Kazuo Takakuda

Kawakita General Hospital, Edo, Tokyo, Japan

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Publications (120)173.05 Total impact

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    Chiaki Tsutsumi · Kazuo Takakuda · Noriyuki Wakabayashi
    [Show abstract] [Hide abstract] ABSTRACT: Objectives: This study investigated the influence of surface reaction-type prereacted glass ionomer (S-PRG) fillers on Candida albicans adhesion on denture base resin. Methods: Discs were prepared by incorporating the S-PRG filler into the polymer powder of a polymethyl methacrylate (PMMA)-based, heat-polymerizing resin at 0 (control), 5%, 10%, and 20% (w/w). The surface roughness of all disc surfaces was measured. Elemental analysis of released Na(+), Sr(2+), SiO3(2-), Al(3-), BO3(3-), and F(-) was performed after water immersion. Each disc was placed in a well with artificial saliva to form acquired pellicle, incubated, washed with phosphate-buffered saline, and immersed in a C. albicans (JCM2085) cell suspension standardized at 10(4) cells/ml. After aerobic incubation at 37°C for 24h, the metabolic mitochondrial activity, total biofilm biomass, and biofilm thickness were evaluated. The morphogenetic transition of C. albicans in the early culture stage (1 and 3h) was observed. Results: There was a slight but significant increase in the surface roughness with an increase in the filler content. The metabolic activity and total biomass volume were significantly lower in all filler groups than in the control group, although there were no significant differences among the filler groups. Groups with at least 5% filler content exhibited a thinner biofilm compared with the control group. All filler groups showed hyphal forms at 3h, with the length of the hyphae being lesser than those in the control group. Conclusions: Although the incorporation of S-PRG filler slightly increases the surface roughness of denture base resin, it reduces the adhesion of C. albicans. Clinical significance: The S-PRG filler has the potential to reduce Candida albicans adhesion on denture base resin and may lower the risk of denture stomatitis. However, filler incorporation can increase the surface roughness of heat-polymerizing denture base resin.
    Full-text · Article · Dec 2015 · Journal of dentistry
  • [Show abstract] [Hide abstract] ABSTRACT: Ti-based bulk metallic glasses are reported with high strength, low Young modulus and high corrosion resistance, suggesting their potentials in biomedical applications. However a thorough in vivo evaluation of its biocompatibilities has not been conducted yet. In this study, we implanted bars of Ti-based bulk metallic glass in the femoral bone of rats, followed up local tissue reaction as well as its component ions' diffusion in local area and whole body. The Ti-based BMG (Ti40Zr10Cu34Pd14Sn2) alloy exhibited favorable features of both high strength and high elasticity. In vivo implant evaluation showed that it has a good tissue compatibility, equivalent bone integration and bonding ability with Ti sample. No component ion diffusion was detected up to 3 months post implantation. The possibility and efficacy of its use for bone implant is confirmed. Thus further long term implant study is recommended.
    No preview · Article · Oct 2015 · Bio-medical materials and engineering
  • Wei Wang · Soichiro Itoh · Kazuo Takakuda
    [Show abstract] [Hide abstract] ABSTRACT: The objective of this study was to compare the results of allogenic and xenogeneic nerve grafts that were treated using decellularization. The sciatic nerves of Sprague-Dawley rats and the median nerves of Japanese white rabbits were decellularized with sodium dodecyl sulfate and Triton X-100 and examined with a scanning electron microscope and immunofluorescence staining. A bridge-graft into the sciatic nerve in Wistar rats was performed with the decellularized nerves (10 mm in length for short-term evaluation; 15 mm in length for long-term evaluation). As a control, an isograft was performed. The specimens were harvested at 4 weeks postoperatively and prepared for immunohistochemistry. Function, electrophysiological and histomorphological analyses were performed to evaluate nerve recovery at 24 weeks postoperatively. The 3-dimensional structure of the basal lamina column, on which the cell adhesion molecules were integrated, was preserved through the decellularization protocols. Limited ED1-positive macrophage invasion was observed, and abundant NF 160-positive axons, which were accompanied by S-100-positive Schwann cells, penetrated through the implanted nerves. The sciatic nerve function and electrophysiological and histomorphological analyses suggest that the xenogeneic nerve graft was statistically indistinguishable from the allogenic nerve graft but slightly inferior to the isograft in supporting the axonal regeneration and functional recovery. This article is protected by copyright. All rights reserved.
    No preview · Article · Oct 2015 · Journal of Biomedical Materials Research Part A
  • [Show abstract] [Hide abstract] ABSTRACT: The authors evaluated the efficacy of decellularized nerve as a scaffold for nerve regeneration. Sciatic nerves harvested from Sprague-Dawley rats were decellularized in combination with sodium dodecyl sulfate and Triton X-100, and examined with scanning electron microscopy and immunofluorescence staining. A graft into the sciatic nerve in Wistar rats was performed with the decellularized Sprague-Dawley rat sciatic nerves [allograft: 10 mm long (n = 3) for short term and 15 mm long (n = 5) for long term]. As a control, a portion of sciatic nerve of Wistar rats was cut, reversed, and resutured in situ [autograft: 10 mm long (n = 3) and 15 mm long (n = 5) for different terms, respectively]. Samples were harvested 4 weeks postoperatively and prepared for immunohistochemistry. Von Frey hair test, static toe spread factor measurement, and electrophysiologic and histomorphologic analyses were carried out to evaluate nerve recovery 24 weeks postoperatively. Scanning electron microscopic images revealed the honeycomb structure, and immunohistology showed that the three-dimensional structure of the basal lamina column on which cell adhesion molecules are integrated is preserved through the decellularization protocols. Limited ED1-positive macrophage invasion was found through the decellularized sciatic nerves, suggesting that antigenicity remained more or less after this treatment. Nevertheless, NF160-positive axons accompanied by S100-positive Schwann cells penetrated through the decellularized sciatic nerves. Sciatic nerve function had recovered, and there were no significant differences in the electrophysiologic and histomorphologic recovery in the groups. These results suggest that the decellularized allogeneic nerve is a suitable scaffold to bridge a nerve gap.
    No preview · Article · Sep 2015 · Plastic and Reconstructive Surgery
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    [Show abstract] [Hide abstract] ABSTRACT: The induction of synovial tissue to the meniscal lesion is crucial for meniscal healing. Synovial MSCs are an attractive cell source because of their high proliferative and chondrogenic potentials. We examined whether transplantation of synovial MSCs promoted healing after meniscal repair of extended longitudinal tear of avascular area in a microminipig model. Longitudinal tear lesion was made in medial menisci and sutured in both knees, and then a synovial MSC suspension was administered for 10 minutes only in unilateral knee. The sutured meniscus was evaluated morphologically and biomechanically at 2, 4, and 12 weeks. The behavior of transplanted MSCs was also examined. The meniscal healing at 12 weeks was significantly better in the MSC group than in the control group; macroscopically, histologically and by T1rho mapping analysis. Transmission electron microscopic analysis demonstrated that the meniscus lesion was occupied by dense collagen fibrils only in the MSC group. Biomechanical analysis revealed that the tensile strength to failure of the meniscus higher in the MSC group than in the control group in each microminipig. Synovial tissue covered better along the superficial layer from the outer zone into the lesion of the meniscus in the MSC group at 2 and 4 weeks in each microminipig. Synovial MSCs labeled with ferucarbotran were detected in the meniscus lesion and adjacent synovium by MRI at 2 weeks. Transplantation of synovial MSCs promoted healing after meniscal repair with induction of synovium into the longitudinal tear in the avascular zone of meniscus in pigs. Copyright © 2015. Published by Elsevier Ltd.
    Full-text · Article · Feb 2015 · Osteoarthritis and Cartilage
  • [Show abstract] [Hide abstract] ABSTRACT: This study introduces the application of method for electrically polarizing titanium implants coated with anatase TiO2 using micro-arc oxidation. It also describes the features of the electrically polarized titanium implants, on which surface charges are generated by the dipole moment of the TiO2, and describes how the surface charges affect the implants' in vivo bone-implant integration capability. A comprehensive assessment using biomechanical, histomorphological and radiographic analyses in a rabbit model was performed on polarized and non-polarized implants. The electrically polarized surfaces accelerated the establishment of implant biomechanical fixation, compared with the non-polarized surfaces. The percentage of the bone-implant contact ratio was higher using polarized implants than using non-polarized implants. In contrast, the bone volume around the implants was not affected by polarization. Thus, using the polarized implant, this study identified that controlled surface charges have a significant effect on the properties of titanium implants. The application of the electrical polarization process and the polarization-enhanced osteoinductivity, which resulted in greater bone-implant integration, was clearly demonstrated.
    No preview · Article · Sep 2014 · Journal of Biomedical Materials Research Part A
  • [Show abstract] [Hide abstract] ABSTRACT: Accordion nerve conduit of poly(lactide-co-glycolide-co-ε-caprolactone) with perforations was developed by excimer laser processing. We evaluated its in vivo function for nerve repairing and discussed the influence of pore size and density. It was found that perforations help inner nerve regeneration remarkably, which effect is unrelated to pore size or density, and is not parallel with revascularization increment. Inducing of permeability only to allow substance exchange but not vessel ingrowth could facilitate nerve regeneration too. Perforating micropores with the size of 100 μm and the density of 25/cm provides permeability and vessel ingrowth both, therefore promotes the axon extension the best, larger, and more pores do not advance axon regeneration more. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
    No preview · Article · May 2014 · Journal of Biomedical Materials Research Part B Applied Biomaterials
  • Atsushi Mita · Atsushi Yagihara · Wei Wang · Kazuo Takakuda
    [Show abstract] [Hide abstract] ABSTRACT: Connective tissue attachment to a mesh structure incorporated on the surface of oral implants and extra-oral endosseous craniofacial implants (EOECI) was investigated. Two types of implants were prepared: TI and TI-Mesh. TI was composed of an upper and a lower component, both comprised of a titanium cylinder, which could be connected using a titanium screw. The composition of the TIMesh was similar, but the lower cylinder had a lateral groove that was covered with a titanium mesh. In animal experiments performed using rat calvaria, the lower component was first implanted and was left submerged for 3 weeks, then the upper component was mounted percutaneously. After an additional 2 weeks, each implant and the surrounding tissues were harvested and evaluated. Histological observations revealed collagen fibers originating from surrounding hypodermal tissues anchored to the mesh structures of the TI-Mesh whereas no such collagen fibers were observed around TI. Significantly greater values of the attachment strength, the thickness of the dermal tissue, the thickness of hypodermal tissue, and the attachment lengths were observed in TI-Mesh than those of TI. Thus connective tissue attachment with collagen fibers anchored to the mesh was achieved by incorporating mesh structures into the percutaneously placed implants.
    No preview · Article · Mar 2014
  • [Show abstract] [Hide abstract] ABSTRACT: Although artificial vessels are available for large diameter arteries, there are no artificial vessels for small diameter arteries of < 4 mm. We created a decellularized vascular scaffold (length, 10 mm; outer diameter, 1.5 mm; inner diameter, 1.3 mm) from rat abdominal arteries. We measured the biomechanical characteristics of the scaffolds, implanted them to defects made in rat carotid arteries, and evaluated their patency and the endothelial cell linings. Silastic grafts were implanted as controls. The decellularized scaffolds demonstrated similar mechanical characteristics to normal arteries. All of the control grafts were occluded. Fibroblast-like cells were discovered in the thrombus, and fibrous organization was apparent. In contrast, patency of the grafts in 10 of 12 animals was observed 4 weeks after implantation. The internal cavity of the patent scaffold was completely lined by endotheliallike cells. Thus, the possibility of small artery reconstruction using decellularized scaffolds was demonstrated.
    No preview · Article · Mar 2014
  • [Show abstract] [Hide abstract] ABSTRACT: This article proposes less-invasive subperiosteal bone-bonding devices capable of realizing rapid osseointegration and the acquisition of fundamental knowledge required for their development. Three candidates were prepared: titanium rod specimens with a machined surface (Bare), hydroxyapatite (HAp) coating, and hydroxyapatite/collagen (HAp/Col) nanocomposite coating. To investigate bone formation around these rods, each specimen was placed under the periosteum of a male Sprague-Dawley rat calvarium. Four weeks after surgery, the samples were evaluated via histomorphometrical analyses and bonding strength tests. All the Bare specimens and more than half of the HAp specimens were encapsulated with fibrous tissue, whereas all the HAp/Col specimens were almost completely surrounded by new bone tissue without encapsulation. Histomorphometrical analyses showed that the HAp/Col group had the greatest bone contact ratio among all candidates (p < 0.05). Further, a bonding strength test indicated that the HAp/Col group exhibited the greatest bonding strength to bone (p < 0.05). Thus, HAp/Col-coated rods are considered as the best candidate materials for achieving rapid osseointegration onto a bone surface. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
    No preview · Article · Aug 2013 · Journal of Biomedical Materials Research Part B Applied Biomaterials
  • Seiji Asoda · Takayuki Arita · Kazuo Takakuda
    [Show abstract] [Hide abstract] ABSTRACT: Soft tissue attachment is a major concern for the improved design of dental and maxillofacial implants. This study evaluated the efficacy of mesh structures for soft tissue attachment in a rat percutaneous model. Four kinds of implant specimens were prepared - TI implants made of titanium cylinders, HA implants of hydroxyapatite-coated titanium, TI-Mesh implants with a titanium mesh covering a groove machined around a titanium cylinder, and similar HA-Mesh implants with a hydroxyapatite-coated mesh. These specimens were implanted percutaneously into the skin tissue of rats. The detachments of the implants were examined during the experimental period of 4 weeks. Survived implants were subjected to mechanical tests for the attachment strength and histological examinations. TI and HA implants demonstrated 0% of survival rates, while TI-Mesh and HA-Mesh showed significantly higher rates of 93.3% and 100% respectively. The attachment strengths were 159 ± 47 kPa in the TI-Mesh and 135 ± 16 kPa in the HA-Mesh. Histological observations revealed that collagen fibers originating from surrounding subcutaneous tissues were anchored to the mesh structures of the TI- and HA-Mesh implants. The results demonstrated the efficacy of the mesh structures for the attachment of soft connective tissues to implants. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
    No preview · Article · May 2013 · Journal of Biomedical Materials Research Part B Applied Biomaterials
  • [Show abstract] [Hide abstract] ABSTRACT: Objective: The objective of this study was to examine subperiosteal bone formation around implanted biomaterials in association with orthodontic anchorage devices. Methods: Three types of titanium rod specimens with a machined surface (Bare), a hydroxyapatite coating (HAp), and a hydroxyapatite/collagen nanocomposite coating (HAp/Col) were prepared. To verify bone-forming capability around these rods, we carried out animal experiments. Experimental animals were 12-week-old male SD rats. The specimen was implanted into their calvaria. The bone-forming capability of each of the five specimens was evaluated after four weeks implantation via histological observations, bonding strength tests, and CT image analysis. The histometrical and mechanical test data were statistically analyzed using multiple comparisons of Wilcoxon’s rank-sum tests in combination with the Bonferroni-Holm correction. Results: In the histological observations, all the Bare specimens were completely encapsulated with soft tissue. In the cases of HAp, the specimens were also encapsulated in three of the five specimens, but the other two specimens were not completely encapsulated. In the case of HAp/Col, all of the specimens were almost completely surrounded by new bone tissue. Significant differences were observed in the bone contact ratios between HAp/Col vs. Bare and HAp/Col vs. HAp. Significant differences were also observed in the new bone height between HAp/Col vs. Bare and HAp vs. Bare. From the bonding strength tests, HAp/Col was found to have the greatest mean strength vs. Bare and HAp, and significant differences were observed among them. In the CT image analysis, fractured bone pieces were observed in the cases of HAp and HAp/Col. The size of these fractured pieces was apparently larger in HAp/Col than in HAp. Conclusion: In an animal experiment utilizing rat calvaria, hydroxyapatite/collagen nanocomposite-coated Ti rods demonstrated new bone formation without fibrous tissue encapsulation as early as within four weeks.
    No preview · Conference Paper · Mar 2013
  • [Show abstract] [Hide abstract] ABSTRACT: Chitosan nonwoven mesh conduit was introduced with perforating pores on the wall by laser-drilling process. The pore size was set at 200 μm and the pore interval at 1mm. Twelve mm long grafts of following 4 groups (N=5, respectively) were implanted to rat sciatic nerve defects: non-pore, 2 lines of pores, 4 lines of pores and isograft. After 12 weeks standard nerve function evaluations were performed including functional test, electro conductivity test and histological analysis. It was found that revascularization of the conduit contents was improved with pores drilled, but accompanied nerve regenerative improvements were only shown as maturation of fasciculi, not with the general parameters of axon diameter and density.
    No preview · Article · Jan 2013 · Journal of Biomechanical Science and Engineering
  • M. Uezono · K. Takakuda · M. Kikuchi · S. Suzuki · K. Moriyama
    No preview · Article · Jan 2013
  • [Show abstract] [Hide abstract] ABSTRACT: The impact of continuous flow left ventricular assist device (LVAD) pumping on platelet aggregation was investigated in animal experiments utilizing six calves. A single-use MagLev centrifugal blood pump, MedTech MagLev, was used to bypass the calves' hearts from the left atrium to the descending aorta at a flow rate of 50 ml/kg/min. The LVAD's impact on blood coagulation activities was evaluated based on the platelet aggregability, which was measured with a turbidimetric assay method during the preoperative, operative, and postoperative periods. Heparin and warfarin were used for anticoagulation, while aspirin was used for the antiplatelet therapy. A decrease in platelet aggregation immediately after the pump started was observed in the cases of successful long-term pump operation, while the absence of such a decrease might have caused coagulation-related complications to terminate the experiments. Thus, the platelet aggregability was found to be significantly affected by the pump, and its initial trend may be related to the long-term outcome of the mechanical circulatory support.
    No preview · Article · Oct 2012 · Journal of Artificial Organs
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    [Show abstract] [Hide abstract] ABSTRACT: The adaptive nature of bone formation under mechanical loading is well known; however, the molecular and cellular mechanisms in vivo of mechanical loading in bone formation are not fully understood. To investigate both mechanisms at the early response against mechanotransduction in vivo, we employed a noninvasive 3-point bone bending method for mouse tibiae. It is important to investigate periosteal woven bone formation to elucidate the adaptive nature against mechanical stress. We hypothesize that cell morphological alteration at the early stage of mechanical loading is essential for bone formation in vivo. We found the significant bone formation on the bone surface subjected to change of the stress toward compression by this method. The histological analysis revealed the proliferation of periosteal cells, and we successively observed the appearance of ALP-positive osteoblasts and increase of mature BMP-2, resulting in woven bone formation in the hypertrophic area. To investigate the mechanism underlying the response to mechanical loading at the molecular level, we established an in-situ immunofluorescence imaging method to visualize molecules in these periosteal cells, and with it examined their cytoskeletal actin and nuclei and the extracellular matrix proteins produced by them. The results demonstrated that the actin cytoskeleton of the periosteal cells was disorganized, and the shapes of their nuclei were drastically changed, under the mechanical loading. Moreover, the disorganized actin cytoskeleton was reorganized after release from the load. Further, inhibition of onset of the actin remodeling blocked the proliferation of the periosteal cells. These results suggest that the structural change in cell shape via disorganization and remodeling of the actin cytoskeleton played an important role in the mechanical loading-dependent proliferation of cells in the periosteum during bone formation.
    Preview · Article · Sep 2011 · PLoS ONE
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    Dataset: Figure S1
    [Show abstract] [Hide abstract] ABSTRACT: Mac-3 staining after treatment in mechanical loading. Tibial histological sections were prepared at day 3. These sections were stained with anti-Mac-3 antibodies. (A, C) In the right tibia, used as a control, Mac-3-positive cells were rarely detected in either short-pulse or long-pulse group. (B) In the left tibia in the short-pulse group, Mac-3-positive cells were detected around the loading point (arrow). (D, E) In the left tibia in the long-pulse group, Mac-3-positive cells were also detected around the loading point (E, arrow), but not at the side opposite to the loading point (D). Non-specific signals were detected in osteogenic layer. Scale bar; 50 µm (A–D), 200 µm (E). Red arrowhead indicates loading direction. (TIF)
    Preview · Dataset · Sep 2011
  • [Show abstract] [Hide abstract] ABSTRACT: A novel hydroxyapatite (HAp)/poly(L-lactic acid) (PLLA) nanocomposite nonwoven fabric, which was coated and mixed with calcined HAp nanocrystals, and has submicron-sized dimples on its surface, was fabricated. First, HAp-mixed PLLA fabric was prepared by electrospinning a HAp nanocrystal dispersion in dichloromethane (DCM)-dissolved PLLA. It was found that most of the HAp nanocrystals were not exposed on the HAp-mixed PLLA fiber surface but covered with the PLLA matrix. A HAp-nanocrystal coating was applied onto the surface of the HAp-mixed PLLA fabric after corona discharge treatment followed by ethanol washing. The submicron-sized dimples were enlarged after the ethanol washing. After the HAp-nanocrystal coating, the HAp-mixed PLLA fabric surface was uniformly coated with the HAp nanocrystals. In vitro cell spread tests showed that the rat osteoblasts spread more on HAp-nanocrystal-coated fabrics than on non-HAp-coated fabrics. Upon covering calvarial defects, the in vivo hard tissue responses suggested earlier restoration of the defects with HAp-nanocrystal-coated fabrics than those with non-HAp-coated fabrics.
    No preview · Article · Jul 2011 · Journal of Artificial Organs
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    [Show abstract] [Hide abstract] ABSTRACT: An experimental periodontal sensor probe (SP) equipped with an optical fiber for recording function was developed. The aim was to test the intraexaminer reproducibility of probing using the SP and to assess the consistency with the manual probe (MP). The SP was assembled with an external sheath covering the probe tip of an MP. The sheath was slid backward by the free gingival margin while probing and the sliding distance was detected by the sensor. The probing was conducted with the walking stroke at six sites for four first molar teeth in six maintenance patients with the SP and the MP at a 1-hour interval. The deepest reading in the vicinity of each site was recorded. The measurements were rerecorded 1 week later. The mean depth was 3.03 and 3.08 mm recorded by the MP and SP, respectively. Although no significant difference was found between the probes (P >0.05) in all measurement sites, the mean depth at the lingual site of the upper left first molar was noticeably lower with the SP. For sites ≥7 mm, significantly lower depth was recorded by the SP (P <0.05). Zero discrepancy in duplicate measurements was found in 76% of all sites with MP and 92% with SP. The reproducibility of the SP was comparable to that of the MP. The results indicate that for sites of maintenance patients with probing depth <7 mm there was excellent agreement obtained by a single examiner using the SP compared to the MP.
    Full-text · Article · May 2011 · Journal of Periodontology
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    Full-text · Chapter · Apr 2011

Publication Stats

2k Citations
173.05 Total Impact Points

Institutions

  • 2015
    • Kawakita General Hospital
      Edo, Tokyo, Japan
  • 1991-2010
    • Tokyo Medical and Dental University
      • • Department of Biodesign
      • • Institute of Biomaterials and Bioengineering
      • • Department of Orthopaedic Surgery
      • • Institute for Medical and Dental Engineering
      • • Tokyo Medical and Dental University Hospital
      Edo, Tōkyō, Japan
  • 2005
    • National Institute for Materials Science
      • Advanced Materials Laboratory
      Tsukuba, Ibaraki, Japan
  • 2000
    • University of Texas at San Antonio
      San Antonio, Texas, United States