Biocompatibility of osteogenic predifferentiated human cord blood stem cells with biomaterials and the influence of the biomaterial on the process of differentiation.

Modern cell-based bone reconstruction therapies offer new therapeutic opportunities and tissue engineering represents a more biological-oriented approach to heal bone defects of the skeleton. Human unrestricted somatic stem cells (USSCs) derived form umbilical cord blood offer new promising aspects e.g., can differentiate into osteogenetic cells. Furthermore these cells have fewer ethical and legal restrictions compared to embryonic stem cells (ESCs). The purpose of this study was to evaluate the compatibility of osteogenic pre-differentiated USSCs with various biomaterials and to address the question, whether biomaterials influence the process of differentiation of the USSCs. After osteogenic differentiation with DAG USSCs were cultivated with various biomaterials. To asses the biocompatibility of USSCs the attachment and the proliferation of the cells on the biomaterial were measured by a CyQUANT(®) assay, the morphology was analyzed by scanning electron microscopy and the influence of the gene expression was analyzed by real time PCR. Our results provide evidence that insoluble collagenous bone matrix followed by β-tricalciumphosphate is highly suitable for bone tissue engineering regarding cell attachment and proliferation. The gene expression analysis indicates that biomaterials influence the gene expression of USSCs. These results are in concordance with our previous study with ESCs.