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Onozawa G, Nagasaka A, Bando Y, Sakiyama K, Yamamoto N, Amano O. Specific localization of fibroblasts at the intercalated duct in the major salivary glands of rats. J Oral Biosci 2024; 66:456-464. [PMID: 38382878 DOI: 10.1016/j.job.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/23/2024]
Abstract
OBJECTIVES Immunohistochemical methods were employed to investigate the morphological heterogeneity and localization of fibroblasts associated with the function of major salivary glands in rats. METHODS Histochemical and electron microscopic observations were made in rat parotid, submandibular, and sublingual glands and pancreas. Fibroblasts were immunostained using their specific marker, 47 kDa heat shock protein (Hsp47). RESULTS Hsp47-immunopositive fibroblasts within the intralobular connective tissue exhibited a notably smaller size compared with the interlobular connective tissue. They were loosely distributed throughout the connective tissue. However, fibroblasts with elongated long processes were explicitly identified at the intercalated ducts in parotid, sublingual, and submandibular glands. Fibroblastic bodies and processes were tightly approximated with the basement membrane of the duct. Electron microscopy confirmed these findings, revealing a thin layer consisting of collagen fibers was found between the fibroblasts and the basement membrane. Double staining of Hsp47 and α-smooth muscle actin (αSMA) in parotid glands indicating that Hsp47-positive fibroblasts enveloped both the duct and αSMA-positive myoepithelial cells. Additionally, They projected long and thin processes longitudinally at the straight portion or circularly at the bifurcated portion of the duct. The three-dimensional reconstruction showed a frame-like structure of fibroblasts surrounding the intercalated duct with longitudinal myoepithelial cells. However, such specific localization of fibroblasts was not detected in the exocrine pancreas lacking myoepithelium. CONCLUSIONS Small fibroblasts with long processes connecting or overwrapping each other and thin collagen layers surround the intercalated ducts in rat major salivary glands, presumably contributing to protecting the ducts from salivary flow and myoepithelial contraction.
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Affiliation(s)
- Go Onozawa
- Division of Histology, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 3500283, Japan; Division of Oral and Maxillofacial Surgery, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 3500283, Japan
| | - Arata Nagasaka
- Division of Histology, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 3500283, Japan
| | - Yasuhiko Bando
- Division of Histology, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 3500283, Japan
| | - Koji Sakiyama
- Division of Anatomy, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitma, 3500283, Japan
| | - Nobuharu Yamamoto
- Division of Oral and Maxillofacial Surgery, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 3500283, Japan
| | - Osamu Amano
- Division of Histology, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama, 3500283, Japan.
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2
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Couoh LR, Bucio L, Ruvalcaba JL, Manoel B, Tang T, Gourrier A, Grandfield K. Tooth acellular extrinsic fibre cementum incremental lines in humans are formed by parallel branched Sharpey's fibres and not by its mineral phase. J Struct Biol 2024; 216:108084. [PMID: 38479547 DOI: 10.1016/j.jsb.2024.108084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/28/2024] [Accepted: 03/10/2024] [Indexed: 03/18/2024]
Abstract
In humans, the growth pattern of the acellular extrinsic fibre cementum (AEFC) has been useful to estimate the age-at-death. However, the structural organization behind such a pattern remains poorly understood. In this study tooth cementum from seven individuals from a Mexican modern skeletal series were analyzed with the aim of unveiling the AEFC collagenous and mineral structure using multimodal imaging approaches. The organization of collagen fibres was first determined using: light microscopy, transmission electron microscopy (TEM), electron tomography, and plasma FIB scanning electron microscopy (PFIB-SEM) tomography. The mineral properties were then investigated using: synchrotron small-angle X-ray scattering (SAXS) for T-parameter (correlation length between mineral particles); synchrotron X-ray diffraction (XRD) for L-parameter (mineral crystalline domain size estimation), alignment parameter (crystals preferred orientation) and lattice parameters a and c; as well as synchrotron X-ray fluorescence for spatial distribution of calcium, phosphorus and zinc. Results show that Sharpey's fibres branched out fibres that cover and uncover other collagen bundles forming aligned arched structures that are joined by these same fibres but in a parallel fashion. The parallel fibres are not set as a continuum on the same plane and when they are superimposed project the AEFC incremental lines due to the collagen birefringence. The orientation of the apatite crystallites is subject to the arrangement of the collagen fibres, and the obtained parameter values along with the elemental distribution maps, revealed this mineral tissue as relatively homogeneous. Therefore, no intrinsic characteristics of the mineral phase could be associated with the alternating AEFC incremental pattern.
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Affiliation(s)
- Lourdes R Couoh
- Dirección de Antropología Física, Instituto Nacional de Antropología e Historia, Paseo de la Reforma y Gandhi, Chapultepec Polanco 11560, CDMX, México.
| | - Lauro Bucio
- Laboratorio de Cristalofísica y Materiales Naturales, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán 04510, CDMX, México
| | - José Luis Ruvalcaba
- Laboratorio Nacional de Ciencias para la Investigación y Conservación del Patrimonio Cultural, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán 04510, CDMX, México
| | - Britta Manoel
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs 38000, Grenoble, France; Bruker AXS Advanced X-ray Solutions GmbH, Östliche Rheinbrückenstraße 49 76187, Karlsruhe, Germany
| | - Tengteng Tang
- Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L7, ON, Canada
| | | | - Kathryn Grandfield
- Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L7, ON, Canada; School of Biomedical Engineering, McMaster University, Hamilton L8S 4L7, ON, Canada.
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3
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Su S, Jia X, Zhan L, Gao S, Zhang Q, Huang X. Automatic tooth periodontal ligament segmentation of cone beam computed tomography based on instance segmentation network. Heliyon 2024; 10:e24097. [PMID: 38293338 PMCID: PMC10827460 DOI: 10.1016/j.heliyon.2024.e24097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 12/18/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024] Open
Abstract
Objective The three-dimensional morphological structures of periodontal ligaments (PDLs) are important data for periodontal, orthodontic, prosthodontic, and implant interventions. This study aimed to employ a deep learning (DL) algorithm to segment the PDL automatically in cone-beam computed tomography (CBCT). Method This was a retrospective study. We randomly selected 389 patients and 1734 axial CBCT images from the CBCT database, and designed a fully automatic PDL segmentation computer-aided model based on instance segmentation Mask R-CNN network. The labels of the model training were 'teeth' and 'alveolar bone', and the 'PDL' is defined as the region where the 'teeth' and 'alveolar bone' overlap. The model's segmentation performance was evaluated using CBCT data from eight patients outside the database. Results Qualitative evaluation indicates that the PDL segmentation accuracy of incisors, canines, premolars, wisdom teeth, and implants reached 100%. The segmentation accuracy of molars was 96.4%. Quantitative evaluation indicates that the mIoU and mDSC of PDL segmentation were 0.667 ± 0.015 (>0.6) and 0.799 ± 0.015 (>0.7) respectively. Conclusion This study analysed a unique approach to AI-driven automatic segmentation of PDLs on CBCT imaging, possibly enabling chair-side measurements of PDLs to facilitate periodontists, orthodontists, prosthodontists, and implantologists in more efficient and accurate diagnosis and treatment planning.
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Affiliation(s)
| | | | - Liping Zhan
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Siyuan Gao
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Qing Zhang
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xiaofeng Huang
- Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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4
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Zhao Y, Zhang S, Cheng B, Feng F, Zhu Y, Liu Y, Wang J, Zou D, Ma H, Xu F, Zhang M. Mechanochemical coupling of MGF mediates periodontal regeneration. Bioeng Transl Med 2024; 9:e10603. [PMID: 38193124 PMCID: PMC10771565 DOI: 10.1002/btm2.10603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 08/26/2023] [Accepted: 09/05/2023] [Indexed: 01/10/2024] Open
Abstract
Clinical evidence shows that the mechanical stimulation obtained from occlusion could enhance periodontal ligament (PDL) remodeling. Mechano-growth factor (MGF) is a growth factor produced specifically following mechanical stimulus Here, we aim to investigate the mechanical enhancement potential and mechanism of the MGF in PDL regeneration. In vivo study found that MGF produced from the PDL under occlusion force could strongly enhance PDL remodeling. In vitro experiments and mathematical modeling further confirmed the mechanical enhancement effect of MGF for PDLSC differentiation toward fibroblasts. A mechanochemical coupling effect of MGF mediated the enhancement of mechanical effect, which was modulated by Fyn-FAK kinases signaling and subsequent MAPK pathway. Finally, enhanced PDL regeneration under the mechanochemical coupling of MGF and occlusal force was verified in vivo. There exists an additive mechanical effect of MGF mediated by Fyn-FAK crosstalk and subsequent ERK1/2 and p38 phosphorylation, which could be developed as an MGF-centered adjuvant treatment to optimize PDL remodeling, especially for patients with weakened bite force or destroyed periodontium.
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Affiliation(s)
- Ying Zhao
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
- Department of Anesthesiology and Perioperative MedicineXi'an People's Hospital (Xi'an Fourth Hospital), Northwest UniversityXi'anPeople's Republic of China
| | - Songbai Zhang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Bo Cheng
- The Key Laboratory of Biomedical Information Engineering of Ministry of EducationSchool of Life Science and Technology, Xi'an Jiaotong UniversityXi’anPeople's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong UniversityXi’anPeople's Republic of China
| | - Fan Feng
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Yue Zhu
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Yanli Liu
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Junjun Wang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Dehui Zou
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Heng Ma
- Department of Physiology & Department of PathophysiologySchool of Basic Medical Sciences, Fourth Military Medical UniversityXi’anPeople's Republic of China
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of EducationSchool of Life Science and Technology, Xi'an Jiaotong UniversityXi’anPeople's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong UniversityXi’anPeople's Republic of China
| | - Min Zhang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and EmergencySchool of Stomatology, Fourth Military Medical UniversityXi’anPeople's Republic of China
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Mahdi Souzani A, Rajeshwari HRS, Selvaganapathy PR, Kishen A. Impact of 3D collagen-based model and hydrostatic pressure on periodontal ligament fibroblast: A morpho-biochemical analysis. J Mech Behav Biomed Mater 2023; 147:106092. [PMID: 37689009 DOI: 10.1016/j.jmbbm.2023.106092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/11/2023]
Abstract
This study developed a customized hydrostatic pressure-based loading environment to investigate the effect of static hydrostatic pressure on the periodontal ligament fibroblasts (PDLf) in a three-dimensional (3D) collagen-based model. The cylindrical tissue constructs were comprised of PDL fibroblast cells seeded in type I collagen matrices and divided into three experimental groups: Control (no load), low-load (∼0.07 kPa), and high-load (∼60 kPa), all subjected to 24 h of experimental duration. Cells in the 3D construct were stained with fluorophore-conjugated antibodies for cytoskeletal protein F-actin and matricellular protein periostin. Cell culture supernatant was assessed for receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) expression. Transmission electron microscopy examined the contact between the cells and the collagen matrix. Ultrastructural changes in the 3D collagen matrix were also analyzed using scanning electron microscopy. Experiments were performed in triplicates, and data was analyzed using one-way ANOVA (p < 0.05). The 3D PDLf constructs from the low-load group demonstrated the highest levels of homogeneous cell distribution and higher expression of F-actin and periostin with enhanced interaction with the matrix. The collagen matrix in this group showed more closely packed fibers forming thicker bundles when compared to the control and the high-load 3D PDLf constructs. Nonuniform cell distribution with decreased expression of F-actin and periostin was observed in the control and high-load PDLf constructs. The high-load group showed the highest RANKL/OPG expression. This study demonstrated low-level hydrostatic pressure's role in regulating PDLf functions and extracellular matrix response, while excessive hydrostatic pressure may be detrimental to PDL fibroblast cell function.
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Affiliation(s)
- Armin Mahdi Souzani
- The Kishen Lab, Dental Research Institute, University of Toronto, Toronto, ON, M5G 1G6, Canada
| | | | - P Ravi Selvaganapathy
- School of Biomedical Engineering, McMaster University, Hamilton, Canada; Department of Mechanical Engineering, McMaster University, Hamilton, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, M5G 1G6, Canada
| | - Anil Kishen
- The Kishen Lab, Dental Research Institute, University of Toronto, Toronto, ON, M5G 1G6, Canada; Department of Dentistry, Mount Sinai Health System, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, M5G 1G6, Canada.
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6
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Gauthier R, Attik N, Chevalier C, Salles V, Grosgogeat B, Gritsch K, Trunfio-Sfarghiu AM. 3D Electrospun Polycaprolactone Scaffolds to Assess Human Periodontal Ligament Cells Mechanobiological Behaviour. Biomimetics (Basel) 2023; 8:biomimetics8010108. [PMID: 36975338 PMCID: PMC10046578 DOI: 10.3390/biomimetics8010108] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/29/2023] Open
Abstract
While periodontal ligament cells are sensitive to their 3D biomechanical environment, only a few 3D in vitro models have been used to investigate the periodontal cells mechanobiological behavior. The objective of the current study was to assess the capability of a 3D fibrous scaffold to transmit a mechanical loading to the periodontal ligament cells. Three-dimensional fibrous polycaprolactone (PCL) scaffolds were synthetized through electrospinning. Scaffolds seeded with human periodontal cells (103 mL-1) were subjected to static (n = 9) or to a sinusoidal axial compressive loading in an in-house bioreactor (n = 9). At the end of the culture, the dynamic loading seemed to have an influence on the cells' morphology, with a lower number of visible cells on the scaffolds surface and a lower expression of actin filament. Furthermore, the dynamic loading presented a tendency to decrease the Alkaline Phosphatase activity and the production of Interleukin-6 while these two biomolecular markers were increased after 21 days of static culture. Together, these results showed that load transmission is occurring in the 3D electrospun PCL fibrous scaffolds, suggesting that it can be used to better understand the periodontal ligament cells mechanobiology. The current study shows a relevant way to investigate periodontal mechanobiology using 3D fibrous scaffolds.
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Affiliation(s)
- Rémy Gauthier
- UCBL, MATEIS UMR CNRS 5510, Bât. Saint Exupéry, Univ Lyon, CNRS, INSA de Lyon, 23 Av. Jean Capelle, 69621 Villeurbanne, France
| | - Nina Attik
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Univ Lyon, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France
- Faculté d'Odontologie, Univ Lyon, Université Claude Bernard Lyon 1, 69008 Lyon, France
| | - Charlène Chevalier
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Univ Lyon, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France
| | - Vincent Salles
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Univ Lyon, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan
- LIMMS, CNRS-IIS UMI 2820, The University of Tokyo, Tokyo 153-8505, Japan
| | - Brigitte Grosgogeat
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Univ Lyon, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France
- Faculté d'Odontologie, Univ Lyon, Université Claude Bernard Lyon 1, 69008 Lyon, France
- Hospices Civils de Lyon, Service d'Odontologie, 69008 Lyon, France
| | - Kerstin Gritsch
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Univ Lyon, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France
- Faculté d'Odontologie, Univ Lyon, Université Claude Bernard Lyon 1, 69008 Lyon, France
- Hospices Civils de Lyon, Service d'Odontologie, 69008 Lyon, France
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7
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Hirashima S, Ohta K, Togo A, Tsuneyoshi R, Kusukawa J, Nakamura KI. Mesoscopic structural analysis via deep learning processing, with a special reference to in vitro alteration in collagen fibre induced by a gap junction inhibitor. Microscopy (Oxf) 2023; 72:18-26. [PMID: 36087097 DOI: 10.1093/jmicro/dfac044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/04/2022] [Accepted: 09/08/2022] [Indexed: 11/12/2022] Open
Abstract
Dense connective tissue, including the ligament, tendon, fascia and cornea, is formed by regularly arranged collagen fibres synthesized by fibroblasts (Fbs). The mechanism by which fibre orientation is determined remains unclear. Periodontal ligament Fbs consistently communicate with their surroundings via gap junctions (GJs), leading to the formation of a wide cellular network. A method to culture Fb-synthesized collagen fibres was previously reported by Schafer et al. ('Ascorbic acid deficiency in cultured human fibroblasts'. J. Cell Biol. 34: 83-95, 1967). This method has been applied to investigate the ability and activity of Fb collagen synthesis/phagocytosis using conventional electron microscopy (EM). However, the three-dimensional mesoscopic architecture of collagen fibres and the influence of GJ inhibitors on collagen fibre formation in vitro are poorly understood. In this study, three-dimensional mesoscopic analysis was used to elucidate the mechanism of directional fibre formation. We investigated the influence of GJ inhibitors on collagen formation driven by periodontal ligament Fbs in vitro, histomorphometrically, and the structural properties of in vitro collagen fibre on a mesoscale quantitatively, using correlative light and EM optimized for picrosirius red staining and focused ion beam-scanning EM tomography. Our results indicate that under culture conditions, in the presence of a GJ inhibitor, the orientation of collagen fibres becomes more disordered than that in the control group. This suggests that the GJ might be involved in determining fibre orientation during collagen fibre formation. Elucidation of this mechanism may help develop novel treatment strategies for connective tissue orientation disorders. Graphical Abstract.
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Affiliation(s)
- Shingo Hirashima
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan.,Dental and Oral Medical Center, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Keisuke Ohta
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan.,Advanced Imaging Research Center, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Akinobu Togo
- Advanced Imaging Research Center, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Risa Tsuneyoshi
- Institute of Animal Experimentation, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Jingo Kusukawa
- Dental and Oral Medical Center, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Kei-Ichiro Nakamura
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan.,Cognitive and Molecular Research Institute of Brain Diseases, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
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8
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Hirashima S, Ohta K, Rikimaru-Nishi Y, Togo A, Funatsu T, Tsuneyoshi R, Shima Y, Nakamura KI. Correlative volume-imaging using combined array tomography and FIB-SEM tomography with beam deceleration for 3D architecture visualization in tissue. Microscopy (Oxf) 2022; 71:187-192. [PMID: 35325180 PMCID: PMC9169539 DOI: 10.1093/jmicro/dfac015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/27/2022] [Accepted: 03/23/2022] [Indexed: 11/17/2022] Open
Abstract
Focused ion beamed (FIB) SEM has a higher spatial resolution than other volume-imaging methods owing to the use of ion beams. However, in this method, it is challenging to analyse entire biological structures buried deep in the resin block. We developed a novel volume-imaging method by combining array tomography and FIB-SEM tomography and investigated the chondrocyte ultrastructure. Our method imparts certainty in determining the analysis area such that cracks or areas with poor staining within the block are avoided. The chondrocyte surface showed fine dendritic processes that were thinner than ultrathin sections. Upon combination with immunostaining, this method holds promise for analysing mesoscopic architectures.
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Affiliation(s)
- Shingo Hirashima
- Department of Anatomy, Division of Microscopic and Developmental Anatomy, Kurume University School of Medicine, Kurume 830-0011, Japan
- Dental and Oral Medical Center, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Keisuke Ohta
- Department of Anatomy, Division of Microscopic and Developmental Anatomy, Kurume University School of Medicine, Kurume 830-0011, Japan
- Advanced Imaging Research Center, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Yukiko Rikimaru-Nishi
- Department of Anatomy, Division of Microscopic and Developmental Anatomy, Kurume University School of Medicine, Kurume 830-0011, Japan
- Department of Plastic and Reconstructive Surgery and Maxillofacial Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Akinobu Togo
- Advanced Imaging Research Center, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Takashi Funatsu
- Advanced Imaging Research Center, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Risa Tsuneyoshi
- Department of Anatomy, Division of Microscopic and Developmental Anatomy, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Yuichi Shima
- Department of Anatomy, Division of Microscopic and Developmental Anatomy, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Kei-ichiro Nakamura
- Department of Anatomy, Division of Microscopic and Developmental Anatomy, Kurume University School of Medicine, Kurume 830-0011, Japan
- Cognitive and Molecular Research Institute of Brain Diseases, Kurume University School of Medicine, Kurume 830-0011, Japan
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9
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Deng R, Xie Y, Chan U, Xu T, Huang Y. Biomaterials and biotechnology for periodontal tissue regeneration: Recent advances and perspectives. J Dent Res Dent Clin Dent Prospects 2022; 16:1-10. [PMID: 35936933 PMCID: PMC9339747 DOI: 10.34172/joddd.2022.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 02/02/2022] [Indexed: 11/09/2022] Open
Abstract
Periodontal tissues are organized in a complex three-dimensional (3D) architecture, including the alveolar bone, cementum, and a highly aligned periodontal ligament (PDL). Regeneration is difficult due to the complex structure of these tissues. Currently, materials are developing rapidly, among which synthetic polymers and hydrogels have extensive applications. Moreover, techniques have made a spurt of progress. By applying guided tissue regeneration (GTR) to hydrogels and cell sheets and using 3D printing, a scaffold with an elaborate biomimetic structure can be constructed to guide the orientation of fibers. The incorporation of cells and biotic factors improves regeneration. Nevertheless, the current studies lack long-term effect tracking, clinical research, and in-depth mechanistic research. In summary, periodontal tissue engineering still has considerable room for development. The development of materials and techniques and an in-depth study of the mechanism will provide an impetus for periodontal regeneration.
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Affiliation(s)
- Rong Deng
- School of Stomatology, Jinan University, Guangdong, China
| | - Yuzheng Xie
- School of Stomatology, Jinan University, Guangdong, China
| | - Unman Chan
- School of Stomatology, Jinan University, Guangdong, China
| | - Tao Xu
- Department of Mechanical Engineering, Tsinghua University, Beijing, China
| | - Yue Huang
- School of Stomatology, Jinan University, Guangdong, China
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10
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House KL, Pan L, O'Carroll DM, Xu S. Applications of scanning electron microscopy and focused ion beam milling in dental research. Eur J Oral Sci 2022; 130:e12853. [PMID: 35288994 DOI: 10.1111/eos.12853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 01/06/2022] [Indexed: 12/15/2022]
Abstract
The abilities of scanning electron microscopy (SEM) and focused ion beam (FIB) milling for obtaining high-resolution images from top surfaces, cross-sectional surfaces, and even in three dimensions, are becoming increasingly important for imaging and analyzing tooth structures such as enamel and dentin. FIB was originally developed for material research in the semiconductor industry. However, use of SEM/FIB has been growing recently in dental research due to the versatility of dual platform instruments that can be used as a milling device to obtain low-artifact cross-sections of samples combined with high-resolution images. The advent of the SEM/FIB system and accessories may offer access to previously inaccessible length scales for characterizing tooth structures for dental research, opening exciting opportunities to address many central questions in dental research. New discoveries and fundamental breakthroughs in understanding are likely to follow. This review covers the applications, key findings, and future direction of SEM/FIB in dental research in morphology imaging, specimen preparation for transmission electron microscopy (TEM) analysis, and three-dimensional volume imaging using SEM/FIB tomography.
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Affiliation(s)
- Krystal L House
- Colgate Palmolive Company, Piscataway, New Jersey, USA.,Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Long Pan
- Colgate Palmolive Company, Piscataway, New Jersey, USA
| | - Deirdre M O'Carroll
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA.,Department of Materials Science and Engineering, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Shiyou Xu
- Colgate Palmolive Company, Piscataway, New Jersey, USA
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11
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Hirashima S, Ohta K, Togo A, Nakamura KI. 3D Mesoscopic Architecture of a Heterogeneous Cellular Network in the Cementum-Periodontal Ligament-Alveolar Bone Complex. Microscopy (Oxf) 2021; 71:22-33. [PMID: 34850074 DOI: 10.1093/jmicro/dfab051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 11/14/2022] Open
Abstract
Cell-to-cell communication orchestrates various cell and tissue functions. This communication enables cells to form cellular networks with each other through direct contact via intercellular junctions. Because these cellular networks are closely related to tissue and organ functions, elucidating the morphological characteristics of cellular networks could lead to the development of novel therapeutic approaches. The tooth, periodontal ligament (PDL), and alveolar bone form a complex via collagen fibres. Teeth depend on the co-ordinated activity of this complex to maintain their function, with cellular networks in each of its three components. Imaging methods for three-dimensional (3D) mesoscopic architectural analysis include focused ion beam/scanning electron microscopy (FIB/SEM), which is characterised by its ability to select observation points and acquire data from complex tissue after extensive block-face imaging, without the need to prepare numerous ultrathin sections. Previously, we employed FIB/SEM to analyse the 3D mesoscopic architecture of hard tissue including the PDL, which exists between the bone and tooth root. The imaging results showed that the cementum, PDL, and alveolar bone networks are in contact and form a heterogeneous cellular network. This cellular network may orchestrate mechanical loading-induced remodelling of the cementum-PDL-alveolar bone complex as the remodelling of each complex component is coordinated, as exemplified by tooth movement due to orthodontic treatment and tooth dislocation due to occlusal loss. In this review, we summarise and discuss the 3D mesoscopic architecture of cellular networks in the cementum, PDL, and alveolar bone as observed in our recent mesoscopic and morphological studies.
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Affiliation(s)
- Shingo Hirashima
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, Kurume, 830-0011, Japan.,Dental and Oral Medical Center, Kurume University School of Medicine, Kurume, 830-0011, Japan
| | - Keisuke Ohta
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, Kurume, 830-0011, Japan.,Advanced Imaging Research Center, Kurume University School of Medicine, Kurume, 830-0011, Japan
| | - Akinobu Togo
- Advanced Imaging Research Center, Kurume University School of Medicine, Kurume, 830-0011, Japan
| | - Kei-Ichiro Nakamura
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, Kurume, 830-0011, Japan.,Cognitive and Molecular Research Institute of Brain Diseases, Kurume University School of Medicine, Kurume, 830-0011, Japan
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12
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Liu X, Zhou Y. Downregulation of lncRNA ANRIL Inhibits Osteogenic Differentiation of Periodontal Ligament Cells via Sponging miR-7 through NF- κB Pathway. Anal Cell Pathol (Amst) 2021; 2021:7890674. [PMID: 34868829 PMCID: PMC8635939 DOI: 10.1155/2021/7890674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/22/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Long noncoding RNAs (lncRNAs) are dysregulated in periodontitis development and involved in osteogenesis. The current study was aimed at investigating the function of lncRNA ANRIL in periodontal ligament cells (PDLCs) and potential molecular mechanisms. METHODS Firstly, the level of ANRIL was tested by qPCR. Then, PDLCs were treated with a mineralizing solution to induce osteogenic differentiation. ALP activity was measured, and protein levels of BMP2, Osterix, and OCN were measured by Western blot. A target of ANRIL was verified using dual-luciferase reporter assay. miR-7 level was measured by qPCR, and the signals of the NF-κB pathway were tested by Western blot. RESULTS ANRIL expression was downregulated in PDL tissues. Next, ALP activity and protein levels of BMP2, Osterix, and OCN were increased to show that PDLCs were differentiated. ANRIL level was increased in differential PDLCs, in which knockdown inhibited osteogenic differentiation. Then, miR-7 was found as a target of ANRIL. The miR-7 level was upregulated in PDL tissues and reduced in differential PDLCs. Inhibition of miR-7 suppressed ALP activity and BMP2, Osterix, and OCN expression. Moreover, inhibition of miR-7 reversed the effects on the osteogenic differentiation induced by knockdown of ANRIL. Besides, the levels of p-P65 and p-IκBα were elevated by ANRIL downregulation and were rescued by suppressing miR-7. CONCLUSIONS Knockdown of ANRIL inhibited osteogenic differentiation via sponging miR-7 through the NF-κB pathway, suggesting that ANRIL might be a therapeutic target for periodontitis.
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Affiliation(s)
- Xinwei Liu
- Department of Stomatology, Beihua University Affiliated Hospital, Jilin 132021, China
| | - Yue Zhou
- Department of Stomatology, Beihua University Affiliated Hospital, Jilin 132021, China
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13
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González-Quintanilla D, Abásolo N, Astudillo P. Wnt Signaling in Periodontal Disease. FRONTIERS IN DENTAL MEDICINE 2021. [DOI: 10.3389/fdmed.2021.763308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Periodontitis is a multifactorial and chronic condition associated with the formation of a dysbiotic biofilm, leading to a pro-inflammatory environment that can modulate cell signaling. The Wnt pathway plays fundamental roles during homeostasis and disease, and emerging evidence suggests its involvement in the maintenance of the periodontium and the development of periodontitis. Here, we summarize the role of the Wnt/β-catenin and non-canonical Wnt signaling pathways in periodontitis. The accumulated data suggests specific roles for each branch of the Wnt pathway. Wnt5a emerges as a critical player promoting periodontal ligament remodeling and impairing regenerative responses modulated by the Wnt/β-catenin pathway, such as alveolar bone formation. Collectively, the evidence suggests that achieving a proper balance between the Wnt/β-catenin and non-canonical pathways, rather than their independent modulation, might contribute to controlling the progression and severity of the periodontal disease.
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14
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Zhong J, Pierantoni M, Weinkamer R, Brumfeld V, Zheng K, Chen J, Swain MV, Weiner S, Li Q. Microstructural heterogeneity of the collagenous network in the loaded and unloaded periodontal ligament and its biomechanical implications. J Struct Biol 2021; 213:107772. [PMID: 34311076 DOI: 10.1016/j.jsb.2021.107772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 07/02/2021] [Accepted: 07/19/2021] [Indexed: 01/17/2023]
Abstract
The periodontal ligament (PDL) is a highly heterogeneous fibrous connective tissue and plays a critical role in distributing occlusal forces and regulating tissue remodeling. Its mechanical properties are largely determined by the extracellular matrix, comprising a collagenous fiber network interacting with the capillary system as well as interstitial fluid containing proteoglycans. While the phase-contrast micro-CT technique has portrayed the 3D microscopic heterogeneity of PDL, the topological parameters of its network, which is crucial to understanding the multiscale constitutive behavior of this tissue, has not been characterized quantitatively. This study aimed to provide new understanding of such microscopic heterogeneity of the PDL with quantifications at both tissue and collagen network levels in a spatial manner, by combining phase-contrast micro-CT imaging and a purpose-built image processing algorithm for fiber analysis. Both variations within a PDL and among the PDL with different shapes, i.e. round-shaped and kidney-shaped PDLs, are described in terms of tissue thickness, fiber distribution, local fiber densities, and fiber orientation (namely azimuthal and elevation angles). Furthermore, the tissue and collagen fiber network responses to mechanical loading were evaluated in a similar manner. A 3D helical alignment pattern was observed in the fiber network, which appears to regulate and adapt a screw-like tooth motion under occlusion. The microstructural heterogeneity quantified here allows development of sample-specific constitutive models to characterize the PDL's functional and pathological loading responses, thereby providing a new multiscale framework for advancing our knowledge of this complex limited mobility soft-hard tissue interface.
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Affiliation(s)
- Jingxiao Zhong
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
| | - Maria Pierantoni
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel; Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Richard Weinkamer
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Vlad Brumfeld
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Keke Zheng
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Junning Chen
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Michael V Swain
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
| | - Steve Weiner
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Qing Li
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia.
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15
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Gauthier R, Jeannin C, Attik N, Trunfio-Sfarghiu AM, Gritsch K, Grosgogeat B. Tissue Engineering for Periodontal Ligament Regeneration: Biomechanical Specifications. J Biomech Eng 2021; 143:1088515. [PMID: 33067629 DOI: 10.1115/1.4048810] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Indexed: 11/08/2022]
Abstract
The periodontal biomechanical environment is very difficult to investigate. By the complex geometry and composition of the periodontal ligament (PDL), its mechanical behavior is very dependent on the type of loading (compressive versus tensile loading; static versus cyclic loading; uniaxial versus multiaxial) and the location around the root (cervical, middle, or apical). These different aspects of the PDL make it difficult to develop a functional biomaterial to treat periodontal attachment due to periodontal diseases. This review aims to describe the structural and biomechanical properties of the PDL. Particular importance is placed in the close interrelationship that exists between structure and biomechanics: the PDL structural organization is specific to its biomechanical environment, and its biomechanical properties are specific to its structural arrangement. This balance between structure and biomechanics can be explained by a mechanosensitive periodontal cellular activity. These specifications have to be considered in the further tissue engineering strategies for the development of an efficient biomaterial for periodontal tissues regeneration.
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Affiliation(s)
- R Gauthier
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France
| | - Christophe Jeannin
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France; Hospices Civils de Lyon, Service d'Odontologie, Lyon 69007, France
| | - N Attik
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France
| | | | - K Gritsch
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France; Hospices Civils de Lyon, Service d'Odontologie, Lyon 69007, France
| | - B Grosgogeat
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France; Hospices Civils de Lyon, Service d'Odontologie, Lyon 69007, France
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16
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Zhang L, Fu L, Zhang X, Chen L, Cai Q, Yang X. Hierarchical and heterogeneous hydrogel system as a promising strategy for diversified interfacial tissue regeneration. Biomater Sci 2021; 9:1547-1573. [DOI: 10.1039/d0bm01595d] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A state-of-the-art review on the design and preparation of hierarchical and heterogeneous hydrogel systems for interfacial tissue regeneration.
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Affiliation(s)
- Liwen Zhang
- State Key Laboratory of Organic–Inorganic Composites; Beijing Laboratory of Biomedical Materials; Beijing University of Chemical Technology
- Beijing 100029
- P.R. China
| | - Lei Fu
- State Key Laboratory of Organic–Inorganic Composites; Beijing Laboratory of Biomedical Materials; Beijing University of Chemical Technology
- Beijing 100029
- P.R. China
| | - Xin Zhang
- Institute of Sports Medicine
- Beijing Key Laboratory of Sports Injuries
- Peking University Third Hospital
- Beijing 100191
- P. R. China
| | - Linxin Chen
- Peking University Third Hospital
- Beijing 100191
- P. R. China
| | - Qing Cai
- State Key Laboratory of Organic–Inorganic Composites; Beijing Laboratory of Biomedical Materials; Beijing University of Chemical Technology
- Beijing 100029
- P.R. China
| | - Xiaoping Yang
- State Key Laboratory of Organic–Inorganic Composites; Beijing Laboratory of Biomedical Materials; Beijing University of Chemical Technology
- Beijing 100029
- P.R. China
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17
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Ellipsoidal mesoscale mineralization pattern in human cortical bone revealed in 3D by plasma focused ion beam serial sectioning. J Struct Biol 2020; 212:107615. [PMID: 32927057 DOI: 10.1016/j.jsb.2020.107615] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 01/24/2023]
Abstract
Visualizing bone mineralization and collagen fibril organization at intermediate scales between the nanometer and the hundreds of microns range, is still an important challenge. Similarly, visualizing cellular components which locally affect the tissue structure requires a precision of a few tens of nanometers at maximum while spanning several tens of micrometers. In the last decade, gallium focused ion beam (FIB) equipped with a scanning electron microscope (SEM) proved to be an extremely valuable structural tool to meet those ends. In this study, we assess the capability of a recent plasma FIB-SEM technology which provides a potential increase in measurement speed over gallium FIB-SEM, thus paving the way to larger volume analysis. Nanometer-scale layers of demineralized and mineralized unstained human femoral lamellar bone were sequentially sectioned over volumes of 6-16,000 μm3. Analysis of mineralized tissue revealed prolate ellipsoidal mineral clusters measuring approximately 1.1 µm in length by 700 nm at their maximum diameter. Those features, suggested by others in high resolution studies, appear here as a ubiquitous motif in mineralized lamellar bone over thousands of microns cubed, suggesting a heterogeneous and yet regular pattern of mineral deposition past the single collagen fibril level. This large scale view retained sufficient resolution to visualize the collagen fibrils while also partly visualizing the lacuno-canalicular network in three-dimensions. These findings are strong evidence for suitability of PFIB as a bone analysis tool and the need to revisit bone mineralization over multi-length scales with mineralized tissue.
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18
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Connizzo BK, Sun L, Lacin N, Gendelman A, Solomonov I, Sagi I, Grodzinsky AJ, Naveh GRS. Nonuniformity in Periodontal Ligament: Mechanics and Matrix Composition. J Dent Res 2020; 100:179-186. [PMID: 33043806 DOI: 10.1177/0022034520962455] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The periodontal ligament (PDL) plays a critical role in providing immediate response to abrupt high loads during mastication while also facilitating slow remodeling of the alveolar bone. The PDL exceptional functionality is permitted by the unique nonuniform structure of the tissue. Two distinct areas that are critical to PDL function were previously identified: the furcation and the dense collar. Despite their hypothesized functions in tooth movement and maintenance, these 2 regions have not yet been compared within the context of their native environment. Therefore, the objective of this study is to elucidate the extracellular matrix (ECM) structure, composition, and biomechanical function of the furcation and the collar regions while maintaining the 3-dimensional (3D) structure in the murine PDL. We identify significant difference between the collar and furcation regions in both structure and mechanical properties. Specifically, we observed unique longitudinal structures in the dense collar that correlate with type VI collagen and LOX, both of which are associated with increased type I collagen density and tissue stiffness and are therefore proposed to function as scaffolds for tooth stabilization. We also found that the collar region is stiffer than the furcation region and therefore suggest that the dense collar acts as a suspense structure of the tooth within the bone during physiological loading. The furcation region of the PDL contained more proteins associated with reduced stiffness and higher tissue remodeling, as well as a dual mechanical behavior, suggesting a critical function in loads transfer and remodeling of the alveolar bone. In summary, this work unravels the nonuniform nature of the PDL within the 3D structural context and establishes understanding of regional PDL function, which opens new avenues for future studies of remodeling, regeneration, and disease.
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Affiliation(s)
- B K Connizzo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - L Sun
- Department of Oral Medicine, Infection and Immunity, School of Dental Medicine, Harvard University, Boston, MA, USA
| | - N Lacin
- Department of Oral Medicine, Infection and Immunity, School of Dental Medicine, Harvard University, Boston, MA, USA
| | - A Gendelman
- Department of Oral Medicine, Infection and Immunity, School of Dental Medicine, Harvard University, Boston, MA, USA
| | - I Solomonov
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - I Sagi
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - A J Grodzinsky
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - G R S Naveh
- Department of Oral Medicine, Infection and Immunity, School of Dental Medicine, Harvard University, Boston, MA, USA
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19
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Svandova E, Peterkova R, Matalova E, Lesot H. Formation and Developmental Specification of the Odontogenic and Osteogenic Mesenchymes. Front Cell Dev Biol 2020; 8:640. [PMID: 32850793 PMCID: PMC7396701 DOI: 10.3389/fcell.2020.00640] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/25/2020] [Indexed: 12/15/2022] Open
Abstract
Within the mandible, the odontogenic and osteogenic mesenchymes develop in a close proximity and form at about the same time. They both originate from the cranial neural crest. These two condensing ecto-mesenchymes are soon separated from each other by a very loose interstitial mesenchyme, whose cells do not express markers suggesting a neural crest origin. The two condensations give rise to mineralized tissues while the loose interstitial mesenchyme, remains as a soft tissue. This is crucial for proper anchorage of mammalian teeth. The situation in all three regions of the mesenchyme was compared with regard to cell heterogeneity. As the development progresses, the early phenotypic differences and the complexity in cell heterogeneity increases. The differences reported here and their evolution during development progressively specifies each of the three compartments. The aim of this review was to discuss the mechanisms underlying condensation in both the odontogenic and osteogenic compartments as well as the progressive differentiation of all three mesenchymes during development. Very early, they show physical and structural differences including cell density, shape and organization as well as the secretion of three distinct matrices, two of which will mineralize. Based on these data, this review highlights the consecutive differences in cell-cell and cell-matrix interactions, which support the cohesion as well as mechanosensing and mechanotransduction. These are involved in the conversion of mechanical energy into biochemical signals, cytoskeletal rearrangements cell differentiation, or collective cell behavior.
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Affiliation(s)
- Eva Svandova
- Laboratory of Odontogenesis and Osteogenesis, Institute of Animal Physiology and Genetics, Academy of Sciences, Brno, Czechia
| | - Renata Peterkova
- Department of Histology and Embryology, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Eva Matalova
- Laboratory of Odontogenesis and Osteogenesis, Institute of Animal Physiology and Genetics, Academy of Sciences, Brno, Czechia.,Department of Physiology, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia
| | - Herve Lesot
- Laboratory of Odontogenesis and Osteogenesis, Institute of Animal Physiology and Genetics, Academy of Sciences, Brno, Czechia
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20
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Development and application of a 3D periodontal in vitro model for the evaluation of fibrillar biomaterials. BMC Oral Health 2020; 20:148. [PMID: 32429904 PMCID: PMC7238548 DOI: 10.1186/s12903-020-01124-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 04/28/2020] [Indexed: 02/07/2023] Open
Abstract
Background Periodontitis is a chronic inflammation of the tooth supporting structures that finally can lead to tooth loss. As chronic periodontitis is associated with systemic diseases multiple approaches have been followed to support regeneration of the destructed tissue. But very few materials are actually used in the clinic. A new and promising group of biomaterials with advantageous biomechanical properties that have the ability to support periodontal regeneration are self-assembling peptides (SAP). However, there is still a lack of 3D periodontal models that can evaluate the migration potential of such novel materials. Methods All experiments were performed with primary human periodontal ligament fibroblasts (HPLF). Migration capacity was assessed in a three-dimensional model of the human periodontal ligament by measuring the migration distance of viable cells on coated (Enamel Matrix Protein (EMP), P11–4, collagen I) or uncoated human dentin. Cellular metabolic activity on P11–4 hydrogels was assessed by a metabolic activity assay. Deposition of ECM molecules in a P11–4 hydrogel was visualized by immunostaining of collagen I and III and fibrillin I. Results The 3D periodontal model was feasible to show the positive effect of EMP for periodontal regeneration. Subsequently, self-assembling peptide P11–4 was used to evaluate its capacity to support regenerative processes in the 3D periodontal model. HPLF coverage of the dentin surface coated with P11–4 increased significantly over time, even though delayed compared to EMP. Cell viability increased and inclusion of ECM proteins into the biomaterial was shown. Conclusion The presented results indicate that the 3D periodontal model is feasible to assess periodontal defect coverage and that P11–4 serves as an efficient supporter of regenerative processes in the periodontal ligament. Clinical relevance The establishment of building-block synthetic polymers offers new opportunities for clinical application in dentistry. Self-assembling peptides represent a new generation of biomaterials as they are able to respond dynamically to the changing environment of the biological surrounding. Especially in the context of peri-implant disease prevention and treatment they enable the implementation of new concepts.
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