Engineering a Replacement Bone Tissue with Adult Adipose-derived Stem Cells

by Holly E. Weiss The current gold standard for bone repair, autologous bone graft, is inherently costly and destructive to the site from which the tissue is harvested. Moreover, the amount of available donor tissue is limited, so it is not always a viable option. The aim of this work was to investigate tissue engineering as an alternative to autograft-based bone repair through the combination of donor cells and three-dimensional cell carriers. Constructs were designed to stimulate either intramembranous or endochondral bone formation upon implantation in vivo, and subsequent tissue analysis was driven by the desire to improve the understanding of qualities necessary for a successful engineered bone replacement. To evaluate the intramembranous bone forming capacity of human adipose-derived stem cells, novel collagen scaffolds with or without hydroxyapatite reinforcement were loaded with cells and treated with growth or an osteogenic differentiation medium. Upon implantation, the cell-scaffold constructs produced varying amounts of immature bone characterized by highly vascularized osteocalcin and osteopontin-positive matrix and an increase in mineralized tissue