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Tissue-engineered Bone (tissue-engineered + bone)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Promotion of osteogenesis in tissue-engineered bone by pre-seeding endothelial progenitor cells-derived endothelial cells

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 8 2008
Haiying Yu
Abstract In addition to a biocompatible scaffold and an osteogenic cell population, tissue-engineered bone requires an appropriate vascular bed to overcome the obstacle of nutrient and oxygen transport in the 3D structure. We hypothesized that the addition of endothelial cells (ECs) may improve osteogenesis and prevent necrosis of engineered bone via effective neovascularization. Osteoblasts and ECs were differentiated from bone marrow of BALB/c mice, and their phenotypes were confirmed prior to implantation. Cylindrical porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffolds were synthesized. ECs were seeded on scaffolds followed by seeding of osteoblasts in the EC-OB group. In the OB group, scaffolds were only seeded with osteoblasts. The cell-free scaffolds were denoted as control group. A 0.4-cm-long segmental femur defect was established and replaced with the grafts. The grafts were evaluated histologically at 6 weeks postimplantation. In comparison with the OB group, the EC-OB group resulted in a widely distributed capillary network, osteoid generated by osteoblasts and absent ischemic necroses. Pre-seeding scaffold with ECs effectively promoted neovascularization in grafts, prevented the ischemic necrosis, and improved osteogenesis. The integration of bone marrow-derived ECs and osteoblasts in porous scaffold is a useful strategy to achieve engineered bone. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1147,1152, 2008 [source]

Early bone in-growth ability of alumina ceramic implants loaded with tissue-engineered bone

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2006
Yasuaki Tohma
Abstract To enhance early bonding of an alumina ceramic implant to bone, we evaluated a method of seeding the implant surface with bone marrow mesenchymal cells that differentiated to osteoblasts and bone matrix prior to implantation. The usefulness of the method was evaluated in Japanese white rabbits. In our study, an alumina ceramic test piece loaded with differentiated osteoblasts and bone matrix by a tissue engineering technique was implanted into rabbit bones. Three weeks after the procedure, evaluation of mechanical bonding and histological examination were performed. Histological examination of the noncell-loaded implant surfaces showed no bone infiltration into the implant gap. However, the cell-loaded implant surfaces exhibited new bone infiltration into the implant gap with mechanical bonding. In the mechanical test, the average failure load was 0.60 kgf for the noncell-loaded side and 1.49 kgf for the cell-loaded side. Preculturing mesenchymal cells on the surface of the alumina ceramic prior to implantation increased the debonding strength by two and half times. The present findings indicate early bonding between the implant and bone three weeks after the procedure. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]

Combining Scaffolds and Osteogenic Cells in Regenerative Bone Surgery: A Preliminary Histological Report in Human Maxillary Sinus Augmentation

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2009
Carlo Mangano DDS
ABSTRACT Purpose: The following case series evaluated the maxillary sinus augmentation responses to tissue-engineered bone graft obtained by a culture of autogenous osteoblasts seeded on polyglycolic,polylactic scaffolds and calcium phosphate. Materials and Methods: Sinus floor augmentation was performed bilaterally in five patients (mean age 58.4 years) with tissue-engineered bone (test site , Oral Bone®, BioTissue, Freiburg, Germany) or calcium phosphate (control site , Biocoral, Novaxa Spa, Milan, Italy). Biopsies were harvested 6 months after sinus augmentation for histometric evaluation. Volumetric measurements were taken at baseline and 6 months after the surgical procedure. Results: The mean of vertical bone gain was 6.47 ± 1.39 mm and 9.14 ± 1.19 mm to test and control sites, respectively. The histological sections depicted mature bone with compact and cancellous areas. All biopsies contained varying percentages of newly formed bone and marrow spaces. The mean of bone tissue in the grafted area was 37.32 ± 19.59% and 54.65 ± 21.17% for tissue-engineered bone and calcium phosphate, respectively. Conclusion: Within the limits of the present report, the histological data in humans confirmed that tissue-engineered bone and calcium phosphate allowed newly formed bone after maxillary sinus augmentation. [source]

Tissue-engineered injectable bone regeneration for osseointegrated dental implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2004
Yoichi Yamada
Abstract: The present study investigated a correlation between osseointegration in dental implants and an injectable tissue-engineered bone, using mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). Initially, the teeth in the mandible region were extracted and the healing period was 1 month. Bone defects on both sides of the mandible were prepared with a trephine bar. The defects were implanted with graft materials as follows: PRP, dog MSCs (dMSCs), and PRP, autogenous particulate cancellous bone and marrow (PCBM), and control (defect only). Two months later, the animals were evaluated by histology, and at the same time dental implants were installed. Two months later, the animals were sacrificed and nondecalcified sections were evaluated histologically and histometrically. According to the histological observations, the dMSCs/PRP group had well-formed mature bone and neovascularization, compared with the control (defect only) and PRP groups, as was the same for the PCBM group. A higher marginal bone level was observed around implants with PRP, PCBM, and dMSCs/PRP compared with the control. Furthermore, the values describing the amount of bone,implant contact (BIC) at the bone/implant interface were significantly different between the PRP, PCBM, dMSCs/PRP, and control groups. Significant differences were also found between the dMSCs/PRP and control groups in bone density. The findings of this experimental study indicate that the use of a mixture of dMSCs/PRP results in good results such as the amount of BIC and bone density comparable with that achieved by PCBM. Résumé L'étude présente a analysé une corrélation entre l'ostéïntégration d'implants dentaires et un os injectable traité en utilisant des cellules souches mésenchymateuses (MSC) et du plasma riche en plaquette (PRP). Initialement, les dents de la région mandibulaire ont été avulsées et la période de guérison a été d'un mois. Les lésions osseuses des deux côtés de la mandibule ont été préparées avec un trépan. Les lésions ont été traitées avec les matériaux de greffe suivants : PRP, MSC canin (dMSC) et PRP, moelle l'os spongieux en petites particules autogènes (PCBM) et contrôle (lésion seulement). Deux mois plus tard, les animaux ont étéévalués et en même temps les implants dentaires ont été placés. Deux mois plus tard, les animaux ont été euthanasiés et des coupes non-décalcifiées ont étéévaluées histologiquement et histométriquement. Suivant les observations histologiques, le groupe dMSC/PRP avait de l'os mûr bien formé et une néovascularisation comparé au contrôle et aux groupes PRP, comme pour le groupe PCBM. Un niveau osseux marginal plus important a été observé autour des implants avec PRP, PCBM et dMSC/PRP comparé au contrôle. De plus les valeurs décrivant la quantité de contact os/implant à l'interface os/implant étaient significativement différentes entre les groupes PRP, PCBM, dMSC/PRP et contrôles. Des différences significatives étaient aussi trouvées entre les groupes dMSC/PRP et contrôle en ce qui concernait la densité osseuse. Ces découvertes indiquent que l'utilisation d'un mélange dMSC/PRP résulte en de bons résultats tels que la quantité de contact os-implant et la densité osseuse comparéà ce qui se passe après l'utilisation du PCBM. Zusammenfassung Gewebemanipulierte injizierbare Knochenregenerate für osseointegrierte dentale Implantate Die vorliegende Studie untersuchte eine Korrelation zwischen der Osseointegration bei dentalen Implantaten und einem injizierbaren gewebemanipulierten Knochenregenerat aus mesenchymalen Stammzellen (MSCs) und plättchenreichem Plasma (PRP). Zuerst wurden die Zähne im Unterkiefer extrahiert. Darauf folgte eine Heilungsperiode von 1 Monat. Auf beiden Seiten der Unterkiefer wurden mit einer Hohlfräse Knochendefekte präpariert. Die Defekte wurden mit folgenden Transplantatmaterialien aufgefüllt: PRP, Hunde MSCs (dMSCs) und PRP, autologer zerkleinerter Knochen und Knochenmark (PCBM) und kein Füllmaterial (Kontrolle). Zwei Monate später wurden die Tiere histologisch untersucht und es wurden dentale Implantate eingesetzt. Nach weiteren zwei Monaten wurden die Tiere geopfert und nicht entkalkte Schnitte wurden histologisch und histometrisch ausgewertet. Gemäss der histologischen Beobachtungen zeigten die dMSCs/PRP Gruppe im Vergleich zur Kontrollgruppe und zur PRP Gruppe gut ausgebildeten reifen Knochen und neue Gefässe. Das Selbe galt für die PCBM Gruppe. Bei den Implantaten mit PRP, PCBM und dMSCs/PRP konnte im Vergleich zur Kontrollgruppe ein höheres marginales Knocheniveau beobachtet werden. Zudem waren die Werte, welche das Ausmass an Knochen-Implantat-Kontakt an der Kochen/Implantat Berührungsfläche beschreiben, zwischen den PRP, PCBM, dMSCs/PRP und der Kontrollgruppe signifikant verschieden. Signifikante Unterschiede wurden auch bezüglich Knochendichte zwischen der dMSCs/PRP und der Kontrollgruppe gefunden. Die Ergebnisse dieser experimentellen Studie zeigen, dass die Anwendung eines Gemisches aus dMSCs/PRP zu guten Resultaten bezüglich Ausmass an Knochen-Implantat-Kontakt und Knochendichte führt. Die erzielten Resultate sind mit den mit PCBM erreichten vergleichbar. Resumen El presente estudio investigó la correlación entre osteointegración en implantes dentales y un tejido-elaborado óseo inyectable, usando células madre mesenquimales (MSCs) y plasma rico en plaquetas (PRP). Inicialmente, se extrajeron los dientes de la mandíbula y el periodo de cicatrización fue de un mes. Se prepararon defectos óseos en ambos lados de la mandíbula con una fresa trépano. Los defectos se implantaron con material de injerto de la siguiente manera: PRP, MSCs de perro (dMSCs) y PRP, partículas de hueso esponjoso y médula autógenos (PCBM), y control (defecto solo). Dos meses mas tarde, los animales se evaluaron por histología, al mismo tiempo se instalaron implantes dentales. Dos meses mas tarde se sacrificaron los animales y se evaluaron secciones no descalcificadas histológica e histometricamente. De acuerdo con las observaciones histológicas, el grupo dMSCs/PRP había formado bien un hueso maduro y una neovascularización, comparado con el control (defecto solo) y grupos PRP, también fue igual para el grupo PCBM. Se observó un nivel óseo marginal mas alto alrededor de los implantes con PRP, PCBM, y dMSCs/PRP comparados con el control. Mas aun, los valores que describen la cantidad de contacto hueso-implante en la interfase hueso/implante fueron significativamente diferentes entre los grupos PRP, PCBM, dMSCs/PRP, y de control en la densidad ósea. Estos hallazgos de este estudio experimental indican que el uso de una mezcla de dMSCs/PRP resulta en buenos resultados tales como la cantidad de contacto hueso-implante y densidad ósea comparable a aquella lograda por PCBM. [source]