• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.51-63
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• 1994

There has been many attempts to develop a method that can regenerate periodontal tissues that were lost due to periodontal diseasd, but none of them was completely successful. This study was designed to investigate the healing and regeneration of periodontal tissue when bone substitutes such as porous replamineform hydroxyapatite and porous resorbable calcium carbonate were used in combination with oxidized cellulose membrane and collagen absorbable hemostat, compared to a control where only oxidized cellulose membrane or collagen absorbable hemostat were used. Chronic periodontitis was induced on mandibular premolars of and adult dog by placing orthodontic elastic ligatures for 10 weeks. After flap operation, the control group were received oxidized cellulose membrane (control- I )or collagen absorbable hemostat (control- II) only, while one experimental group was given either porous replamineform hydroxyapatite or porous resorbable calcium carbonate in addition to oxidized cellulose membrane (Experimental I-A, I-B), and another experimental group was treated by using either porous replamineform hydroxyapatite or porous resorbable calcium carbonate in addition to collagen absorbable hemostat. (Experimental II-A, II-B) After 56 weeks, healing was histologically analyzed with the following results. 1. Apical migration of junctional epithelium was observed only in areas coronal to the notch for both control and experimental group. 2. Inflammatory cell infiltration was not observed in any groups. 3. Oxidized cellulose membrane and collagen absorbable hemostat were completely resorbed. 4. Newly-formed cementum was observed up to the level where junctional epithelium was located, for both control and experimental groups. 5. Bone formation was limited of the middle portion of the notch in the control group, where as experimental groups showed bone formation up to the level of implant materials coronal to the notch. 6. Minute resorption of apically located portions of implanted materials was observed in experimental group I-B and II-B only.

• 대한두개안면성형외과학회지
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• 제20권5호
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• pp.289-296
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• 2019

Background: Topical hemostatic agents are used when ligation, electrocauterization, or other conventional hemostatic methods are impractical. Because a hemostatic agent is a foreign body, it can cause foreign body reactions, inflammation, and infections that can interfere with the wound healing process. Therefore, we should select hemostatic agents after considering their effects on wound healing. Here, we compared the effects of hemostatic agents on wound healing in a rectus abdominis muscle defect in rats. Methods: Twelve Sprague Dawley rats were subjected to creation of a $6{\times}6mm$ defect in the rectus abdominis muscle and divided into four groups: control group; group A, Tachosil fibrin sealant patch; group B, Surgicel Fibrillar oxidized regenerated cellulose; and group C, Surgicel Snow oxidized regenerated cellulose. For the histologic analysis, biopsies were performed on the 3rd, 7th, and 27th days. Results: The foreign body reaction was the weakest in group A and most significant in group C. The inflammatory cell infiltration was the weakest in group A and similar in groups B and C. Muscle regeneration differed among periods. The rats in group A were the most active initially, while those in group C showed prolonged activity. Conclusion: Tachosil and Surgicel administration increased inflammation via foreign body reactions, but the overall wound healing process was not significantly affected. The increased inflammation in the Surgicel groups was due to a low pH. We recommend using Tachosil, because it results in less intense foreign body reactions than Surgicel and faster wound healing due to the fibrin action.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권2호
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• pp.112-126
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• 1998

In dentistry, bony defects can be formed by cyst, tumor, inflammation, trauma and surgery in maxilla and mandible. If the overlying soft tissue invades and preoccupies the jaw bony defects, regenerated bony tissue same as adjacent bone can not replace whole space of the defects, thus preventing osteogenesis from occurring. Guided bone regeneration(GBR) is based on the prevention of overlying soft tissue from entering the bony defect during the initial healing periods. E-polytetrafluoroethylene(e-PTFE) is one of an effective and widely used barrier membrane for GBR, but it has the disadvantages such as surgical removal and high price. To overcome such disadvantages of e-PTFE, many investigators have proposed various absorbable barrier membranes. Inexpensive oxidized cellulose($Surgicel^{(R)}$) membrane was shown to have potential for use as an absorbable barrier membrane for regenerative procedure and it would not require surgical removal. The purpose of this study is to investigate the absorption periods of oxidized cellulose at the implant site and usefulness as a mechanical barrier, preventing the ingrowth of the overlying soft tissue into the bony defects. Two bony defects were made in each tibia of a dog using drill and one defect covered with oxidized cellulose and the other covered with periosteum directly as control. The experimental animals were sacrificed at 1st-7th, 10th, 14th, 21th, 28th day postoperatively, Inspection of the specimens was done to evaluate gross changes. Specimens were examined histopathologically by hematoxylin-eosin and Masson's trichrome staining under light microscope. The results were as follows : 1. There was no significant differences of inflammatory reaction between the experimental and the control group. 2. The resorption of oxidized cellulose was almost completed within 14th day. 3. Histologically, bone formation in the experimental group was somewhat more than that of the control group at 10th, 14th, 21th and 28th day postoperatively. The bone forming pattern of the experimental group was more regular than that of the control group. 4. There was no evidence of soft tissue invasion into the bony defect in the experimental group. In conclusion, oxidized cellulose membrane might be used as an alternative absorbable barrier membrane to prevent overlying soft tissue invasion into the bony defects.

• 한국식품영양과학회지
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• 제43권4호
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• pp.516-521
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• 2014

야관문 추출물의 피부재생능력을 알아보고, 창상을 유발한 실험동물 모델에서 창상 치유 효과를 검증하고자 6개 군(NO, CO, PC, LCL, LCM, LCH)으로 나누어 5주간 실험하였다. Elastase 저해 활성을 평가한 결과 LCM군에서 항산화제인 BHA보다 2.7%($52.39{\pm}4.52$ vs $53.88{\pm}1.85$) 낮은 수치를 나타내었으며, collagenase 저해 활성을 평가한 결과 LCM군에서 BHA보다 7%($37.68{\pm}2.91$ vs $35.19{\pm}7.80$) 더 높은 활성을 나타내었다. 창상유발 21일에 LCL군, LCM군 및 LCH군의 왼쪽 창상 면적은 CO군과 비교하여 각각 54.2%, 53.5% 및 48.7% 현저한 창상면적 감소를 보였다. 이로서 야관문 추출물은 피부상피조직의 재생과 교원질의 합성을 도와 외과적 창상에 치료 효과가 있는 것으로 판단된다.

• 방사선산업학회지
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• 제4권4호
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• pp.373-379
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• 2010

Cellulose, chitin, chitosan and hyaluronic acid are well known as polysaccharides. These polysaccharides have many effects on cell growth and differentiation. Cell activation increases with increasing the polysaccharides concentration. In this study, gelatin scaffold containing microorganism fermented cellulose, citrus gel were prepared by using irradiation technique. Physical properties of the scaffolds were investigated as a function of the concentrations of gelatin and citrus gel and the cell attachment, cell morphology and inflammation of the scaffolds also were characterized for regeneration of skin tissue.

• Journal of the Korean Wood Science and Technology
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• 제41권4호
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• pp.302-309
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• 2013

Sodium hydroxide-urea 수용액을 이용한 다공성 셀룰로오스계 에어로겔은 용해, 겔화, 재생, 유기용매 치환과 동결건조과정에 의해 제조되었다. 에어로겔의 구조적 특성과 다공성은 주사전자현미경과 질소흡착장치를 이용하여 분석하였다. 그 결과, 용해펄프는 완전히 용해되었지만, 여과지와 홀로셀룰로오스는 원심분리과정에서 수용액에 용해된 부분과 용해되지 않은 부분으로 구분되었다. 용해펄프 에어로겔의 표면은 다공성 공극, 내부는 그물모양의 망목상 구조가 관찰되었다. 여과지와 홀로셀룰로오스 에어로겔은 표면이 압축된 다공성 네트워크 형태였고, 내부는 open-pore 구조의 나노피브릴 네트워크로 구성되었다. 홀로셀룰로오스 에어로겔에서 수용액에 용해되지 않는 형태의 섬유들이 관찰되었다. 용해펄프로부터 만들어진 에어로겔의 비표면적은 260~326 $m^2/g$ 범위였고, 농도 증가와 함께 감소하였다. 그러나 여과지 에어로겔의 비표면적(198~418 $m^2/g$)은 농도 증가와 함께 증가하였다. 홀로셀룰로오스 에어로겔은 2% 농도에서는 137 $m^2/g$로 농도의 증가와 함께 증가하여 4% 농도에서 401 $m^2/g$로 최댓값을 보여주었고, 5% 농도에서 감소하였다.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.851-870
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• 2000

The major goals of periodontal therapy is the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. There have been increasing interest on the chitosan made by chitin. Chitin is second only to cellulose as the most abundant natural biopolymer. It is a structural component of the exoskeleton of invertebrates(e.g., shrimp, crabs, lobsters), of the cell wall of fungi, and of the cuticle of insects. Chitosan is a derivative of chitin made by deacetylation of side chains. Many experiments using chitosan in various animal models have proven its beneficial effects. The aim of this study is to evaluate the osteogenesis of chitosan on the calvarial critical size defect in Sprague Dawley rats. An 8 mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into two groups: Untreated control group versus experimental group with 50mg of soluble chitosan gel. The animals were sacrificed at 2, 4 and 8 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric and radiodensitometric analyses. The results are as follows: 1. The length of newly formed bone in the defects was $102.91{\pm}25.46{\mu}m$, $219.46{\pm}97.81{\mu}m$ at the 2 weeks, $130.95{\pm}39.24{\mu}m$, $212.39{\pm}89.22{\mu}m$ at the 4 weeks, $181.53{\pm}76.35{\mu}m$ and $257.12{\pm}51.22{\mu}m$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. But, there was no statistically significant difference between the two groups. 2. The area of newly formed bone in the defects was $2962.06{\pm}1284.48{\mu}m^2$, $5194.88{\pm}1247.88{\mu}m^2$ at the 2 weeks, $5103.25{\pm}1375.88{\mu}m^2$, $7751.43{\pm}2228.20{\mu}m^2$ at the 4 weeks and $8046.20{\pm}818.99{\mu}m^2$, $15578.57{\pm}5606.55{\mu}m^2$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. 3. The density of newly formed bone in the defects was $14.26{\pm}6.33%$, $27.91{\pm}6.65%$ at the 2 weeks, $20.06{\pm}9.07%$, $27.86{\pm}8.20%$ at the 4 weeks and $22.99{\pm}3.76%$, $32.17{\pm}6.38%$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. These results suggest that the use of chitosan on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself

• 한국동물학회지
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• 제36권3호
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• pp.367-372
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• 1993

재생쥐간에서 분리한 topoisomerase II에서 protein kinase 활성이 발견되었다. ,topo II 활성 및 kinase 활성은 hydroxyapatite, phosphocellulose, double strand DNA cellulose chromatography 등의 순수 분리 과정 중에도 서로 분리되지 않았으며 glycerol gradient sedimentation 분석에서도 같은 분획에서 활성이 존재하였다. Kinase는 topo II 저해제인 N-ethylmaleimide와 novobiocin 등에 의해 그 활성이 저해되었다. 그러나 이러한 증거들 만으로 kinase 활성이 topo II가 아닌 다른 polypeptide에 의한 것일 가능성을 완전히 배제 할 수는 없다. Topo II와 결합된 kinase 활성에는 Mg++가 절대적으로 필요하였으며 다른 일가 또는 이가 이온으로는 그 효과가 대체되지 않았다. Histone H1은 kinase 활성을 증가 시키며 또 kinase에 의해 강하게 인산화된다. 이러한 효과는 다른 histone 류 및 casein 등에 의해 대체되지 않았다.

• Journal of Plant Biotechnology
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• 제6권1호
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• pp.1-7
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• 2004

Forestry sector has witnessed some unprecedented events in the recent past both in terms of galloping biotechnological developments and heated environmental debates over risks associated with release of transgenic trees. Improvements in the in vitro propagation techniques has made it possible to develop tissue culture based plant regeneration protocols just for about any tree species. And with the inclusion of every new species within the realms of tissue culture technology, it becomes a candidate for genetic improvement through recombinant DNA technology, the so called genetic engineering. Poplars and their hybrids serve as the model tree species on which most of the genetic transformation work as been carried out. A lot of work has also gone in genetic transformation of fruit trees and trees of horticultural interests. Trees have been successfully transformed for traits ranging from reduction of length of juvenile phase to alteration of tree architecture to altering wood quality by lignin and cellulose modification. More-over trees have been genetically engineered successfully to combat various types of insect pests and pathogens causing diseases. But all these developments have ignited controversies over the possible benefits and risks associated with transgenic plantations by various environmental agencies and activists. Solutions to most of these concerns can be found out with more intensive prioritized research.

• 한국염색가공학회지
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• 제27권1호
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• pp.1-10
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• 2015

The aim of the current study is to identify the dimerization and decomposition kinetics of the F-$D_M$ type. The regeneration of F-VS from $F_iF_j-D_M$ or the reversibility of the dimerizations were investigated. The order of real rate constants of the dimerization('$K_D{^{ij}}$) would seem to be similar to that of rate constants of a dimerization($K_D{^{ij}}$) for VS dyes at a given pH because of the constancy of the equilibrium constants($K_a{^j}$-value). The reverse reactions of the $D_M$ types are appeared to occur in two steps, the deprotonation of ${\alpha}$-carbon of the $D_M$ types and disproportionation. The ratio of the decomposition of the $D_M$ type to F-Hy and F-VS appears to be related with the ratio of $K_i/K_j$. Similarities were also found among various other reactions, including homo- and mixed dimerization. VS dyes undergoing fast hydrolysis have difficulty in forming a dimer. The higher the reactivity with cellulose or hydroxide ion, the smaller the dimerization. The easiness of the dimerization was thus found to be inversely proportional to the rate of hydrolysis.