12 research outputs found
Mesenchymal stem cell-mediated functional tooth regeneration in swine
No full textMesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla). Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs) to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance.Wataru Sonoyama, Yi Liu, Dianji Fang, Takayoshi Yamaza, Byoung-Moo Seo, Chunmei Zhang, He Liu, Stan Gronthos, Cun-Yu Wang,Songtao Shi and Songlin Wan
Periodontal ligament stem cell-mediated treatment for periodontitis in miniature swine
No full textThe definitive version may be found at www.wiley.comPeriodontitis is a periodontal tissue infectious disease and the most common cause for tooth loss in adults. It has been linked to many systemic disorders, such as coronary artery disease, stroke, and diabetes. At present, there is no ideal therapeutic approach to cure periodontitis and achieve optimal periodontal tissue regeneration. In this study, we explored the potential of using autologous periodontal ligament stem cells (PDLSCs) to treat periodontal defects in a porcine model of periodontitis. The periodontal lesion was generated in the first molars area of miniature pigs by the surgical removal of bone and subsequent silk ligament suture around the cervical portion of the tooth. Autologous PDLSCs were obtained from extracted teeth of the miniature pigs and then expanded ex vivo to enrich PDLSC numbers. When transplanted into the surgically created periodontal defect areas, PDLSCs were capable of regenerating periodontal tissues, leading to a favorable treatment for periodontitis. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to treat periodontal diseases.Yi Liu, Ying Zheng, Gang Ding, Dianji Fang, Chunmei Zhang, Peter Mark Bartold, Stan Gronthos, Songtao Shi and Songlin Wan
Method for transaction analysis of hydro-thermal system
No full textA transaction pricing and evaluating method for maximizing profits in a interconnecting hydro-thermal system is described. The method is based on the Nash bargaining game for power flow analysis in which every transaction and its price are determined in a fair way. The method considers the important effect of short term system scheduling such as unit commitment and hydro-thermal schedule. The transaction losses are also considered. Test examples and a real scale system result present the merits of the proposed method.link_to_subscribed_fulltex
Analytical Modeling of Permanent Magnet Eddy Current Couplings Using the Subdomain Method
No full text© 2017 Chin. Soc. for Elec. Eng. Permanent magnet eddy current transmission devices can transfer torque without any mechanical contact and wear and thus they are widely applicable to many industrial applications. The Eulerian formulation and the Lagrangian formulation respectively corresponding to the moving conductor eddy current problem described in moving coordinates and that in fixed coordinates were derived, and the two formulations proved to be equivalent to each other. Based on the subdomain method, a four-layered analytical model of permanent magnet eddy current couplings where the permanent magnet array, the air gap, the conductor and its back iron were taken into account was presented, the multi-layer boundary value problem was solved, and a very simple torque expression represented by the Fourier series was derived. To economize the amount of permanent magnet material as much as possible, an optimization method for exploiting the permanent magnet array was proposed by using the developed analytical model of permanent magnet eddy current couplings. By analyzing the examples and comparing the results obtained by the three-dimensional finite element analysis and the experiments, the effectiveness of the analytical model and the optimization scheme proposed in this paper was verified
Transplantation of mesenchymal stem cells is an optimal approach for plastic surgery
No full textMesenchymal stem cells (MSCs) are able to differentiate into a variety of cell types, offering promising approaches for stem cell-mediated tissue regeneration. Here, we explored the potential of utilizing MSCs to reconstruct orofacial tissue, thereby altering the orofacial appearance. We demonstrated that bone marrow MSCs were capable of generating bone structures and bone-associated marrow elements on the surfaces of the orofacial bone. This resulted in significant recontouring of the facial appearance in mouse and swine. Notably, the newly formed bone and associated marrow tissues integrated with the surfaces of the recipient bones and re-established a functional bone marrow organ-like system. These data suggested that MSC-mediated tissue regeneration led to a body structure extension, with the re-establishment of all functional components necessary for maintaining the bone and associated marrow organ. In addition, we found that the subcutaneous transplantation of another population of MSCs, the human periodontal ligament stem cells (PDLSCs), could form substantial amounts of collagen fibers and improve facial wrinkles in mouse. By contrast, bone marrow MSCs failed to survive at 8 weeks post-transplantation under the conditions used for the PDLSC transplantation. This study suggested that the mutual interactions between donor MSCs and recipient microenvironment determine long-term outcome of the functional tissue regeneration. Disclosure of potential conflicts of interest is found at the end of this article.
Disclosure of potential conflicts of interest is found at the end of this article
Characterization of human SCAP in comparison with DPSCs.
No full text<div><p>(<b>A</b>) Western blot analysis to confirm protein expression of genes identified in microarray studies showed greater abundance of survivin in SCAP than in DPSCs, with similar levels of DSP and Cbfa1/Runx2.</p>
<p>(<b>B</b>) Flow cytometric analysis showed that <i>ex vivo</i> expanded SCAP contained approximately 7.5% CD24-positive cells, but DPSCs exhibited 0.5% positive staining for CD 24.</p>
<p>(<b>C</b>) The proliferation rates of SCAP and DPSCs, derived from the same tooth, were assessed by co-culture with BrdU for 6 hours.</p>
<p>The number of BrdU-positive cells was presented as a percentage of the total number of cells counted from five replicate cultures.</p>
<p>SCAP showed a significantly higher proliferation rate in comparison with DPSCs (<b>*</b><i>P</i> = 0.0042).</p>
<p>(<b>D</b>) Single colony-derived SCAP were able to proliferate to over 70 population doublings, which was significantly higher than DPSCs (<b>*</b><i>P</i> = 0.0192).</p>
<p>(<b>E</b>) Dentin regeneration capacity of SCAP was significantly higher than that of DPSCs when transplanted into the same immunocompromised mice (<b>*</b><i>P</i> = 0.0489) using Scion Image analysis system (Scion Image, Rockville, MD).</p>
<p>(<b>F</b>) SCAP showed a significant higher telomerase activity than DPSCs at passage 1 (<b>*</b><i>P</i> = 0.015).</p>
<p>Cultured BMMSCs at passage 1 were used as a negative control to show an absence of telomerase activity.</p>
<p>The telomerase activity was assessed by real time PCR based quantitative telomerase detection kit as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000079#s4" target="_blank">Materials and Methods</a>.</p>
<p>(<b>G</b>) Cell motility assessed by a scratch assay.</p>
<p>A representative area of SCAP and DPSCs at 72 hours after scratch was presented.</p>
<p>Red arrows indicate the ranges of cell migration during 72 hours (<b>*</b><i>P</i> = 0.0033).</p></div
Isolation of Stem Cells from Root Apical Papilla (SCAP).
No full text<div><p>(<b>A</b>) Human apical papilla tissue was positive for STRO-1, an early mesenchymal progenitor marker, staining by immunofluorescence (arrows).</p>
<p>(<b>B)</b> Single colonies were formed after human SCAP were plated at a low density (5×10<sup>3</sup>/T25 flask) and cultured for 10 days.</p>
<p>(<b>C</b>) When human SCAP were cultured in odontogenic/osteogenic inductive conditions containing L-ascorbate-2-phosphate, dexamethasone, and inorganic phosphate for 4 weeks, mineralized nodules were found by Alizarin red S staining.</p>
<p>(<b>D</b>) Cultured human SCAP formed Oil red O positive lipid clusters following 5 weeks of adipogenic induction in the presence of 0.5 mM isobutylmethylxanthine, 0.5 µM hydrocortisone, 60 µM indomethacin, and 10 µg/ml insulin.</p>
<p>(<b>E</b>) Eight weeks after transplantation in immunocompromised mice, human SCAP differentiated into odontoblasts (arrows) that formed dentin (<i>D</i>) on the surfaces of a hydroxyapatite tricalcium (<i>HA</i>) carrier.</p>
<p>(<b>F</b>) Immunohistochemical staining showed that human SCAP differentiated into odontoblasts (arrows) that were positive for anti-human specific mitochondria antibody staining.</p>
<p>(<b>G</b>) Immunohistochemical staining showed that human SCAP-generated dentin (<i>D</i>) was positive for anti-DSP antibody staining (arrows).</p>
<p>(<b>H</b>) Pre-immunoserum negative control of human SCAP transplant.</p>
<p>(<b>I</b>) SCAP isolated from swine were capable of forming a single colony cluster when plated at a low cell density.</p>
<p>(<b>J</b>) When transplanted into immunocompromised mice for 8 weeks, swine SCAP differentiate into odontoblasts (arrows) to regenerate dentin (<i>D</i>) on the surface of the hydroxyapatite carrier (<i>HA</i>).</p>
<p>(<b>K</b>) Swine PDLSCs were capable of forming a single colony cluster.</p>
<p>(<b>L</b>) After transplantation into immunocompromised mice, swine PDLSCs formed cementum (<i>C</i>) on the surface of hydroxyapatite carrier (<i>HA</i>).</p>
<p>Collagen fibers were found to connect to newly formed cementum.</p></div
Swine SCAP/PDLSC-mediated root/periodontal structure as an artificial crown support for the restoration of tooth function in swine.
No full text<div><p>(<b>A</b>) Extracted minipig lower incisor and root-shaped HA/TCP carrier loaded with SCAP.</p>
<p>(<b>B</b>) Gelfoam containing 10×10<sup>6</sup> PDLSCs (open arrow) was used to cover the HA/SCAP (black arrow) and implanted into the lower incisor socket (open triangle).</p>
<p>(<b>C</b>) HA/SCAP-Gelfoam/PDLSCs were implanted into a newly extracted incisor socket.</p>
<p>A post channel was pre-created inside the root shape HA carrier (arrow).</p>
<p>(<b>D</b>) The post channel was sealed with a temporary filling for affixing a porcelain crown in the next step.</p>
<p>(<b>E</b>) The HA/SCAP-Gelfoam/PDLSC implant was sutured for 3 months.</p>
<p>(<b>F</b>) The HA/SCAP-Gelfoam/PDLSC implant (arrow) was re-exposed and the temporary filling was removed to expose the post channel.</p>
<p>(<b>G</b>) A pre-made porcelain crown was cemented to the HA/SCAP-Gelfoam/PDLSC structure.</p>
<p>(<b>H</b>) The exposed section was sutured.</p>
<p>(<b>I</b> and <b>J</b>) Four weeks after fixation, the porcelain crown was retained in the swine after normal tooth use as shown by open arrows.</p>
<p>(<b>K</b>) After 3 months implantation, the HA/SCAP-Gelfoam/PDLSC implant had formed a hard root structure (open arrows) in the mandibular incisor area as shown by CT scan image.</p>
<p>A clear PDL space was found between the implant and surrounding bony tissue (triangle arrows).</p>
<p>(<b>L</b> and <b>M</b>) H&E staining showed that implanted HA/SCAP-Gelfoam/PDLSC contains newly regenerated dentin (<i>D</i>) inside the implant (<b>L</b>) and PDL tissue (<i>PDL</i>) on the outside of the implant (<b>M</b>).</p>
<p>(<b>N</b>) Compressive strength measurement showed that newly formed bio-roots have much higher compressive strength than original HA/TCP carrier (<b>*</b><i>P</i> = 0.0002), but lower than that in natural swine root dentin (<b>*</b><i>P</i> = 0.003) (NR: natural minipig root, BR: newly formed bio-root, HA: original HA carrier).</p></div
Comined human SCAP/PDLSC-mediated tissue regeneration.
No full text<div><p>(<b>A</b>) On the outside of the HA/TCP carrier (<i>HA</i>), PDLSCs can form structures resembling Sharpey's fibers (arrows) connecting with newly formed cementum (<i>C</i>) on the surface of HA/TCP particles (<i>HA</i>).</p>
<p>(<b>B</b>) Immunohistochemical staining showed that SCAP/PDLSC-generated tissues were positive for human specific mitochondria antibody staining (arrows).</p></div
Surface Molecule Characterization of human SCAP.
No full text<div><p>(<b>A</b>) Flow cytometric analysis of cultured SCAP at passage 1 revealed expression of STRO-1 (18.12%), CD146 (72.3%), CD24 (7.56%), CD166 (93.74%), CD73 (94.14%), CD90 (95.54%), CD105 (9.23%), CD106 (32.7%), CD29 (88.1%) and ALP (11.43%), but was negative for surface molecules CD18, CD14, CD34, CD45, and CD 150.</p>
<p>(<b>B</b>) After 2 weeks osteo-induction <i>in vitro</i> with L-ascorbate-2-phosphate, dexamethasone, and inorganic phosphate, SCAP differentiated into odontoblasts with a decrease in CD24 expression from 7.56% to 0.22%.</p>
<p>In contrast, ALP expression increased significantly from 11.43% to 86.59%.</p></div
