• Title/Summary/Keyword: regenerative material

Search Result 88, Processing Time 0.025 seconds

Investigation of Nanofiber and Thermosensitive Scaffold for Intervertebral Disc through Organ Culture (기관배양을 통한 추간판 재생용 나노파이버 및 온도 감응성 지지체에 대한 검증)

  • Lee, Yong-Jae;Shin, Ji-Won;Shin, Ho-Jun;Kim, Chan-Hwan;Park, Ki-Dong;Bae, Jin-Woo;Seo, Hyoung-Yeon;Kim, Young-Jick;Shin, Jung-Woog
    • Journal of Biomedical Engineering Research
    • /
    • v.28 no.4
    • /
    • pp.512-519
    • /
    • 2007
  • The purpose of this study is to investigate the potential of a novel tissue engineering approach to regenerate intervertebral disc. In this study, thermosensitive scaffold (chitosan-Pluronic hydrogel) and nanofiber were used to replace the nucleus pulposus (NP) and annulus fibrosus of a degenerated intervertebral disc, leading to an eventual regeneration of the disc using the minimally invasive surgical procedure and organ culture. In preliminary study, disc cells were seeded into the scaffolds and cellular responses were assessed by MTT assay and scanning electron microscopy (SEM). Based on these results, we could know that tissue engineered scaffolds might provide favorable environments for the regeneration of tissues. Organ culture was performed in fresh porcine spinal motion segments with endplates on both sides. These spinal motion segments were classified into three groups: control (Intact), injured NP (Defect), and inserting tissue engineered scaffolds (Insert). The specimens were cultivated for 7 days, subsequently structural stability, cell proliferation and morphological changes were evaluated by the relaxation time, quantity of DNA, GAG and histological examination. In these results, inserting group showed higher relaxation time, reduced decrement of DNA contents, and accumulated GAG amount. Consequently, the tissue engineered scaffolds used in this study seen to be a promising base scaffolds for regenerative intervertebral disc due to its capacity to absorb external dynamic loading and the possible ideal environment provided for disc cell growing.

The effects of Hydroxyapatite nano-coating implants on healing of surgically created circumferential gap in dogs

  • Chae, Gyung-Joon;Lim, Hyun-Chang;Choi, Jung-Yoo;Chung, Sung-Min;Lee, In-Seop;Cho, Kyoo-Sung;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
    • /
    • v.38 no.sup2
    • /
    • pp.373-384
    • /
    • 2008
  • Purpose: The aim of this study is to compare the healing response of various Hydroxyapatite(HA) coated dental implants by Ion-Beam Assisted Deposition(IBAD) placed in the surgically created circumferential gap in dogs. Materials and methods: In four mongrel dogs, all mandibular premolars and the first molar were extracted. After an 8 weeks healing period, six submerged type implants were placed and the circumferential cylindrical 2mm coronal defects around the implants were made surgically with customized step drills. Groups were divided into six groups : anodized surface, anodized surface with 150nm HA and heat treatment, anodized surface with 300nm HA and heat treatment, anodized surface with 150nm HA and no heat treatment, and anodized surface with 150nm HA, heat treatment and bone graft, anodized surface with bone graft. The dogs were sacrificed following 12 weeks healing period. Specimens were analyzed histologically and histomorphometrically. Results: During the healing period, healing was uneventful and implants were well maintained. Anodized surface with HA coating and $430^{\circ}C$ heat treatment showed an improved regenerative characteristics. Most of the gaps were filled with newly regenerated bone. The implant surface was covered with bone layer as base for intensive bone formation and remodeling. In case that graft the alloplastic material to the gaps, most of the coronal gaps were filled with newly formed bone and remaining graft particles. The bone-implant contact and bone density parameters showed similar results with the histological findings. The bone graft group presented the best bone-implant contact value which had statistical significance. Conclusion: Within the scope of this study, nano-scale HA coated dental implants appeared to have significant effect on the development of new bone formation. And additional bone graft is an effective method in overcoming the gaps around the implants.

The Effects of Gamisipjeon-tang on the Skin Regeneration of Deep Second Degree Burns in Mice

  • Yu, Hyun-Jung;Hong, Seung-Ug
    • The Journal of Korean Medicine
    • /
    • v.31 no.3
    • /
    • pp.107-121
    • /
    • 2010
  • Objective: This study aimed to ascertain the curative effects of Gamisipjeon-tang (GST) used for wound healing on the skin regeneration of deep second degree burns in mice. Material & Methods: In vitro, the $I{\kappa}B$ kinase (IKK) mRNA expression, inducible nitric oxide synthase (iNOS) mRNA expression, and cyclooxygenase-2 (COX-2) mRNA expression in the GST concentration from 1 mg/$m{\ell}$ to 10 mg/$m{\ell}$ were measured. In vivo, the mice were divided into four groups : the normal group, the BE group (burn-elicited group, control group), the DC group (Duoderm CGF-treated group after burn elicitation), and the GST group (Gamisipjeon-tang treated group after burn elicitation). To determine the anti-inflammatory effects, nuclear factor (NF)-${\kappa}B$ p65, iNOS, COX-2 positive reaction were measured by immunohistochemistry. To estimate the skin regenerative effects, change of burn area, 5-bromo-2'-deoxyuridine (BrdU), and fibroblast growth factor (FGF) positive reaction were analyzed. Results: In vitro, the iNOS, IKK, COX-2 mRNA expression decreased according to the increase of GST concentration. The significant decrease of COX-2, iNOS, NF-${\kappa}B$ positive reaction were the highest in the GST group, followed by the DC group and the BE group (p<0.05). The diameter of burn area was significantly decreased in the GST group as compared to that in the DC and BE group (p<0.05). The BrdU and FGF positive reaction increased more significantly in the GST group than in the DC group, and more significantly in the DC group than in the BE group on the 3rd and 7th day after burn (p<0.05). FGF positive reaction increased in the BE and DC group, whereas it decreased significantly in the GST group on the 14th day (p<0.05). The BrdU positive reaction increased in the BE group, whereas it decreased significantly in the DC and GST group on the 14th day (p<0.05). Conclusions: This study shows that GST could decrease the inflammatory response and accelerate the skin regeneration as compared to the duoderm CGF in mice with deep second degree burns.

Histologic evaluation of various membranes on periodontal tissue regeneration of 1-wall intrabony defects in dogs (성견 1벽성 골내낭 결손부의 조직재생에 대한 수종의 차폐막의 조직학적 평가)

  • Yang, Jin-Hyuk;Chae, Gyung-Joon;Yun, Jeong-Ho;Song, Si-Eun;Lee, Yong-Keun;Cho, Kyoo-Sung;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
    • /
    • v.38 no.1
    • /
    • pp.51-58
    • /
    • 2008
  • Purpose: In dental clinical fields, various periodontal membranes are currently used for periodontal regeneration. The periodontal membranes are categorized into two basic types: resorbable and non-resorbable. According to the case, clinician select which membrane is used. Comparing different membranes that are generally used in clinic is meaningful. For this purpose, this study evaluates histological effects of various membranes in canine one wall intrabony defect models and it suggest a valuation basis about study model. Material and Method: The membranes were non-resorbable TefGen $Plus^{(R)}$, resorbable Gore Resolut $XT^{(R)}$ and resorbable $Osteoguide^{(R)}$. One wall intrabony defects were surgically created at the second and the mesial aspect of the fourth mandibular premolars in either right or left jaw quadrants in two dogs. The animals were euthanized 8 weeks post-surgery when block sections of the defect sites were collected and prepared for histological evaluation. Results: 1. While infiltration of inflammatory cells were observed in control, TefGen $Plus^{(R)}$ and Gore Resolut $XT^{(R)}$, it was not observed in $Osteoguide^{(R)}$. 2. TefGen $Plus^{(R)}$ had higher integrity than others and $Osteoguide^{(R)}$ was absorbed with folding shape. Gore Resolut $XT^{(R)}$ was divided everal parts during resorbtion and it was also absorbed from inside. 3. Quantity of new bone and new cementum was not abundant in all membranes. 4. For histologic evaluation of membranes we should consider infiltration of inflammatory, migration of junctional epithelium, integrity of membrane, quantity of new bone and new cementum, connective tissue formation and aspect of resorption. Conclusion: This histologic evaluation suggests that $Osteoguide^{(R)}$ provides periodontal regenerative environment with less inflammatory state. It is meangful that this study model suggests a valuation basis about other study model.

Study of chitosan's effects on periodontal tissue regeneration: a meta-analysis of the histomorphometry (키토산의 치주조직 재생력에 대한 연구의 고찰: 조직계측학적 메타분석)

  • Yang, Jin-Hyuk;Chae, Gyung-Joon;Yun, Jeong-Ho;Jung, Ui-Won;Lee, Yong-Keun;Cho, Kyoo-Sung;Chai, Jung-Kiu;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
    • /
    • v.38 no.1
    • /
    • pp.7-14
    • /
    • 2008
  • Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.29 no.6
    • /
    • pp.327-340
    • /
    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

Evaluation on the bone regenerative capacity of hyaluronic acid applied poly (D,L-lactic-co-glycolic acid) membranes in rabbit calvarial defect (Rabbit calvaria를 이용하여 hyaluronic acid (HA)를 처리한 poly (D,L-lactic-co-glycolic acid) 차폐막들의 골 생성능력에 대한 비교 연구)

  • Kim, Nam-Sook;Yun, Kwi-Dug;Vang, Mong-Sook;Yang, Hong-So;Lim, Hyun-Phil;Kang, Sung-Soo;Park, Sang-Won
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.48 no.2
    • /
    • pp.158-165
    • /
    • 2010
  • Purpose: The objective of the present study was to histologically evaluate durability and bone regeneration capacity of new synthetic membranes in comparison to clinically available collagen membrane. Material and methods: To the skulls of 12 rabbits, we created 4 bone defects of 6 mm in diameter on each of them. Each of defects were covered with at least one of 5 membranes; No membrane, Collagen ($Ossix^{TM}$), PLGA, HA-coated-PLGA and HA-PLGA/PLGA. After 4, 8, 12 weeks, we cut the skulls and dyed with H-E. And then, the histologic observation was done. Results: In current study, the control group which did not use the membrane showed bone regeneration at 12 weeks and covered the bone defect partially. New bones were formed through the underneath of endocranium, and the upper defect was filled with connective tissues and fats. Collagen membrane ($Ossix^{TM}$) showed new bones after 4 weeks, and they were formed through the membrane which maintained until 12 weeks. PLGA, HA-coated-PLGA, HA-PLGA/PLGA showed bone regeneration after 4 weeks and after 8 weeks, they mostly filled defects. At 12 weeks, we could find new bones and previous bones almost look alike and also, they united well. Membranes were unnoticeable after 4 weeks and were absorbed. Conclusion: Bone formation and maturation of PLGA, HA-coated-PLGA and HA-PLGA/PLGA were faster than the control group. They showed no difference on the application of HA and after 4 weeks, they were absorbed.

The Bone regenerative effects of tetracycline blended chitosan membranes on the calvarial critical size defect in Sprague dawley rats (백서 두개골 결손부에서 항생제를 함유한 키토산 차단막의 골재생 유도 효과)

  • Chae, Gyung-Joon;Kim, Tae-Gyun;Jung, Ui-Won;Lee, Soo-Bok;Jung, Yong-Sik;Lee, Yong-Keun;Kim, Chang-Sung;Chae, Jung-Kiu;Cho, Kyoo-Sung;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
    • /
    • v.35 no.4
    • /
    • pp.1019-1037
    • /
    • 2005
  • The major goals of periodontal therapy are 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 chtin. Chitosan is a derivative of chitin made by deacetylation of side chains. Chitosan has been widely studied as bone substitution and membrane material in periodontology. Many experiments using chitosan in various animal models have proven its beneficial effects. Tetracycline has been considered for use in the treatment of chronic periodontal disease and gingivitis. The aim of this study is to evlauate the osteogenesis of tetracycline blended chitosan membranes on the calvarial critical size defect in Sprague Dawley rats. An 8mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into five groups: Untreated control group versus four experimental group. Four types of membranes were made and comparative study was been done. Two types of non-woven membranes were made by immersing non-woven chitosan into either the tetracycline solution or chitosan-tetracycline solution. Other two types of sponge membranes were fabricated by immersing chitosan sponge into the tetracycline solution, and subsequent freeze-drying. The animals were sacrificed at 2 and 8 weeks after surgical procedure. The specimens were examined by histologic analyses. The results are as follows: 1. Clinically the use of tetracycline blended chitosan membrane showed great healing capacity. 2. The new bone formations of all the experimental group, non-woven and sponge type membranes were greater than those of control group. But, there was no significant difference between the experimental groups. 3. Resorption of chitosan membranes were not shown in any groups at 2 weeks and 8 weeks. These results suggest that the use of tetracycline blended chitosan membrane on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself. And it implicate that tetracycline blended chitosan membrane might be useful for guided tissue regeneration.