• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1697-1699
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• 2008

The purpose of tissue engineering is to repair or replace damaged tissues or organs by a combination of cells, scaffold, suitable biochemical and physio-chemical factors. Among the three components, the biodegradable scaffold plays an important role in cell attachment and migration. In this study, we designed 3D porous scaffold by Rapid Prototyping (RP) system and fabricated layer-by-layer 3D structure using Polycarprolactone (PCL) - one of the most flexible biodegradable polymer. Furthermore, the physical and mechanical properties of the scaffolds were evaluated by changing the pore size and the strand diameter of the scaffold. We changed nozzle diameter (strand diameter) and strand to strand distance (pore size) to find the effect on the mechanical property of the scaffold. And the surface morphology, inner structure and storage modulus of PCL scaffold were analyzed with SEM, Micro-CT and DMA.

• 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 PSK Conference
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• 2003.10b
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• pp.122.2-122.2
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• 2003

Gelatin protein is derived from animal collagen tissues and is therefore present in many kinds of animal protein food. The biological origin and biocompatibility of gelatin has led to wide-ranging applications in the pharmaceutical and medical fields; for example, as sealants for vascular prostheses, bone-repairing materials, wound healing agents and scaffolds for tissue engineering purposes. In the present study, we investigated the effects of collagen and gleatin on the cyclooxygenase-2 (COX-2) gene which plays a crucial role in many physiological and pathological processes in macrophages. (omitted)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.58-65
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• 2016

This study was a preparatory experiment aimed the development of membrane scaffolds for tissue engineering. A PCL composite solution contained sodium chloride(NaCl). PCL porous membrane scaffolds were formed on a glass casting plate using a film applicator and immersed in distilled water to remove the NaCl reaching after drying. NaCl was used as a pore former for a 3 dimensional pore net-work. The dry condition parameters were $4^{\circ}C$, room temperature (RT) and $40^{\circ}C$ for each different temperatures in the drying experiment. SEM revealed the morphology of the pores in the membrane after drying and evaluated the in vitro cytotoxicity for basic bio-compatibility. The macro and micro pores existed together in the scaffold and showed a 3-dimensional pore net-working morphology at RT. The in vitro cytotoxicity test result was "grade 2" in accordance with the criterion for cytotoxicity by ISO 10993-5. The dry condition affected the formation of a 3 dimensional pore network and micro and macro pores. Therefore, these results are expected provide the basic process for the development of porous membrane scaffolds to control degradation and allow drug delivery.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.1-6
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• 2008

Purpose: In tissue engineering, it is important that the scaffolds have high affinity with cells for making efficient use of cells. The authors studied the binding affinity of human adipose stem cells(ASCs) to micronized acellular dermal matrix(alloderm) using biotin and avidin linkages.Methods: Human ASCs were harvested from adipose tissue obtained by abdominoplasty. ASCs($1{\times}10^4$, $5{\times}10^4$, $1{\times}10^5$, $5{\times}10^5$, $1{\times}10^6$, $5{\times}10^6$ cells) were attached to micronized alloderm(1mg) in three groups; 1) control group in which no ASCs and alloderm was treated; 2) serum group in which alloderm was exposed to fetal bovine serum; and 3) biotin group in which biotinylated cells were attached to biotinylated alloderm. The binding affinities were determined 1 day after making ASC-alloderm complexes. The proliferation rates were determined by XTT assays in 4, 7, 14, and 21 days and scanning electron microscopic examination was performed in 7 and 21 days after culture of ASC-alloderm complexes.Results: The binding affinities of the biotin group were significantly increased in all cell concentrations. Maximum binding affinity was observed at $5{\times}10^4/mg$ of micronized dermal matrix in biotin group. The viabilities were lowest in biotin group in contrast to binding affinity, but the difference was not significant. SEM showed well attachment of cells to micronized dermal matrix in all groups. Conclusion: The use of avidin/biotin facilitated human ASCs attaching to micronized acellular dermal matrix. This attachment would not disturb adipose stem cells viabilities. The present study suggests that avidin/ biotin can be used as making efficient use of cells in adipose tissue engineering.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.273-298
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• 2008

Purpose: The aim of this review is to introduce a novel bone-graft material for hard-tissue regeneration based on the calcium phosphate glass(CPG). Materials and Methods: CPG was synthesized by melting and subsequent quenching process in the system of CaO-$CaF_2-P_2O_5$-MgO-ZnO having a much lower Ca/P ratio than that of conventional calcium phosphates such as HA or TCP. The biodegradability and bioactivity were performed. Effects on the proliferation, calcification and mineralization of osteoblast-like cells were examined in vitro. Influence in new bone and cementum formations was investigated in vivo using calvarial defects of Sprague-Dawley rats as well as 1-wall intrabony defect of beagle dogs. The application to the tissue-engineered macroporous scaffold and in vitro and in vivo tests was explored. Results: The extent of dissolution decreased with increasing Ca/P ratio. Exposure to either simulated body fluid or fetal bovine serum caused precipitation on the surface. The calcification and mineralization of osteoblast-like cells were enhanced by CPG. CPG promoted new bone and cementum formation in the calvarial defect of Sprague-Dawley rats after 8 weeks. The macroporous scaffolds can be fabricated with $500{\sim}800{\mu}m$ of pore size and a three-dimensionally interconnected open pore system. The stem cells were seeded continuously proliferated in CPG scaffold. Extracellular matrix and the osteocalcin were observed at the $2^{nd}$ days and $4^{th}$ week. A significant difference in new bone and cementum formations was observed in vivo (p<0.05). Conclusion: The novel calcium phosphate glass may play an integral role as potential biomaterial for regeneration of new bone and cementum.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1153-1159
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• 2015

Recently, synthetic biopolymers and bioceramics such as poly (${\varepsilon}$-caprolactone)(PCL), hydroxyapatite, tricalcium phosphate, biphasic calcium phosphate(BCP), and zirconia have been used as substrates to generate various tissues or organs in tissue engineering. Thus, the purpose of this study was the characterization of $ZrO_2$/BCP/PCL(ZBP) scaffold for bone tissue regeneration. Based on the result of single-line test, blended 3D ZBP scaffolds with fully interconnected pores and new complex pore pattern of $45^{\circ}+135^{\circ}$-type and staggered-type were successfully fabricated using a polymer deposition system. Furthermore, the effect of ZBP scaffold on mechanical property was analyzed. In addition, in vitro cell interaction of ZBP scaffold on MG63 cells was evaluated using a cell counting kit-8(CCK-8) assay.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.302-307
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• 2013

Microbial fermented cellulose gel, citrus gel (CG), was successfully fabricated to porous foam by radiation treatment and freeze drying. The chemically induced radiation was used to create highly porous foam and further freeze drying of the CG produced tough foams with interconnected open pores for use in tissue engineering. The microstructure of the CG foam was controlled by varying the irradiation dose and quenching temperature with pore size ranging from several microns to a few hundred microns. Tensile strength and Gurley value of the CG foam were influenced by irradiation dose. These radiation induced CG foams are promising scaffolds for tissue engineering.

• 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.

• Textile Coloration and Finishing
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• v.34 no.4
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• pp.284-301
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• 2022

The limitations of food production caused by global warming, consumption of soil fertility, and land shortage have demanded the development of alternative foods. Their market has been increasing, and in particular, there is an urgent need for an alternative meat. Among them, the non-slaughtered cell-cultured meat that can be manufactured in the laboratory, that is, cultured meat, is in the spotlight, which can solve the problem of meat consumption while including the advantages of meat. It is classified into minced cultured meat and structured one with a structure similar to that of real meat. The latter is currently facing limitations related scaffolds, cells, and the multiplicative problems, and many attempts are being made to solve them. The complex problem is related to secure texture and taste as well as structural similarity to actual meat. To solve the problems, it is necessary to lay emphasis on cells, there are fat cells and vascular cells, and the most fundamental cells, muscle cells. These are the main cells that control the texture and nutrients of meat, and unlike other cells, they grow in the form of fibers. A myofibril (also known as a muscle fibril) is a basic rod-like organelle of a muscle cell, which is a quantitatively major component of meat, and one of the tissues that maintain the appearance of the body and bones. In this review article, we focused on the growth of muscle cells into long, tubular cells known as muscle fibers using the fabricated fibrous scaffold, and reviewed not only research results for muscle tissue engineering but also various results in the related fields for the last five years.