Tissue-Engineered Interlocking Scaffold Blocks for the Regeneration of Bone

The duration of time over which bone growth is initiated in large bone defects using tissue-engineered scaffolds is still too long to be of practical relevance. Here, we report a unique design of mechanically stable interlocking blocks wherein the large defect shape is filled using interlocking scaffold blocks coated with bone morphogenic proteins (BMP-2 and BMP-7). The nanocomposite scaffold blocks are made using polycaprolactone and amino acid-modified nanoclays intercalated with mineralized hydroxyapatite. On seeding with human mesenchymal stem cells and osteoblasts, BMP-coated scaffolds showed higher ECM formation. Also, when assembled, accelerated tissue growth was observed compared with the similar-sized scaffold. Enhanced osteogenic differentiation of MSCs was observed at the interfaces between the blocks as well as the formation of defined fibril-like collagen. The block assembly does not compromise the mechanical integrity of a single cylindrical scaffold. Thus, here a novel BMP-coated interlocking blocks system is presented for accelerated bone growth.