Min-Huey Chen

National Taiwan University, T’ai-pei, Taipei, Taiwan

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Publications (45)123.96 Total impact

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    ABSTRACT: The incidence and mortality rate of oral cancer continue to rise, partly due to the lack of effective early diagnosis and increasing environmental exposure to cancer-causing agents. To identify new markers for oral cancer, we used a sialylation probe to investigate the glycoproteins differentially expressed on oral cancer cells. Of the glycoproteins identified, B7 Homolog 3 (B7-H3) was significantly overexpressed in oral squamous cell carcinoma (OSCC), and its overexpression correlated with larger tumor size, advanced clinical stage, and low survival rate in OSCC patients. In addition, knockdown of B7-H3 suppressed tumor cell proliferation, and restoration of B7-H3 expression enhanced tumor growth. It was also found that the N-glycans of B7-H3 from Ca9-22 oral cancer cells contain the terminal α-galactose and are more diverse with higher fucosylation and better interaction with DC-SIGN [DC-specific intercellular adhesion molecule-3 (ICAM-3)-grabbing nonintegrin] and Langerin on immune cells than that from normal cells, suggesting that the glycans on B7-H3 may also play an important role in the disease.
    Full-text · Article · Oct 2015 · Proceedings of the National Academy of Sciences
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    ABSTRACT: To develop a cell-based approach to tooth regeneration, we isolated dental stem cells from tooth buds of mini pigs and culture-expanded them for about three weeks. Flow cytometry revealed that the majority of the proliferating cells were positive for stem cell surface markers, including CD105, CD29, CD44, CD71. These dental stem cells were then seeded in biodegradable agarose gel for autograft in various areas of the jaw bone. Mini pigs with tooth buds removed without transplantation of dental stem cells served as control. After one year, well differentiated tooth crown and root sheath were formed in mini pigs in the experimental group. The tooth formed by dental stem cells transplanted in alveolar bone was similar in size to original tooth crown (approximately 2 cm × 2 cm × 2 cm). The teeth formed by dental stem cells transplanted under the roots of the anterior teeth and in the cortical bone area were smaller. In the control group, the space where the tooth bud was extracted without cell transplantation was seen to be closed by forward movement of the posterior teeth. Histological analysis showed the structures of enamel, dentin and pulp in the regenerated tooth crown. Immunohistochemical analysis of amelogenin, type I collagen and bone sialoprotein confirmed enamel and dentin formation. Enamel and dentin structures on the regenerated tooth were also identified using scanning electron microscopy. These findings demonstrate a successful model of tooth regeneration from dental stem cells in mini pigs. In addition, local environment and available space also significantly affect the extent of tissue regeneration. Our study demonstrates the feasibility of using dental stem cells for tooth regeneration in clinical applications.
    No preview · Article · Aug 2015
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    ABSTRACT: It has been confirmed that polyphenolic compounds present in food have various pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. The culture medium with CP was developed to inhibit the proliferation of oral cancer cells. CP could be used as a supplemental compound for topical application for oral cancer patients. In this study, the metabolic activity and cell toxicity of CP (at concentrations of 1%, 0.1%, and 0.01%) for oral and cervical cancer cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays (n = 6). Furthermore, the effects of CP on motilities of oral and cervical cancer cells were also evaluated using a scratch assay model. We found that the growth of Ca9-22 and HeLa cells on tissue culture polystyrene was greatly inhibited when 1% CP was added to the medium. In addition, significant differences (p < 0.01) in cytotoxicities of oral and cervical cancer cells were observed after 6 days in the culture medium to which 1% CP was added. Furthermore, using a scratch assay model to evaluate the migratory abilities of oral and cervical cancer cells, it was also found that CP could inhibit the migratory abilities of cancer cells. The results confirmed the feasibility of the topical application of CP as a supplemental compound for inhibition of cancer cell proliferation and migration. Copyright © 2015. Published by Elsevier B.V.
    No preview · Article · Jun 2015 · Journal of the Formosan Medical Association
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    ABSTRACT: Traditionally, guide bone regeneration (GBR) was a widely used method for repairing bone lost from periodontal disease. There were some disadvantages associated with the GBR method, such as the need for a stable barrier membrane and a new creative cavity during the surgical process. To address these disadvantages, the purpose of this study was to evaluate a novel microinjector developed for dental applications. The microinjector was designed to carry bone graft substitutes to restore bone defects for bone regeneration in periodontal diseases. The device would be used to replace the GBR method. In this study, the injected force and ejected volume of substitutes (including air, water, and ethanol) were defined by Hooke's law (n = 3). The optimal particle size of bone graft substitutes was determined by measuring the recycle ratio of bone graft substitutes from the microinjector (n = 3). Furthermore, a novel agarose gel model was used to evaluate the feasibility of the microinjector. The current study found that the injected force was less than 0.4 N for obtaining the ejected volume of approximately 2 mL, and when the particle size of tricalcium phosphate (TCP) was smaller than 0.5 mm, 80% TCP could be ejected from the microinjector. Furthermore, by using an agarose model to simulate the periodontal soft tissue, it was also found that bone graft substitutes could be easily injected into the gel. The results confirmed the feasibility of this novel microinjector for dental applications to carry bone graft substitutes for the restoration of bone defects of periodontal disease. Copyright © 2015. Published by Elsevier B.V.
    No preview · Article · Jun 2015 · Journal of the Formosan Medical Association
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    ABSTRACT: Background/purpose We explored changes in salivary gland function of head-and-neck cancer patients after radiotherapy, including pH of saliva, stimulated salivary flow rate, and saliva buffering capacity. The pH of saliva included that of parotid gland, submaxillary gland, and total resting saliva. We also investigated whether the acidity of dental plaque lowered pH of saliva. Materials and methods From a total of 62 patients, 11 had repeated measurements taken before and every month after radiotherapy. The remaining 51 patients had a single measurement taken after radiotherapy. Seven normal patients served as the control group. Results In the repeated measurement group, all examinations decreased dramatically in the 1st month after radiotherapy (P < 0.0001), and recovered from the 3rd month to the 6th month, but the flow rate could not return to pretreatment level. In the single measurement group, unilabiate linear regression analysis showed that the time-period after radiotherapy was a significant predictor influencing the pH of the submaxillary gland and total resting saliva. Pearson correlation coefficient analysis showed that the pH of dental plaque had a positive linear correlation with that of saliva. Concerning the influence of time-period, within 1 year after radiotherapy, all examinations were dropped. After 1 year the pH of resting saliva and plaque began to increase over time. The stimulated flow rate, pH of stimulated saliva, and buffering capacity, dropped < 1 year after radiotherapy group, increased 1-5 years after radiotherapy group, but dropped again > 5 years after radiotherapy group. Conclusion Our results indicated that oral hygiene care is important especially during the early period after radiotherapy. © 2015, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.
    No preview · Article · May 2015 · Journal of dental sciences
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    ABSTRACT: Various polyphenolic compounds from plants have been confirmed to have different pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. A medium with CP was developed to improve oral wound healing. The CP could be used as a supplemental compound in mouthwash for periodontal diseases. In this study, the metabolic activity and cell toxicity of CP (1%, 0.1%, and 0.01%) for fibroblasts were investigated by MTT and lactate dehydrogenase assays (n = 6). The effect of CP on motility of fibroblast was also evaluated via a wound healing model. The growth of Hs68 cells on TCPS was greatly increased in the presence of 0.01% CP. In addition, the significant difference (p<0.01) of cell toxicity of fibroblast was observed after 6 days in 0.01% CP medium. Using the wound healing model, it was also found that CP could enhance the migratory ability of fibroblasts. The results confirm the feasibility of CP be a supplemental compound in mouthwash for treatment of periodontal diseases in dental application to improve wound healing in the mouth. Copyright © 2015. Published by Elsevier B.V.
    No preview · Article · Feb 2015 · Journal of the Formosan Medical Association
  • Yuan-Yu Tu · Chien-Ying Yang · Rung-Shu Chen · Min-Huey Chen
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    ABSTRACT: Chlorhexidine (CHX) is a type of chemical antiseptic that is widely used in dental practice. Stem cells from human exfoliated deciduous teeth (SHED) are multipotent cells. However, there is little knowledge about the effects of chlorhexidine on SHED cells. The purpose of this study is to investigate the effects of CHX on SHED. SHED cells were treated with 0.1%, 0.01%, 0.001%, and 0.0001% CHX for 10 seconds to test the effects of different concentrations of CHX on SHED cells. The cells were also treated with 0.01% CHX for 10 seconds, 1 minute, and 5 minutes to test the time effects of CHX on SHED cells. Cell proliferation was investigated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and an autonomously replicating sequence (ARS) assay was used for the evaluation of the mineralization potential. This study demonstrated that different concentrations of CHX had cytotoxic effects on SHED cells in a dose- and time-dependent manner. The proliferation of SHED cells was inhibited by approximately 50% by the use of 0.01% CHX. It was also found that the cell proliferation and mineralization potential of SHED cells were inhibited to some degree by different concentrations of CHX. Different concentrations of CHX can inhibit SHED cell proliferation in a dose- and time-dependent manner. In addition, the mineralization potential of SHED cells is inhibited to some degree by different concentrations of CHX. Copyright © 2013. Published by Elsevier B.V.
    No preview · Article · Jan 2015 · Journal of the Formosan Medical Association
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    ABSTRACT: The present work demonstrates a biomimetic electrospun scaffold based on polyurethane (PU) and ethyl cellulose (EC), featuring uniform fibrous nanostructures and three dimensional porous networks. The analytical relation between processing conditions and fibrous nanostructures is established which guides the rational processing with tunable fiber diameters. Additionally, the developed scaffold template reveals biocompatibility in retention and proliferation of cardiac myoblast H9C2 cells. The high mechanical strength of the PU/EC scaffolds enables the processing and handling of ultrathin patch. Their elastomeric characteristics revealed the compatibility between the patch and contractile tissues. Furthermore, anisotropic PU/EC scaffolds with aligned nanofibers were successfully fabricated, exhibiting higher mechanical strength and essential cues for the survival and function of cardiac cells with native anisotropy. This work newly demonstrates a bioengineered PU/EC fibrous scaffold with uniform nanostructural webs and provides insight into the relation among processing control, nanostructures and associated properties toward promising potential in cardiac tissue engineering.
    No preview · Article · Dec 2014 · RSC Advances
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    ABSTRACT: Traditional dental care, which includes long-term oral hygiene maintenance and scheduled dental appointments, requires effective communication between dentists and patients. In this study, a new system was designed to provide a platform for direct communication between dentists and patients. A new mobile app, Dental Calendar, combined with cloud services specific for dental care was created by a team constituted by dentists, computer scientists, and service scientists. This new system would remind patients about every scheduled appointment, and help them take pictures of their own oral cavity parts that require dental treatment and send them to dentists along with a symptom description. Dentists, by contrast, could confirm or change appointments easily and provide professional advice to their patients immediately. In this study, 26 dentists and 32 patients were evaluated by a questionnaire containing eight dental-service items prior to and after using this system. Paired sample t test was used for statistical analysis. After using the Dental Calendar combined with cloud services, dentists were able to improve appointment arrangements significantly, taking care of the patients with sudden worse prosthesis (p < 0.05). Patients also achieved significant improvement in appointment reminder systems, rearrangement of appointments in case of sudden worse prosthesis, and establishment of a direct relationship with dentists (p < 0.05). Our new mobile app, Dental Calendar, in combination with cloud services, provides efficient service to both dentists and patients, and helps establish a better relationship between them. It also helps dentists to arrange appointments for patients with sudden worsening of prosthesis function.
    No preview · Article · May 2014 · Journal of the Formosan Medical Association
  • Tai-Ting Lai · Min-Huey Chen
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    ABSTRACT: Background/purpose The purpose of this retrospective study was to evaluate the factors affecting the clinical success of orthodontic anchorage by using temporary anchorage devices (TADs). Materials and methods One hundred and twenty nine consecutive patients (54 males, 75 females; mean age, 20.2 years old) with a total of 266 TADs of three different types were examined. The variables related to TAD success were assessed through five categories: implant-related (type 1, type 2, and type 3 with different diameters and lengths), patient-related (sex, age, and type of malocclusion), location-related (jaw, site, side, bone quality, and the type of soft tissue), orthodontic-related (the timing of force application), and implant-maintenance factors (local inflammation around a TAD: mild, moderate, and severe). Results The overall success rates were 97%. The clinical variables of all implant-related factors (diameter and length), all patient-related factors (sex, age, and type of malocclusion), and one of location-related factors (side) did not show any statistically significant difference in success rates. The clinical variables of most location-related factors [jaw (mandible), site (lingual), bone quality (Q4), and the type of soft tissue around TADs (mucosa)], orthodontic-related factors [timing of force application equal to 2 weeks)], and implant-maintenance factors [local inflammation (mild–moderate and moderate–severe)] showed less success with statistically significant differences. Conclusion In order to improve the success rates, local inflammation should be monitored and controlled, force application should be 4 weeks after insertion, and the location for placement of TADs should be good quality bone with keratinized mucosa.
    No preview · Article · Mar 2014 · Journal of dental sciences
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    ABSTRACT: Traditionally, tooth germ is observed by histological investigation with hematoxylin and eosin stain and information may loss during the process. The purpose of this study is to use multiphoton laser fluorescence microscopy to observe the developing tooth germs of mice for building up the database of the images of tooth germs and compare with those from conventional histological analysis. Tooth germs were isolated from embryonic and newborn mice with age of Embryonic Day 14.5 and Postnatal Days 1, 3, 5, and 7. Comparison of the images of tooth germ sections in multiphoton microscopy with the images of histology was performed for investigating the molar tooth germs. It was found that various signals arose from different structures of tooth germs. Pre-dentin and dentin have strong second-harmonic generation signals, while ameloblasts and enamel tissues were shown with strong autofluorescence signals. In this study, a novel multiphoton microscopy database of images from developing tooth germs in mice was set up. We confirmed that multiphoton laser microscopy is a powerful tool for investigating the development of tooth germ and is worthy for further application in the study of tooth regeneration.
    No preview · Article · Jan 2014 · Journal of the Formosan Medical Association
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    ABSTRACT: Background/Purpose Traditional dental care, which includes long-term oral hygiene maintenance and scheduled dental appointments, requires effective communication between dentists and patients. In this study, a new system was designed to provide a platform for direct communication between dentists and patients. Methods A new mobile app, Dental Calendar, combined with cloud services specific for dental care was created by a team constituted by dentists, computer scientists, and service scientists. This new system would remind patients about every scheduled appointment, and help them take pictures of their own oral cavity parts that require dental treatment and send them to dentists along with a symptom description. Dentists, by contrast, could confirm or change appointments easily and provide professional advice to their patients immediately. In this study, 26 dentists and 32 patients were evaluated by a questionnaire containing eight dental-service items prior to and after using this system. Paired sample t test was used for statistical analysis. Results After using the Dental Calendar combined with cloud services, dentists were able to improve appointment arrangements significantly, taking care of the patients with sudden worse prosthesis (p < 0.05). Patients also achieved significant improvement in appointment reminder systems, rearrangement of appointments in case of sudden worse prosthesis, and establishment of a direct relationship with dentists (p < 0.05). Conclusion Our new mobile app, Dental Calendar, in combination with cloud services, provides efficient service to both dentists and patients, and helps establish a better relationship between them. It also helps dentists to arrange appointments for patients with sudden worsening of prosthesis function.
    No preview · Article · Jan 2014
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    ABSTRACT: Background/Purpose Novel liquid crystalline epoxy nanocomposites, which exhibit reduced polymerization shrinkage and effectively bond to tooth structures, can be applied in esthetic dentistry, including core and post systems, direct and indirect restorations, and dental brackets. The purposes of this study were to investigate the properties of liquid crystalline epoxy nanocomposites including biocompatibility, microhardness, and frictional forces of bracket-like blocks with different filler contents for further clinical applications. Methods In this study, we evaluated liquid crystalline epoxy nanocomposite materials that exhibited various filler contents, by assessing their cell activity performance using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and their microhardness with or without thermocycling. We also evaluated the frictional force between bracket-like duplicates and commercially available esthetic bracket systems using Instron 5566. Results The liquid crystalline epoxy nanocomposite materials showed good biocompatibility. The materials having high filler content demonstrated greater microhardness compared with commercially available bracket materials, before and after the thermocycling treatment. Thus, manufacturing processes are important to reduce frictional force experienced by orthodontic brackets. Conclusion The microhardness of the bracket-like blocks made by our new material is superior to the commercially available brackets, even after thermocycling. Our results indicate that the evaluated liquid crystalline epoxy nanocomposite materials are of an appropriate quality for application in dental core and post systems and in various restorations. By applying technology to refine manufacturing processes, these new materials could also be used to fabricate esthetic brackets for orthodontic treatment.
    No preview · Article · Jan 2014 · Journal of the Formosan Medical Association
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    ABSTRACT: This research was designed to investigate the effects of low pressure radio-frequency (RF) oxygen plasma treatment (OPT) on the surface of commercially pure titanium (CP-Ti) and Ti6Al4V. Surface topography, elemental composition, water contact angle, cell viability, and cell morphology were surveyed to evaluate the biocompatibility of titanium samples with different lengths of OP treating time. CP-Ti and Ti6Al4V discs were both classified into 4 groups: untreated, treated with OP generated by using oxygen (99.98%) for 5, 10, and 30 min, respectively. After OPT on CP-Ti and Ti6Al4V samples, scanning probe microscopy, X-ray photoelectron spectrometry (XPS), and contact angle tests were conducted to determine the surface topography, elemental composition and hydrophilicity, respectively. The change of surface morphology was further studied using sputtered titanium on silicon wafers. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and F-actin immunofluorescence stain were performed to investigate the viability and spreading behavior of cultivated MG-63 cells on the samples. The surface roughness was most prominent after 5 min OPT in both CP-Ti and Ti6Al4V, and the surface morphology of sputtered Ti sharpened after the 5 min treatment. From the XPS results, the intensity of Ti(°), Ti(2+), and Ti(3+) of the samples' surface decreased indicating the oxidation of titanium after OPT. The water contact angles of both CP-Ti and Ti6Al4V were increased after 5 min OPT. The results of MTT assay demonstrated MG-63 cells proliferated best on the 5 min OP treated titanium sample. The F-actin immunofluorescence stain revealed the cultivated cell number of 5 min treated CP-Ti/Ti6Al4V was greater than other groups and most of the cultivated cells were spindle-shaped. Low pressure RF oxygen plasma modified both the composition and the morphology of titanium samples' surface. The CP-Ti/Ti6Al4V treated with 5 min OPT displayed the roughest surface, sharpest surface profile and best biocompatibility.
    Full-text · Article · Dec 2013 · PLoS ONE
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    ABSTRACT: Our previous work has demonstrated that rat bone marrow stem cells (BMSCs) can transdifferentiate into α-amylase-producing cells after coculture with rat submandibular gland acinar cells. These transdifferentiated cells may be used for regeneration of damaged salivary gland. The purpose of this study was to investigate the global gene expression of rat BMSCs cocultured with rat submandibular gland acinar cells and the factors inducing this transdifferentiation. Rat BMSCs were indirectly cocultured with rat submandibular gland acinar cells by using the double chamber system for 5 and 10 days. The global gene expression of BMSCs during transdifferentiation into acinar cells was investigated by microarray analysis. A total of 45,018 probes were used and 41,012 genes were detected. After coculture for 5 days, 1409 genes were upregulated more than twofold and 1417 genes were downregulated more than twofold (p<0.005). Moreover, after coculture for 10 days, 1356 genes were upregulated more than twofold and 1231 genes were downregulated more than twofold (p<0.005). Bone morphogenetic protein (BMP)-6 was one of the top-ranked upregulated genes. The hub genes were interleukin-6 and CCAAT/enhancer-binding protein β (CEBPB) in the early and late response gene groups, respectively. This is believed to be the first study on the global gene expression of rat BMSCs cocultured with rat acinar cells. Many genes related to the function of salivary acinar cells such as those responsible for the production of α-amylase protein were upregulated and many genes related to the differentiation of BMSCs into adipocytes and osteoblasts were downregulated. In addition, BMP-6 gene was found to be highly upregulated. We proposed that three target genes, BMP-6, interleukin-6 and CEBPB, play important roles in the transdifferentiation of BMSCs into acinar cells, and are worthy of further investigation.
    No preview · Article · Nov 2013 · Journal of the Formosan Medical Association
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    Yun-Yuan Tai · Rung-Shu Chen · Yi Lin · Thai-Yen Ling · Min-Huey Chen
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    ABSTRACT: Background Epithelial invagination is important for initiation of ectodermal organogenesis. Although many factors regulate ectodermal organogenesis, there is not any report about their functions in real-time study. Electric cell-substrate impedance sensing (ECIS), a non-invasive, real-time surveillance system, had been used to detect changes in organ cell layer thickness through quantitative monitoring of the impedance of a cell-to-microelectrode interface over time. It was shown to be a good method for identifying significant real-time changes of cells. The purpose of this study is to establish a combined bioengineered organ-ECIS model for investigating the real time effects of fibroblast growth factor-9 (FGF-9) on epithelial invagination in bioengineered ectodermal organs. We dissected epithelial and mesenchymal cells from stage E14.5 murine molar tooth germs and identified the real-time effects of FGF-9 on epithelial-mesenchymal interactions using this combined bioengineered organ-ECIS model. Results Measurement of bioengineered ectodermal organ thickness showed that Fibroblast growth factor-9 (FGF-9) accelerates epithelial invagination in reaggregated mesenchymal cell layer within 3 days. Gene expression analysis revealed that FGF-9 stimulates and sustains early Ameloblastin and Amelogenin expression during odontogenesis. Conclusions This is the first real-time study to show that, FGF-9 plays an important role in epithelial invagination and initiates ectodermal organogenesis. Based on these findings, we suggest FGF-9 can be applied for further study in ectodermal organ regeneration, and we also proposed that the ‘FGF-BMP balancing system’ is important for manipulating the morphogenesis of ectodermal organs. The combined bioengineered organ-ECIS model is a promising method for ectodermal organ engineering and regeneration research.
    Full-text · Article · Nov 2012 · Cell Communication and Signaling
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    ABSTRACT: Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility, comparable to commercialized composites. The results indicate that this novel LC nanocomposite is worthy of development and has potential for further applications in clinical dentistry.
    No preview · Article · Jul 2012 · Acta biomaterialia
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    ABSTRACT: Previous studies have shown that zinc chloride (ZnCl(2)) can induce metallthionein (MT) in the liver and kidney to protect tissues against toxicants and shows a better corneal wound healing than conventional drugs do. We hypothesized that ZnCl(2) can promote odontogenesis of dental pulp stem cells (DPSCs) via MT. The purpose of this study was to investigate the effects of ZnCl(2) on human DPSCs and the expression of MT. DPSCs were isolated by flow cytometry with selective surface marker CD146 and STRO-1. After they grew into confluence, DPSCs were induced into odontoblasts with or without ZnCl(2) supplemented in the culture medium for 21 days. The effect of ZnCl(2) on DPSCs differentiation was examined followed by alkaline phosphatase staining/activity and quantitative real-time polymerase chain reaction analysis. By treating DPSCs with ZnCl(2), the duration of mineralization was shortened and expressions of differentiation markers into odontoblasts were more significant than those without ZnCl(2) stimulation. Besides, the MT gene expression was increased with the increasing expressions of odontoblasts' markers after treated with ZnCl(2). This was the first report that ZnCl(2) could promote odontoblastic differentiation of DPSCs through the up-regulation of gene MT.
    Full-text · Article · Feb 2011 · Journal of endodontics
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    ABSTRACT: Growth factors and morphogens secreted by bone marrow mesenchymal stem cells (BMSCs) of bone marrow fluid may promote tooth regeneration. Accordingly, a tissue engineering approach was utilized to develop an economical strategy for obtaining the growth factors and morphogens from BMSCs. Unerupted second molar tooth buds harvested from miniature pigs were cultured in vitro to obtain dental bud cells (DBCs). Bone marrow fluid, which contains BMSCs, was collected from the porcine mandible before operation. DBCs suspended in bone marrow fluid were seeded into a gelatin/chondoitin-6-sulfate/hyaluronan tri-copolymer scaffold (GCHT scaffold). The DBCs/bone marrow fluid/GCHT scaffold was autografted into the original alveolar sockets of the pigs. Radiographic and histological examinations were applied to identify the structure of regenerated tooth at 40 weeks postimplantation. The present results showed that one pig developed a complete tooth with crown, root, pulp, enamel, dentin, odontoblast, cementum, blood vessel, and periodontal ligament in indiscriminate shape. Three animals had an unerupted tooth that expressed dentin matrix protein-1, vascular endothelial growth factor, and osteopontin; and two other pigs also had dental-like structure with dentin tubules. This study reveals that DBCs adding bone marrow fluid and a suitable scaffold can promote the tooth regeneration in autogenic cell transplantation.
    No preview · Article · Nov 2010 · Artificial Organs
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    ABSTRACT: Human mesenchymal stem cells (hMSCs) are characterized by their abilities to differentiate into different lineages, including osteoblasts. Besides soluble factors, mechanical strain and extracellular matrix (ECM) proteins play important roles in osteogenic differentiation of hMSCs. However, interactions between them are still not fully understood. The purpose of this study was to investigate the combined effects of insoluble chemical and mechanical factors (ECM proteins vs. cyclic stretching) in driving hMSCs into osteogenic differentiation. To avoid the influence from osteogenic supplements, hMSCs were cultured in regular medium and subjected to cyclic mechanical stretching using a Flexcell Tension system (3% elongation at 0.1 Hz) when they were grown on substrates coated with various ECM proteins (collagen I (Col I), vitronectin (VN), fibronectin (FN), and laminin (LN)). Using alkaline phosphatase (ALP) activity and mineralized matrix deposition as respective indicators of the early and late stages of osteogenesis, we report herein that all of the ECM proteins tested supported hMSC differentiation into osteogenic phenotypes in the absence of osteogenic supplements. Moreover, cyclic mechanical stretching activated the phosphorylation of focal adhesion kinase (FAK), upregulated the transcription and phosphorylation of core-binding factor alpha-1 (Cbfa1), and subsequently increased ALP activity and mineralized matrix deposition. Among the ECM proteins tested, FN and LN exhibited greater effects of supporting stretching-induced osteogenic differentiation than did Col I and VN. The ability of ECM proteins and mechanical stretching to regulate osteogenesis in hMSCs can be exploited in bone tissue engineering via approximate matrix design or application of mechanical stimulation.
    No preview · Article · Dec 2009 · Journal of Cellular Biochemistry