
between RK and the PVA/GE matrix in RK incorporated
PVA/GE fibrous scaffold.
3.4. Mechanical Properties
Figure 5 shows the stress-strain curves of RK incorpo-
rated PVA/GE fibrous scaffolds at different cross-linking
times. Based on the stress-strain curves, respective ten-
sile properties in terms of tensile strength and strain at
break are summarized in Table 1.
The tensile results indicated that cross-linking im-
proved the mechanical performance of the RK incorpo-
rated PVA/GE fibrous scaffolds. The tensile strength of
RK incorporated PVA/GE fibrous scaffold increased as
Figure 3. XRD profile of RK (a), RK incorporated PVA/GE
fibrous sc fold (b) and PVA/GE fibrous scaffold (c).
Figure 4. DSC spectra of RK (a) and RK incorporated PVA/
GE fibrous scaffold (b).
Figure 5. Stress-strain curves of RK incorporated PVA/GE
fibrous scaffolds after 0 hour (RKPVA/GE-0), 4 hours (RKPVA/
GE-4), 8 hours (RKPVA/GE-8) and 16 hours (RKPVA/GE-16)
of cross-linking.

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
5
the cross-linking time increased.
3.5. SEM Morphology of Fibrous Scaffolds after
W ater -Resistant Ability Testing
After RK incorporated PVA/GE fibrous scaffolds were
treated in GTA vapor for 0, 4, 8 and 16 hours, their wa-
ter-resistant behaviors were evaluated and summarized
in Table 2. In these experiments, samples untreated,
treated up to 4 and 8 hours were found to be totally dis-
solved in 37˚C water after being immersed for 1, 2 and 3
days, respectively. In contrast, the sample cross-linked
for 16 hours remained intact after immersion in water at
37˚C.
SEM images of the scaffolds at different cross-linking
times are shown in Figure 6. Based on the analysis of
the SEM images, many break points were observed in
the fiber when not treated with GTA (Figure 6(a)). After
the cross-linking time was increased to 4 hours, the fi-
bers were devoid of break points, and the fibers appeared
smooth with less points of erosion (Figure 4(b)). In the
case of 8 hours of cross-linking (Figure 1(c)), the sur-
face of the fibers appeared homologous and uniform and
some pores were clearly visible. However, when the
Table 1. Tensile properties of RK incorporated PVA/GE fi-
brous scaffold depending on cross-linking times.
Samples Tensile strength (M Pa) Strain at break (%)
RKPVA/GE-0 1.0 ± 0.4 4.2 ± 0.2
RKPVA/GE-4 2.1 ± 0.9 5.7 ± 0.8
RKPVA/GE-8 3.3 ± 0.7 17.6 ± 1.6
RKPVA/GE-16 6.2 ± 0.6 30.1 ± 2.3
Ta b le 2 . Effect of cross-linking time on water resistant ability
of PVA/GE fibrous scaffolds.
Time of cross-linking
Immersi o n time
at 37°C 0 hour4 hours 8 hours 16 hours
Day 1 Y Y Y Y
Day 2 N Y Y Y
Day 3 N N Y
Y denotes samples remained and N denotes sample dissolved.
(a) (b)
(c) (d)
Figure 6. SEM images of RK incorporated PVA/GE fibrous scaffolds at different cross-linking
times: 0 hour (a), 4 hours (b), 8 hours (c) and 16 hours (d) after immersion in water at 37°C for
one day.

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
6
samples were cross-linked for 16 hours (Figure 6(d)),
the fibers appeared to adhere to each other. The surface
of the scaffold was dense and contained many small
pores. The results of these experiments demonstrated that
the cross-linking treatment improved the water-resistant of
electro-spun of RK incorporated PVA/GE fibrous scaf-
folds.
3.6. Cytotoxicity Results
Figure 7 shows the cytotoxicity results of RK incorpo-
rated PVA/GE fibrous scaffolds after 0, 4, 8 and 16
hours cross-linking by quantitative analysis using the
MTT test [24]. After allowing the cells to spread for 3
days at various extract dilutions (0, 12.5, 25, 50 and
100%), the proliferation of L-929 cells was measured
using the MTT assay. In this analysis, we found that the
cells proliferated better on RKPVA/GE-8 than on RKPVA/
GE-16 scaffolds. However, the proliferation of cells was
significantly higher on RKPVA/GE-0 compared to both
RKPVA/GE-4 and RKPVA/GE-8 scaffolds. Based on
these results, it appears that the extracts of the scaffolds
displayed no cytotoxic reactivity in this test and cell me-
tabolism of RK incorporated PVA/GE fibrous scaffolds
decreased with an increase in the cross-linking time.
3.7. SEM Morphology of Cell Proliferation and
Spreading
The cell morphology of RKPVA/GE-8 fibrous scaffold
was examined by SEM at days 1, 3 and 5, and the results
are shown in Figure 8. It was estimated that at day 1
(Figures 8(a) and (b)) L-929 fibroblast cells only at-
tached to the surfaces through discrete filodia. After just
3 days, the shape of the fibroblast cells changed from
round to elongated (Figures 8(b) and (c)), they stretched
across the nanofibrous substrates and increased in num-
bers. Subsequently, L-929 fibroblast cell proliferation
and growth continued progressively, and by day 5 (Fig-
ure 8(d)) the cells had increased significantly in num-
bers. Thus, the RKPVA/GE-8 scaffold was almost com-
pletely covered with a continuous L-929 fibroblast cell
monolayer. These SEM images demonstrated that the
L-929 fibroblast cells successfully proliferated and spread
on RKPVA/GE-8. Based on these results, the RKPVA/
GE-8 fibrous scaffold has promise for use in biomedical
applications.
4. DISCUSSION
The effects of electro-spinning parameters, such as
polymer concentration, electrical field and tip-to-collector
distance on the morphology of nanofibers was previ-
ously investigated [3,23]. In addition, Duppi et al. [5]
examined the effect of feed rate and reported that an
Figure 7. The cytotoxicity of RK incorporated PVA/GE fi-
brous scaffolds after 0 hour (RKPVA/GE-0), 4 hours (RKPVA/
GE-4), 8 hours (RKPVA/GE-8) and 16 hours (RKPVA/GE-16)
of cross-linking.
increase solution feed rate could increase the fiber di-
ameter, when the jet is properly stretched by the electric
force, or cause the formation of beads. The results of our
work are consistent with that study and the SEM images
shown in Figure 1 clearly demonstrates that the diameter
of the PVA/GE nanofiber significantly increased when the
solution feed rate was increased from 0.05 ml.h-1 to 1
ml.h-1. Combined with our previous study [23], we pro-
duced a homogeneous, non-woven and fine PVA/GE
fibrous scaffold by using a PVA/GE blend ratio of 8/2,
electrical field of 24 kV, tip-to-collector distance of 10
cm, and solution feed rate of 1 ml.h-1. An acetic acid
–water solution was used as a solvent for the elec-
tro-spun PVA/GE fibrous scaffolds.
RK was incorporated into electro-spun PVA/GE nano-
fibers because of its biological effects in influencing cell
behavior. Incorporation of RK did not significantly in-
fluence the morphology of the resulting fibers as the
both RK-free and RK-loaded composite fibers remained
unaltered, microscopically and uniform nanofibers (Fig-
ure 2) with an average fiber diameter higher than that of
their analogous unloaded system were observed. The
formation of a uniform fiber and fibrous structure, re-
flected the high conductivity of acetic acid [23] and the
stability of the applied optimized conditions of elec-
tro-spinning. However, after RK incorporation, some
stump-like structures were observed, which was due to
the fragility of the polymer fibers [25]. On the other
hand, RK possesses a crystal structure at room tempera-
ture. The structure of RK in the PVA/GE matrix and ace-
tic acid applying under the high electrical potential that
was used here in electro-spinning is still unknown. To
determine if the structure of RK was altered under these
conditions, RK incorporated PVA/GE fibrous scaffold
were investigated by XRD and DSC. Figure 3 shows the
XRD profile of RK, PVA/GE fibrous scaffold and RK

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
7
(a) (b)
(c) (d)
Figure 8. SEM images of L-929 fibroblast cell on RKPVA/GE-8 fibrous scaffold after 1, 3 and 5 days of cul-
ture cell: control sample (a), 1 day (b), 3 days (c) and 5 days of culture cell (d).
incorporated PVA/GE fibrous scaffold. In this analysis,
the structural integrity of RK in RK incorporated PVA/
GE fibrous scaffold was not preserved, since peaks cor-
responding to RK disappeared and some new peaks were
observed in the XRD profile of RK incorporated PVA/
GE fibrous scaffold. Based on these results, we believe
that strong interactions occur between PVA/GE and RK
in the acetic acid environment. The results from XRD
were supported by DSC analysis. In addition, the sharp
melting peak of RK was shifted toward a high tempera-
ture and the melting peak became broader (from 67˚C to
105˚C), as shown in Figure 4. These results confirmed
the crystal structure of RK changed when it was incor-
porated into the PVA/GE fibrous scaffold.
Yang et al. [21] previously reported that RK, PVA and
GE are water-soluble molecules. Therefore, when com-
ing into contact with an aqueous medium, RK incorpo-
rated PVA/GE fibrous scaffold may partially dissolve
and it may lose its fibrous structure upon exposure to
high ambient humidity for a certain period of time. To
increase the stability of RK incorporated PVA/GE fi-
brous scaffold in applications that require exposure to an
aqueous medium or high humidity, further cross-linking
is necessary. Figure 5 shows that the tensile strength and
strain at break of RK incorporated PVA/GE fibrous
scaffolds increased as the cross-linking time was in-
creased. The results from the water-resistant ability tests
demonstrated that the degree of cross-linking signifi-
cantly impacted its water resistance. It was found that
the grossly degree was increased as the cross-linking
time was increased and similarly the density of the sur-
face of the fibrous scaffold was also increased, which
was demonstrated by the fact that the fibers at junctions
were fused together through bonds. When the RK in-
corporated PVA/GE fibrous scaffold were cross-linked
for 16 hours they were found to still be water resistant
after 3 days of incubation. Therefore, a longer cross-
linking time increased the mechanical properties and
improved the water resistant ability of RK incorporated
PVA/GE fibrous scaffolds. However, it has been re-

T. Q. Bao et al. / J. Biomedical Science and Engineering 4 (2011) 1-9
8
ported that the chemically cross-linked biomaterials,
un-reacted cross-linking agents and leached material
during degradation may be cytotoxicity [26]. Figure 7
shows that the cytotoxicity of the RK incorporated
PVA/GE fibrous scaffolds increased as the cross-linking
time increased. Based on these combined results, RK
incorporated PVA/GE fibrous scaffold after cross-linked
for 8 hours (RKPVA/GE-8) was chosen for subsequent
in vitro experiments to evaluate the proliferation and
spreading of L-929 fibroblast cells after 1, 3 and 5 days
culture cell. Figure 8 shows the proliferation and spreading
of fibroblast cells, as well as its interaction with the
RKPVA/GE-8 over a cell culture period of 5 days. Car-
roll [27] reported that the insulin-like growth factor-I
(IGF-I) has various important biological effects such as
promoting differentiation of various cell types, potent
anti-apoptotic activity, and an anabolic effect. Further-
more, Harada et al. [28] reported that RK might increase
dermal IGF-I production through neuron activation,
thereby promoting hair growth and increasing skin elas-
ticity. The PVA/GE fibrous scaffolds have a large surface
area, non-woven fibers, randomly arrayed fibers and is
highly porous, all of which may have promoted cell pro-
liferation and spreading on RKPVA/GE-8 after 5 days of
culture. Thus, this scaffold could be used to promote
faster restoration and increase the biocompatibility of
wound dressings.
5. CONCLUSION
PVA/GE fibrous scaffolds were successfully fabricated
by the ES method. In this process, different solution feed
rates were shown to affect the morphology of nanofibers.
XRD and DSC analysis demonstrated that the RK crystal
structure changed when incorporated in the PVA/GE
fibrous scaffold. The mechanical property, water resis-
tant ability, and cytotoxicity of the fibrous scaffolds in-
creased as the cross-linking time increase. The in vitro
analysis demonstrated that RK incorporated PVA/GE
fibrous scaffold after 8 hours of cross-linking (RKPVA/
GE-8) were highly biocompatible. Therefore, RKPVA/
GE-8 holds promise for use in tissue engineering and
wound dressing devices.
6. ACKNOWLEDGEMENTS
This work was supported by Mid-career Research Program through
NRI grant funded by the MEST (2009-0092808).
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