Abstract: 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.
Abstract: Poly ε-caprolactone(PCL)/hydroxyapatite(HA) composite scaffolds were fabricated by
particulate leaching and freeze drying routes with different HA content. Porosity was decreased
with HA addition, while mean pore size was maintained at around porogen size regardless of HA
content. Compressive modulus was increased with increasing HA content. In this study, the
optimum content of HA was around 40% in weight against PCL to obtain the highest compressive
modulus with keeping porosity above 85%. HA apparently enhanced proliferation of osteoblast-like
MG63 cells in PCL/HA composite scaffolds. Typical adhesion, migration and aggregation
procedure of MG63 cells were found on PCL, while spreading morphology only was found on HA
even at the early stage of adhesion without migration or aggregation.
Abstract: 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
Abstract: 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
Abstract: 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.
Abstract: Poly (D,L-latic-co-glycolic acid) (PLGA) has been used as the artificial scaffold for
blood vessel formation. In order to hinder smooth muscle cell (SMC) angiogenesis, new scaffold
design method of loading Epigallocatechin 3-O-gallate (EGCG) on PLGA film was introduced.
PLGA and EGCG were dissolved in acetone and film-shape scaffold was manufactured. Antiangiogenetic
effect of EGCG released on scaffold was analyzed for SMC and human umbilical vein
endothelial cell (HUVEC) and method for selective inhibition from the difference of growth of
SMC and HUVEC was suggested.
Abstract: This paper compares the characteristics of chondrocyte adhesion on two types of threedimensional
(3-D) scaffold: types A and B. These 3-D scaffolds can be repeatedly constructed with
the same dimensions using microstereolithography, a system that allows the fabrication of predesigned
internal structures, such as pore size and porosity, by stacking the photopolymerized
material. In tissue engineering, chondrocyte adhesion to a scaffold should have a major effect on the
regeneration of cartilage. In this regard, we evaluated chondrocyte adhesion to two types of scaffold
and found that chondrocyte adhesion was better on the type B scaffold than on the type A,
demonstrating the importance of scaffold geometry in chondrocyte adhesion.
Abstract: The purpose of this study is to confirm the possibility of regenerating actual fat tissue
using human adipose tissue-derived stem cells (ASCs) and hyaluronic acid-collagen sponge in
animal model. Human ASCs of young female adults were isolated and culture expanded in basal
media. At the second passage, cultured ASCs suspension containing 106 cells was applied on prewetted
scaffolds the hyaluronic acid-collagen sponge and the sponges was exposed to adipogenic
media for the 1week. Then the tissue engineered constructs were implanted into the subcutaneous
pocket on the back of immunodeficient athymic nude mice for 3 weeks. Hyaluronic acid-collagen
sponges without human ASCs were used as the control. After 3 weeks, specimens were harvested
and adipogenic potentials were assessed with histological examination, RT-PCR for PPAR-γ2
expression and G-3-PDH activity.
Tissue engineered fat tissue from ASCs and hyaluronic acid-collagen sponges demonstrated
PPAR-γ2 positive expression and positive Oil red O staining. The histologic study showed
definitive adipose tissue and rich vascular tissue within the engineered fat. Two-fold higher
activities of G-3-PDH were identified in experimental group after 3 weeks as compared to control.
By contrast, the specimen from control group did not show active vessel ingrowth and contained
only few cellular elements within the scaffold. The control specimens failed to demonstrate
adipogenic gene markers and were negative in oil red O staining.
In conclusion, human ASCs can be differentiated into adipocytes and actual fat tissue engineering
was possible with combination of adequate scaffold materials, such as hyaluronic acid-collagen
sponges. These data demonstrate that fat tissue engineered from human ASCs can retain predefined
shape and dimension for soft tissue augmentation and reconstruction of defects.
Abstract: To improve ostegenic healing efficiency by demineralized bone matrix, we evaluated
the ectopic bone formation induced by variously demineralized allogenic cortical bone matrices
at subcutaneous and muscular sites in rats. The rat tubular cortical bone matrices were
demineralized in heated 0.6N HCl at 60 °C for 5 and 20 mins, respectively, using a controlledheat
ultrasonic cleaner and implanted in rat dorsal subcutaneous pouches and thigh muscles for
1-3 weeks. The influence of the demineralized condition of bone matrix on cellular proliferation
and osteogenic differentiation was also evaluated in vitro by MTT assay and ALP staining. The
cortical matrices were completely demineralized within 20 mins by sonication and heating of
diluted 0.6 N HCl. The sonicated bone matrices in heated acidic solution at 60 °C revealed no
adverse immunogenic and inflammatory response in vivo regardless of demineralized condition.
Cellular proliferation and osteoblastic differentiation was facilitated by more fully
demineralized. Ectopic bone formation was induced only by demineralized bone matrices and
were more favorable in fully demineralized matrices. The ectopic bone induction was more
favorably in subcutaneous pouches than in muscular tissue. These findings suggest that a fully
demineralized cortical bone matrix maximizes osteogenic repair by exposing more bioactive
molecules which in turn induce chondro- and osteognic differentiation of mesenchymal cells
around the implanted matrices, and that the sonication of diluted 0.6 N HCl heated at 60 ° C is a
rapid and effective method for sterile demineralized graft preparation.
Abstract: Porous and bioactive composite scaffolds based on poly ε-caprolactone(PCL) and
hydroxyapatite(HA) were successfully fabricated by solvent casting and salt leaching method. The
scaffolds have interconnected pore structure with pore size ranging from 10μm to 500μm. The pore
size of PCL scaffold and PCL/HA scaffold were similar to that of the salt particles. The pore walls
became thick and the small pores on the surface of macropores were formed as the HA increased.
MTT assay showed that HA content did not affect initial cell attachment in both PCL scaffolds and
PCL/HA scaffolds. The osteoblasts proliferated in both scaffolds, but the cell number was higher in
the PCL/HA composite scaffolds. It was found that the incorporation of hydroxyapatite enhances
bone cell proliferation rather than initial cell attachment in PCL/HA composite scaffolds. The
results suggest that the PCL/HA composite scaffolds have a potential for the bone tissue