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Materials for Hard Tissue Repair and Regeneration
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Materials for Hard Tissue Repair and Regeneration

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Biomaterials".

Deadline for manuscript submissions: closed (31 October 2021) | Viewed by 46779

Special Issue Editor

Dr. Keisuke Nakano

E-Mail Website
Guest Editor
Department of Oral Pathology and Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan
Interests: histopathology; biomaterials; tumorigenesis; tissue repair; regenerative medicine
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

During tissue repair and regenerative process, stem cells, growth factors, and the extracellular matrix (ECM) constitute the elements needed for cell growth and differentiation. In ECM research, artificial biomaterials composed of various substances have been researched and developed to reproduce the extracellular microenvironment for induction cell growth and differentiation and tissue formation. Regarding hard tissue repair and regeneration in a clinical setting, highly biocompatible materials such as hydroxyapatite, tricalcium phosphate (TCP), and titanium as a metal material have been developed and are already used widely. Recently, it has been suggested that not only the composition of the artificial biomaterial but also the optimal geometrical structure is important for inducing cell differentiation and tissue formation.

This Special Issue focuses on several aspects of biological response induced by biomaterials in the tissue repair and regeneration process, such as cell differentiation, tissue development, and tissue regeneration ability, and we invite contributions of reviews and original papers reporting on recent efforts in the field of hard tissue regeneration.

Dr. Keisuke Nakano
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Hard tissue
  • regeneration
  • biomaterials
  • biocompatibility
  • implant
  • remodeling
  • medical
  • dental

Published Papers (24 papers)

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10 pages, 24240 KiB  
Article
Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer
by Mariko Yamamoto Kawai, Ryosuke Ozasa, Takuya Ishimoto, Takayoshi Nakano, Hiromitsu Yamamoto, Marina Kashiwagi, Shigeki Yamanaka, Kazumasa Nakao, Hiroki Maruyama, Kazuhisa Bessho and Kiyoshi Ohura
Materials 2022, 15(3), 993; https://doi.org/10.3390/ma15030993 - 27 Jan 2022
Cited by 2 | Viewed by 2428
Abstract
The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) [...] Read more.
The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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10 pages, 2136 KiB  
Article
Heat Shock Protein Overexpression-Mediated Periodontal Ligament Regeneration: A Fundamental Approach to Generate a Potential Biomaterial
by Rina Muraoka, Keisuke Nakano and Toshiyuki Kawakami
Materials 2022, 15(3), 809; https://doi.org/10.3390/ma15030809 - 21 Jan 2022
Viewed by 1332
Abstract
The periodontal ligament (PDL) is a cell-rich fibrous connective tissue supporting the tooth roots. The tissue helps to maintain homeostasis and exhibits regenerative and repairing ability, which is mediated by the heat shock protein (HSP). Here, we experimentally created PDL tissue with notable [...] Read more.
The periodontal ligament (PDL) is a cell-rich fibrous connective tissue supporting the tooth roots. The tissue helps to maintain homeostasis and exhibits regenerative and repairing ability, which is mediated by the heat shock protein (HSP). Here, we experimentally created PDL tissue with notable ability to regenerate hard tissue and evaluated it as a potential biomaterial. We immunohistochemically examined the mechanical load-induced HSP overexpression in mouse PDL. Following mechanical load application and release, HSP70 localization in the PDL was altered immediately, suggesting that the HSP70 function may differ with the timing of its expression in PDL. HSP70 expressed in the cytoplasm and nucleus of fibroblasts in PDL on the tension side not only participated in periodontium repair, but also functioned as a molecular chaperone during protein expression involved in osteogenesis to restructure injured tissue. This study highlights the potential of artificially created highly functional PDL tissues as biomaterials. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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10 pages, 4333 KiB  
Article
A Pilot Study of Seamless Regeneration of Bone and Cartilage in Knee Joint Regeneration Using Honeycomb TCP
by Kiyofumi Takabatake, Hidetsugu Tsujigiwa, Aki Yoshida, Takayuki Furumatsu, Hotaka Kawai, May Wathone Oo, Keisuke Nakano and Hitoshi Nagatsuka
Materials 2021, 14(23), 7225; https://doi.org/10.3390/ma14237225 - 26 Nov 2021
Cited by 1 | Viewed by 1290
Abstract
The knee joint is a continuous structure of bone and cartilage tissue, making it difficult to regenerate using artificial biomaterials. In a previous study, we succeeded in developing honeycomb tricalcium phosphate (TCP), which has through-and-through holes and is able to provide the optimum [...] Read more.
The knee joint is a continuous structure of bone and cartilage tissue, making it difficult to regenerate using artificial biomaterials. In a previous study, we succeeded in developing honeycomb tricalcium phosphate (TCP), which has through-and-through holes and is able to provide the optimum microenvironment for hard tissue regeneration. We demonstrated that TCP with 300 μm pore diameters (300TCP) induced vigorous bone formation, and that TCP with 75 μm pore diameters (75TCP) induced cartilage formation. In the present study, we regenerated a knee joint defect using honeycomb TCP. 75TCP and 300TCP were loaded with transforming growth factor (TGF)-β alone or bone morphogenic protein (BMP)-2+TGF-β with or without Matrigel and transplanted into knee joint defect model rabbits. 75TCP showed no bone or cartilage tissue formation in any of the groups with TGF-β alone and BMP-2+TGF-β with/without Matrigel. However, for 300TCP and BMP-2+TGF-β with or without Matrigel, vigorous bone tissue formation was observed in the TCP holes, and cartilage tissue formation in the TCP surface layer was continuous with the existing cartilage. The cartilage area in the TCP surface was larger in the group without Matrigel (with BMP-2+TGF-β) than in the group with Matrigel (with BMP-2+TGF-β). Therefore, honeycomb TCP can induce the seamless regeneration of bone and cartilage in a knee joint. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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13 pages, 1208 KiB  
Article
Parameters of Hemostasis in Sheep Implanted with Composite Scaffold Settled by Stimulated Mesenchymal Stem Cells—Evaluation of the Animal Model
by Aleksandra Pliszczak-Król, Zdzisław Kiełbowicz, Jarosław Król, Agnieszka Antończyk, Marianna Gemra, Piotr Skrzypczak, Przemysław Prządka, Dariusz Zalewski, Janusz Bieżyński and Jakub Nicpoń
Materials 2021, 14(22), 6934; https://doi.org/10.3390/ma14226934 - 16 Nov 2021
Viewed by 1387
Abstract
Implantation of composite scaffolds could be potentially associated with the risk of hemostatic disturbances in a recipient. However, there is a lack of information on possible alterations in clotting mechanisms resulting from such a procedure. The aim of the present work was to [...] Read more.
Implantation of composite scaffolds could be potentially associated with the risk of hemostatic disturbances in a recipient. However, there is a lack of information on possible alterations in clotting mechanisms resulting from such a procedure. The aim of the present work was to investigate changes in hemostatic parameters in sheep implanted with a scaffold composed of poly(ε-caprolactone) and hydroxyapatite and tricalcium phosphate (9:4.5:4.5), settled previously with mesenchymal stem cells stimulated by fibroblast growth factor-2 and bone morphogenetic protein-2. Nine Merino sheep were examined for 7 days, and measurements of clotting times (PT, aPTT), activities of antithrombin, protein C and clotting factors II-XII, and concentrations of fibrinogen and D-dimer were carried out before and 1 h, 24 h, 3 days and 7 days after scaffold implantation. The introduction of scaffold initially resulted in a slowdown of the clotting processes (most evident 24 h after surgery); PT and aPTT increased to 14.8 s and 33.9 s, respectively. From the third day onwards, most of these alterations began to return to normal values. The concentration of fibrinogen rose throughout the observation period (up to 8.4 g/L), mirroring the ongoing inflammatory reaction. However, no signals of significant disturbances in hemostatic processes were detected in the sheep tested. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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13 pages, 31100 KiB  
Article
Model of Ploughing Cortical Bone with Single-Point Diamond Tool
by Jing Ni, Yang Wang, Zhen Meng, Jun Cai, Kai Feng and Hongwei Zhang
Materials 2021, 14(21), 6530; https://doi.org/10.3390/ma14216530 - 29 Oct 2021
Cited by 1 | Viewed by 1346
Abstract
Generating topological microstructures on the surface of cortical bone to establish a suitable microenvironment can guide bone cells to achieve bone repair. Single-point diamond tools (SPDTs) have advantages in efficiency and flexibility to fabricate surface microstructures. However, the cutting force during ploughing cannot [...] Read more.
Generating topological microstructures on the surface of cortical bone to establish a suitable microenvironment can guide bone cells to achieve bone repair. Single-point diamond tools (SPDTs) have advantages in efficiency and flexibility to fabricate surface microstructures. However, the cutting force during ploughing cannot be predicted and controlled due to the special properties of cortical bone. In this paper, a novel cutting model for ploughing cortical bone using an SPDT was established, and we comprehensively considered the shear stress anisotropy of the bone material and the proportional relationship between the normal force and the tangential force. Then, the orthogonal cutting experiment was used to verify the model. The results show that the error of calculated value and the experimental data is less than 5%. The proposed model can be used to assist the fabrication of microstructures on cortical bone surface using an SPDT. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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11 pages, 4816 KiB  
Article
Histological Evaluation of Porous Additive-Manufacturing Titanium Artificial Bone in Rat Calvarial Bone Defects
by Naoko Imagawa, Kazuya Inoue, Keisuke Matsumoto, Michi Omori, Kayoko Yamamoto, Yoichiro Nakajima, Nahoko Kato-Kogoe, Hiroyuki Nakano, Phuc Thi Minh Le, Seiji Yamaguchi and Takaaki Ueno
Materials 2021, 14(18), 5360; https://doi.org/10.3390/ma14185360 - 17 Sep 2021
Cited by 4 | Viewed by 1609
Abstract
Jaw reconstruction using an additive-manufacturing titanium artificial bone (AMTAB) has recently attracted considerable attention. The synthesis of a titanium artificial bone is based on three-dimensional computed tomography images acquired before surgery. A histological evaluation of porous AMTAB (pAMTAB) embedded in rat calvarial bone [...] Read more.
Jaw reconstruction using an additive-manufacturing titanium artificial bone (AMTAB) has recently attracted considerable attention. The synthesis of a titanium artificial bone is based on three-dimensional computed tomography images acquired before surgery. A histological evaluation of porous AMTAB (pAMTAB) embedded in rat calvarial bone defects was conducted. This study examined three groups: rats implanted with mixed-acid and heat-treated pAMTAB, rats implanted with untreated pAMTAB, and rats with no implant. In both pAMTAB groups, bone defects were created in rat calvarial bones using a 5-mm trephine bar, followed by pAMTAB implantation. The pAMTAB was fixed to the defect using the fitting force of the surrounding bones. The rats were sacrificed at 4, 8, and 16 weeks after implantation, and the skull was dissected. Undecalcified ground slides were prepared and stained with Villanueva Goldner. Compared with the no implant control group, both pAMTAB groups exhibited new bone formation inside the defect, with greater bone formation in the mixed-acid and heat-treated pAMTAB group than in the untreated pAMTAB group, but the difference was not significant. These data suggest that pAMTAB induces bone formation after implantation in bone defects. Bone formation appears to be enhanced by prior mixed-acid and heat-treated pAMTAB. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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11 pages, 5527 KiB  
Article
Mineral Trioxide Aggregate (MTA) Upregulates the Expression of DMP1 in Direct Pulp Capping in the Rat Molar
by Maiko Yamada, Motohiko Nagayama, Yuka Miyamoto, Satoshi Kawano, Yoshiaki Takitani, Masashi Tanaka, Michiko Ehara, Juna Nakao, Takanaga Ochiai, Yoshihiro Shibukawa and Takakazu Yoshida
Materials 2021, 14(16), 4640; https://doi.org/10.3390/ma14164640 - 18 Aug 2021
Cited by 8 | Viewed by 2320
Abstract
Mineral trioxide aggregate (MTA) is an alternative endodontic material that predicts conductive or inductive calcified tissue formation from immature pulp mesenchymal stem cells (IPMSCs). The purpose of this study was to investigate whether MTA could promote reparative odontoblast differentiation via IPMSCs in the [...] Read more.
Mineral trioxide aggregate (MTA) is an alternative endodontic material that predicts conductive or inductive calcified tissue formation from immature pulp mesenchymal stem cells (IPMSCs). The purpose of this study was to investigate whether MTA could promote reparative odontoblast differentiation via IPMSCs in the early phase of regeneration and compare with calcium hydroxide (CH). Direct pulp capping using calcium hydroxide (CH), MTA, and MTA with platelet-rich plasma (MTA + PRP) was performed on maxillary first molars of 8-week-old male Wistar rats (n = 36). After 3, 7, or 14 days, the teeth were analyzed for mineral density (MD) and volume of MD (VMD) via micro-focusing computed tomography (µCT), nestin, dentin matrix acidic phosphoprotein 1 (DMP1) immunohistochemistry, and real-time PCR for DMP1 mRNA expression. MTA stimulated the early phase differentiation of the IPMSCs into odontoblasts, with positive results for nestin and DMP1 compared with CH. Moreover, MTA + PRP stimulated calcified granule and dentin bridge formation through calcium mineral deposition, following the induction of DMP1 mRNA expression in IPMSCs. Our results suggested that the combination of MTA and PRP is an effective and clinically applicable method for activating endogenous dental pulp stem cells into odontoblasts in the early stages of pulp regeneration. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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11 pages, 23592 KiB  
Article
Osteoblast-like Cell Proliferation, ALP Activity and Photocatalytic Activity on Sintered Anatase and Rutile Titanium Dioxide
by Yukiko Yokoi
Materials 2021, 14(16), 4414; https://doi.org/10.3390/ma14164414 - 06 Aug 2021
Cited by 9 | Viewed by 1535
Abstract
This study aimed to create a biomaterial from titanium dioxide (TiO2), which has been known to have photocatalytic and bone formation promoting effects. I expected that anatase titanium dioxide-based implants could promote bone augmentation and induce bone formation. Powdery anatase TiO [...] Read more.
This study aimed to create a biomaterial from titanium dioxide (TiO2), which has been known to have photocatalytic and bone formation promoting effects. I expected that anatase titanium dioxide-based implants could promote bone augmentation and induce bone formation. Powdery anatase TiO2 was compression molded and sintered at 700, 800, 900, and 1000 °C to prepare sintered compact samples. X-ray diffraction and scanning electron microscopy were used to observe the surface of these samples. Furthermore, mouse osteoblast-like cells (MC3T3-E1 cell line) were seeded on the samples sintered at different temperatures, and cell proliferation was observed to evaluate the cell proliferation of the samples. The sample sintered at 700 °C was composed of anatase TiO2. The samples sintered at 800 °C and 900 °C were confirmed to consist of a mixture of anatase and rutile TiO2 crystalline phases. Moreover, the sample sintered at 700 and 800 °C, which contained anatase TiO2, showed remarkable photocatalytic activity. Those samples sintered at 1000 °C were transformed to the rutile TiO2. The cell proliferation after 7–14-days culturing revealed that cells cultured on the 700 °C sample decreased in number immediately after initiation of culturing. The cells cultured on TiO2 sintered at 900 °C markedly proliferated over time with an increase in the alkaline phosphatase activity, showing good MC3T3-E1 cell compatibility of the samples. The sample sintered at 1000 °C, which is rutile TiO2, showed the highest increase. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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8 pages, 1902 KiB  
Article
Preparation of Absorption-Resistant Hard Tissue Using Dental Pulp-Derived Cells and Honeycomb Tricalcium Phosphate
by Kiyofumi Takabatake, Keisuke Nakano, Hotaka Kawai, Yasunori Inada, Shintaro Sukegawa, Shan Qiusheng, Shigeko Fushimi, Hidetsugu Tsujigiwa and Hitoshi Nagatsuka
Materials 2021, 14(12), 3409; https://doi.org/10.3390/ma14123409 - 20 Jun 2021
Cited by 1 | Viewed by 1471
Abstract
In recent years, there has been increasing interest in the treatment of bone defects using undifferentiated mesenchymal stem cells (MSCs) in vivo. Recently, dental pulp has been proposed as a promising source of pluripotent mesenchymal stem cells (MSCs), which can be used in [...] Read more.
In recent years, there has been increasing interest in the treatment of bone defects using undifferentiated mesenchymal stem cells (MSCs) in vivo. Recently, dental pulp has been proposed as a promising source of pluripotent mesenchymal stem cells (MSCs), which can be used in various clinical applications. Dentin is the hard tissue that makes up teeth, and has the same composition and strength as bone. However, unlike bone, dentin is usually not remodeled under physiological conditions. Here, we generated odontoblast-like cells from mouse dental pulp stem cells and combined them with honeycomb tricalcium phosphate (TCP) with a 300 μm hole to create bone-like tissue under the skin of mice. The bone-like hard tissue produced in this study was different from bone tissue, i.e., was not resorbed by osteoclasts and was less easily absorbed than the bone tissue. It has been suggested that hard tissue-forming cells induced from dental pulp do not have the ability to induce osteoclast differentiation. Therefore, the newly created bone-like hard tissue has high potential for absorption-resistant hard tissue repair and regeneration procedures. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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12 pages, 4745 KiB  
Article
Accelerated Bone Induction of Adult Rat Compact Bone Plate Scratched by Ultrasonic Scaler Using Acidic Electrolyzed Water
by Mamata Shakya, Masaru Murata, Kenji Yokozeki, Toshiyuki Akazawa, Hiroki Nagayasu, Bhoj Raj Adhikari and Chandan Upadhyaya
Materials 2021, 14(12), 3347; https://doi.org/10.3390/ma14123347 - 17 Jun 2021
Cited by 4 | Viewed by 1539
Abstract
Fresh compact bone, the candidate graft material for bone regeneration, is usually grafted for horizontal bone augmentation. However, the dense calcified structure inhibits the release of growth factors and limits cellular and vascular perfusion. We aimed to create mechano-chemically altered dense skull bone [...] Read more.
Fresh compact bone, the candidate graft material for bone regeneration, is usually grafted for horizontal bone augmentation. However, the dense calcified structure inhibits the release of growth factors and limits cellular and vascular perfusion. We aimed to create mechano-chemically altered dense skull bone by ultrasonic treatment, along with partial demineralization using commercially available acidic electrolyzed water (AEW). The parietal skull bone of an 11-month-old Wistar rat was exposed and continuously treated with a piezoelectric ultrasonic scaler tip for 1 min, using AEW (pH 2.3) or distilled water (DW, pH 5.6) as irrigants. Treated parietal bone was removed, cut into plates (5 × 5 × 1 mm3), grafted into the back subcutaneous tissues of syngeneic rats, and explanted at 1, 2, and 3 weeks. AEW bone showed an irregular surface, deep nano-microcracks, and decalcified areas. SEM-EDS revealed small amounts of residual calcium content in the AEW bone (0.03%) compared to the DW bone (0.86%). In the animal assay, the AEW bone induced bone at 2 weeks. Histomorphometric analysis showed that the area of new bone in the AEW bone at 2 and 3 weeks was significantly larger. This new combination technique of AEW-demineralization with ultrasonic treatment will improve the surface area and three-dimensional (3D) architecture of dense bone and accelerate new bone synthesis. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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11 pages, 3243 KiB  
Article
Biological Effects of Bioresorbable Materials in Alveolar Ridge Augmentation: Comparison of Early and Slow Resorbing Osteosynthesis Materials
by Hotaka Kawai, Shintaro Sukegawa, Keisuke Nakano, Kiyofumi Takabatake, Sawako Ono, Hitoshi Nagatsuka and Yoshihiko Furuki
Materials 2021, 14(12), 3286; https://doi.org/10.3390/ma14123286 - 14 Jun 2021
Cited by 4 | Viewed by 1685
Abstract
The purpose of this study was to investigate the bone healing properties and histological environment of a u-HA/PLLA/PGA (u-HA—uncalcined and unsintered hydroxyapatite, PLLA—Poly L-lactic acid, PGA—polyglycolic acid) composite device in humans, and to understand the histological dynamics of using this device for maxillofacial [...] Read more.
The purpose of this study was to investigate the bone healing properties and histological environment of a u-HA/PLLA/PGA (u-HA—uncalcined and unsintered hydroxyapatite, PLLA—Poly L-lactic acid, PGA—polyglycolic acid) composite device in humans, and to understand the histological dynamics of using this device for maxillofacial treatments. Twenty-one subjects underwent pre-implant maxillary alveolar ridge augmentation with mandibular cortical bone blocks using u-HA/PLLA or u-HA/PLLA/PGA screws for fixation. Six months later, specimens of these screws and their adjacent tissue were retrieved. A histological and immunohistochemical evaluation of these samples was performed using collagen 1a, ALP (alkaline phosphatase), and osteocalcin. We observed that alveolar bone augmentation was successful for all of the subjects. Upon histological evaluation, the u-HA/PLLA screws had merged with the bone components, and the bone was directly connected to the biomaterial. In contrast, direct bone connection was not observed for the u-HA/PLLA/PGA screw. Immunohistological findings showed that in the u-HA/PLLA group, collagen 1a was positive for fibers that penetrated vertically into the bone. Alkaline phosphatase was positive only in the u-HA/PLLA stroma, and the stroma was negative for osteocalcin. In this study, u-HA/PLLA showed a greater bioactive bone conductivity than u-HA/PLLA/PGA and a higher biocompatibility for direct bone attachment. Furthermore, u-HA/PLLA was shown to have the potential for bone formation in the stroma. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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12 pages, 2523 KiB  
Article
A Novel Bone Substitute Based on Recombinant Type I Collagen for Reconstruction of Alveolar Cleft
by Masaaki Ito, Taku Toriumi, Takahiro Hiratsuka, Hideto Imura, Yasunori Akiyama, Ichinnorov Chimedtseren, Yoshinori Arai, Kazuhiro Yamaguchi, Akihiko Azuma, Ken-ichiro Hata, Nagato Natsume and Masaki Honda
Materials 2021, 14(9), 2306; https://doi.org/10.3390/ma14092306 - 29 Apr 2021
Cited by 5 | Viewed by 1802
Abstract
This study aimed to examine the optimal cross-link density of recombinant peptide (RCP) particles, based on human collagen type I, for bone reconstruction in human alveolar cleft. Low- (group 1), medium- (group 2), and high- (group 3) cross-linked RCP particles were prepared by [...] Read more.
This study aimed to examine the optimal cross-link density of recombinant peptide (RCP) particles, based on human collagen type I, for bone reconstruction in human alveolar cleft. Low- (group 1), medium- (group 2), and high- (group 3) cross-linked RCP particles were prepared by altering the duration of the heat-dependent dehydration reaction. Rat palatine fissures (n = 45), analogous to human congenital bone defects, were examined to evaluate the potential of bone formation by the three different RCP particles. Microcomputed tomography images were obtained to measure bone volume and bone mineral density at 4, 8, 12, and 16 weeks post grafting. Specimens were obtained for histological analysis at 16 weeks after grafting. Additionally, alkaline phosphatase and tartrate acid phosphatase staining were performed to visualize the presence of osteoblasts and osteoclasts. At 16 weeks, bone volume, bone mineral density, and new bone area measurements in group 2 were significantly higher than in any other group. In addition, the number of osteoblasts and osteoclasts on the new bone surface in group 2 was significantly higher than in any other group. Our results demonstrated that medium cross-linking was more suitable for bone formation—and could be useful in human alveolar cleft repairs as well. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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10 pages, 3327 KiB  
Article
Antibacterial Effect of Amino Acid–Silver Complex Loaded Montmorillonite Incorporated in Dental Acrylic Resin
by Kumiko Yoshihara, Noriyuki Nagaoka, Aya Umeno, Akinari Sonoda, Hideki Obika, Yasuhiro Yoshida, Bart Van Meerbeek and Yoji Makita
Materials 2021, 14(6), 1442; https://doi.org/10.3390/ma14061442 - 16 Mar 2021
Cited by 4 | Viewed by 2233
Abstract
Several dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver [...] Read more.
Several dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver antibacterial agents that can be useful in the mouth, we synthesized two novel amino acid (methionine or histidine)–silver complexes (Met or His–Ag) loaded with montmorillonite (Mont) and analyzed their antibacterial efficacy. At first the complexes were characterized using nuclear magnetic resonance (NMR), and amino acid–Ag complex-loaded Mont (amino acid–Ag–Mont) were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of these materials in dental acrylic resin was then investigated by bacterial growth measurement using a spectrophotometer. As controls, commercially available silver-loaded zeolite and silver-zirconium phosphate were also tested. Dental acrylic resin incorporating His–Ag–Mont strongly inhibited Streptococcus mutans growth. This was explained by the fact that His-Ag complex revealed the highest amounts of silver ions in the presence of chloride. The structure of the amino acid–Ag complexes affected the silver ion presence in chloride and the antibacterial efficacy. His–Ag–Mont might be used as antibacterial agents for dental materials. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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10 pages, 3254 KiB  
Article
Bio-Absorption of Human Dentin-Derived Biomaterial in Sheep Critical-Size Iliac Defects
by Md Arafat Kabir, Masaru Murata, Mamata Shakya, Katsuhisa Yamada and Toshiyuki Akazawa
Materials 2021, 14(1), 223; https://doi.org/10.3390/ma14010223 - 05 Jan 2021
Cited by 14 | Viewed by 2326
Abstract
The aim of this study was to evaluate the bio-absorption and bone regeneration of human tooth-derived dentin scaffold, entitled as perforated root-demineralized dentin matrix (PR-DDM), after in vivo implantation into the critical-size iliac defects. The dentin scaffolds were prepared from human vital, non-functional [...] Read more.
The aim of this study was to evaluate the bio-absorption and bone regeneration of human tooth-derived dentin scaffold, entitled as perforated root-demineralized dentin matrix (PR-DDM), after in vivo implantation into the critical-size iliac defects. The dentin scaffolds were prepared from human vital, non-functional teeth. Thirty artificial macro-pores (Ø 1 mm) were added after removing the enamel portion. The modified teeth were supersonically demineralized in 0.34 N HNO3 for 30 min. The microstructure was observed by scanning electron microscope (SEM). The 3D micro-CT and histological analysis were carried out to evaluate the bio-absorption of PR-DDM at 2 and 4 months. A smooth dentin collagen surface with symmetrical macro-pores and tube-type dentinal tubules (Ø 1–2 µm) with micro-cracks were observed on the perforated region. A significant number of custom-made macro-pores disappeared, and the size of the macro-pores became significantly wider at 4 months compared with the 2 months (p < 0.05) evaluated by 3D micro-CT. Histological images revealed the presence of multinucleated giant cells attached to the scalloped border of the PR-DDM. The morphological changes due to bio-absorption by the cellular phagocytes were comparable to the 3D micro-CT and histological images at 2 and 4 months. Altogether, the results demonstrated that the PR-DDM block was gradually absorbed by multinucleated giant cells and regenerated bone. Human PR-DDM might serve as a unique scaffold for extraoral bone regeneration. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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15 pages, 4053 KiB  
Article
Tryptophan and Kynurenine Enhances the Stemness and Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stromal Cells In Vitro and In Vivo
by Hai Thanh Pham, Mitsuaki Ono, Emilio Satoshi Hara, Ha Thi Thu Nguyen, Anh Tuan Dang, Hang Thuy Do, Taishi Komori, Ikue Tosa, Yuri Hazehara-Kunitomo, Yuya Yoshioka, Yasutaka Oida, Kentaro Akiyama and Takuo Kuboki
Materials 2021, 14(1), 208; https://doi.org/10.3390/ma14010208 - 04 Jan 2021
Cited by 5 | Viewed by 2759
Abstract
Aging tissues present a progressive decline in homeostasis and regenerative capacities, which has been associated with degenerative changes in tissue-specific stem cells and stem cell niches. We hypothesized that amino acids could regulate the stem cell phenotype and differentiation ability of human bone [...] Read more.
Aging tissues present a progressive decline in homeostasis and regenerative capacities, which has been associated with degenerative changes in tissue-specific stem cells and stem cell niches. We hypothesized that amino acids could regulate the stem cell phenotype and differentiation ability of human bone marrow-derived mesenchymal stromal cells (hBMSCs). Thus, we performed a screening of 22 standard amino acids and found that D-tryptophan (10 μM) increased the number of cells positive for the early stem cell marker SSEA-4, and the gene expression levels of OCT-4, NANOG, and SOX-2 in hBMSCs. Comparison between D- and L-tryptophan isomers showed that the latter presents a stronger effect in inducing the mRNA levels of Oct-4 and Nanog, and in increasing the osteogenic differentiation of hBMSCs. On the other hand, L-tryptophan suppressed adipogenesis. The migration and colony-forming ability of hBMSCs were also enhanced by L-tryptophan treatment. In vivo experiments delivering L-tryptophan (50 mg/kg/day) by intraperitoneal injections for three weeks confirmed that L-tryptophan significantly increased the percentage of cells positive for SSEA-4, mRNA levels of Nanog and Oct-4, and the migration and colony-forming ability of mouse BMSCs. L-kynurenine, a major metabolite of L-tryptophan, also induced similar effects of L-tryptophan in enhancing stemness and osteogenic differentiation of BMSCs in vitro and in vivo, possibly indicating the involvement of the kynurenine pathway as the downstream signaling of L-tryptophan. Finally, since BMSCs migrate to the wound healing site to promote bone healing, surgical defects of 1 mm in diameter were created in mouse femur to evaluate bone formation after two weeks of L-tryptophan or L-kynurenine injection. Both L-tryptophan and L-kynurenine accelerated bone healing compared to the PBS-injected control group. In summary, L-tryptophan enhanced the stemness and osteoblastic differentiation of BMSCs and may be used as an essential factor to maintain the stem cell properties and accelerate bone healing and/or prevent bone loss. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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9 pages, 1974 KiB  
Article
Osteoinduction in Novel Micropores of Partially Dissolved and Precipitated Hydroxyapatite Block in Scalp of Young Rats
by Masaru Murata, Jun Hino, Md. Arafat Kabir, Kenji Yokozeki, Michiko Sakamoto, Takehiko Nakajima and Toshiyuki Akazawa
Materials 2021, 14(1), 196; https://doi.org/10.3390/ma14010196 - 03 Jan 2021
Cited by 9 | Viewed by 1733
Abstract
Osteoinduction in muscles by porous ceramics has been reported to be a real phenomenon. In this study, osteoinduction in connective tissues was found in highly porous hydroxyapatite (HAp) ceramics with large specific surface areas. We have developed the combination method of the partial [...] Read more.
Osteoinduction in muscles by porous ceramics has been reported to be a real phenomenon. In this study, osteoinduction in connective tissues was found in highly porous hydroxyapatite (HAp) ceramics with large specific surface areas. We have developed the combination method of the partial dissolution-precipitation (PDP) technique involving the stirring-supersonic treatment in 1.7 × 10−2 N HNO3 solution containing Ca2+ and PO43− to improve the surface and the bulk of commercially available synthetic HAp block (82.5% in porosity, 50–300 µm in pore size). The modified HAp was named as a partially dissolved and precipitated HAp (PDP-HAp). The PDP-HAp exhibited the porosities of 85–90%, the macropore sizes of 50–200 µm, and the specific surface areas of 1.0–2.0 m2/g, with microcracks. The aim of this study was to observe bone induction by the PDP-HAp with or without BMP-2 in scalp tissues of four-week-old rats. Young rats were divided into the PDP-HAp alone group and the PDP-HAp/BMP-2 group for a long-term observation. In the PDP-HAp group, bone induction occurred inside the many pores at nine months, and the ratio of induced bone was 12.0%. In the PDP-HAp/BMP-2 group, bone induction occurred in almost all pores at three months, and compact bone was found at nine months. The ratios of induced bone were 77.0% at three months and 86.0% at nine months. We believe that osteoinduction by the PDP-HAp might be different from the process of BMP-loaded HAp-induced bone formation, because the PDP-HAp has osteogenic microporous compartments with partially absorbable HAp crystals. The PDP technique may contribute to create bioceramics with osteoinductive property for bone regenerative medicine. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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11 pages, 4771 KiB  
Article
Human Fresh Fibrin Membrane with Bone Morphogenetic Protein-2 (BMP-2) Induces Bone Formation in the Subcutaneous Tissues of Nude Mice
by Keiko Onji, Md. Arafat Kabir, Bowen Zhu, Kenji Yokozeki, Takashi Saito, Toshiyuki Akazawa and Masaru Murata
Materials 2021, 14(1), 150; https://doi.org/10.3390/ma14010150 - 31 Dec 2020
Cited by 6 | Viewed by 2519
Abstract
Autologous blood-derived fibrin glue with platelets, called the concentrated growth factor (CGF), can be prepared immediately by only the decided centrifuge without the addition of coagulation factors. Collagen materials combined with recombinant human BMP-2 have been commercially available for clinical use. The fresh [...] Read more.
Autologous blood-derived fibrin glue with platelets, called the concentrated growth factor (CGF), can be prepared immediately by only the decided centrifuge without the addition of coagulation factors. Collagen materials combined with recombinant human BMP-2 have been commercially available for clinical use. The fresh CGF is auto-clot with wettability and elasticity, while most collagen membranes are derived from the cow or pig. The fresh CGF has wettability and elasticity, while collagen membranes are dry materials without elasticity. The aim of this study was to observe the microstructures of human CGF membrane and evaluate its behavior as a delivery scaffold of rhBMP-2 in the subcutaneous tissues of nude mice. Twenty-four nude mice (5-week-old, male) were used for the assessment of in vivo ectopic bone formation. Mice were received the CGF membrane as the controls and the CGF/rhBMP-2 membrane as the experimental group in the subcutaneous tissues, and harvested at 7, 10, and 14 days after the graft. Harvested samples were evaluated for the histological examination and the histomorphometric measurement was conducted to compare the residue of the CGF, as well as the new bone. Mature fibrin fibers assembled from multiple fibrillary elements and platelets with the rhBMP-2 membrane induced several bony islands and cartilage without residues of CGF at 14 days, while the CGF membrane alone was almost absorbed at 10 days and failed to induce bone formation at 14 days. These results demonstrated that the fresh, human CGF membrane could contribute to a short-term, sticky fibrin matrix for the delivery of rhBMP-2. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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14 pages, 2703 KiB  
Article
Long-Term Effect of Honeycomb β-Tricalcium Phosphate on Zygomatic Bone Regeneration in Rats
by Ryoko Nakagiri, Satoko Watanabe, Kiyofumi Takabatake, Hidetsugu Tsujigiwa, Toshiyuki Watanabe, Hiroshi Matsumoto and Yoshihiro Kimata
Materials 2020, 13(23), 5374; https://doi.org/10.3390/ma13235374 - 26 Nov 2020
Cited by 7 | Viewed by 1756
Abstract
In recent years, artificial bones with high biocompatibility have been developed for hard tissue reconstruction. However, current bone replacement methods are inadequate for large defects, causing infection, exposure, and damage. We have developed a new honeycomb β-tricalcium phosphate (TCP) material, which achieved good [...] Read more.
In recent years, artificial bones with high biocompatibility have been developed for hard tissue reconstruction. However, current bone replacement methods are inadequate for large defects, causing infection, exposure, and damage. We have developed a new honeycomb β-tricalcium phosphate (TCP) material, which achieved good bone regeneration after implantation in a rat complete zygomatic bone defect. In this study, we further investigated the ability of honeycomb β- TCP for remodeling after bone regeneration as a long-term result. Bone morphogenic protein (BMP)-2-free honeycomb β-TCP (TCP group) and honeycomb β-TCP with BMP-2 (BMP group) were implanted in the zygomatic bone of rats. Micro-computed tomography was performed to track the zygomatic bone morphology, and specimens were histologically examined for osteogenesis and remodeling. In the TCP group, no bone formation was observed at 1 month, but it was observed at 6 months. Bone formation was observed in the BMP group at 1 month, and β-TCP absorption reproducing the zygomatic bone morphology was observed at 6 months. This honeycomb β-TCP with BMP-2 may provide appropriate remodeling that reproduces good bone formation in the early stage and good morphology in the long term, offering an alternative bone reconstruction material to vascularized bone grafts. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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10 pages, 50800 KiB  
Article
Geometrical Structure of Honeycomb TCP to Control Dental Pulp-Derived Cell Differentiation
by Kiyofumi Takabatake, Hidetsugu Tsujigiwa, Keisuke Nakano, Yasunori Inada, Shan Qiusheng, Hotaka Kawai, Shintaro Sukegawa, Shigeko Fushimi and Hitoshi Nagatsuka
Materials 2020, 13(22), 5155; https://doi.org/10.3390/ma13225155 - 16 Nov 2020
Cited by 1 | Viewed by 1670
Abstract
Recently, dental pulp has been attracting attention as a promising source of multipotent mesenchymal stem cells (MSCs) for various clinical applications of regeneration fields. To date, we have succeeded in establishing rat dental pulp-derived cells showing the characteristics of odontoblasts under in vitro [...] Read more.
Recently, dental pulp has been attracting attention as a promising source of multipotent mesenchymal stem cells (MSCs) for various clinical applications of regeneration fields. To date, we have succeeded in establishing rat dental pulp-derived cells showing the characteristics of odontoblasts under in vitro conditions. We named them Tooth matrix-forming, GFP rat-derived Cells (TGC). However, though TGC form massive dentin-like hard tissues under in vivo conditions, this does not lead to the induction of polar odontoblasts. Focusing on the importance of the geometrical structure of an artificial biomaterial to induce cell differentiation and hard tissue formation, we previously have succeeded in developing a new biomaterial, honeycomb tricalcium phosphate (TCP) scaffold with through-holes of various diameters. In this study, to induce polar odontoblasts, TGC were induced to form odontoblasts using honeycomb TCP that had various hole diameters (75, 300, and 500 μm) as a scaffold. The results showed that honeycomb TCP with 300-μm hole diameters (300TCP) differentiated TGC into polar odontoblasts that were DSP positive. Therefore, our study indicates that 300TCP is an appropriate artificial biomaterial for dentin regeneration. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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12 pages, 4171 KiB  
Article
Oxidized Low-Density Lipoprotein Promotes In Vitro Calcification
by Mamiko Yamashita, Yoshiaki Nomura, Misao Ishikawa, Shinji Shimoda and Nobuhiro Hanada
Materials 2020, 13(22), 5120; https://doi.org/10.3390/ma13225120 - 13 Nov 2020
Viewed by 1489
Abstract
Calcification plays an important role in the human body in maintaining homeostasis. In the human body, the presence of a high amount of oxidized low-density lipoprotein (ox-LDL) is a consistent feature of the local areas that are common sites of ectopic calcification, namely [...] Read more.
Calcification plays an important role in the human body in maintaining homeostasis. In the human body, the presence of a high amount of oxidized low-density lipoprotein (ox-LDL) is a consistent feature of the local areas that are common sites of ectopic calcification, namely dental calculus, renal calculus, and the areas affected by arteriosclerosis. Hence, ox-LDL may have some effect on calcification. Scanning electron microscopy (SEM) observation revealed a high amount of amorphous calcium phosphate (ACP) when ox-LDL was included in the solution. In the in vitro experiment, the highest amount of precipitation of calcium phosphate was observed in the solution containing ox-LDL compared to the inclusion of other biomaterials and was 4.2 times higher than that of deionized water for 4.86 mM calcium and 2.71 mM phosphate. The morphology of calcium phosphate precipitates in the solution containing ox-LDL differed from that of the precipitates in solutions containing other biomaterials, as determined by transmission electron microscopy (TEM). Through the time course observation of the sediments using TEM, it was observed that the sediments changed from spherical or oval shape to a thin film shape. These results indicate that sediments acquired a long-range order array, and the phase transitioned from non-crystalline to crystalline with an increased time and density of ACP. Thus, it is concluded that ox-LDL promoted ACP precipitation and it plays an important role in ectopic calcification. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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12 pages, 25918 KiB  
Article
Mechanical, Histological, and Scanning Electron Microscopy Study of the Effect of Mixed-Acid and Heat Treatment on Additive-Manufactured Titanium Plates on Bonding to the Bone Surface
by Naoko Imagawa, Kazuya Inoue, Keisuke Matsumoto, Ayako Ochi, Michi Omori, Kayoko Yamamoto, Yoichiro Nakajima, Nahoko Kato-Kogoe, Hiroyuki Nakano, Tomiharu Matsushita, Seiji Yamaguchi, Phuc Thi Minh Le, Shinpei Maruyama and Takaaki Ueno
Materials 2020, 13(22), 5104; https://doi.org/10.3390/ma13225104 - 12 Nov 2020
Cited by 10 | Viewed by 1802
Abstract
The additive manufacturing (AM) technique has attracted attention as one of the fully customizable medical material technologies. In addition, the development of new surface treatments has been investigated to improve the osteogenic ability of the AM titanium (Ti) plate. The purpose of this [...] Read more.
The additive manufacturing (AM) technique has attracted attention as one of the fully customizable medical material technologies. In addition, the development of new surface treatments has been investigated to improve the osteogenic ability of the AM titanium (Ti) plate. The purpose of this study was to evaluate the osteogenic activity of the AM Ti with mixed-acid and heat (MAH) treatment. Fully customized AM Ti plates were created with a curvature suitable for rat calvarial bone, and they were examined in a group implanted with the MAH-treated Ti in comparison with the untreated (UN) group. The AM Ti plates were fixed to the surface of rat calvarial bone, followed by extraction of the calvarial bone 1, 4, 8, and 12 weeks after implantation. The bonding between the bone and Ti was evaluated mechanically. In addition, AM Ti plates removed from the bone were examined histologically by electron microscopy and Villanueva–Goldner stain. The mechanical evaluation showed significantly stronger bone-bonding in the MAH group than in the UN group. In addition, active bone formation was seen histologically in the MAH group. Therefore, these findings indicate that MAH resulted in rapid and strong bonding between cortical bone and Ti. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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9 pages, 3518 KiB  
Article
Micro-Architectural Investigation of Teleost Fish Rib Inducing Pliant Mechanical Property
by Yu Yang Jiao, Masahiro Okada, Emilio Satoshi Hara, Shi Chao Xie, Noriyuki Nagaoka, Takayoshi Nakano and Takuya Matsumoto
Materials 2020, 13(22), 5099; https://doi.org/10.3390/ma13225099 - 12 Nov 2020
Cited by 4 | Viewed by 1968
Abstract
Despite the fact that various reports have been discussing bone tissue regeneration, precise bone tissue manipulation, such as controlling the physical properties of the regenerated bone tissue, still remains a big challenge. Here, we focused on the teleost fish ribs showing flexible and [...] Read more.
Despite the fact that various reports have been discussing bone tissue regeneration, precise bone tissue manipulation, such as controlling the physical properties of the regenerated bone tissue, still remains a big challenge. Here, we focused on the teleost fish ribs showing flexible and tough mechanical properties to obtain a deeper insight into the structural and functional features of bone tissue from different species, which would be valuable for the superior design of bone-mimicking materials. Herein, we examined their compositions, microstructure, histology, and mechanical properties. The first rib of Carassius langsdorfii showed a higher Young’s modulus with a small region of chondrocyte clusters compared with other smaller ribs. In addition, highly oriented collagen fibers and osteocytes were observed in the first rib, indicating that the longest first rib would be more mature. Moreover, the layer-by-layer structure of the oriented bone collagen was observed in each rib. These microarchitectural and compositional findings of fish rib bone would give one the useful idea to reproduce such a highly flexible rib bone-like material. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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13 pages, 3813 KiB  
Article
Effect of Honeycomb β-TCP Geometrical Structure on Bone Tissue Regeneration in Skull Defect
by Toshiyuki Watanabe, Kiyofumi Takabatake, Hidetsugu Tsujigiwa, Satoko Watanabe, Ryoko Nakagiri, Keisuke Nakano, Hitoshi Nagatsuka and Yoshihiro Kimata
Materials 2020, 13(21), 4761; https://doi.org/10.3390/ma13214761 - 25 Oct 2020
Cited by 7 | Viewed by 2323
Abstract
The effect of the geometric structure of artificial biomaterials on skull regeneration remains unclear. In a previous study, we succeeded in developing honeycomb β-tricalcium phosphate (β-TCP), which has through-and-through holes and is able to provide the optimum bone microenvironment for bone tissue regeneration. [...] Read more.
The effect of the geometric structure of artificial biomaterials on skull regeneration remains unclear. In a previous study, we succeeded in developing honeycomb β-tricalcium phosphate (β-TCP), which has through-and-through holes and is able to provide the optimum bone microenvironment for bone tissue regeneration. We demonstrated that β-TCP with 300-μm hole diameters induced vigorous bone formation. In the present study, we investigated how differences in hole directions of honeycomb β-TCP (horizontal or vertical holes) influence bone tissue regeneration in skull defects. Honeycomb β-TCP with vertical and horizontal holes was loaded with BMP-2 using Matrigel and Collagen gel as carriers, and transplanted into skull bone defect model rats. The results showed that in each four groups (Collagen alone group, Matrigel alone group, Collagen + BMP group and Matrigel + BMP-2), vigorous bone formation was observed on the vertical β-TCP compared with horizontal β-TCP. The osteogenic area was larger in the Matrigel groups (with and without BMP-2) than in the Collagen group (with and without BMP-2) in both vertical β-TCP and horizontal β-TCP. However, when BMP-2 was added, the bone formation area was not significantly different between the Collagen group and the Matrigel group in the vertical β-TCP. Histological finding showed that, in vertical honeycomb β-TCP, new bone formation extended to the upper part of the holes and was observed from the dura side to the periosteum side as added to the inner walls of the holes. Therefore, we can control efficient bone formation by creating a bone microenvironment provided by vertical honeycomb β-TCP. Vertical honeycomb β-TCP has the potential to be an excellent biomaterial for bone tissue regeneration in skull defects and is expected to have clinical applications. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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20 pages, 50340 KiB  
Study Protocol
Transplantation of Mature Adipocyte-Derived Dedifferentiated Fat Cells Facilitates Periodontal Tissue Regeneration of Class II Furcation Defects in Miniature Pigs
by Daisuke Akita, Tomohiko Kazama, Naoki Tsukimura, Yoshiki Taniguchi, Rie Takahashi, Yoshinori Arai, Niina Tsurumachi-Iwasaki, Hiroyasu Yasuda, Takahisa Okubo, Koichiro Kano, Taro Matsumoto and Masaki Honda
Materials 2022, 15(4), 1311; https://doi.org/10.3390/ma15041311 - 10 Feb 2022
Cited by 3 | Viewed by 2334
Abstract
Adipose tissue is composed mostly of adipocytes that are in contact with capillaries. By using a ceiling culture method based on buoyancy, lipid-free fibroblast-like cells, also known as dedifferentiated fat (DFAT) cells, can be separated from mature adipocytes with a large single lipid [...] Read more.
Adipose tissue is composed mostly of adipocytes that are in contact with capillaries. By using a ceiling culture method based on buoyancy, lipid-free fibroblast-like cells, also known as dedifferentiated fat (DFAT) cells, can be separated from mature adipocytes with a large single lipid droplet. DFAT cells can re-establish their active proliferation ability and transdifferentiate into various cell types under appropriate culture conditions. Herein, we sought to compare the regenerative potential of collagen matrix alone (control) with autologous DFAT cell-loaded collagen matrix transplantation in adult miniature pigs (microminipigs; MMPs). We established and transplanted DFAT cells into inflammation-inducing periodontal class II furcation defects. At 12 weeks after cell transplantation, a marked attachment gain was observed based on the clinical parameters of probing depth (PD) and clinical attachment level (CAL). Additionally, micro computed tomography (CT) revealed hard tissue formation in furcation defects of the second premolar. The cemento-enamel junction and alveolar bone crest distance was significantly shorter following transplantation. Moreover, newly formed cellular cementum, well-oriented periodontal ligament-like fibers, and alveolar bone formation were observed via histological analysis. No teratomas were found in the internal organs of recipient MMPs. Taken together, these findings suggest that DFAT cells can safely enhance periodontal tissue regeneration. Full article
(This article belongs to the Special Issue Materials for Hard Tissue Repair and Regeneration)
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