bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromium Ions Induced Cytotoxicity and Oxidative Stress in the MG63 Cell Lines
Authors: Fu Jun , Liang Xing , Wang Shao An , Tang Li , Zhang Ning
Published: March 2009

The present study was designed to test the hypothesis that oxidative stress mediates
chromium-induced cytotoxicity in MG63 cells and antioxidant N-acetyl-cysteine (NAC) can
provide protection for osteoblasts against chromium-induced oxidative stress. We assessed the
effects of chromium ions on cell viability, the level of intracellular reactive oxygen species (ROS)
and intracellular ultrastructure in the presence or absence of NAC. A time- and concentrationdependent
increased cytotoxicity, intracellular ROS generation was found and intracellular
ultrastructure was damaged when cells were exposed to Cr+6. NAC afforded dose-dependent
reduction to the cytotoxicity and level of cellular oxidative stress induced by Cr+6. Intracellular
ultrastructural alterations were reduced by the NAC pretreatment, too. Cr+3 had no significantly
negative influence in MG63 (5-20μM). Our results suggest that oxidative stress might be involved
in Cr+6 induced cytotoxicity in osteoblasts. NAC can play a critical role against Cr+6- induced
cytotoxicity. Cr+3 (5 -20μM) had no significant cytotoxicity in MG63 cells and cellular oxidative
stress was not found, too.
Fabrication and Bioactivity of Porous Titanium Implant
Authors: Lu Xia , Xing Li Ang , Wang Pei Zhi , Fu Jun
Published: March 2009

The aim of this study is to fabricate an implant framework for tissue engineering by
sintering titanium beads and coating with hydroxyapatite and test its biocompatibility and
bioactivity in vitro. The porous titanium with and without hydroxyapatite coating were involved in
study groups. Osteoblastic proliferation, activity of alkaline phosphatase, mRNA of osteocalcin and
bone sialoprotein were detected by MTT-assay, ALP test and real-time polymerase chain reaction
respectively. The results indicated that the porous titanium material with/without HA coating could
promote osteoblastic proliferation significantly contrast to the control group. However, only porous
titanium with HA coating increased alkaline phosphatase, osteocalcin and bone sialoprotein gene
expression apparently and had statistically differences with the other two groups.
Abstract no. is TE-Po-044
Osteogenic Repair by Bovine Bone Ash Derived Porous HA Ceramic Formed by Foaming Method
Authors: Yoon J.H. , Park J.H. , Park Eui Kyun , Kim Shin Yoon , Lee J.H. , Park I.K. , Kim H.J. , Shin Hong In
Published: March 2009

To develop a suitable scaffold optimizing bone regeneration, we developed bovine
bone ash derived fully connected porous HA ceramic scaffolds adopting a foaming method.
They revealed excellent biocompatibility. The attached cells on the scaffolds proliferated in
multi-layers with osteoblastic differentiation. The bone defects grafted with bovine bone ash
derived fully interconnected porous HA ceramics having average 500 μm sized spherical pores
and average 150 μm sized interconnecting interpores with average 80% porosity were favorably
healed without any pathologic changes within 3 weeks. New bone ingrowth with excellent
osteoconduction through the spherical pores along the inner surface was noted from 1 week
after implantation. Each spherical pore was filled with hematopoietic marrow and newly formed
bone which with time was well integrated with the porous HA ceramic scaffold with time.
These findings suggest that the bovine bone ash-derived fully interconnected porous HA
ceramic formed by foaming method can be a promising bone substitute and a scaffold for bone
tissue engineering.
Constructing Bone Graft with Calcium Phosphate Ceramics in Different Non-Osseous Tissue
Authors: Bao C.Y. , Yao Jin Feng , Fan Hong Song , Sun L.Y. , Zhang Bi , Wang Xin Long , Zhang Xing Dong
Published: March 2009

The study is aimed at to explore the construction of bone graft with calcium phosphate
ceramics implanted in subcutaneous fat, and provide applying technique for the in vivo bone tissue
engineering. Forty-eight calcium phosphate ceramics (Ca-P ceramics) columns with Φ 5×8 mm
were prepared, and eight dogs were used in this experiment. Six samples were implanted in each
dog. Three in dorsal muscles while the others in subcutaneous fat. The specimens were harvested at
4, 6, 12 and 24 weeks post operation, for gross observation, SPECT and histological studies. The
osseous or osteoid tissue formation at different times in the two non-osseous sites was compared
and the new bone grafts in subcutaneous fat and intramuscular implantations were evaluated. The
results demonstrated that the bone graft could be constructed not only in muscle but also in
subcutaneous fat. Compared to that in muscle, constructing bone graft in subcutaneous fat could
have brighter prospect to clinical application.
A Novel Method for Porous Chitosan Scaffold
Authors: Lim Jin Ik , Kim Gun Woo , Na Jae Sik , Noh In Sup , Son Young Sook , Kim Chun Ho
Published: March 2009

This study is to develop a novel method for preparation of the chitosan scaffold having
interconnected open pore structure and controlled pore distribution. For this, the effects of addition
of non-solvent on chitosan solution were estimated. The porous scaffolds were typically prepared
by solid-liquid separation and subsequent sublimation of solvent. Alcohol was used as non-solvent
for chitosan. The difference of freezing temperature of each of the components induced the liquidliquid
and the liquid-solid phase separation via demixing solution (solvent/non-solvent/chitosan).
The morphology, heterogeneous pore distribution and mechanical properties of the scaffolds were
examined. The addition of non-solvent in chitosan solution was to make the controlled
homogeneous micropores and improved interconnectivity between pores without any surface skin
layer. For control chitosan scaffold, the pore size was mainly about 80~100 μm. On the contrary,
Pore diameters could be controlled mainly within the range 30~100 μm, with a variation of
solvent/non-solvent ratio. The number of minute pore (4~25 μm) over chitosan scaffold increased
with increasing ratio of non-solvent. New prepared scaffold exhibited larger value of breaking
elongation, more elasticity, but less tensile strength than that of control scaffold.
Dissolution of Calcium Phosphate Powders with Different Compositions in Simulated Body Fluid
Authors: Seo Dong Seok , Song Dae Sung , Lee Jong Kook
Published: March 2009

Dissolution of calcium phosphate powders with different compositions in simulated body
fluid was investigated. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) powders were
synthesized by a precipitation method and by controlling pH of the solution. Biphasic calcium
phosphate (BCP) powders were prepared by mixing the HA and β-TCP powders with ratio of 80:20
and 60:40 in weight % in a planetary mill for 4 h. For dissolution test, 0.5g of each β-TCP, HA and
BCP powders were immersed in 50 ml of SBF at 37°C for 3-28 days. HA powders with
stoichiometric composition showed no significant morphological change regardless of the
immersion time. β-TCP powders were not dissolved in SBF in spite of its high solubility. The
surface of BCP powders became rough due to dissolution with increasing immersion time. This
surface dissolution gradually extended into the core region of the particles resulting in
disintegration of the dense particle into fine crystallites. It may be caused that the milling process
during preparation of BCP powders may induce stress concentration or formation of dislocation on
the surface of particles.
Preparation of α-Tricalcium Phosphate Bone Cement: Effect of Citric Acid
Authors: Seo Mi Jung , Lee Ki Youn , Jung Sun Nye , Kim Sung Soo
Published: March 2009

α-Tricalcium phosphate (α-TCP) is one of the main reactants of the powder phase of
several bioactive calcium phosphate bone cements. After preparing TCP, the TCP was determined
by the measurement of X-ray diffraction, particle size, and scanning electron microscopy. Cements
were characterized using viscosity measurements, X-ray diffraction, scanning electron microscopy,
and compressive and tensile strengths etc. When citric acid was added as dispersant at different
concentration to α-tricalcium phosphate bone cements, it was found to act as a fluidizing agent
during the first stages of cement mixing. The setting time for cement without citric acid was 300
min, while setting times for cements prepared with 0.5-2.5 M citric acid were at a minimum of 4
min and a maximum of 35 min, respectively. The dissolution-precipitation reaction of α-tricalcium
phosphate was accelerated by adding citric acid and compressive and diametral tensile strength
increased.
Preparation and Characterization of Small Intestinal Submucosa Coated with Alginate/Gelatin as a Wound Dressing
Authors: Lee Min Suk , Song In Bum , Khang Gil Son , Kim Moon Suk , Lee Hai Bang
Published: March 2009

To develop a wound dressing that can be removed from the injured skin without the
damage and supporting rapid healing, we made hybrid dressing of small intestinal submucosa (SIS)
and hydrogels. Alginate and gelatin used as a dressing material in hydrogels were selected to coat
SIS sheets. Characteristics and tendency of wound healing of prepared sheets were investigated.
Water uptake ability was greater when the sheets were coated with gelatin than alginate although
both showed higher water absorption than the native SIS sheets, but the degradation rate of
alginate/gelatin coated SIS was slower than that of native SIS because both polymers may delay
contact time of enzyme to the SIS surface in solution. It was observed that less of fibroblasts
attached to the natural polymer coated SIS sheets. This property will make easy for the detachment
of the sheet from the defected tissue. Wound closure examination showed that prepared sheets
enhanced wound healing. It was concluded that prepared alginate/gelatin coated SIS sheets are
positively regarded as an appropriate biodegradable wound dressing that is reducing patient’s pain
during change of the dressing.
Self-Degradable Bioadhesive
Authors: Nakajima Naoki , Sugai Hajime , Tsutsumi Sadami , Hyon Suong Hyu
Published: March 2009

To improve the conventional and commercially-available medical adhesives such as
cyanoacrylate, aldehyde-based, and fibrin glue, new bioadhesive has been prepared using medical
and food additives as starting materials. Aldehyde groups could be easily introduced in dextran in
the presence of sodium periodate in aqueous media, and the extent of the introduction could also be
controlled. In vitro degradation speed of the hydrogel prepared by mixing of aldehyded dextran
with ε-poly(L-lysine) at 37oC significantly varied by acetic anhydride concentration added to
ε-poly(L-lysine) from < 5h to > 5 weeks. Bonding strength of the glue was 4 times higher than that
of commercial fibrin glue and almost no cytotoxicity was observed, suggesting the development of
novel self-degradable bioadhesive.
Preparation and Swelling Behavior of Superporous Hydrogels: Control of Pore Structure and Surface Property
Authors: Choi You Mee , Im Su Jin , Myung Sung Woon , Choi Ho Suk , Park Ki Nam , Huh Kang Moo
Published: March 2009

Superporous hydrogels (SPHs) with interconnected pores of several hundreds
micrometers were prepared using radical polymerization of acrylic acid (AA) and acrylamide
(AAm) in the presence of N,N’-methylenebisacrylamide (BIS). A gas blowing method using
bicarbonate as a foaming agent was applied to introduce the porous structure under different pH
conditions (pH 2~7). The pore structures of the prepared SPHs were examined by a scanning
electron microscope. The SPHs obtained at pHs of 4.5 and 4.75 were observed to have a
interconnected pore structure with homogeneous distribution and swell to an equilibrium state
within several minutes. The O2 plasma reactor has been used for surface modification of SPHs. The
plasma-treated SPHs showed much faster swelling behavior due to the improvement of surface
hydrophilicity. The swelling ratio of SPHs was also enhanced by using a wetting agent, such as
triacetin and glycerol, during a washing procedure.
The Biocompatibility of Silk Scaffold for Tissue Engineered Ligaments
Authors: Seo Young Kwon , Choi Gung Min , Kwon Soon Yong , Lee Hwa Sung , Park Yong Soon , Song Kye Yong , Kim Young Jin , Park Jung Keug
Published: March 2009

The aim of this study was to estimate the mechanical properties and evaluate the
biocompatibility of silk and PGA scaffolds as an artificial ligament to an ACL reconstruction. The
scaffold for the artificial ligament was braided / knitted silk or PGA thread. The mechanical
properties, cell growth, and subcutaneous tissue reactions were determined for both types of
scaffolds. The breaking load of the PGA scaffold was double that of the sericin removed silk
scaffold (SRSS). However, the initial attachment and growth of human ACL cells on the SRSS was
superior to the PGA scaffold. In addition, the immune response was significantly higher on the PGA
scaffold after 72 h (p<0.05) compared with the sericin removed silk scaffold by T lymphocyte and
mononuclear cells (MNCs) in vitro cultures. In vivo, the ACL scaffold made from silk or PGA were
implanted in the subcutaneous layer in rats and harvested 1 week later. A histological evaluation of
the scaffolds explants revealed the presence of monocytes in the SRSS, and an absence of giant
cells in all cases. An inflammatory tissue reaction was more conspicuous around the silk scaffold
containing sericin and even more around the PGA scaffold compared with SRSS. These results
support the conclusion that a properly prepared SRSS, aside from providing benefits in terms of
biocompatibility both in vitro and in vivo, can provide suitable scaffolds for the support of ACL cell
growth. These results suggest that a SRSS for ACL repair can overcome the current limitations with
the PGA scaffold. And SRSS is biocompatible, and the in vitro T cell and MNCs culture model
showed inflammatory responses that were comparable to those observed in vivo.
Effect of Hydroxyapatite-Tricalcium Phosphate Micro-Particles on the Cellular Interaction of In Situ Hyaluronic Acid-Poly(Ethylene Oxide) Hydrogel
Authors: Kim Mi Sook , Choi Yoon Jeong , Kim Gun Woo , Noh In Sup , Park Yong Doo , Lee Kyu Back , Kim In Sook , Hwang Soon Jung
Published: March 2009

In vitro cell behaviors of calvarial osteoblasts (MC3T3) were evaluated by seeding them on both the surface and inside of in situ hyaluronic acid-poly(ethylene oxide) (HA-PEO) hydrogel, either after or before incorporation of mixture micro-particles of hydroxyapatite-β-tricalcium phosphate on/inside the hydrogel, respectively. Cellular behaviors such as adhesion and proliferation on the surface and inside the gel were evaluated with light microscopy and a microplate reader by focusing on the interactions of cell-HA-PEO as well as cell-hydroxyapatitetricalcium phosphate micro-particle surface in the gel. Cell adhesion and spreading seemed to be enhanced by supplying the micro-particles to the inside the HA-PEO hydrogel, compared to the results of the HA-PEO hydrogel itself.
The Study of Human Epithelium Cell Attachment to the Surface of Anode-Oxidized Titanium
Authors: Wu Yao , Yang Bang Cheng , Gu Zhong Wei , Zhang Xing Dong
Published: March 2009

The achievement of biological sealing is determined by the quality of the skin attachment
on the surface of the percutaneous implant in the area where the implant penetrates the skin. It has
been known that certain surface features of the implants can significantly influence the interactions
between cells and substrate. In this study, titanium plates were bioactivated through
anode-oxidization firstly, and then cultured with human epithelium cells for 72h. Untreated Ti plates
were used as control. After the samples were dehydrated, the morphology of the cultured epithelium
cells was tested with Scanning electron microscopy (SEM). The surfaces of control group did not
enhance epithelium cell attachment and growth, while the bioactivated microporous surface of
anode-oxidized group would be beneficial to induce the formation of the pseudopod of epithelium
cell, and then interlock the human epithelium cells through the pseudopod, which imply that the
surface modification method of anode oxidization may be one of the most effective methods to
resolve the biological sealing.
Effects of Herbal Extracts on Dental Plaque Formation and Human Gingival Fibroblasts
Authors: Choi Choong Ho , Kim B.I. , Kwon H.K. , Hong Suck Jin
Published: March 2009

The purpose of this study was to investigate the effects of Galla Rhois, Psoralea
corylifolia, Camellia sinensis, Salvia miltiorrhiza and Platcodon grandiflorum on the inhibition of
artificial dental plaque formation and the cytotoxicity of the herbal extracts on human gingival
fibroblasts. The analysis was carried out with the measurment of dental plaque weight and the cell
survival rate of human gingival fibroblasts. It showed that Galla Rhois, Psoralea corylifolia,
Camellia sinensis and Salvia miltiorrhiza inhibited the artificial dental plaque formation and did not
reduce the cell viability of human gingival fibroblasts.
Adhesion to Cells of Enzyme Conjugated Phospholipid Polymer Nanoparticles
Authors: Ito Tomomi , Konno Tomohiro , Takai Madoka , Ishihara Kazuhiko
Published: March 2009

We investigated the bioconjugation of proteins on polymer nanoparticles covered with
bio-inert phosphorylcholine groups. Poly[2-methacryloyloxyethyl phosphorylcholine-co-n-butyl
methacrylate-co-p-nitrophenyloxycarbonyl polyethyleneglycol methacrylate] was used as an
emulsifier and a surface modifier to prepare the poly (L-lactic acid) nanoparticles by a solvent
evaporation technique. The diameter and surface potential of the nanoparticles were
approximately 260 nm and –5 mV, respectively. We considered that the polymer chain that
transformed the conformation by change in pH may be used as a method of controlling the bioreaction.
The enzyme activity in a different pH under the coexistence of poly (glutamic acid)
(PGA) and the enzyme was measured. Therefore, the enzyme activity increased in pH 6 in
PGA/enzyme mixture system compared with that in pH 7 while the activity was constant in the
enzyme single conjugation regardless of the pH change.
Surface Modification of Magnetite Nanoparticles with Doxorubicin and RGD Peptide and their Biomedical Application
Authors: Kamruzzaman Selim K.M. , Park Mi Jin , Kim Hong Mi , Kang Inn Kyu
Published: March 2009

In the present study, superparamagnetic maltotrionic acid-coated magnetite nanoparticles
(MAM) were surface modified with doxorubicin (DOX) and RGD peptide to improve their
intracellular uptake, ability to target tumor cells and antitumer effect. RGD was added to the distal
end of MAM aiming to construct an enhanced tumor targeting delivery system. To test its targeting
effect, DOX, a widely used anticancer drug, was immobilized on the RGD-modified magnetite
nanoparticles. DOX-coated magnetite nanoparticles were also prepared as a control. KB cell culture
experiment showed that both DOX-modified nanoparticles and DOX-RGD peptide-modified
magnetite nanoparticles (DRMAM) were internalized into the cells. But the uptake amount of
DRMAMs was higher than that of DOX-modified nanoparticles. This result indicates that
DRMAMs have a great potential to be used as contrast agent and antitumor medicine.
Toxicity Test of Wound Covering Material on Animals
Authors: Lim Hye Ryeon , Baek Hyun Sook , Lee Mi Hee , Woo Yeon I , Lee Tek Hyung , Park Jong Chul
Published: March 2009

Adhesions are abnormal attachments between tissues, caused by an inflammatory stimulus or
trauma. It was generally used physical barriers and various agents to prevent from adhesions
formation. In this study, we made an experiment on animals with wound covering material of
substance to prevent tissue adhesion. It was performed in sub-acute toxicity, and tested local effects
after implantation.
Occlusion Effect of Dentinal Tubules of the Dentifrice Containing Nano-Sized Carbonate Apatite
Authors: Lee Su Young , Jang Sun Ok , Kwon H.K. , Cho Young Sik , Kim B.I.
Published: March 2009

Exposed dentine with patent tubules allows the movement of the tubule fluid leading to dentine
sensitivity. An occlusion of patent dentinal tubules can effectively reduce the state of dentine
hypersensitivity. Strontium chloride (SrCl2) has been known as a representative component of a
desensitizing dentifrice. Recently, a desensitizing dentifrice containing nano-sized Carbonated
Apatites (n-CAPs) was released onto the market. The aim of this in vitro study was to evaluate the
occlusion effects of dentinal tubules in dentifrices containing several concentrations of the n-CAPs.
One hundred human dentine specimens were embedded into a Teflon mold and ground with
silicone carbide papers to expose the dentin surface. The dentin surface was etched with 37%
phosphoric acid for 60 seconds and washed ultrasonically for 1 hour. The dentifrices were classified
into five groups: experimental dentifrices Group 1: n-CAPs 5%, group 2: n-CAPs 15%, group 3: n-
CAPs 0% and group 4: n-CAPs 30%, and the control dentifrice group 5: SrCl2 10%. The dentifrice
slurries were prepared as 20 grams of dentifrice in 80 ml of distilled water. Fifty specimens were
brushed with the dentifrice slurries using a V8 Cross Brushing Machine. Tooth brushing was
performed 5,000 times using a back-and–forth stroke. Images showing the sizes of the dentinal
tubules were taken by scanning electron microscopy (×3000) and the changes in the tubule sizes
were analyzed using a digital analyzer. The n-CAPs used in this study had a high solubility and
affinity to bone minerals. In addition, the n-CAPs were well deposited on patent dentinal tubules.
The group 1 dentifrice (n-CAPs 5% and silica 25%) showed the highest dentinal tubule occlusion,
and there was a statistically significant difference between group 4 and the control (p<0.05). Overall,
the dentifrice containing 5% nano carbonated apatite and 25% silica is the most effective in
occluding dentinal tubules.
Investigation of Biomechanics Behavior in Unstable Pertrochanteric Fracture Treated with Three Typical Nails by FEA
Authors: Shi X.H. , Zheng L. , Luo J.M. , Yang Li , Wu Yao , Zhang Xing Dong
Published: March 2009

Fixation nail systems , such as DHS, DCS and the standard Gamma-nail, are widely
applied for the 31-A2 intertrochanteric unstable fractures treatment, but which one would be of
more curative effect is still remained as a disputed problem. In this work, precise femur model with
31-A2 fracture was rebuilt based on the CT data, and fixation nail models were built by CAD. By
the means of finite element analysis (FEA), the biomechanical data of femur and nail systems were
achieved under typical loading. The results show that under the same load, the maximal stresses on
the fracture sections for DCS, DHS and Gamma nail systems are 48MPa, 24MPa and 19MPa,
separately; and the directional deformation is the highest with DCS fixation systems, while lowest
with Gamma nail fixation system. Considering the mechanical safety, Gamma nail is more suitable
for 31-A2 intertrochanteric unstable fractures treatment.
Comparison of a PGA Sheet with a Commercial ePTFE Sheet as a Staple-Line Reinforcement in Lung Surgery
Authors: Jo Keon Hyeon , Moon Seok Whan , Kim Young Du , Sa Young Jo , Choi Si Young , Yoon Jeong Sub , Wang Young Pil , Yeo Guw Dong , Bae Cheol Min
Published: March 2009

To prevent prolonged air leakage after lung surgery, we developed a
biodegradable polyglycolic acid (PGA) sheet and compared it with an expanded
polytetrafluoethylene (ePTFE). Eighteen adult mongrel dogs were used in this
experiment. The airway pressures at which air first leaked at the stapled resection
margins were measured immediately after surgery in group I (N=5), 2 days after surgery
in group II (N=5), and 7 days after surgery in group IIII (N=5), Based on the presence
of SLR, there were 3 subgroups in each group: there was no SLR in subgroup a; ePTFE
in subgroup b; PGA sheet in subgroup c. The histologic examination was performed 2
months after surgery (N=3). In group I, there was a significant difference in air leakage
pressures (mm Hg) between no reinforcement and SLR. We observed the same results
in group II and III with statistical significance. However, there was no significant
difference between the reinforcement groups. The histologic findings demonstrated
more severe adhesions and biodegradation in the dogs in which the PGA sheet was used.
Our PGA sheet was considered a useful reinforcement material, because it had a similar
threshold for air leakage with the ePTFE with excellent biodegradation.
Observation of Proliferation and Attachment of Three Different Cell Types on Nano-Fibrous Silk Film & Scaffold
Authors: Baek Hyun Sook , Park Young Hwan , Seok Ki Chang , Park Jong Chul , Rah Don Kyun
Published: March 2009

Attachment and viability of different cell types(fibrioblast, chondrocyte and osteoblast )
was observed on two forms of silk (mat & Three-dimensional scaffolds). The osteoblasts behaviors
cultured on silk mat were significantly higher than that found on 3-D silk fibroin scaffold (3-D SF
scaffold). In the MTT assay, the cell viability of fibroblasts, chondrocyte and osteoblasts seeded on
2-D nanofiber mat was (2-D mat) significantly higher than that found on 3-D SF scaffold. Similar
result could be seen from SEM observation and cell attachment study. However, alkaline
phosphatase activity was significantly increased on 3-D SF scaffold than on2-D nanofiber
A Novel Non-Destructive Method for Measuring Elastic Moduli of Cultivated Cartilage Tissues
Authors: Jung Duk Young , Kang Yu Bong , Tsuchiya Toshie , Tsutsumi Sadami
Published: March 2009

Accurate measurement of the mechanical properties of artificial or cultivated cartilage is
a major factor for determining successive regeneration of defective soft tissues. In this study, we
developed a novel method that enabled the bulk modulus (k-modulus) to be measured
nondestructively using the relationship between volume and pressure of living soft tissues. In order
to validate this method we estimated the bulk modulus of soft silicone rubbers using our new
method and a conventional method. The results showed a 5 ~ 10% difference between the results
obtained with the two methods. Our method was used subsequently to measure the mechanical
properties of cultivated cartilage samples (collagen gel type), that had been incubated for four
weeks in the presence or absence of human articular chondrocytes (HACs). Our experiments
showed that cultivated cartilage tissues grown in the presence of HACs had a higher bulk modulus
(120 ± 20 kPa) than samples grown without HACs (90 ± 15 kPa). The results indicated that our
novel method offered an effective method for measurement of volume changes in minute living soft
tissues, with the measurements having a high degree of accuracy and precision. Furthermore, this
method has significant advantages over conventional approaches as it can be used to rapidly and
accurately evaluate the strength of soft tissues during cultivation without causing damage to the
specimen.
The Effects of Antibiotics Blended Chitosan Membranes on the Calvarial Critical Size Defect in Sprague Dawley Rats
Authors: Chae Gyung Joon , Lee Sang Bae , Jung Ui Won , Lee Yong Keun , Kim Chong Kwan , Choi Seong Ho
Published: March 2009

The purpose of this study was to evaluate the osteogenesis of tetracycline blended chitosan
membranes on the calvarial critical size defect in Sprague Dawley. An 8 mm surgical defect was
created with a trephine bur in the area of the midsagittal suture. Forty rats were divided into four
groups: negative control group, positive control group and two experimental groups. Three types of
membranes were made and a comparative study was done. One type of non-woven membrane was
made by chitosan for positive control. The other two types of non-woven membranes were made by
immersing non-woven chitosan into either the tetracycline solution or the chitosan-tetracycline
solution. Histologic analysis was done at 2 weeks and 8 weeks of healing periods. We concluded that
that the use of tetracycline blended chitosan membrane on the calvarial defects in rats has a significant
effect on the regeneration of bone tissue in itself. In addition it implicates that tetracycline blended
chitosan membrane may be useful for guided tissue regeneration.
Immobilization of the Horseradish Peroxide on the Multi-Wall Nanotube and its Application for H2O2 Sensing
Authors: Seo Kang Deuk , Oh Seong Dae , Choi Seong Ho , Oh Sang Hyub , Woo Jin Chun , Kim Sang Ho
Published: March 2009

In order to immobilize enzyme to multi-wall nanotube (MWNT), the MWNT was coated
by the electrochemical polymerization of aniline. The horseradish peroxide (HRP) was immobilized
on the surface of the polyaniline (PANI)-coated MWNT (PANI-MWNT film) by using gold
nanoparticle (physical immobilization). The HRP was also immobilized on the surface of PANIMWNT
film by using 2-aminothiophenol and Au nanoparticle (self-assembling immobilization).
HRP was immobilized on the surface of PANI-MWNT electrode by using glutaric dialdehyde
(covalent immobilization). The sensing efficiency of HRP-MWNT electrodes for H2O2 was
evaluated by amperometric method. The sensing efficiency of HRP-MWNT electrodes for H2O2
was as following order; physical immobilization > covalent immobilization > self-assembling
immobilization.
Hydrothermal Synthesis of Hydroxyapatite Powders Using Alkyl Ammonium Bromides as Surfactants
Authors: Park Hyun Jung , Dabhade Vikram V. , Kim Kyung Ja , Kim Soo Ryong , Kwon Woo Teck , Kim Y.
Published: March 2009

Rod shaped nanocrystalline powders of hydroxyapatite (HAp) were synthesized by a low
temperature chemical route involving calcium nitrate tetrahydrate and sodium phosphate. Three
types of alkyl ammonium bromide surfactants i.e. tetrapropylammonium bromide,
tetraethylammonium bromide and tetramethylammonium bromide were used to regulate the
nucleation and crystal growth. The synthesized powders were characterized by XRD, SEM and FTIR.
The effect of the various alkyl ammonium bromide surfactants on the phase formation, particle
size and morphology of the hydroxyapatite powders has been investigated and reported.
Well Defined Surface Preparation with Phospholipid Polymers for Highly Sensitive Immunoassays
Authors: Poilane Nadia , Takai Madoka , Ishihara Kazuhiko
Published: March 2009

Plastic substrates were modified with 2-methacryoyloxyethyl phosphorylcholine (MPC) copolymer
brushes by surface-initiated atom transfer radical polymerization (ATRP) with a mean chain density
of 2.44 chains/nm2 and a chain length around 50nm. Ellipsometry, X-ray photoelectron
spectroscopy, gel permeation chromatography, nuclear magnetic resonance and atomic force
microscopy were used to characterize the modified surfaces.MPC was copolymerized with a
methacrylate monomer including an active ester unit which can link covalently with antibodies.
They latter were immobilized on these well-defined surfaces for characterization and a further use
in enzyme-linked immunosorbent assay (ELISA).All kinds of surfaces displayed a good density of
immobilized antibodies mainly forming globular packs of around 500 units. A water-soluble MPC
polymer-based stabilizer added to the antibody solution could further their individual
immobilization.
Human Cartilage Tissue Engineering with Pluronic and Cultured Chondrocyte Sheet
Authors: Jeong Jae Ho , Moon Y.M. , Kim S.O. , Yun S.S. , Shin Hong In
Published: March 2009

Despite many outstanding research works on cartilage tissue engineering, actual
clinical application is not quite successful because of the absorption and progressive distortion of
tissue engineered cartilage. We have developed a new method of cartilage tissue engineering
comprising chondrocyte mixed Pluronic F-127 and cultured chondrocyte cell sheet which entirely
cover the cell-Pluronic complex. We believe the addition of cultured chondrocyte cell sheet
enhances the efficacy of chondrogenesis in vivo.
Human ear cartilage piece was enzymatically dissociated and chondrocyte suspension was
acquired. Chondrocytes were cultured and expanded as the routine manner. Cultured chondrocytes
were plated in high-density monolayer and cultured with Chondrogenic media in 5% CO2 incubator.
After 3 weeks of culture, chondrocyte cell sheet was formed and complete single sheet of
chondrocyte could be harvested by gentle manipulation of culture plate with a cell scraper.
Chondrocyte-Pluronic complex was established by mixing 1x 106 cells with 0.5 of Pluronic F-
127. Chondrocyte-Pluronic complex was completely covered with a sheet of cultured chondrocyte.
The completed tissue engineered constructs were implanted into the subcutaneous tissue pocket of
nude mice on the back. Tissue engineered constructs without cultured cell sheet were used as
control. Samples were harvested at 8 weeks postoperatively and they were subjected to histological
analysis and assayed for glycosaminoglycan (GAG), and type II collagen. Grossly, the size of
cartilage specimen of cultured chondrocyte cell sheet covered group was larger than that of the
control. On histologic examination, the specimen of cultured chondrocyte cell sheet covered group
showed lacunae-containing cells embedded in a basophilic matrix. The chondrocyte cell sheet
covered group specimen resembled mature or immature cartilage. The result of measurement of
GAG and type II collagen of cartilage specimen of cultured chondrocyte sheet covered group was
higher than that of the control.
In conclusion, the new method of cartilage tissue engineering using chondrocyte cell sheet seems
to be an effective method providing higher cartilage tissue gain and reliable success rate for
cartilage tissue engineering.
Fluoride Releasing from Dental Pit and Fissure Sealant Including Sodium Fluoride and Stannous Fluoride
Authors: Choi Eun Mi , Lee Sang Bae , Oh Young Il , Lee Ju Hye , Choi Shin Kyu , Oh Myung Hwan , Kim Kwang Mahn
Published: March 2009

The 2% NaF and 8% SnF2 have been used in topical fluoridation method in the dental office to increase the resistance of enamel to acid dissolution. Bis-GMA based monomers have been used for the basic materials in the dental pit and fissure sealants. Therefore, the resinous pit and fissure sealant including fluorides may increase the effect of preventing dental caries. In this study, we made a novel dental pit and fissure sealant and evaluated some properties, especially fluoride release. In order to make experimental pit and fissure sealant including fluoride, NaF and SnF2 powder were added into self-made monomer composed of Bis-GMA, TEGDMA, UDMA and photo initiator system by weight percent of 2% and 8% respectively. The just monomer without fluoride powder was used for control. Uncured film thickness and depth of cure were measured according to ISO specification 6874:1988 and the viscosity was measured using rheometer. The five disc specimens were made using light curing unit to evaluate fluoride releasing and each specimen was immersed in the artificial saliva of 10 mL. Fluoride ion concentrations in extracts were measured for 3 days using fluoride electrode at every 12 hrs. There was no significant difference between experimental and control group in the depth of cure, uncured film thickness, and viscosity (p>0.05). The released fluoride ion concentration was continuously retained for 72 hrs.
Improved Non-Invasive Biomechanical Evaluation Method for the Virtue of Risedronate
Authors: Ko Chang Yong , Lee Tae Woo , Woo Dae Gon , Kim Han Sung , Lee Beob Yi
Published: March 2009

New medicines for treatment of osteoporotic bones have developed. In the previous
studies, there were lots of pre-clinical experiments on animals to analyze the virtue of new medicine.
However, the previous methods sacrificed a number of animals. They induced lots of expenses and
ethical problems. In the present study, to investigate the effect of a medicine for osteoporosis by
using in-vivo micro computed tomography (In-vivo Micro-CT, skyscan 1076, skyscan, Belgium)
and micro finite element (*FE) analysis, morphological and mechanical characteristic changes of
rat bone were detected and tracked. The 8 female Sprague-Dawley rats, used in the experiment,
were randomized into 3 groups (Control, Sham and Risedronate group). The Risedronate (actonel,
0.58mg/Kg and 5days/week) for 8 weeks was administered in RIS group. The 4th lumbar vertebrae
of rats were scanned by In-vivo Micro-CT with 35*m at week 0 (just before dose) and week 8 (after
dose). Three-dimensional (3D) structural parameters were calculated. Simulated compression tests
of 3D FE models were carried out to investigate the mechanical characteristics in the whole
vertebral bone model of the 4th lumbar vertebra. The change rate of quantity and structure in
Risedronate (RIS) group was smaller than that of control (CON) group. The change rate of
structural modulus in RIS group was also smaller than that of CON group. This result shows the
virtue of risedronate quantitatively as well as qualitatively. The study introduced the improved noninvasive
biomechanical evaluation method, combined with In-vivo Micro-CT and *FE analysis,
which was more effective and useful than the previous pre-clinical experiments.
Development of Guidelines for Nanobiosensor Evaluation as Medical Devices
Authors: Roh H.W. , Cho Y.H. , Jung H.S. , Lee N.R. , Kim H.C. , Chung T.D. , Kim J.W. , Lee H.K. , Lee Seung Jin , Ryu G.H.
Published: March 2009

To use nanobiosensors as diagnostic devices, they should be evaluated and approved as
medical devices before marketing. This study was performed to establish appropriate evaluation
guidelines that provide how to verify the safety and effectiveness of a novel nanobiosensor as a
medical device. We prepared an enzymeless glucose sensor with nanoporous platinum electrode
to evaluate performance and stability by comparing it with a commercial enzyme-based glucose
sensor. Through these evaluation studies, we developed guidelines, and the guidelines consist of
five parts: evaluation of analytical performance, clinical performance, safety, stability, and design
and quality control systems. Analytical and clinical performance of nanobiosensors should be
evaluated by accuracy, sensitivity, reproducibility, cut-off value, and other specific performance
characteristics. Also, electric, mechanical, and biological safety should be evaluated. With the
performance and safety, validation of storing conditions and shelf life should be established with
evaluation and characterization of nano-structured parts for stability evaluation. Then, design and
quality control systems should be evaluated in the aspect of quality requirements, material,
manufacturing process, and final product. These guidelines will be helpful for facilitating the
commercialization of the safe, effective, and novel diagnostic nanobiosensors into market place.
Remineralization Effects of Herbal Extracts with Fluoride on Artificial Caries Enamel
Authors: Hong Suck Jin , Kim B.I. , Kwon H.K. , Choi Choong Ho
Published: March 2009

The purpose of this study was to investigate the remineralization effect of Galla Rhois
and Psoralea corylifolia extracts with sodium fluoride (NaF), and interaction between the herbal
extracts and NaF in dentifrice using the microbiological pH cycling model on artificial caries
enamel. For the analysis, Surface hardness score of the enamel lesion on bovine teeth was measured,
before and after the microbiological pH cycling sequences for 15 days. It showed that fluoride
group was more higher surface hardness score than non fluoride group, and there were no
significant differences among test dentifrices in each group. Thus, it is suggested that Galla Rhois
and Psoralea corylifolia extracts with NaF have the remineralization effect on tooth surface. And
there was no antagonistic interaction between those herbal extarcts and NaF in dentifrice.
The Effect of Molecular Weight of Drugs on Transdermal Delivery System Using Microneedle Device
Authors: Lee Chang Rae , Kim Moon Suk , Lee Hai Bang , Lee Han Ku , Rhee John M. , Khang Gil Son
Published: March 2009

We developed the successive roller type of microneedle system without pain to improve
the permeation of drug through the skin barrier. The permeation rates of FITC-ovalbumin (OVA,
MW: 45,000g/mole), FITC-insulin (MW: 5,733 g/mole) and FITC-bufexamac (MW: 227.37
g/mole) as model drugs were determined by modified Franz diffusion cells using the microneedle
device with four times treatment. The average penetration fluxes of FITC- OVA, FITC-insulin and
FITC-bufexamac were steeply increased from 13.4 to 83.3, 10.1 to 110.6 and 11.9 to 242.6
pmol/cm2 with treatment for 12 hrs, respectively. The lower the molecular weight of the drugs, the
more the permeation flux investigated. In conclusion, we confirmed the possibility of the
application for transdermal delivery of the larger molecular drugs as protein using the designed
microneedle treatment device.
The Effect of Sheet and Material Properties on Springback in Air Bending
Authors: D'Urso Gianluca Danilo , Pellegrini Giuseppe , Maccarini Giancarlo
Published: March 2009

Angle control in air bending is achieved either by exploiting direct angle measurement
(adaptive forming) or by controlling punch displacement. In general, the desired angle is supplied as
input to CNC press brakes and the choice of punch stroke relies on either analytical or empirical
models. Process geometry and material properties affect the outcome, therefore, full knowledge of
these values is critical. Since a major source of inaccuracies is due to errors in material description
(sheet thickness is critical as well), material data (or, more generally, sheet behavior information)
collection in process is advisable. In air bending, process control can be improved by studying the
total load as a function of punch displacement. This approach becomes more and more interesting
since devices for load measurement are now available on the market.
The aim of this work is to analyze some experimental load measures, collected in actual working
conditions, to evaluate the accuracy of such technique and its potential for in process applications.
Several sheet materials (ferrous and non-ferrous alloys) are studied through both bending and tensile
tests; the resulting material properties (tensile and bending) are evaluated and compared. After data
treatment of punch force signal, the ability of predicting punch displacement needed to reach a
defined bending angle (after springback) is discussed.
Economical and Ecological Benefits of Process-Integrated Surface Structuring
Authors: Thome M. , Hirt Gerhard
Published: March 2009

Properties and functional behavior of modern products are strongly influenced by their
surface characteristics - like their appearance and haptics as well as their optical, tribological and
fluidic performance [1]. In present production processes these functional features are mostly
generated by surface treatment processes (e. g. grinding, etching, coating). In contrast to these costintensive
and complex off-line sequences rolling provides an opportunity to apply functional
structures on sheet metal products using non-pollutive synergy-potentials of the process.
High Temperature Strength of Three ODS Ferritic/ Martensitic Steels
Authors: Yoon Han Ki , Kimura Akihiko
Published: March 2009

Oxide dispersion strengthened (ODS) materials is leading candidates for blanket/first-wall
structures of the fusion reactor. ODS materials for structure application in fusion rector would allow
to increase the operating temperature to approximately 650. Therefore, this work focused on the
optimization of metallurgical features to improve high temperature strength and elongation through
understanding of contents of Cr and Al. In the study, the three kinds of ODS steels such as 19Cr-ODS
(K1), 13Cr-Al-ODS (K2) and 19Cr-Al-ODS (K4) with Y2O3 content of 0.37wt% have been produced.
And tensile test were performed on three ODS ferritic/martensitic steel between RT, 300, 400 and
600Dispersion hardening represents an interesting approach to improve the mechanical properties
at elevated temperature, as they are foreseen in the future fusion reactor It has been successfully
demonstrated that it is possible to expanse the temperature range for the application of fusion reactor.
Residual Stress and Oxidation Properties of NITE-SiC Ceramics by Heat Treatment
Authors: Kim Seong Hoon , Yoon Han Ki
Published: March 2009

In this study, Nano Infiltration Transient Eutectic Phase SiC ceramics (NITE-SiC) was
fabricated by hot press method with nano-SiC powder which a particle size is about 30nm, and
alumina, yttria and silica were used for sintering additives. Process condition of NITE-SiC was given
temperature of 1800oC, pressure of 20Mpa and holding time of 1Hr. NITE-SiC was optimization for
densification and good mechanical properties by preceding researches. As a result, weight loss was
occurred heat treatment temperature of all. Surface of heat treated specimens was occurred reacting of
oxidation or erosion. All Point was occurred residual stress, but residual Stress was show Relaxant
properties by effect of heat treatment.
Corrosion Resistance and Mechanical Properties of Carbon Steel under a High Temperature Pressurized Water
Authors: Lee Sang Ll , Lee Moon Hee , Lee Jin Kyung , Bae Dong Su , Lee Joon Hyun
Published: March 2009

The long-term corrosion strength properties for the carbon steels under pressurized water
atmosphere have been investigated, in the conjunction with the detailed analysis of their
microstructures. The corrosion test for carbon steels was carried out at the temperature of 200°C
under a water pressure of 10 MPa. The corrosion test samples were maintained up to 50 weeks in the
tube shaped reactor. The mechanical strength and the microstucture of carbon steels suffered from the
long term corrosion test were evaluated by SEM, XRD and tensile test. The weight loss of carbon
steel by the corrosion test was also examined. The tensile strength of carbon steels decreased with the
increase of corrosion time under a pressurized water atmosphere, accompanying the creation of severe
corrosion damages like stress corrosion crack.
Friction and Wear of Flange and Shaft in Compressor under the Environments of PAG Oil and Carbon Dioxide as a Refrigerant
Authors: Lee Kyu Sun , Jeon Hong Gyu , Cho Sung Oug , Lee Young Ze
Published: March 2009

In order to protect the global environment, especially on the point of the greenhouse
effect, carbon dioxide should be used as a natural refrigerant. Because new compressors with CO2
are going to be operated under the high pressure, the interaction between sliding surfaces in the
compressor becomes very important. To develop new compressor, especially rotary type, the
friction and wear characteristics of sliding surfaces were very important. In this paper, the surface
interactions between a shaft and a flange, which were one of the contacting parts in compressor,
were evaluated. The frictional forces and wear amounts in boundary lubricated sliding condition
were measured using the pin-on-disk tester. Two types of refrigerants were used, namely R410A
and CO2 to compare the tribological characteristics of conventionally used one with new natural
refrigerant. It was found that CO2 lead to a bad lubricity as compared with R410A or pure oil due to
the formation of relatively thin protective layer on the sliding surface. Smooth surface of shaft
produced lower values of friction and wear than rough surfaces. The smooth surfaces represented
much more spheroidal graphite, which had very favorable tribological characteristics, on the sliding
surfaces.