Tissue Engineering mit mesenchymalen Stammzellen zur Knorpel- und Knochenneubildung

Abstract

Tissue engineering offers the possibility to fabricate living substitutes for tissues and organs by combining histogenic cells and biocompatible carrier materials. Pluripotent mesenchymal stem cells are isolated and subcultured ex vivo and then their histogenic differentiation is induced by external factors. The fabrication of bone and cartilage constructs, their combinations and gene therapeutic approaches are demonstrated. Advantages and disadvantages of these methods are described by in vitro and in vitro testing. The proof of histotypical function after implantation in vivo is essential. The use of autologous cells and tissue engineering methods offers the possibility to overcome the disadvantages of classical tissue reconstruction--donor site morbidity of autologous grafts, immunogenicity of allogenic grafts and loosening of alloplastic implants. Furthermore, tissue engineering widens the spectrum of surgical indications in bone and cartilage reconstruction.

Joint Preserving Surgery for Osteonecrosis and Osteochondral Defects after Chemotherapy in Childhood

“…We used additional bone marrow aspirates combined with bone grafting in 3 cases to achieve a maximum of cell potential within the area to be regenerated. Different authors reported on the possible use of progenitor cells from different tissues like bone marrow and periosteum with or without scaffolds for bone and cartilage repair [1,2,7,13,17,28,34]. Although there are no clinical trials with a longer follow up, the high potential of these cellbased strategies is evident.…”

Vorteile von Biomatrices bei der Chondrogenese von pluripotenten mesenchymalen Stammzellen

“…Chondrozyten, welche aus hMSC gewonnen werden, dedifferenzieren in vitro zunehmend zu fibroblastischen Zellen. Diese morphologische Veränderung geht mit einem Switch der Kollagensynthese von Typ II zu Typ I einher [68]. Dieses Phänomen ist unter anderem für die gegenwärtig bevorzugte Verwendung von bereits ausdifferenzierten Chondrozyten für die Zelltherapie (autologe Chondrozytentransplantation) mitverantwortlich.…”

Utilization of a genetically modified muscle flap for local BMP-2 production and its effects on bone healing: a histomorphometric and radiological study in a rat model

“…Limitations of this approach, however, include 1) high cost and 2) need for repeated applications secondary to the short half-life of the protein. Other experimental therapies include the development of injectable biological bone substitutes as well as exposure of human mesenchymal stem cells to BMP-2 ex vivo , thus, inducing their osteoblastic differentiation [ 7 , 8 ]. Transduction of target cells with a replication-deficient adenovirus, designed to carry cDNA encoding for BMP-2, represents a novel approach for local delivery of BMP-2 to the region of interest.…”

“…The concept of using genetically altered soft tissue flaps as biologic pumps has been demonstrated by Liu et al and Michaels et al in a rat model [ 13 - 15 ]. The present study represents the first attempt of assessing whether muscle flaps can be altered genetically so as to not only provide soft tissue coverage but also enhance osseous healing by local production of growth factors, as muscle tissue is known to possess an ample quantity of mesenchymal stem cells capable of osteoblastic differentiation [ 8 ]. Furthermore, BMP-2 has an angiogenetic potential, which could aid in facilitating the healing process [ 16 ].…”