• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.237.3-238
• /
• 2003

Tissue engineering may be adequately defined as the science of persuading the body to regenerate or repair tissue that fail to regenerate or heal spontaneously. In the various techniques of cartilage tissue engineering, the use of 3-dimensional polymeric scaffolds implanted at a tissue defect site is usually involved. These scaffolds provided a framework for cells to attach, proliferate, and form extracellular matrix(ECM). The scaffolds may also serve as carriers for cells and/or growth factors. In the ideal case, scaffold absorb at a predefined rate so that the 3-dimensional space occupied by the initial scaffold is replaced by regenerated host tissue. (omitted)

• BMB Reports
• /
• v.57 no.9
• /
• pp.400-416
• /
• 2024

Matricellular proteins are integral non-structural components of the extracellular matrix. They serve as essential modulators of immunometabolism and tissue homeostasis, playing critical roles in physiological and pathological conditions. These extracellular matrix proteins including thrombospondins, osteopontin, tenascins, the secreted protein acidic and rich in cysteine (SPARC) family, the Cyr61, CTGF, NOV (CCN) family, and fibulins have multi-faceted functions in regulating immune cell functions, metabolic pathways, and tissue homeostasis. They are involved in immune-metabolic regulation and influence processes such as insulin signaling, adipogenesis, lipid metabolism, and immune cell function, playing significant roles in metabolic disorders such as obesity and diabetes. Furthermore, their modulation of tissue homeostasis processes including cellular adhesion, differentiation, migration, repair, and regeneration is instrumental for maintaining tissue integrity and function. The importance of these proteins in maintaining physiological equilibrium is underscored by the fact that alterations in their expression or function often coincide with disease manifestation. This review contributes to our growing understanding of these proteins, their mechanisms, and their potential therapeutic applications.

• Journal of Periodontal and Implant Science
• /
• v.44 no.4
• /
• pp.194-200
• /
• 2014

Purpose: The purpose of this study was to assess and compare the clinical and radiographic outcomes of guided tissue regeneration therapy for human periodontal intrabony defects using two different collagen membranes: a porous nonchemical cross-linking collagen membrane (NC) and a bilayer collagen membrane (BC). Methods: Thirty subjects were randomly assigned and divided into the following 3 groups: a test group (NC+BM), in which a NC was used with xenograft bone mineral (BM), a positive control group (BC+BM), in which a BC was used with xenograft BM, and a negative control group (BM), in which only xenograft BM was used. The following clinical measurements were taken at baseline and 3 months after surgery: plaque index, gingival index, probing pocket depth, gingival recession, and clinical attachment level. Radiographic analysis was performed at baseline, 1 week and 3 months after surgery. Results: Membrane exposure was not observed in any cases. Significant probing depth reduction, attachment-level gain and bone fill were observed for both test and control groups compared to baseline at 3 months after surgery (P<0.05). However, there were no statistically significant differences in clinical improvement and radiographic bone fill between treatment protocols (P>0.05). Conclusions: Within the limitations of this study, the results suggest that both NC and BC were comparable in terms of clinical and radiographic outcomes for the treatment of periodontal intrabony defects in human subjects.

• The Korean Journal of Physiology and Pharmacology
• /
• v.13 no.1
• /
• pp.15-22
• /
• 2009

This study was undertaken to elucidate the underlying mechanisms of ATP depletion-induced membrane transport dysfunction and cell death in renal proximal tubular cells. ATP depletion was induced by incubating cells with 2.5 mM potassium cyanide(KCN)/0.1 mM iodoacetic acid(IAA), and membrane transport function and cell viability were evaluated by measuring $Na^+$-dependent phosphate uptake and trypan blue exclusion, respectively. ATP depletion resulted in a decrease in $Na^+$-dependent phosphate uptake and cell viability in a time-dependent manner. ATP depletion inhibited $Na^+$-dependent phosphate uptake in cells, when treated with 2 mM ouabain, a $Na^+$ pump-specific inhibitor, suggesting that ATP depletion impairs membrane transport functional integrity. Alterations in $Na^+$-dependent phosphate uptake and cell viability induced by ATP depletion were prevented by the hydrogen peroxide scavenger such as catalase and the hydroxyl radical scavengers(dimethylthiourea and thiourea), and amino acids(glycine and alanine). ATP depletion caused arachidonic acid release and increased mRNA levels of cytosolic phospholipase $A_2(cPLA_2)$. The ATP depletion-dependent arachidonic acid release was inhibited by $cPLA_2$ specific inhibitor $AACOCF_3$. ATP depletion-induced alterations in $Na^+$-dependent phosphate uptake and cell viability were prevented by $AACOCF_3$. Inhibition of $Na^+$-dependent phosphate uptake by ATP depletion was prevented by antipain and leupetin, serine/cysteine protease inhibitors, whereas ATP depletion-induced cell death was not altered by these agents. These results indicate that ATP depletion-induced alterations in membrane transport function and cell viability are due to reactive oxygen species generation and $cPLA_2$ activation in renal proximal tubular cells. In addition, the present data suggest that serine/cysteine proteases play an important role in membrane transport dysfunction, but not cell death, induced by ATP depletion.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.13 no.2
• /
• pp.203-216
• /
• 1991

Nerve allografts as a bridge of regeneration is useful in the repair of peripheral nerve defect resulting from trauma, and leprosy. But immunological rejection and complicated scar formation is an unavoidable problem in the application of allogeneic nerves. This article is intended to study of the regeneration of allogeneic nerve grafts in rats with histopathologically, scanning electron microscopically. 24 adult male Sprague-Dawley rats were used as the experimental animals. A 2cm skin incision was made on the lateral aspects of limb, parallel to femur. Segments of sciatic nerve trunk taken from rats, 10mm was resected at the middle of the thigh, nerve graft was inserted between the ends of gaps with perineural and epineural suture method with 10-0 prolene. Obsrevation was made simultaneously at 3 day, 1, 2, 3, 4, 5, 6, 8 weeks after surgery. The results were as follows. 1. In light and electronic microscopic studies, marked degenerative change of the graft nerves were observed at 2 weeks after surgery. 2. After surgery, blood clot fromation was observed at 3 day, granualtion tissue formation was observed at 2 week, and fibrous tissue proliferation was observed at 3 week. 3. In change of nerve fiber, there were Wallerian degeneration at early stage, decrease in degeneration at 4 week but degeneration of myeline was continuded at 8 week. 4. At 4 week, schwann cells proliferate at its cut ends to join with the distal and proximal stump of the damaged nerve. 5. Fibrous scar tissues are formed at 2 weeks and increased progressively in 8 weeks, which was interrupted the regeneration of grafted nerve.

• Journal of Korean Academy of Nursing
• /
• v.36 no.3
• /
• pp.523-531
• /
• 2006

Purpose: The purpose of this study was to examine the effects of the ulmus root-bark dressing on tissue regeneration in experimentally-induced pressure ulcers in rats. Method: A randomized pretest/post-test control group time-series study design was used. Thirty-three male Sprague-Dawley rats were used in this study. The rats were anesthetized with 100mg/kg of ketamine. Pressure ulcers were induced at 140mmHg for three hours using a personally-designed pressing apparatus. For four weeks, the ulmus root-bark dressing was applied every other day in the experimental group (n=18) and a wet gauze dressing in the control group (n=15). For data analysis, the statistical program SPSS WIN 12 was used. The wounds were examined by light microscopy andelectron microscopy. Result: There were significant statistical differences in the size of the pressure ulcers as time went by(p=0.006). It should be noted that there were no significant statistical differences in the number of capillaries. Using light microscopy the inflammatory infiltration and neovascularization in the dermis in the experimental group emerged densely in the early stages, but recovered rapidly at the latter stages. In addition, the reepithelization of the epidermis occurred earlier than in the control group. By electron microscopy, the cell organelles of the capillary endothelial cells and the basal lamina of capillaries in the experimental group showed a more rapid maturation during the latter stages, compared with the control group. Conclusion: According to this study, it can be concluded that the ulmus root-bark dressing is effective regarding the healing of pressure ulcers.

• International Journal of Oral Biology
• /
• v.37 no.2
• /
• pp.63-68
• /
• 2012

It has been documented that SPA0355 exerts antiinflammatory effects via the inhibition of nuclear factor-kappaB activation. In present study, we investigated the inhibitory effects of SPA0355 on periodontitis in an animal model. Periodontitis was induced by ligation of the cervix of the 1st molar in the left mandible in rats. After ligature, the rats were randomly divided into four groups and topically applied with SPA0355 (0.5, 1, and 2%) or the vehicle alone once daily for 10 days. Body weight and food intake were measured daily throughout the experimental period. At day 10 post-ligature, the infiltration of inflammatory cells and distance of the cementoenamel junction (CEJ) to the alveolar bone crest (ABC) in the distal area of ligatured tooth were estimated histopathologically. No changes in body weight or food intake were found between the control and SPA0355 groups. The degree of inflammation was decreased in all three SPA0355 application groups. A decrease CEJ-ABC distance was observed in the 0.5% and 1% SPA0355 groups. These results indicate that SPA0355 inhibits the infiltration of inflammatory cells and alveolar bone resorption and suggests its potential as a therapeutic agent for periodontitis.

• The Journal of Advanced Prosthodontics
• /
• v.9 no.6
• /
• pp.453-462
• /
• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

• The Journal of Korean Medicine
• /
• v.24 no.3
• /
• pp.35-44
• /
• 2003

Objective : This study was performed to evaluate the effects of Palmijihwang-hwan (Baweidehuang-wan) and Obaeja (Galla Rhois) on the regeneration of periodontal tissue. Methods : In this study, we used MC3T3-El cells, such as osteoblast-like cell lines and human periodontal ligament fibroblasts, for experimental material. We separated each type of cells into a control group and an experimental group. In the control group, the cells were cultivated for 48 hours with distilled water and media which contained 10% fetal bovine serum (FBS) and penicillin (l00unit/ml)-streptomycin ($l00{\mu\textrm{g}}/ml$) at $37^{\circ}$ in 5% $CO_2$ gas. In the experimental group, the cells were cultivated for 48 hours with Palmijihwang-hwan extract and Obaeja extract (concentrations $1{\mu\textrm{g}}/ml,{\;}25{\mu\textrm{g}}/ml,{\;}50{\mu\textrm{g}}/ml$) under the same conditions as the control group. Investigating the regeneration of periodontal tissue was performed by evaluating proliferation, the activity of alkaline phosphatase and the synthetic ability of proteins using those cultivated cells by means of microculture tetrazolium (MTT) assay, alkaline phosphatase substrate kit and protein assay kit. Results : 1. In vitro, Palmijihwang-hwan extract increased the proliferation of MC3T3-El cells. 2. In vitro, Obaeja extract increased the activity of alkaline phosphatase and the synthetic ability of protein in MC3T3-El cells and human periodontal ligament fibroblasts depending on Obaeja extract's concentration. Conclusion : Obaeja extract can be developed as a subsidiary medicine for the regeneration of periodontal tissue. Further studies to evaluate the different concentrations the Obaeja extract and clinical trials in vivo are suggested.

• Journal of Periodontal and Implant Science
• /
• v.27 no.1
• /
• pp.151-163
• /
• 1997

The purpose of this study was to evaluate on the biodegradability, biocompatibility and tissue regenerative capacity of synthetic biodegradable $mernbranes-Resolut^{(R)}$, $Guidor^{(R)}$ and $Biomesh^{(R)}$. To evaluate the cell attachment on the membranes, in vitro, the number of gingival fibroblasts attached to each membrane was counted by hemocytometer. Cytotoxicity test for the membranes was performed by MTT test with gingival fibroblast For evaluation of guided- bone regenerative potential, the amount of new bone formation in the rat calvarial defects(5mm in diameter) beneath the membranes was observed for two weeks and examined of the specimens by Massons trichrome staining. Biodegradability was observed for 2, 4, 8 and 12 weeks after implantation of each materials under the skin of rats and examined the specimens with H & E staining. The number of cell attachment were the greatest in $Biomesh^{(R)}$ and followed by $Resolut^{(R)}$. Cell viability of three membranes was almost similar levels. Biodegradability of $Resolut^{(R)}$ was the highest among three membrane and the potential of guided bone regeneration was the greatest in the $Biomesh^{(R)}$ and $Resolut^{(R)}$ was followed. These results suggested that commercially available biodegradable membranes were non-toxic and highly potential to guided bone regeneration.