Influence of Emotional Intelligence, Job Stress, and Social Support on Resilience among Hospital Nurses / 한국직업건강간호학회지

Purpose@#The aim of this study was to identify the influence of emotional intelligence, job stress, and social support on resilience of hospital nurses. The study will provide the basic material necessary to improve nursing interventions for the development of nurses' resilience. @*Methods@#The sample of this study comprised 193 nurses working at general hospitals in B City. Data were analyzed through the SPSS 25.0 program using ANOVA, t-test, Scheffé́ ́ test, Pearson's correlation coefficient, and stepwise multiple regression. @*Results@#The factors with the greatest influence on the level of nurses' resilience were emotional intelligence (β=.54, p<.001), social support (β=.23, p<.001), and job stress (β=-.11, p=.39). These factors had an explanatory power of 46.7% for resilience. @*Conclusion@#To improve nurses’ resilience, the application and development of intervention programs to increase their emotional intelligence is necessary. Moreover, organizational management and policy are needed to reduce nurses' job stress.

The bactericidal effect of an atmospheric-pressure plasma jet on Porphyromonas gingivalis biofilms on sandblasted and acid-etched titanium discs

PURPOSE: Direct application of atmospheric-pressure plasma jets (APPJs) has been established as an effective method of microbial decontamination. This study aimed to investigate the bactericidal effect of direct application of an APPJ using helium gas (He-APPJ) on Porphyromonas gingivalis biofilms on sandblasted and acid-etched (SLA) titanium discs. METHODS: On the SLA discs covered by P. gingivalis biofilms, an APPJ with helium (He) as a discharge gas was applied at 3 different time intervals (0, 3, and 5 minutes). To evaluate the effect of the plasma itself, the He gas–only group was used as the control group. The bactericidal effect of the He-APPJ was determined by the number of colony-forming units. Bacterial viability was observed by confocal laser scanning microscopy (CLSM), and bacterial morphology was examined by scanning electron microscopy (SEM). RESULTS: As the plasma treatment time increased, the amount of P. gingivalis decreased, and the difference was statistically significant. In the SEM images, compared to the control group, the bacterial biofilm structure on SLA discs treated by the He-APPJ for more than 3 minutes was destroyed. In addition, the CLSM images showed consistent results. Even in sites distant from the area of direct He-APPJ exposure, decontamination effects were observed in both SEM and CLSM images. CONCLUSIONS: He-APPJ application was effective in removing P. gingivalis biofilm on SLA titanium discs in an in vitro experiment.

Effects of the Empowering Leadership by Nurse Managers on Organizational Citizenship Behavior of Nurses: Mediating Effects of Followership / 간호행정학회지

PURPOSE: The objective of this study was to verify a mediating effect of followership in the relationship of organizational citizenship behavior and nurse managers' empowering leadership as perceived by nurses. METHODS: The study was a descriptive research involving 222 nurses working on nursing units in a university hospital. Data were analyzed using independent t-test, one way ANOVA, Mann-Whitney U, Scheffé test, Pearson correlation coefficients, and simple and multiple regression techniques with the SPSS 23.0 program. Mediation analysis was performed according to the Baron and Kenny method and Sobel test. RESULTS: Nurse managers' empowering leadership and followership showed a positive correlation (r=.22, p=.001), and a significantly positive correlation with organizational citizenship behavior (r=.32, p<.001). Also, followership and organizational citizenship behavior showed a positive correlation (r=.52, p<.001). The results of the study verified that nurses' followership had a mediating effect on organizational citizenship behavior in nurse unit managers' empowering leadership, a positive effect on organizational citizenship behavior and ultimately an increase in organizational achievement. CONCLUSION: Nurse managers need to be aware of the importance of empowering leadership, and endeavor to enhance it further. As for the organizational level, support to strengthen empowering leadership is required.

Periodontal pathogens and the association between periodontitis and rheumatoid arthritis in Korean adults

PURPOSE: Periodontitis and rheumatoid arthritis (RA) share a similar inflammatory pathogenesis. Porphyromonas gingivalis (Pg) can induce anticyclic-citrullinated peptide autoantibodies (anti-CCP antibodies), a key factor in the development of RA. This study aimed at evaluating the relationships between the 2 diseases and identifying the clinical implications thereof, with a focus on periodontal pathogens in Korean adults. METHODS: A total of 260 RA patients and 86 age- and sex-matched control patients without arthritis were enrolled in this prospective cross-sectional study. Periodontal indices and the prevalence and amount of periodontal pathogens were compared between the groups. Correlations between periodontal and RA indices were examined, as were correlations between 9 periodontal pathogens and RA indices. RESULTS: The RA group had significantly higher values than the control group for all investigated periodontal indices (P < 0.05) except the number of teeth. The gingival index (GI) was correlated with the disease activity score 28 (DAS28) (r = 0.125, P = 0.049), RA disease duration (r = 0.253, P < 0.001), erythrocyte sedimentation rate (ESR) (r = 0.162, P = 0.010), and anti-CCP antibody titer (r = 0.205, P = 0.004). Probing pocket depth (PPD) was correlated with ESR (r = 0.139, P = 0.027) and anti-Pg antibody titer (r = 0.203, P = 0.001). Bleeding on probing (BOP) was correlated with DAS28 (r = 0.137, P = 0.030), RA disease duration (r = 0.202, P = 0.001), ESR (r = 0.136, P = 0.030), anti-Pg antibody titer (r = 0.177, P = 0.005), and anti-CCP antibody titer (r = 0.188, P = 0.007). Clinical attachment level (CAL) and periodontitis severity were correlated with anti-Pg antibody titer (the former r = 0.201, P = 0.002; the latter r = 0.175, P = 0.006). The quantity of Pg was positively correlated with the serum anti-Pg antibody titer (r = 0.148, P = 0.020). CONCLUSIONS: The GI, BOP, and PPD showed positive relationships with several RA indices. The anti-Pg antibody titer had positive relationships with PPD, BOP, CAL, and periodontitis severity. Thus, increasing values of periodontal indices could be used as a risk indicator of disease development in RA patients, and an increasing anti-Pg antibody titer could be considered as a warning sign in RA patients suffering with periodontitis.

Magnoliae Cortex and maize modulate Porphyromonas gingivalis-induced inflammatory reactions

PURPOSE: The aim of this study was to evaluate the capacity of single and combined applications of the bark of the stems and roots of Magnolia officinalis Rehd. et Wils. (Magnoliae Cortex) and Zea mays L. (maize) to modulate inflammation in RAW 264.7 cells stimulated with Porphyromonas gingivalis. METHODS: RAW 264.7 cells were stimulated with P. gingivalis, and Magnoliae Cortex and/or maize was added. Cytotoxicity and the capacity to modulate inflammation were determined with a methylthiazol tetrazolium (MTT) assay, nitrite production, enzyme-linked immunosorbent assay (ELISA), and western blotting. RESULTS: Treatment with Magnoliae Cortex and/or maize inhibited nuclear transcription factor κB (NF-κB) pathway activation and nuclear p44/42 mitogen-activated protein kinase (MAPK) and inducible nitric oxide synthase (iNOS) protein expression in P. gingivalis-stimulated RAW 264.7 cells. Moreover, the treatments suppressed cytokines (prostaglandin E2 [PGE2], interleukin [IL]-1β, and IL-6) and nitrite production. CONCLUSIONS: Both Magnoliae Cortex and maize exerted an anti-inflammatory effect on P. gingivalis-stimulated RAW 264.7 cells, and this effect was more pronounced when the extracts were combined. These findings show that these extracts may be beneficial for slowing the progression of periodontal disease.

Rabbit maxillary sinus augmentation model with simultaneous implant placement: differential responses to the graft materials

PURPOSE: This study was performed to establish an experimental rabbit model for single-stage maxillary sinus augmentation with simultaneous implant placement. METHODS: Twelve mature New Zealand white rabbits were used for the experiments. The rabbit maxillary sinuses were divided into 3 groups according to sinus augmentation materials: blood clot (BC), autogenous bone (AB), and bovine-derived hydroxyapatite (BHA). Small titanium implants were simultaneously placed in the animals during the sinus augmentation procedure. The rabbits were sacrificed 4 and 8 weeks after surgery and were observed histologically. Histomorphometric analyses using image analysis software were also performed to evaluate the parameters related to bone regeneration and implant-bone integration. RESULTS: The BC group showed an evident collapse of the sinus membrane and limited new bone formation around the original sinus floor at 4 and 8 weeks. In the AB group, the sinus membrane was well retained above the implant apex, and new bone formation was significant at both examination periods. The BHA group also showed retention of the elevated sinus membrane above the screw apex and evident new bone formation at both points in time. The total area of the mineral component (TMA) in the area of interest and the bone-to-implant contact did not show any significant differences among all the groups. In the AB group, the TMA had significantly decreased from 4 to 8 weeks. CONCLUSIONS: Within the limits of this study, the rabbit sinus model showed satisfactory results in the comparison of different grafting conditions in single-stage sinus floor elevation with simultaneous implant placement. We found that the rabbit model was useful for maxillary sinus augmentation with simultaneous implant placement.

Effects of immunosuppressants, FK506 and cyclosporin A, on the osteogenic differentiation of rat mesenchymal stem cells

PURPOSE: The purpose of this study was to investigate the effects of the immunosuppressants FK506 and cyclosporin A (CsA) on the osteogenic differentiation of rat mesenchymal stem cells (MSCs). METHODS: The effect of FK506 and CsA on rat MSCs was assessed in vitro. The MTT assay was used to determine the deleterious effect of immunosuppressants on stem cell proliferation at 1, 3, and 7 days. Alkaline phosphatase (ALP) activity was analyzed on days 3, 7, and 14. Alizarin red S staining was done on day 21 to check mineralization nodule formation. Real-time polymerase chain reaction (RT-PCR) was also performed to detect the expressions of bone tissue-specific genes on days 1 and 7. RESULTS: Cell proliferation was promoted more in the FK506 groups than the control or CsA groups on days 3 and 7. The FK506 groups showed increased ALP activity compared to the other groups during the experimental period. The ALP activity of the CsA groups did not differ from the control group in any of the assessments. Mineralization nodule formation was most prominent in the FK506 groups at 21 days. RT-PCR results of the FK506 groups showed that several bone-related genes-osteopontin, osteonectin, and type I collagen (Col-I)-were expressed more than the control in the beginning, but the intensity of expression decreased over time. Runx2 and Dlx5 gene expression were up-regulated on day 7. The effects of 50 nM CsA on osteonectin and Col-I were similar to those of the FK506 groups, but in the 500 nM CsA group, most of the genes were less expressed compared to the control. CONCLUSIONS: These results suggest that FK506 enhances the osteoblastic differentiation of rat MSCs. Therefore, FK506 might have a beneficial effect on bone regeneration when immunosuppressants are needed in xenogenic or allogenic stem cell transplantation to treat bone defects.

Gene expression profile in mesenchymal stem cells derived from dental tissues and bone marrow

PURPOSE: The aim of this study is to compare the gene expression profile in mesenchymal stem cells derived from dental tissues and bone marrow for characterization of dental stem cells. METHODS: We employed GeneChip analysis to the expression levels of approximately 32,321 kinds of transcripts in 5 samples of bone-marrow-derived mesenchymal stem cells (BMSCs) (n=1), periodontal ligament stem cells (PDLSCs) (n=2), and dental pulp stem cells (DPSCs) (n=2). Each cell was sorted by a FACS Vantage Sorter using immunocytochemical staining of the early mesenchymal stem cell surface marker STRO-1 before the microarray analysis. RESULTS: We identified 379 up-regulated and 133 down-regulated transcripts in BMSCs, 68 up-regulated and 64 down-regulated transcripts in PDLSCs, and 218 up-regulated and 231 down-regulated transcripts in DPSCs. In addition, anatomical structure development and anatomical structure morphogenesis gene ontology (GO) terms were over-represented in all three different mesenchymal stem cells and GO terms related to blood vessels, and neurons were over-represented only in DPSCs. CONCLUSIONS: This study demonstrated the genome-wide gene expression patterns of STRO-1+ mesenchymal stem cells derived from dental tissues and bone marrow. The differences among the expression profiles of BMSCs, PDLSCs, and DPSCs were shown, and 999 candidate genes were found to be definitely up- or down-regulated. In addition, GOstat analyses of regulated gene products provided over-represented GO classes. These data provide a first step for discovering molecules key to the characteristics of dental stem cells.

The evaluation of the correlation between histomorphometric analysis and micro-computed tomography analysis in AdBMP-2 induced bone regeneration in rat calvarial defects

PURPOSE: Micro-computed tomography (micro-CT) has been widely used in the evaluation of regenerated bone tissue but the reliability of micro-CT has not yet been established. This study evaluated the correlation between histomorphometric analysis and micro-CT analysis in performing new bone formation measurement. METHODS: Critical-size calvarial defects were created using a 8 mm trephine bur in a total of 24 Sprague-Dawley rats, and collagen gel mixed with autogenous rat bone marrow stromal cells (BMSCs) or autogenous rat BMSCs transduced by adenovirus containing bone morphogenic protein-2 (BMP-2) genes was loaded into the defect site. In the control group, collagen gel alone was loaded into the defect. After 2 and 4 weeks, the animals were euthanized and calvaria containing defects were harvested. Micro-CT analysis and histomorphometric analysis of each sample were accomplished and the statistical evaluation about the correlation between both analyses was performed. RESULTS: New bone formation of the BMP-2 group was greater than that of the other groups at 2 and 4 weeks in both histomorphometric analysis and micro-CT analysis (P=0.026, P=0.034). Histomorphometric analysis of representative sections showed similar results to histomorphometric analysis with a mean value of 3 sections. Measurement of new bone formation was highly correlated between histomorphometric analysis and micro-CT analysis, especially at the low lower threshold level at 2 weeks (adjusted r2=0.907, P<0.001). New bone formation of the BMP-2 group analyzed by micro-CT tended to decline sharply with an increasing lower threshold level, and it was statistically significant (P<0.001). CONCLUSIONS: Both histomorphometric analysis and micro-CT analysis were valid methods for measurement of the new bone in rat calvarial defects and the ability to detect the new bone in micro-CT analysis was highly influenced by the threshold level in the BMP-2 group at early stage.

Response of osteoblast-like cells cultured on zirconia to bone morphogenetic protein-2

PURPOSE: The aim of this study was to compare osteoblast behavior on zirconia and titanium under conditions cultured with bone morphogenetic protein-2. METHODS: MC3T3-E1 cells were cultured on sandblasted zirconia and sandblasted/etched titanium discs. At 24 hours after seeding MC3T3-E1, the demineralized bone matrix (DBM) gel alone and the DBM gel with bone morphogenetic protein-2 (BMP-2) were added to the culture medium. The surface topography was examined by confocal laser scanning microscopy. Cellular proliferation was measured at 1, 4, and 7 days after gel loading. Alkaline phosphatase activity was measured at 7 days after gel loading. The mRNA expression of ALPase, bone sialoprotein, type I collagen, runt-related transcription factor 2 (Runx-2), osteocalcin, and osterix were evaluated by real-time polymerase chain reaction at 4 days and 7 days. RESULTS: At 1, 4, and 7 days after loading the DBM gel alone and the DBM gel with BMP-2, cellular proliferation on the zirconia and titanium discs was similar and that of the groups cultured with the DBM gel alone and the DBM gel with BMP-2 was not significantly different, except for titanium with BMP-2 gel. ALPase activity was higher in the cells cultured with BMP-2 than in the other groups, but there was no difference between the zirconia and titanium. In ALPase, bone sialoprotein, osteocalcin, Runx-2 and osterix gene expression, that of cells on zirconia or titanium with BMP-2 gel was much more highly increased than titanium without gel at day 7. The gene expression level of cells cultured on zirconia with BMP-2 was higher than that on titanium with BMP-2 at day 7. CONCLUSIONS: The data in this study demonstrate that the osteoblastic cell attachment and proliferation of zirconia were comparable to those of titanium. With the stimulation of BMP-2, zirconia has a more pronounced effect on the proliferation and differentiation of the osteoblastic cells compared with titanium.

Initial adhesion of bone marrow stromal cells to various bone graft substitutes

PURPOSE: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. METHODS: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with beta-tricalcium phosphate (TCP), and pure beta-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. RESULTS: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. CONCLUSIONS: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment.

Immunomodulatory effect of canine periodontal ligament stem cells on allogenic and xenogenic peripheral blood mononuclear cells

PURPOSE: The aim of this study was to investigate the immunomodulatory effects of canine periodontal ligament stem cells on allogenic and xenogenic immune cells in vitro. METHODS: Mixed cell cultures consisting of canine stem cells (periodontal ligament stem cells and bone marrow stem cells) and allogenic canine/xenogenic human peripheral blood mononuclear cells (PBMCs) were established following the addition of phytohemagglutinin. The proliferation of PBMCs was evaluated using the MTS assay. The cell division of PBMCs was analyzed using the CFSE assay. The apoptosis of PBMCs was assessed using the trypan blue uptake method. RESULTS: Periodontal ligament stem cells and bone marrow stem cells inhibited the proliferation of allogenic and xenogenic PBMCs. Both periodontal ligament stem cells and bone marrow stem cells suppressed the cell division of PBMCs despite the existence of a mitogen. No significant differences in the percentages of apoptotic PBMCs were found among the groups. CONCLUSIONS: Canine periodontal ligament stem cells have an immunomodulatory effect on allogenic and xenogenic PBMCs. This effect is not a product of apoptosis of PBMCs but is caused by the inhibition of cell division of PBMCs.

Effect of combinatorial bone morphogenetic protein 2 and bone morphogenetic protein 7 gene delivery on osteoblastic differentiation / 대한치주과학회지

PURPOSE: Gene therapy (ex vivo) has recently been used as a means of delivering bone morphogenetic proteins (BMPs) to sites of tissue regeneration. In the present study, we investigated the effect of co-transduction of adenoviruses expressing BMP-2 and BMP-7 on osteogenesisof C2C12 cells in vitro. METHODS: A replication-defective human adenovirus 5 (Ad5) containing a cDNA for BMPs in the E1 region of the virus (Ad5BMP-2 and Ad5BMP-7) was constructed by in vivo homologous recombination. Functional activity of Ad5BMP-2 and Ad5BMP-7 were evaluated in mouse stromal cells (W20-17cells). C2C12 cells are transduced with various MOI (multiplicity of infection) of Ad5BMP-2 and Ad5BMP-7 to assess most effective and stable titer. Based on this result, C2C12 cells were transduced with Ad5BMP-2 and Ad5BMP-7 alone or by combination. BMPs expression, alkaline phosphatase (ALPase) activity, cell proliferation, and mineralization were assessed. RESULTS: Ad5BMP-2 and Ad5BMP-7 are successfully transduced to W20-17 cells, and secreted BMPs stimulated cell differentiation. Also, C2C12 cells transduced with Ad5BMPs showed expression of BMPs and increased ALPaseactivity. In all groups, cell proliferation was observed over times. At 7days, cells co-transduced with Ad5BMP-2 and Ad5BMP-7 showed lower proliferation than the others. C2C12 cells co-transduced with Ad5BMP-2 and Ad5BMP-7 had greater ALPaseactivity than that would be predicted if effect of individual Ad5BMPs were additive. Little mineralized nodule formation was detected in cells transduced with individual Ad5BMPs. In contrast, Ad5BMP-2 and Ad5BMP-7 combination stimulated mineralization after culturing for 10 days in mineralizing medium. CONCLUSIONS: Present study demonstrated that adenoviruses expressing BMPs gene successfully produced BMPs protein and these BMPs stimulated cells to be differentiated into osteoblastic cells. In addition, the osteogenic activity of Ad5BMPs can be synergistically increased by co-transduction of cells with Ad5BMP-2 and Ad5BMP-7.

Investigation of postnatal stem cells from canine dental tissue and bone marrow / 대한치주과학회지

PURPOSE: The aim of this study was to evaluate the stemness of cells from canine dental tissues and bone marrow. METHODS:Canine periodontal ligament stem cells (PDLSC), alveolar bone stem cells (ABSC) and bone marrow stem cells(BMSC) were isolated and cultured. Cell differentiations (osteogenic, adipogenic and chondrogenic) and surface antigens (CD146, STRO-1, CD44, CD90, CD45, CD34) were evaluated in vitro. The cells were transplanted into the subcutaneous space of nude mice to assess capacity for ectopic bone formation at 8 weeks after implantation. RESULTS: PDLSC, ABSC and BMSC differentiated into osteoblasts, adipocytes and chondrocytes under defined condition. The cells expressed the mesenchymal stem cell markers differently. When transplanted into athymic nude mice, these three kinds of cells with hydroxyapatite /beta tricalcium phosphate (HA/TCP) carrier showed ectopic bone formation. CONCLUSIONS: This study demonstrated that canine dental stem cells have stemness like bone marrow stem cells. Transplantation of these cells might be used as a therapeutic approach for dental stem cell-mediated periodontal tissue regeneration.

Evaluation of tightness of proximal tooth contact in permanent dentition / 대한치과보철학회지

STATEMENT OF PROBLEM: Proximal contact plays an important role in the stability and maintenance of the integrity of the dental arches. However, it is difficult to evaluate quantitatively the tightness of proximal tooth contact (TPTC). PURPOSE: The aim of this study was to measure the TPTC in permanent dentition. MATERIAL AND METHODS: Ten young adult volunteers with healthy dentition participated in this experiment. The TPTC between the teeth of both the maxilla and the mandible was measured at rest state by a novel device which records the TPTC by pulling of a stainless steel strip (0.03 mm thick) using the electric motor. One-way ANOVA test was used to compare the values in all measured area. When a statistically significant difference was calculated, Bonferroni correction was applied. Independent samples t-test was used to compare the values in male and female. RESULTS: The lowest TPTC and the highest TPTC was measured between the lower central incisors (0.87 +/- 0.20 N), and between the lower left first molar and second molar (1.99 +/- 0.68 N), respectively. All TPTC per quadrant demonstrated a similar pattern of a continuous increased gradient in an anterior-posterior direction. There are no significant difference between the maxilla and mandible. CONCLUSION: The TPTC was measured quantitatively by a novel device and decreased progressively in a posterior-anterior direction.

Stem cell properties of cells derived from canine periodontal ligament / 대한치주과학회지

In spite of the attention given to the study of mesenchymal stem cells derived periodontal ligament (PDL), there is a lack of information about canine PDL cells. In this study, we characterized canine PDL cells to clarify their stem cell properties, including self renewal, proliferate rate, stem cell markers and multipotency. PDL cells were obtained from extracted premolars of canines, following a colony forming assay and proliferation rate of sub-confluent cultures of cells for self-renewal, immunostaining for STRO-1 and CD146/MUC18 and a differentiation assay for multipotency. Canine PDL cells formed single-cells colonies and 25% of the PDL cells displayed positive staining for BrdU. The cells expressed the mesenchymal stem-cell markers, STRO-1 and CD146/MUC18. Under defined culture conditions, the cells differentiated into osteoblasts and adipocytes, but the cells didn't differentiated into chondrocytes. The findings of this study indicated that the canine PDL cells possess crucial stem cells properties, such as self-renewal and multipotency, and express the mesenchymal stem cell markers on their surface. The isolation and characterization of canine PDL cells makes it feasible to pursue preclinical models of periodontal regeneration in canine.

Osteogenic effects of polyethyleneimine-condensed BMP-2 genes in vitro and in vivo / 대한치주과학회지

Naked DNA and standard vectors have been previously used for gene delivery. Among these, PEI can efficiently condense DNA and has high intrinsic endosomal activities. The aim of this study is to investigate whether the cationic polycation PEI could increase the transfection efficiency of BMP expressing DNA using a vector-loaded collagen sponge model. BMP-2/pcDNA3.1 plasmid was constructed by subcloning human BMP-2 cDNA into the pcDNA3.1 plasmid vector. PEI/DNA complexes were prepared by mixing PEI and BMP-2/pcDNA3.1 and the constructed complexes were loaded into the collagen sponges. In vitro studies, BMSCs were transfected with the PEI/BMP-2/pcDNA3.1 complexes from collgen sponge. The level of secreted BMP-2 and alkaline phosphatase activities of transfected BMSCs were significantly higher in PEI/BMP-2/pcDNA3.1 group than in BMP-2/pcDNA3.1 group (p<0.05). Transfected BMSCs were cultured and mineralization was observed only in cells treated with PEI/BMP-2/pcDNA3.1 complexes. In vivo studies, PEI/BMP-2/pcDNA3.1/collagen, BMP-2/pcDNA3.1/collagen and blank collagen were grafted in skeletal muscle of nude mice. Ectopic bone formation was shown in PEI/BMP-2/pcDNA3.1/collagen grafted mouse 4 weeks postimplantation, while not in BMP-2/pcDNA3.1 grafted tissue. This study suggests that PEI-condensed DNA encoding for BMP-2 is capable of inducing bone formation in ectopic site and might increase the transfection rate of BMP-2/pcDNA3.1. As a non-viral vector, PEI offers the potential in gene therapy for bone engineering.

A study on the differentiation of MC3T3-E1 incubated on the layer-built silica/polycaprolactone non-woven fabric produced by electrospinning / 대한치주과학회지

Silica is known as a promising osteoconductive material, and polycaprolactone is a bioactive and degradable material. The purpose of this study was to monitor the differentiation of MC3T3-E1 cells cultured on the layer-built silica/poly caprolactone non-woven fabric produced by electrospinning. Non-woven fabric (silica, polycaprolactone, PSP, SPS) was made by electrospinning and they were inserted in the 48 well cell culture plate. MC3T3-E1 cells were prepared by subculture. Cells were seeded to each well 1x10(5) concentration per well. Dulbecco's modified eagle medium with 10% FBS and 1% antibiotic-antimycotic solution was used. Confocal laser scanning microscope was taken 4 hours after incubation (95% air, 5% CO2, 37degrees C). Cell proliferation was monitored by spectrophotometer on 1, 7, 14 days, and the morphology of the growing cells was observed by field emission scanning electron microscope. To monitor the differentiation of osteoblasts on the materials, MC3T3-E1 cells were incubated in 48 well culture plate after seeding with the density of 1x10(5) concentration. Then ELISA kit & EIA kit were used on to assess osteocalcin and osteopontin expression respectively. The other conditions were the same as above. MC3T3-E1 cells were proliferated well on all of the materials. There were no statistical differences among them. The osteopontin expression of silica, PSP, SPS was significantly higher than other groups on day 3 (p<0.05), but after that time, there were no statistically signigicant differences. The osteocalcin expression was significantly higher in silica and PSP than other groups on day 14. These findings show that PSP was as good as silica on the effect of osteoblast differentiation. The PSP non-woven fabric may have the possibility as bone graft materials.

A study on the osteoblast differentiation using osteocalcin gene promoter controlling luciferase expression / 대한치주과학회지

The aim of this study is to monitor reporter gene expression under osteocalcin gene promoter, using a real-time molecular imaging system, as tool to investigate osteoblast differentiation. The promoter region of mouse osteocalcin gene 2 (mOG2), the best-characterized osteoblast- specific gene, was inserted in promoterless luciferase reporter vector. Expression of reporter gene was confirmed and relationship between the reporter gene expression and osteoblastic differentiation was evaluated. Gene expression according to osteoblstic differentiation on biomaterials, utilizing a real-time molecular imaging system, was monitored. Luciferase was expressed at the only cells transduced with pGL4/mOGP and the level of expression was statistically higher at cells cultured in mineralization medium than cells in growth medium. CCCD camera detected the luciferase expression and was visible differentiation-dependent intensity of luminescence. The cells produced osteocalcin with time-dependent increment in BMP-2 treated cells and there was difference between BMP-2 treated cells and untreated cells at 14days. There was difference at the level of luciferase expression under pGL4/mOGP between BMP-2 treated cells and untreated cells at 3days. CCCD camera detected the luciferase expression at cells transduced with pGL4/mOGP on Ti disc and was visible differentiation-dependent intensity of luminescence This study shows that 1) expression of luciferase is regulated by the mouse OC promoter, 2) the CCCD d etection s ys tem is a r eliable quantitative gene d etection t ool f or t he o s teoblas t differentiation, 3) the dynamics of mouse OC promoter regulation during osteoblast differentiation is achieved in real time and quantitatively on biomaterial. The present system is a very reliable system for monitoring of osteoblast differentiation in real time and may be used for monitoring the effects of growth factors, drug, cytokines and biomaterials on osteoblast differentiation in animal.

The effects of enamel matrix derivatives on the proliferation and gene expression of PDL fibroblast, SaOs2 cells and Cementum derived cells / 대한치주과학회지

No abstract available.