• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1493-1494
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• 2013

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.1-7
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• 2014

Recent experimental observations support the hypothesis that mechanical stimuli play a role in regulating the specialized molecular expression of articular cartilage in vitro and in vivo. Other studies have demonstrated that the continuous passive motion(CPM)bioreactor for whole joints can provide a platform for possible future in vitro studies and applications, including possible interactions of bio-mechanical and biochemical signals. In this study, we have developed acustom-made bioreactor capable of bending and stretching with circular type motion, and a biomimetic knee joint model, using a 3D printer. This system could be used to investigate the effects of rehabilitative joint motion of dynamic culture.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.100.1-100.1
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• 2003

Tissue engineering has arisen to address the extreme shortage of tissues and organs for transplantation and repair. One of the most successful techniques has been the seeding and culturing cells on three-dimensional biodegradable scaffolds in vitro followed by implantaion in vivo. We used PLA and PLGA as biodegradable polymers and rabbit chondrocytes were isolated and applied to PLA and PLGA to make artificial cartilage. To evaluate the biocompatibility and biological safety of polymers, in vitro cytotoxicity and in vivo animal tests were investigated. (omitted)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.173-174
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• 2006

Understanding chondrocyte behavior inside complex, three-dimensional environments with controlled patterning of geometrical factors would provide significant insights into the basic biology of tissue regenerations. One of the fundamental limitations in studying such behavior has been the inability to fabricate controlled 3D structures. To overcome this problem, we have developed a three-dimensional microfabrication system. This system allows fabrication of predesigned internal architectures and pore size by stacking up the photopolymerized materials. Photopolymer SL5180 was used as the material for 3D scaffolds. The results demonstrate that controllable and reproducible inner-architecture can be fabricated. Chondrocytes harvested from human nasal septum were cultured in two kinds of 3D scaffolds to observe cell adhesion behavior. Such 3D scaffolds might provide effective key factors to study cell behavior in complex environments and could eventually lead to optimum design of scaffolds in various tissue regenerations such as cartilage, bone, etc. in a near future.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.34-39
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• 2017

In this study, intermolecular crosslinked carboxymethyl cellulose sodium salt (CMC) and porcine Cartilage Acellular Matrix (PCAM) blended hydrogel films for anti-adhesive barriers were prepared by gamma-ray radiation. The effects of the CMC/PCAM concentration and blending ratio on the morphology, gel fraction, gel strength, and degree of swelling were determined. The results indicated that crosslinked CMC/PCAM films show significantly lower the gel-fraction than CMC films. The degree of attachment and proliferation of human vascular endothelial cells on CMC/PCAM films was lower than the CMC films. We show the capacity of the CMC and PCAM to be hydrogel films, and the ability to reduce cell adhesion and proliferation on these films by modification with cell anti-adhesion molecules of PCAM. In conclusion, this study suggests that radiation cross-linked CMC/PCAM hydrogel films endowed with anti-adhesion ligands may allow for improved regulation of cell anti-adhesion behavior for prevent peritoneal adhesions.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.251-263
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• 2015

Scaffolds play a crucial role in the tissue engineering. Biodegradable polymers with great processing flexibility and biocompatability are predominant scaffolding materials. New developments in biodegradable polymers and their nanocomposites for the tissue engineering are discussed. Recent development in the scaffold designs that mimic nano and micro features of the extracellular matrix (ECM) of bones, cartilages, and vascular vessels are presented as well.

• Polymer Science and Technology
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• v.10 no.6
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• pp.732-742
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• 1999

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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• pp.781-791
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• 2018

BACKGROUND: Glucosamine hydrochloride (GlcN HCl) has been shown to inhibit cell growth and matrix synthesis, but not with N-acetyl-glucosamine (GlcNAc) supplementation. This effect might be related to an inhibition of critical growth factors (GF), or to a different metabolization of the two glucosamine derivatives. The aim of the present study was to evaluate the synergy between GlcN HCl, GlcNAc, and GF on proliferation and cartilage matrix synthesis. METHOD: Bovine chondrocytes were cultivated in monolayers for 48 h and in three-dimensional (3D) chitosan scaffolds for 30 days in perfusion bioreactors. Serum-free (SF) medium was supplemented with either growth factors (GF) $TGF-{\beta}$ ($5ng\;mL^{-1}$) and IGF-I ($10ng\;mL^{-1}$), GlcN HCl or GlcNAc at 1mM each or both. Six groups were compared according to medium supplementation: (a) SF control; (b) SF + GlcN HCl; (c) SF + GlcNAc; (d) SF + GF; (e) SF + GF + GlcN HCl; and (f) SF + GF + GlcNAc. Cell proliferation, proteoglycan, collagen I (COL1), and collagen II (COL2) synthesis were evaluated. RESULTS: The two glucosamines showed opposite effects in monolayer culture: GlcN HCl significantly reduced proliferation and GlcNAc significantly augmented cellular metabolism. In the 30 days 3D culture, the GlcN HCl added to GF stimulated cell proliferation more than when compared to GF only, but the proteoglycan synthesis was smaller than GF. However, GlcNAc added to GF improved the cell proliferation and proteoglycan synthesis more than when compared to GF and GF/GlcN HCl. The synthesis of COL1 and COL2 was observed in all groups containing GF. CONCLUSION: GlcN HCl and GlcNAc increased cell growth and stimulated COL2 synthesis in long-time 3D culture. However, only GlcNAc added to GF improved proteoglycan synthesis.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.518-523
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• 2004

PLGA was suggested. Under various conditions, their diameters and porosity as well as mechanical strength were evaluated. In addition to those, cell(chondrocyte) proliferation and formation of extracelluar matrices were also investigated along with the conventional membrane type PLGA scaffolds for the potential use in tissue engineering. As conclusions, this type of scaffold showed a potential of application to tissue engineering in view of mechanical stability as well as cellular responses.

• KSBB Journal
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• v.31 no.2
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• pp.120-125
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• 2016

Two-dimensional cultivation is typically used for cell growth, but the method reduces the characteristics of chondrocytes and stem cells, and limits culture area. Therefore, development of three-dimensional culture method is needed to mimic in vivo environment, improve quality of cells and scale-up efficiently. Improving proliferation and chondrogenesis is available by co-culture of chondrocytes and mesenchymal stem cells (MSCs) that leads to interaction between two kinds of cells. However, the co-culture has problems that permeability of sphere diminishes as aggregate size increased and ratio of two kinds of cells composing each spheres is different. In this work, co-cultivation method using controlled sphere composed of chondrocytes and MSCs was established and enhanced chondrogenesis. Periosteum-derived progenitor cells (PDPCs) that are appropriate for cell therapy source of articular cartilage were used as MSCs. Controlled spheres were formed in the hanging-drop plates and shifted for being induced chondrogenesis in 35-mm non-adhesive culture dishes at a rotation rate of 60 rpm. After inducing chondrogenesis, gene expressions related with chondrogenesis were found to be improved and it was apparent that the utilization of controlled spheres promoted chondrogenesis. As a result, available numbers of cells per unit area were increased and chondrogenic differentiation ability was improved compared to typical two-dimensional culture. This approach shows the potential in cartilage regeneration as it can provide sufficient numbers of chondrocytes.