• The Journal of Korean Academy of Prosthodontics
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• v.34 no.1
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• pp.187-200
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• 1996

After loss of tooth, initial healing process is critical to preserve residual alveolar process. This study was conducted to compare the effect of hydroxylapatite particle synthetic graft and guided tissue regeneration procedure on healing of extraction wounds in 5 mongrel dogs. To investigate the maturity of bone and velocity of bone heating, bone-labeled tracers were used. After 16 weeks healing period, dogs were sacrificed. The specimens were treated with Villanueva bone stain. Fluorescence microscopy and polarized microscopy were performed to exam the pattern of bone formation in the extraction socket. The results were following ; 1. Pattern of bone regeneration in the group of hydroxylapatie graft and the group of membrane protection after hydroxylapatite graft was following ; bone regeneration was slow, regenerated bone was immature, and thickness of cortical layer was thin compare to that of untreated control group. 2. Cortical layers in membrane protected group were somewhat thicker but less condense to that of untreated control group. 3. Infiltration of inflammation cells were found in the groups using hydroxylapatite graft and membrane. We concluded that grafting of replamineform hydroxylapatite particles into the extraction socket delayed healing of the wound and disturbed the formation of cortical bone at the roof of extraction socket. The placement of expanded polytetrafluoroethylene membranes on the extraction socket promotes the bone regeneration. But newly formed bone in cortical layer consists of the cortico-cancellous bone in comparison with the cortical bone of the control group.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.609-619
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• 2000

Cyclosporin A(CsA) is now widely used to treat organ transplant recipients. But CsA has various short-and long-term side effects. Especially, gingival hyperplasia is not easy to resolve since its nature is still unknown. This study discusses the pathogenesis of CsA-induced gingival hyperplasia on the basis of data obtained from light and electron microscopic studies of biopsis from patients on CsA treatment after kidney transplantation. Light microscopically, the multilayered squamous epithelium showed an irregular surface of parakeratosis and deep invaginations in the subepithelial tissue. At lamina propria, we observed bundles of irregularly arranged collagen fiber, some fibroblasts, numerous capillary vessels and a large diffuse infiltration of plasma cells. Ultrastructurally, many fibroblasts, collagen fibers, collagen fibrils were present in lamina propria. On the basis of the data collected, we propose that the morphological features of the dimensional increase in gingival tissue associated with CsA treatment in kidney transplant patients may be considered proliferative fibroblasts, collagen fibers, collagen fibrils in lamina propria.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.277-290
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• 2012

Dental implants are universal restorative method on edentulous site in oral cavity and generally recognized by patients as well as clinicians. Rapid bone resorption of labial portion of maxillary anterior area is performed due to dental trauma, chronic periodontitis, and so on. Accordingly, Implants on maxillary anterior alveolar ridge with narrow labiopalatal width would lead to bony defects of dehiscence or fenestration. In this case, guided bone regeneration procedure is used to augment maxillary anterior alveolar ridge. It can have mechanical and biological advantages to mix tissue adhesive with bone graft materials in guided bone regeneration procedure. In these cases, when the dehiscence or fenestration defects was occurred by dental implants on maxillary anterior alveolar ridge with narrow labiopalatal width, guided bone regeneration procedures were performed with various combination of particle bone graft materials(allograft, xenograft, and alloplast) mixed with fibrin glue, excepting autogerous bone. We reported that all of 4 cases showed favorable alveolar ridge augmentations.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.235-240
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• 2007

Optimum tissue culture conditions for an efficient induction of embryogenic callus from mature seeds of perennial ryegrass (Lolium perenne L.) and regeneration of plants from callus tissues were investigated. MS medium containing 3 mg/L 2,4-D and 0.1 mg/L BA was optimal for embryogenic callus induction from mature seeds. The highest plant regeneration frequency (58.3%) was observed when the embryogenic callus tissues were cultured on N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Regenerated plants were grown normally when shoots transplanted to the soil. A short tissue culture period and high-frequency regeneration system would be helpful for molecular breeding of perennial ryegrass through Agrobacterium-mediated genetic transformation.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.355-362
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• 2008

Purpose: The carrier for the delivery of bone morphogenetic proteins(BMPs) should also serve as a scaffold for new bone growth. In addition, predictable bone formation in terms of the volume and shape should be guaranteed. This study evaluated the ectopic bone formation of recombinant human BMP-2(rhBMP-2) using a micro macroporous biphasic calcium phosphate (MBCP: mixture of ${\beta}TCP$ and HA) block as a carrier in a rat subcutaneous assay model. Materials and Methods: Subcutaneous pockets were created on the back of 40 male Sprague-Dawley rats. In the pockets, rhBMP-2/MBCP and MBCP alone were implanted. The blocks were evaluated by histological and histometric parameters after a healing interval of 2 weeks (each 10 rats; MBCP and rhBMP-2/MBCP) or 8 weeks (each 10 rats; MBCP and rhBMP-2/MBCP). Results: The shape and volume of the block was maintained stable over the healing period. No histological bone forming activity was observed in the MBCP alone sites after 2 weeks and there was minimal new bone formation at 8 weeks. In the rhBMP-2/MBCP sites, new bone formation was evident in the macropores of the block. The new bone area at 8 weeks was greater than at 2 weeks. There was a further increase in the quantity of new bone with the more advanced stage of remodeling. Conclusions: A MBCP block could serve as a carrier system for predictable bone tissue engineering using rhBMPs.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.369-377
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• 2023

Background: In this study, we investigated the potential use of keratin for oral tissue regeneration. Keratin is well-known for its effectiveness in skin regeneration by promoting keratinization and enhancing the elasticity and activity of fibroblasts. Because of its structural stability, high storability, biocompatibility, and safety in humans, existing research has predominantly focused on its role in skin wound healing. Herein, we propose using keratin proteins as biocompatible materials for dental applications. Methods: To assess the suitability of alpha-keratin protein as a substrate for cell culture, keratin was extracted from human hair via PEGylation. Viabilities of primary human gingival fibroblasts (HGFs) and human oral keratinocytes (HOKs) were assessed. Fluorescence immunostaining and migration assays were conducted using a fluorescence microscope and confocal laser scanning microscope. Wound healing and migration assays were performed using automated software to analyze the experimental readout and gap closure rate. Results: We confirmed the extraction of alpha-keratin and formation of the PEG-g-keratin complex. Treatment of HGFs with keratin protein at a concentration of 5 mg/ml promoted proliferation and maintained cell viability in the test group compared to the control group. HOKs treated with 5 mg/ml keratin exhibited a slight decrease in cell proliferation and activity after 48 hours compared to the untreated group, followed by an increase after 72 hours. Wound healing and migration assays revealed rapid closure of the area covered by HOKs over time following keratin treatment. Additionally, HOKs exhibited changes in cell morphology and increased the expression of the mesenchymal marker vimentin. Conclusion: Our study demonstrated the potential of hair keratin for soft tissue regeneration, with potential future applications in clinical settings for wound healing.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.137-143
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• 2009

An efficient system for high frequency plant regeneration was established through investigating various factors such as plant growth regulator combinations, explant types and ages, and addition of $AgNO_3$ influenced on shoot regeneration in Brassica juncea L. cv. BARI sarisha-10. Murashige and Skoog (MS) medium supplemented with 0.1 mg/L NAA (1-naphthaleneacetic acid) and 1 mg/L BA (6-benzyladenine) showed the maximum shoot regeneration frequency (56.67%) among the different combinations of NAA and BA. Explant type, explant age, and addition of $AgNO_3$ also significantly affected shoot regeneration. Of the four type of explants (cotyledon, hypocotyl, root, and leaf explants)- cotyledon explants produced the highest shoot regeneration frequency and hypocotyls explants produced the highest number of shoots per explant, whereas root explants did not produce any shoot. The cotyledonary explants from Four-day-old seedlings showed the maximum shoot regeneration frequency and number of shoots per explant. Shoot regeneration frequency increased significantly by adding $AgNO_3$ to the medium. Two mg/L $AgNO_3$ appeared to be the best for shoot regeneration with the highest shoot regeneration frequency (86.67%) and number of shoots per explant (7.5 shoots). Considerable variation in shoot regeneration from cotyledonay explants was observed within the B. juncea L. genotypes. The shoot regeneration frequency ranged from 47.78% for cv. Shambol to 91.11% for cv. Rai-5. In terms of the number of shoots produced per explant, B. juncea L. cv. Daulot showed the maximum efficiency. MS medium supplemented with 0.1 mg/L NAA showed the highest frequency of rooting. The regenerated plantlets were transferred to pot soil and grown to maturity in the greenhouse. All plants were fertile and morphologically identical with the source plants.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.67-76
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• 1993

After periodontal surgery, the potential healing responses were occurred by interaction among junctional epithelium, gingival connective tissue, alveolar bone and periodontal ligament. The only cell that created periodontal regeneration was derived from periodontal ligament. The aim of the study was to evaluate the regenerative effects of the collagen membrane($collacote^{\circ}C$) and autogenous connective tissure graft with periosteum. Experimental periodontitis were created in furcation area of 4 adult dogs with bone removal and gutta percha packing. After 6 weeks later, the gutta percha was removed and experiment was performed divided by 3 groups. 1) Flap operation(control group). 2) Flap operation with collage membrane(Experimental group I). 3) Flap operation with autogenous connective tissue graft with periosteum (Experimental group II). After dogs were sacrificed after two and three weeks, specimens were prepared and stained with hematoxylin-eosin and masson-trichrome stain for light microscopic study. The results were as follows : 1. In all gruoups, connective tissue compartments were increased from two to three weeks especially in experimental group I. 2. Collagen membrane and connective tissue were increased collagen deposits of periodontal ligament. Therefore collagen fiber attached to tooth surface was seen. 3. In al experimental groups, newly forming alveolar bone was seen. 4. Collagen membrane and connective tissue were which prevented proliferation of epithelium, aided connective tissue new attachment and influenced periodontal regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.2
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• pp.55-62
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• 2013

Bone tissue engineering is one of the important therapeutic approaches to the regeneration of bones in the entire field of regeneration medicine. Mesenchymal stem cells (MSCs) are actively discussed as material for bone tissue engineering due to their ability to differentiate into autologous bone. MSCs are able to differentiate into different lineages: osteo/odontogenic, adipogenic, and neurogenic. The tissue of origin for MSCs defines them as bone marrow-derived stem cells, adipose tissue-derived stem cells, and, among many others, dental stem cells. According to the tissue of origin, DSCs are further stratified into dental pulp stem cells, periodontal ligament stem cells, stem cells from apical papilla, stem cells from human exfoliated deciduous teeth, dental follicle precursor cells, and dental papilla cells. There are numerous in vitro/in vivo reports suggesting successful mineralization potential or osteo/odontogenic ability of MSCs. Still, there is further need for the optimization of MSCs-based tissue engineering methods, and the introduction of genes related to osteo/odontogenic differentiation into MSCs might aid in the process. In this review, articles that reported enhanced osteo/odontogenic differentiation with gene introduction into MSCs will be discussed to provide a background for successful bone tissue engineering using MSCs with artificially introduced genes.

• Archives of Plastic Surgery
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• v.39 no.6
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• pp.593-599
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• 2012

Background This study aimed to investigate the possibility of isolating mesenchymal stem cells (MSCs) from human thigh adipose tissue and the ability of human thigh adipose stem cells (HTASCs) to differentiate into hepatocytes. Methods The adipose-derived stem cells (ADSCs) were isolated from thigh adipose tissue. Growth factors, cytokines, and hormones were added to the collagen coated dishes to induce the undifferentiated HTASCs to differentiate into hepatocyte-like cells. To confirm the experimental results, the expression of hepatocyte-specific markers on undifferentiated and differentiated HTASCs was analyzed using reverse transcription polymerase chain reaction and immunocytochemical staining. Differentiation efficiency was evaluated using functional tests such as periodic acid schiff (PAS) staining and detection of the albumin secretion level using enzyme-linked immunosorbent assay (ELISA). Results The majority of the undifferentiated HTASCs were changed into a more polygonal shape showing tight interactions between the cells. The differentiated HTASCs up-regulated mRNA of hepatocyte markers. Immunocytochemical analysis showed that they were intensely stained with anti-albumin antibody compared with undifferentiated HTASCs. PAS staining showed that HTASCs submitted to the hepatocyte differentiation protocol were able to more specifically store glycogen than undifferentiated HTASCs, displaying a purple color in the cytoplasm of the differentiated HTASCs. ELISA analyses showed that differentiated HTASCs could secrete albumin, which is one of the hepatocyte markers. Conclusions MSCs were islolated from human thigh adipose tissue differentiate to heapatocytes. The source of ADSCs is not only abundant abdominal adipose tissue, but also thigh adipose tissue for cell therapy in liver regeneration and tissue regeneration.