Use of 3-dimensional environments to engineer osseous-like tissue

Abstract

We have previously reported enhanced aggregate formation and accelerated mineralization of human mesenchymal preosteoblastic cells (HEPM) when cultured without scaffolds in 3D-rotary wall vessel chambers. From those studies we hypothesized that, rotary wall vessel environments could be used to engineer osseous tissue. Thus, HEPM preosteoblastic cells were cultured in rotary wall vessels for up to 7 days. Progression of mineralization in 3D cultures was evident by 3 days as shown by micro-CT. A uniform ring of dense mineral on the outermost surface with an amorphous pattern of mineral within the aggregate was noted starting at 3 days. Interestingly, this expression of mineral correlated to the spatial-temporal expression of BMP2. By 7 days, when mineralization appeared complete, BMP2 expression was significantly reduced. Minimal BMP2 expression was noted in the control 2D osteoblast tissue cultures. EDAX analysis showed that, mineralization decreased significantly in aggregates treated with BMP2 antibody (p<0.0001). VEGF was found to be consistently expressed regardless of time in both 2D and 3D cultures. Our results suggest that osseous like tissues can be engineered in small volumes from preosteoblasts cultured 3-dimensionally in rotary wall vessels. These methods may someday translate clinically into use for engineering osseous like tissue for repair of small intraoral osseous defects. Key words: Tissue engineering, bone, mineralization, osteoblasts, osseointegration.