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1.
J Biomed Mater Res A ; 94(3): 800-5, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20336748

RESUMO

Recently, the possibility of tooth tissue engineering has been reported. Although there are a number of available materials, information about scaffolds for tooth tissue engineering is still limited. To improve the manageability of tooth tissue engineering, the effect of scaffolds on in vivo tooth regeneration was evaluated. Collagen and fibrin were selected for this study based on the biocompatibility to dental papilla-derived cells and the results were compared with those of polyglycolic acid (PGA) fiber and beta-tricalcium phosphate (beta-TCP) porous block, which are commonly used for tooth, dentin and bone tissue engineering. Isolated porcine tooth germ-derived cells were seeded onto one of those scaffolds and transplanted to the back of nude mice. Tooth bud-like structures were observed more frequently in collagen and fibrin gels than on PGA or beta-TCP, while the amount of hard tissue formation was less. The results showed that collagen and fibrin gel support the initial regeneration process of tooth buds possibly due to their ability to support the growth of epithelial and mesenchymal cells. On the other hand, maturation of tooth buds was difficult in fibrin and collagen gels, which may require other factors.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Dente/fisiologia , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Transplante de Células , Camundongos , Camundongos Nus , Regeneração/fisiologia , Suínos , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos
2.
J Biomed Mater Res A ; 90(3): 730-41, 2009 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18570318

RESUMO

For successful tissue engineering, neovascularization of the implanted tissue is critical. Factors generated by endothelial cells are also considered crucial for the process of osteogenesis. The direct effects of supplementing tissue engineered constructs with cultured endothelial progenitor cells (EPCs) for enhancing bone regeneration have not been reported. In this study, we investigated the potential of EPCs to facilitate neovascularization in implants and evaluated their influence on bone regeneration. The influence of EPC soluble factors on osteogenic differentiation of mesenchymal stem cells (MSCs) was tested by adding EPC culture supernatant to MSC culture medium. To evaluate the influence of EPCs on MSC osteogenesis, canine MSCs-derived osteogenic cells and EPCs were seeded independently onto collagen fiber mesh scaffolds and co-transplanted to nude mice subcutaneously. Results from coimplant experiments were compared to implanted cells absent of EPCs 12 weeks after implantation. Factors from the culture supernatant of EPCs did not influence MSC differentiation. Coimplanted EPCs increased neovascularization and the capillary score was 1.6-fold higher as compared to the MSC only group (p < 0.05). Bone area was also greater in the MSC + EPC group (p < 0.05) and the bone thickness was 1.3-fold greater in the MSC + EPC group than the MSC only group (p < 0.05). These results suggest that soluble factors generated by EPCs may not facilitate the osteogenic differentiation of MSCs; however, newly formed vasculature may enhance regeneration of tissue-engineered bone.


Assuntos
Células Endoteliais/transplante , Transplante de Células-Tronco Mesenquimais/métodos , Neovascularização Fisiológica , Osteogênese , Animais , Regeneração Óssea , Diferenciação Celular , Cães , Células-Tronco Mesenquimais , Camundongos , Camundongos Nus , Transplante de Células-Tronco , Células-Tronco , Engenharia Tecidual/métodos
3.
Clin Oral Implants Res ; 19(3): 289-94, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18081869

RESUMO

OBJECTIVES: This study aimed to demonstrate the feasibility of a cultured periosteum (CP) membrane for use in guided bone regeneration at sites of implant dehiscence. MATERIAL AND METHODS: Four healthy beagle dogs were used in this study. Implant dehiscence defects (4 x 4 x 3 mm) were surgically created at mandibular premolar sites where premolars had been extracted 3 months back. Dental implants (3.75 mm in diameter and 7 mm in length) with machined surfaces were placed into the defect sites (14 implants in total). Each dehiscence defective implant was randomly assigned to one of the following two groups: (1) PRP gel without cells (control) or (2) a periosteum membrane cultured on PRP gel (experimental). Dogs were killed 12 weeks after operation and nondecalcified histological sections were made for histomorphometric analyses including percent linear bone fill (LF) and bone-to-implant contact (BIC). RESULTS: Bone regeneration in the treatment group with a CP membrane was significantly greater than that in the control group and was confirmed by LF analysis. LF values in the experimental and the control groups were 72.36+/-3.14% and 37.03+/-4.63%, respectively (P<0.05). The BIC values in both groups were not significantly different from each other. The BIC values in the experimental and the control groups were 40.76+/-10.30% and 30.58+/-9.69%, respectively (P=0.25) and were similar to native bone. CONCLUSION: This study demonstrated the feasibility of a CP membrane to regenerate bone at implant dehiscence defect.


Assuntos
Regeneração Óssea , Implantação Dentária Endóssea/efeitos adversos , Regeneração Tecidual Guiada Periodontal/métodos , Membranas Artificiais , Periósteo , Deiscência da Ferida Operatória/terapia , Animais , Implantes Dentários , Cães , Estudos de Viabilidade , Feminino , Implantes Experimentais , Plasma Rico em Plaquetas , Distribuição Aleatória , Deiscência da Ferida Operatória/etiologia , Técnicas de Cultura de Tecidos
4.
Cryobiology ; 52(2): 182-92, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16360651

RESUMO

Evidence has accumulated that periosteal cells have a great potential to regenerate bone. We have demonstrated that cultured periosteum (CP) in membrane form is an effective device to regenerate alveolar bone. To increase the availability of CP in a clinical environment, an effective cryopreservation protocol for CP has been developed. In this study, three different cryoprotectants (Me(2)SO, glycerol, and ethylene glycol) were used. The effect on cell viability of pre-incubation temperature, pre-incubation time, and agitation during incubation was investigated. Samples were stored at -196 degrees C for 10 days. Cell viability was assessed by a colorimetric cell viability assay using a tetrazolium salt, and the assay results were confirmed by confocal laser scanning microscopy after staining with a combination of calcein AM and ethidium homodimer-1. The activity of the cells after thawing was assessed by alkaline phosphatase assay. To assess the osteogenic potential of cryopreserved CP, the CP was grafted to calvarial defects in athymic rats. The greatest cell viability was obtained in the group equilibrated at 37 degrees C for 30 min with Me(2)SO, under agitation, showing 63.3 +/- 10.5% recovery. After cryopreservation, the cell growth of surviving cells was identical when Me(2)SO was used as a cryoprotectant. Alkaline phosphatase (ALP) activity was maintained in the groups cryopreserved with Me(2)SO and glycerol. The transplantation experiment showed that the calvarial defects were completely closed by grafting cryopreserved CP, which demonstrates that the osteogenic property of CP was well maintained. An efficient cryopreservation protocol for CP has been developed and this will provide a convenient and effective treatment option for bone regeneration in clinics.


Assuntos
Técnicas de Cultura de Células/métodos , Criopreservação , Crioprotetores/farmacologia , Preservação de Órgãos , Osteogênese , Periósteo , Fosfatase Alcalina/metabolismo , Animais , Regeneração Óssea , Bovinos , Proliferação de Células , Sobrevivência Celular , Fluoresceínas/metabolismo , Microscopia Confocal , Periósteo/citologia
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