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2015
Journal Article
Titel
Pre-vascularized bone implant composed of cell-seeded naturally derived collagen matrix and synthetic ß-TCP
Abstract
Bone regeneration is a major challenge regarding defects that exceed a critical size. The current standard of autologous bone transplantation faces problems as donor site morbidity or limited availability of transplantable bone. Methods of tissue engineering present an alternative to established procedures by in vitro assembly of bone implants that can be equipped with vascular structures for enhanced regeneration potential. The present studies' bone implants consist of synthetic ß-TCP granules with osteoconductive properties and a naturally derived collagen matrix (BioVaSc) that provides vascular structures. The BioVaSc is a de-cellularized porcine jejunum that can be reseeded with endothelial cells in order to re-establish the function of its inherent vessels. After re-endotheliaziation in a bioreactor system, the tubular-shaped BioVaSc was filled with ß-TCP granules which were seeded with osteoblasts or mesenchymal progenitor cells. The combination of BioVaSc and ß-TCP granules results in a construct that presents characteristics that favor fast bone formation by introducing cells with osteogenic potential on a material with osteoconductive properties as well as a matrix that provides nutritional support for the resident cells via its vascular structures that can be connected to a host's circulatory system. The regenerative potential of the implant was assessed in a tibia defects as well as in defects in the mandible in sheep. This study describes the in vitro construction of cell-seeded bone substitutes with pre-vascularization via bioreactor technology. Additionally, it gives an insight into the regenerative potential of the bone substitute and illustrates the feasibility of the anastomosis of such an implant.