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Hirotaka Koyanagi,
Keisuke Ae,
Hidetsugu Maehara,
Masato Yuasa,
Tomokazu Masaoka,
Tsuyoshi Yamada,
Takashi Taniyama,
Masanori Saito,
Yuki Funauchi,
Toshitaka Yoshii,
Atsushi Okawa, Shinichi Sotome
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ABSTRACT: Bone marrow-derived stromal cells (BMSCs) contain mesenchymal stem cells that are capable of forming various mesenchymal tissues. We hypothesized that BMSCs and β-tricalcium phosphate (β-TCP) composites would promote the remodeling of large-sized autologous devitalized bone grafts; therefore, the aim of this study was to evaluate the effects of the composites on the remodeling of autologous devitalized bone grafts. Autologous BMSCs cultured in culture medium containing dexamethasone (10(-7) M) were loaded into porous β-TCP granules under low-pressure. Theses BMSC/TCP composites were put into the bone marrow cavity of autologous heat-treated bone (femoral diaphysis, 65-mm long, 100°C, 30 min) and put back to the harvest site. In the contralateral side, β-TCP without BMSC were used in the same manner as the opposite side as the control. Treatment with the BMSC/TCP composites resulted in a significant increase in thickness, bone mineral density, and matured bone volume of the cortical bone at the center of the graft compared to the control. Histological analysis showed matured regenerated bone in the BMSC loaded group. These results indicate that BMSC/TCP composites facilitated bone regeneration and maturation at the graft site of large-sized devitalized bone. This method could potentially be applied for clinical use in the reconstruction of large bone defects such as those associated with bone tumors. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res XX:XXX-XXX, 2013.
Journal of Orthopaedic Research 04/2013; · 2.81 Impact Factor
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Toshitaka Yoshii,
Masato Yuasa, Shinichi Sotome,
Tsuyoshi Yamada,
Kyohei Sakaki,
Takashi Hirai,
Takashi Taniyama,
Hiroyuki Inose,
Tsuyoshi Kato,
Yoshiyasu Arai,
Shigenori Kawabata,
Shoji Tomizawa,
Mitsuhiro Enomoto,
Kenichi Shinomiya,
Atsushi Okawa
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ABSTRACT: Study Design. A prospective analysisObjective. Our aim was to investigate the efficacy of new synthetic porous/dense composite hydroxyapatite (HA) for use in anterior cervical discectomy and fusion (ACDF).Summary of Background Data. Iliac crest bone graft (ICBG) has been traditionally used as the golden standard for ACDF. The significant complication rate associated with harvesting tricortical ICBG, however, has encouraged development of alternative graft substitutes.Methods. The morphology of the porous/dense HA was observed by scanning electron microscopy (SEM), and the in vitro compressive strength of the composite HA was measured. From April 2005, 51 consecutive patients underwent 81 levels of ACDF using the composite HA with percutaneously harvested trephine bone chips. Clinical and radiological evaluation was performed during the postoperative hospital stay and at follow-up. Furthermore, the outcomes in ACDF using the composite HA were compared with those using tricortical ICBG.Results. The SEM images demonstrated 100 - 300 mm pores (approximately 40% of porosity) in the porous layers of the HA. The compressive strength of the composite HA was 203.1±4.1MPa. In the clinical study, the demographic data of the patients were similar in HA and ICBG groups. The fusion rates in HA group were comparable to those in ICBG group. The cervical lordosis were enhanced postoperatively in both groups and well preserved at 2-year follow-up without significant differences between the groups. The intraoperative blood loss in HA group was significantly smaller than that in ICBG group. Donor site complications were found in 29.2% of the patients in ICBG group, whereas no donor site morbidity was found in HA group. No major collapse or fragmentation of the composite HA was found.Conclusion. The hybrid graft of composite HA and percutaneously harvested trephine chips seemed promising as a graft substitute for ACDF.
Spine 12/2012; · 2.08 Impact Factor
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Takashi Hirai,
Mitsuhiro Enomoto,
Akira Machida,
Mariko Yamamoto,
Hiroya Kuwahara,
Mio Tajiri,
Yukihiko Hirai, Shinichi Sotome,
Hidehiro Mizusawa,
Kenichi Shinomiya,
Atsushi Okawa,
Takanori Yokota
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ABSTRACT: Gene therapy for neurological diseases requires efficient gene delivery to target tissues in the central and peripheral nervous systems. Although adeno-associated virus is one of the most promising vectors for clinical use against neurological diseases, it is difficult to get it across the blood-brain barrier. A clinically practical approach to using a vector based on adeno-associated virus to decrease the expression of a specific gene in both the central and the peripheral nervous system has yet to be established. Here, we analyzed whether upper lumbar intrathecal administration of a therapeutic vector incorporating adeno-associated virus and short-hairpin RNA against superoxide dismutase-1 bypassed the blood-brain barrier to target the spinal cord and dorsal root ganglia. The therapeutic vector effectively suppressed mRNA and protein expression of endogenous superoxide dismutase-1 in the lumbar spinal cord and dorsal root ganglia. Moreover, neither neurological side effects nor toxicity due to the incorporated short-hairpin RNA occurred after the injection. We propose that this approach could be developed into novel therapies for motor neuron diseases and chronic pain conditions, such as complex regional pain syndrome, through silencing of the genes responsible for pathologies in the spinal cord and dorsal root ganglia.
Human gene therapy methods. 05/2012; 23(2):119-27.
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ABSTRACT: Flap necrosis remains a major complication of reconstructive surgery. To improve skin flap survival, various treatments with vasodilators, antiplatelet drugs, or the local administration of growth factors have been performed. However, the sufficient prevention of skin necrosis is not well established. Platelet-rich plasma has been used as an autologous factor and includes various growth factors. The authors evaluated whether or not platelet-rich plasma can improve skin flap survival in an experimental rat model.
Cranially based dorsal cutaneous flaps were elevated in 48 rats. The animals received subcutaneous injections of either platelet-rich plasma (100 μl) or platelet-poor plasma (100 μl). The rats were divided into three groups: the platelet-rich plasma group (n = 16), the platelet-poor plasma group (n = 16), and the nontreatment group (n = 16). Flap survival was measured and histologic specimens were collected on day 7. Real-time polymerase chain reaction specimens were collected after 8 hours, 24 hours, 3 days, and 7 days.
Platelet-rich plasma significantly improved flap survival rates (61.2 percent) compared with the platelet-poor plasma treatment (35.8 percent) and nontreatment groups (28.0 percent). A histologic analysis showed that significantly fewer inflammatory cells and an increased blood vessel density were observed in the platelet-rich plasma rats versus the platelet-poor plasma or nontreatment rats. In addition, platelet-rich plasma treatment significantly increased the mRNA levels of vascular endothelial growth factor and platelet-derived growth factor.
Platelet-rich plasma modulates the genes involved in angiogenesis and improves skin flap survival.
Plastic and reconstructive surgery 04/2012; 129(4):858-66. · 2.74 Impact Factor
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Tsuyoshi Yamada,
Toshitaka Yoshii, Shinichi Sotome,
Masato Yuasa,
Tsuyoshi Kato,
Yoshiyasu Arai,
Shigenori Kawabata,
Shoji Tomizawa,
Kyohei Sakaki,
Takashi Hirai,
Kenichi Shinomiya,
Atsushi Okawa
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ABSTRACT: A prospective, comparative study.
We developed a hybrid graft (HBG) of porous β-tricalcium phosphate ceramics/percutaneously harvested bone sticks/autologous bone marrow aspirate for lumbar posterolateral fusion (PLF). The aim of this study was to investigate the efficacy of the HBG as a substitute for conventional corticocancellous iliac autografts.
Iliac crest bone graft (ICBG) has been traditionally used as the golden standard for lumbar spinal fusion. The significant complication rate associated with harvesting corticocancellous ICBG, however, has encouraged development of alternative graft substitutes.
From September 2005, 61 consecutive patients underwent decompressive laminotomy and 1-level instrumented PLF. Each patient in this study had the constructs of the HBG placed on 1 side of the intertransverse process gutter. An autologous local bone graft (LBG) harvested during decompressive laminotomy was placed on the other side as a control. Radiographic evaluation was performed at 6 months, 1 year after surgery, and subsequently on an annual basis. The fusion statuses on either side of vertebra were compared.
The flexion-extension motion in the dynamic x-rays at the target level decreased over time. Only 1 case exhibited over 5° of angular motion 2 years after surgery. In the evaluation of fusion status, the fusion rate for the HBG side (68.9% at 6 months, 83.6% at 1 year, 93.5% at 2 years) was higher than that for the LBG side (49.2% at 6 months, 75.4% at 1 year, 89.1% at 2 years) with a significant difference at 6 months after surgery. No significant complications at the donor site were found postoperatively.
The HBG promoted posterolateral spinal fusion without significant donor site morbidity. Because of its efficacy and safety, this hybrid construct seems promising as an alternative to conventional iliac bone grafts for lumbar spinal fusion.
Spine 06/2011; 37(3):E174-9. · 2.08 Impact Factor
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04/2011; , ISBN: 978-953-307-165-7
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ABSTRACT: Neutrotrophin-3 (NT3) plays a protective role in injured central nervous system tissues through interaction with trk receptors. To enhance the regeneration of damaged tissue, a combination therapy with cell transplantation and neurotrophins has been under development. We examined whether the transplantation of neural progenitor cells (NPCs) secreting NT3/D15A, a multi-neurotrophin with the capacity to bind both trkB and trkC, would enhance the repair of damaged tissues and the functional recovery in a chronic phase of spinal cord injury. The cultured NPCs with lentiviral vector containing either GFP or NT3/D15A were transplanted into the contused spinal cord at 6 weeks after the initial thoracic injury. Eight weeks after the transplantation, the NT3/D15A transplants displayed better survival than the GFP transplants, and they exhibited enhanced myelin formation and partial improvement of hindlimb function. Our study revealed that NT3/D15A produced positive effects in injured spinal cords even in the chronic phase. These effects suggest an enhanced neurotrophin-trk signaling by NT3/D15A.
Biochemical and Biophysical Research Communications 02/2010; 393(4):812-7. · 2.48 Impact Factor
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Hidetsugu Maehara, Shinichi Sotome,
Toshitaka Yoshii,
Ichiro Torigoe,
Yuichi Kawasaki,
Yumi Sugata,
Masato Yuasa,
Masahiro Hirano,
Naomi Mochizuki,
Masanori Kikuchi,
Kenichi Shinomiya,
Atsushi Okawa
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ABSTRACT: Articular cartilage has a limited capacity for self-renewal. This article reports the development of a porous hydroxyapatite/collagen (HAp/Col) scaffold as a bone void filler and a vehicle for drug administration. The scaffold consists of HAp nanocrystals and type I atelocollagen. The purpose of this study was to investigate the efficacy of porous HAp/Col impregnated with FGF-2 to repair large osteochondral defects in a rabbit model. Ninety-six cylindrical osteochondral defects 5 mm in diameter and 5 mm in depth were created in the femoral trochlear groove of the right knee. Animals were assigned to one of four treatment groups: porous HAp/Col impregnated with 50 microl of FGF-2 at a concentration of 10 or 100 microg/ml (FGF10 or FGF100 group); porous HAp/Col with 50 microl of PBS (HAp/Col group); and no implantation (defect group). The defect areas were examined grossly and histologically. Subchondral bone regeneration was quantified 3, 6, 12, and 24 weeks after surgery. Abundant bone formation was observed in the HAp/Col implanted groups as compared to the defect group. The FGF10 group displayed not only the most abundant bone regeneration but also the most satisfactory cartilage regeneration, with cartilage presenting a hyaline-like appearance. These findings suggest that porous HAp/Col with FGF-2 augments the cartilage repair process.
Journal of Orthopaedic Research 11/2009; 28(5):677-86. · 2.81 Impact Factor
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ABSTRACT: In this study, the effects of gamma-ray irradiation on the mechanical properties, absorbability, and osteoconductivity of porous hydroxyapatite/collagen (HAp/Col) were investigated. Porous HAp/Col was exposed to 16, 25, 35, or 50 kGy of gamma-ray irradiation. The compressive elastic modulus showed irradiation dose-dependence, with a particularly pronounced decrease in the 50-kGy treatment group. An in vitro enzymatic digestion test showed that gamma-ray irradiation of porous HAp/Col resulted in accelerated degradation by collagenase. For in vivo studies, porous HAp/Col was transplanted into the back muscles or bone defects in the femoral condyle of rats. Specimens were obtained at 2, 4, and 8 weeks postoperatively. Absorption of the implants in the muscle was time- and irradiation dose-dependent, with notable absorption for the 35- and 50-kGy groups at 2 weeks. At the skeletal sites, porous HAp/Col demonstrated high osteoconductivity in all irradiation treatment groups. Interestingly, not only implant absorption but also bone formation was irradiation dose-dependent at early time points.
Journal of Biomedical Materials Research Part B Applied Biomaterials 10/2009; 92(1):161-7. · 2.15 Impact Factor
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ABSTRACT: Trabecular bone fragments can be percutaneously harvested from the ilium using methods that are similar in invasiveness to aspiration of bone marrow. In this study, we investigated the use of the trabecular bone as a cell source for bone tissue engineering. Trabecular bone-derived progenitor cells (TB cells) were isolated with a simple method in which trabecular fragments were first cultured as explants, and then the cells were released by trypsin digestion and advanced to a monolayer culture. The properties of TB cells prepared in this procedure were compared with bone marrow-derived progenitor cells (BM cells). A large number of TB cells could be obtained with less variation among donors, compared with BM cells. In multiple harvests of donor tissue through the same aspiration hole at the cortex, TB cells could be more consistently obtained in primary culture. The proliferative potential of BM and TB cells was similar in serial subculture. TB cells showed a higher alkaline phosphatase expression in the surface marker analysis and greater in vitro osteogenic abilities than BM cells after the initial 14 days of culture. In in vivo bone formation studies, TB cells also showed a higher osteogenic potential than BM cells. The results of this study suggest that TB cells can be considered an attractive source for clinical bone regeneration.
Tissue Engineering Part A 10/2009; 16(3):933-42. · 4.64 Impact Factor
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ABSTRACT: To potentiate the bone formation capability of bone marrow stromal cell (BMSC)/beta-tricalcium phosphate (beta-TCP) constructs, we devised an autologous plasma-based construct. We tested its effectiveness and investigated the effects of its components on a monkey ectopic bone formation model. The autologous plasma (platelet-rich plasma, PRP, or platelet-poor plasma, PPP)/BMSC/beta-TCP construct (R group or P group) showed significantly more bone formation at 3 and 6 weeks after implantation than a conventional BMSC/beta-TCP construct using a culture medium (M group). There was no significant difference between the P and R groups. Moreover, the P group constructs with a 10-fold lower cell concentration yielded equivalent bone formation to the M group at 5 weeks after implantation. To elucidate the effect of fibrin and serum contained in the plasma, five constructs were prepared using the following cell vehicles: autologous serum + fibrinogen (0, 1, 4, or 16 mg/mL) or phosphate-buffered saline + fibrinogen (4 mg/mL). The serum + fibrinogen (4 mg/mL, physiological concentration of monkeys) construct showed the most abundant bone formation at 3 weeks after implantation, though at 5 weeks no statistical difference existed among the groups. Autologous plasma efficiently promoted osteogenesis of BMSCs/porous beta-TCP constructs, and both fibrin and serum proved to play significant roles in the mechanism.
Tissue Engineering Part A 03/2009; 15(7):1489-99. · 4.64 Impact Factor
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ABSTRACT: Recent advances in tissue engineering techniques have allowed porous biomaterials to be combined with osteogenic cells for effective bone regeneration. We developed a simple low-pressure cell-loading method using only syringes and stopcocks, and examined the effect of this method on osteogenesis when applied to the combination of highly porous beta-tricalcium phosphate (beta-TCP) and fresh autologous bone marrow. Both block and granule beta-TCP scaffolds were used to prepare implants in three different ways: without bone marrow as a control, with bone marrow that was allowed to penetrate spontaneously under atmospheric pressure (AP group), and with bone marrow that was seeded under low pressure (ULP group). These implants were transplanted into rabbit intramuscular sites, and the samples were examined biologically and histologically. The penetration efficiency of the block implants after marrow introduction was significantly higher in the ULP group than in the AP group. In the transplanted block samples, alkaline phosphatase activity was significantly higher in the ULP group at 2 weeks after implantation, and significantly more newly formed bone was observed in the ULP group at both 5 and 10 weeks compared with the AP group. Similar results were observed even in the experiment using beta-TCP granules, which are smaller than the blocks and frequently used clinically. Because of its convenience and safety, this low-pressure method might be a novel, effective treatment to promote osteogenesis with bone marrow in clinical bone reconstruction surgeries.
Journal of Orthopaedic Research 01/2009; 27(1):1-7. · 2.81 Impact Factor
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ABSTRACT: A porous hydroxyapatite/collagen composite (HAp/Col) was developed that consists of hydroxyapatite nanocrystals and atelocollagen. In this study, cylindrical (diameter: 5 mm, height: 3 mm) porous HAp/Col implants with different pore sizes (diameter: 160 or 290 microm) were prepared, and the influences of pore size and implanted volume were evaluated using a rabbit bone defect model. In the implant groups, one or three (diameter: 5 mm, total height: 9 mm) implants were transplanted into bone holes created in the anteromedial site of the proximal tibiae, while a group without implantation was used as a control. Histological observation revealed that at two weeks after implantation, bone formation was initiated not only from the periosteum but in regions where the implants bordered on bone marrow. At four weeks, bone formation expanded from the marrow cavity side into the center of the implants, particularly in those implants with large pores. At twelve weeks, four implant groups showed repair of cortical defects and implant absorption, which was thought to be the result of natural bone remodeling mechanisms. The control group showed bone formation developed from the periosteum without bone induction in the marrow cavity, and at four weeks, the bone hole was almost healed. pQCT analysis revealed that the expansion rates of bone tissue were higher in the large-pore implant groups than in the small-pore groups. These data demonstrate the osteoconductivity of porous HAp/Col and the importance of its porous structure.
Journal of medical and dental sciences 03/2008; 55(1):91-9.
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ABSTRACT: Neural progenitor cells (NPCs) and bone marrow stromal cells (BMSCs), both of which can differentiate into neural phenotypes, are important candidates for transplantation therapy in the central nervous system (CNS). In most cases of BMSC transplantation, functional recovery is recognized even if few transplanted cells survive in the host tissue. A reason for this may be that transplanted cells produce neurotrophic factors (NFs), which enhance neuronal survival and neurite outgrowth after CNS injury. To provide additional insight into cell therapy, we investigated the types of NFs and receptors that are expressed in NPCs and BMSCs in vitro. Both cells expressed the mRNA of nerve growth factor (NGF), cilliary neurotrophic factor (CNTF), glial cell line-derived neurotrophic factor (GDNF), and their receptors in the proliferative state. Real-time PCR analysis showed that mRNA expression of GDNF was relatively low in NPCs although its receptor was highly expressed. We thus tested if the overexpression of GDNF in NPCs affected neural differentiation without FGF-2. The overexpression of GDNF did not affect mRNA expression of beta-III tubulin and neuron specific enolase (NSE), but both GDNF and GFRalpha1 overexpression increased the expression of neuronal markers. These results suggest that augmentation of both GDNF and GFRalpha1 could have positive effects during neural tissue repair.
Journal of medical and dental sciences 03/2008; 55(1):121-8.
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ABSTRACT: Bone marrow stromal cells (MSCs) have multi-lineage differentiation capabilities and are focused on as a cell source for various cell therapies. To facilitate the availability of MSCs, cryopreservation technique is one of the critical factors for the cell therapies. In this study, effects of cryopreservation on capabilities of MSCs derived from a nonhuman primate were tested, aimed at a clinical application for tissue-engineered bone reconstruction. Effects of cryopreservation on the MSCs' adhesion rate, proliferation, and osteogenic differentiation in vitro were compared with non-cryopreserved MSCs. Bone formation capabilities were also tested using an extraskeletal bone induction model. The bone formation inducted by the combination of cryopreserved MSCs and an artificial bone scaffold was confirmed in all cases. The amount of bone formation at each case was irregular, but the results were suggested the possibility of cryopreserved MSCs on clinical use.
Journal of medical and dental sciences 03/2008; 55(1):137-43.
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ABSTRACT: Porous hydroxyapatite/collagen (HAp/Col) composite is a promising biomaterial and a scaffold for bone tissue engineering. The effect of fibril formation of Col in the porous composite on bioresorbability and mechanical strength was investigated. The fibril formation, in mixing a self-organized HAp/Col nanocomposite and sodium phosphate buffer at a neutral condition, occurred during incubation at 37 degrees C, resulting in gelation of the mixture. The porous composites with and without the incubation were obtained by freeze-drying technique, in which macroscopic open pores were formed. The compressive strength of the porous composite with the incubation (34.1 +/- 1.6 kPa) was significantly higher than that without the incubation (28.0 +/- 3.3 kPa) due to the fibril formation of Col. The implantations of the porous composites treated with a dehydrothermal treatment in bone holes revealed that bioresorption was clearly depended on the fibril formation. The bioresorbability in vivo was almost matched to the in vitro test using enzymatic reaction of collagenase.
Journal of Materials Science Materials in Medicine 12/2007; 18(11):2179-83. · 2.32 Impact Factor
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ABSTRACT: Human bone marrow-derived mesenchymal cells (hBMMCs) originate from cell populations in the bone marrow and are capable of differentiating along multiple mesenchymal lineages. To differentiate hBMMCs into osteoblasts, adipocytes and chondrocytes, dexamethasone has been used as a differentiation reagent. We hypothesized that dexamethasone would augment the responsiveness of BMMCs to other differentiation reagents and not define the lineage. This study investigated the effect of continuous treatment with 100 nM dexamethasone on the differentiation of BMMCs into three different lineages. hBMMCs cultured with continuous dexamethasone treatment (100 nM) exhibited higher mRNA expression levels of osteogenic markers and higher positive rates of colony forming unit assays for osteogenesis compared to hBMMCs treated with dexamethasone only during the differentiation culture. Furthermore, continuous dexamethasone treatment augmented bone formation capability of monkey-derived BMMCs in a bone induction experimental model at an extra skeletal site. In addition, continuously dexamethasone-treated hBMMCs formed larger chondrogenic pellets and expressed SOX9 at higher level than the control BMMCs. Likewise, continuous dexamethasone treatment facilitated adipogenic differentiation based on mRNA level and colony forming unit analysis. To investigate the mechanism of the augmentation of differentiation, further studies on apoptosis were conducted. The studies indicated that dexamethasone selectively induced apoptosis of some populations of hBMMCs which were thought to have poor differentiation capability.
Bone 11/2007; 41(4):575-83. · 4.02 Impact Factor
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ABSTRACT: A three-dimensional porous hydroxyapatite/collagen (HAp/Col) composite with a random pore structure was fabricated using freeze-drying processes; the self-organized HAp/Col nanocomposite with a weight ratio of 80.5:19.5, freeze-dried, was kneaded in 100 mM sodium phosphate buffer, frozen at -20 degrees C and freeze-dried. The cross-linkage of Col molecules was introduced dehydrothermally at 140 degrees C in vacuo. The porous composite had a porosity of 94.7% with pore sizes between 200 and 500 microm. The compressive stress for the wet porous composite in phosphate buffer saline (PBS) was gradually decreased during 20 days incubation with a small amount of weight loss. The cyclic and time-course compression tests showed good repeatability of stress and well-recovery of its height, and caused no collapse of the porous composite. The implantation of the porous composite in rat bone holes showed the biodegradable property and new bone formation occurred in the pores without inflammatory response. The porous composite fabricated has good flexibility and rubber-like elasticity, and is a promising bone regenerative material.
Journal of Biomaterials Science Polymer Edition 02/2007; 18(4):393-409. · 1.69 Impact Factor
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ABSTRACT: This study investigated the effects of the three-dimensional (3-D) pore structure of a porous hydroxyapatite/collagen (HAp/Col) composite on their mechanical properties and in vivo tissue ingrowth. The unique 3-D pore structure, comprising unidirectionally interconnected pores, was fabricated by the unidirectional growth of ice crystals by using a cooling stage and a subsequent freeze-drying process. The unidirectional pores had a spindle-shaped cross section, and their size gradually increased from the bottom to the upper face. The porous composite showed an elastic property and anisotropic compressive strength for the pore directions. While the strength and modulus parallel to the pore axis were 1.3- and twofold higher than those of the porous composite with spherical pores formed randomly, the strength and modulus perpendicular to the pore axis showed the lowest values. The subcutaneous implantations revealed that when compared with the random pores, the unidirectional pores promote the ingrowth of the surrounding tissues into the pores.
Journal of Biomedical Materials Research Part B Applied Biomaterials 02/2007; 80(1):166-73. · 2.15 Impact Factor
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ABSTRACT: The efficient seeding of cells into porous scaffolds is important in bone tissue engineering techniques. To enhance efficiency, we modified the previously reported cell seeding techniques using low-pressure conditions. In this study, the effects of low pressure on bone marrow-derived stromal cells (BMSCs) of rats and the usefulness of the modified technique were assessed. There was no significant difference found in the proliferative and osteogenic capabilities among various low-pressure (50-760 mmHg, 1-10 min) conditions. To analyze the efficacies of the cell seeding techniques, BMSCs suspended in the plasma of rats were seeded into porous beta-tricalcium phosphate (beta-TCP) blocks by the following three procedures: 1) spontaneous penetration of cell suspension under atmospheric pressure (SP); 2) spontaneous penetration and subsequent low pressure treatment (SPSL), the conventional technique; and 3) spontaneous penetration under low pressure conditions (SPUL), the modified technique. Subsequently, these BMSCs/beta-TCP composites were used for the analysis of cell seeding efficiency or in vivo bone formation capability. Both the number of BMSCs seeded into beta-TCP blocks and the amount of bone formation of the SPUL group were significantly higher than those of the other groups. The SPUL method with a simple technique permits high cell seeding efficiency and is useful for bone tissue engineering using BMSCs and porous scaffolds.
Cell Transplantation 02/2007; 16(7):729-39. · 5.13 Impact Factor
