• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.385-387
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• 1997

Plasma luminescence spectroscopy was used or precise ablation of bone tissue during ultrashort pulse laser (USPL) micro-spinal surgery. Strong contrast of the luminescence spectra between bone marrow and spinal cord provided the real time feedback control so that only bone tissue can be selectively ablated while preserving the spinal cord.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

• International Journal of Stem Cells
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• v.16 no.4
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• pp.406-414
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• 2023

Dedifferentiated fat cells (DFATs) isolated from mature adipocytes have a multilineage differentiation capacity similar to mesenchymal stem cells and are considered as promising source of cells for tissue engineering. Bone morphogenetic protein 9 (BMP9) and low-intensity pulsed ultrasound (LIPUS) have been reported to stimulate bone formation both in vitro and in vivo. However, the combined effect of BMP9 and LIPUS on osteoblastic differentiation of DFATs has not been studied. After preparing DFATs from mature adipose tissue from rats, DFATs were treated with different doses of BMP9 and/or LIPUS. The effects on osteoblastic differentiation were assessed by changes in alkaline phosphatase (ALP) activity, mineralization/calcium deposition, and expression of bone related genes; Runx2, osterix, osteopontin. No significant differences for ALP activity, mineralization deposition, as well as expression for bone related genes were observed by LIPUS treatment alone while treatment with BMP9 induced osteoblastic differentiation of DFATs in a dose dependent manner. Further, co-treatment with BMP9 and LIPUS significantly increased osteoblastic differentiation of DFATs compared to those treated with BMP9 alone. In addition, upregulation for BMP9-receptor genes was observed by LIPUS treatment. Indomethacin, an inhibitor of prostaglandin synthesis, significantly inhibited the synergistic effect of BMP9 and LIPUS co-stimulation on osteoblastic differentiation of DFATs. LIPUS promotes BMP9 induced osteoblastic differentiation of DFATs in vitro and prostaglandins may be involved in this mechanism.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.169-170
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• 2013

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.483-509
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• 1999

Biodegradable barrier membrane has been demonstrated to have guided bone regeneration capacity on the animal study. The purpose of this study is to evaluate the effects of cultured calvarial cell inoculated on the biodegradable barrier membrane for the regeneration of the artificial bone defect. In this experiment 35 Sprague-Dawley male rats(mean BW 150gm) were used. 30 rats were divided into 3 groups. In group I, defects were covered periosteum without membrane. In group II, defects were repaired using biodegradable barrier membrane. In group III, the defects were repaired using biodegradable barrier membrane seeded with cultured calvarial cell. Every surgical procedure were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). After anesthesia, 5 rats were sacrificed by decapitation to obtain the calvaria for bone cell culture. Calvarial cells were cultured with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. The number of cell inoculated on the membrane were $1{\times}10^6$ Cells/ml. The membrane were inserted on the artificial bone defect after 3 days of culture. A single 3-mm diameter full-thickness artificial calvarial defect was made in each animal by using with bone trephine drill. After the every surgical intervention of animal, all of the animals were sacrificed at 1, 2, 3 weeks after surgery by using of perfusion technique. For obtaining histological section, tissues were fixed in 2.5% Glutaraldehyde (0.1M cacodylate buffer, pH 7.2) and Karnovsky's fixative solution, and decalcified with 0.1M disodium ethylene diaminetetraacetate for 3 weeks. Tissue embeding was performed in paraffin and cut parallel to the surface of calvaria. Section in 7${\mu}m$ thickness of tissue was done and stained with Hematoxylin-Eosin. All the specimens were observed under the light microscopy. The following results were obtained. 1 . During the whole period of experiment, fibrous connective tissue was revealed at 1week after surgery which meant rapid soft tissue recovery. The healing rate of defected area into new bone formation of the test group was observed more rapid tendency than other two groups. 2 . The sequence of healing rate of bone defected area was as follows ； test group, positive control, negative control group. 3 . During the experiment, an osteoclastic cell around preexisted bone was not found. New bone formation was originated from the periphery of the remaing bone wall, and gradually extended into central portion of the bone defect. 4 . The biodegradable barrier membrane was observed favorable biocompatibility during this experimental period without any other noticeable foreign body reaction. And mineralization in the newly formed osteoid tissue revealed relatively more rapid than other group since early stage of the healing process. Conclusively, the cultured bone cell inoculated onto the biodegradable barrier membrane may have an important role of regeneration of artificial bone defects of alveolar bone. This study thus demonstrates a tissue-engineering the approach to the repair of bone defects, which may have clinical applications in clinical fields of the dentistry including periodontics.

• The Journal of Advanced Prosthodontics
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• v.12 no.2
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• pp.67-74
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• 2020

PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.2
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• pp.71-78
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• 2022

This study was conducted to review the efficacy of different sources of stem cells in bone regeneration of cleft palate patients. The majority of previous studies focused on the transplantation of bone marrow mesenchymal stem cells. However, other sources of stem cells have also gained considerable attention, and dental stem cells have shown especially favorable outcomes. Additionally, approaches that apply the co-culture and co-transplantation of stem cells have shown promising results. The use of different types of stem cells, based on their accessibility and efficacy in bone regeneration, is a promising method in cleft palate bone regeneration. In this regard, dental stem cells may be an ideal choice due to their efficacy and accessibility. In conclusion, stem cells, despite the lengthy procedures required for culture and preparation, are a suitable alternative to conventional bone grafting techniques.

• Korean Journal of Veterinary Research
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• v.50 no.3
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• pp.171-177
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• 2010

The purpose of this study was to evaluate the osteogenic capacity of water extract of danshen (Salvia miltiorrhiza Bunge). We have established in rat critical-sized calvarial defect model using the combination with collagen scaffold and danshen hydrophilic extract. All rats were extinguished at 8 weeks after bone graft surgery, and the bone regeneration ability of bone grafting sides was evaluated by plain radiography and micro-CT. These results revealed water extract of danshen had the potential to promote osteogenesis especially continuous oral administration with local treatment compared to one-shot local treatment. This compound may provide a new alternative agent for growth factors to promote bone healing and bone regeneration. In conclusion, these results suggest that danshen hydrophilic extract have the potential to promote osteogenesis in bone defects. Further studies about fusion technology with salvianolic acid B, peptides, growth factors, and scaffolds using of the combination of tissue engineering, cell engineering and mechanical engineering are needed.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.136-137
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• 2005

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.159-159
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• 2017

Ti-6Al-4V alloy have been used for dental implant because of its excellent biocompatibility, corrosion resistance, and mechanical properties. However, the integration of such implant in bone was not in good condition to achieve improved osseointergraiton. For solving this problem, calcium phosphate (CaP) has been applied as coating materials on Ti alloy implants for hard tissue applications because its chemical similarity to the inorganic component of human bone, capability of conducting bone formation and strong affinity to the surrounding bone tissue. Various metallic elements are known to play an important role in the bone formation and also affect bone mineral characteristics. Especially, Zn is essential for the growth of the human and Zn coating has a major impact on the improvement of corrosion resistance. Plasma electrolytic oxidation (PEO) is a promising technology to produce porous and firmly adherent inorganic Zn containing TiO2(Zn-TiO2)coatings on Ti surface, and the a mount of Zn introduced in to the coatings can be optimized by altering the electrolyte composition. In this study, effect of Zn content on the corrosion behavior of Ti-6Al-4V alloy after plasma electrolytic oxidation were studied by SEM, EDS, XRD, AC impedance, and potentiodynamic polarization test. The potentiodynamic polarization and AC impedance tests for corrosion behaviors were carried out in 0.9% NaCl solution at similar body temperature using a potentiostat with a scan rate of 1.67 mV/s and potential range from -1500 mV to +2000 mV. Also, AC impedance was performed at frequencies ranging from 10 MHz to 100 kHz for corrosion resistance.