Our designed BioBricks containing the gene for the mature region of mouse Bone Morphogenetic Protein 2 (BMP2) all possess a level of risk. As a mammalian biochemical agent, it is known to elicit a wide variety of biological effect on human tissue organs, of which the most well known are bone and cardiac cell differentiation induction. However, as a defining member of the Transforming Growth Factor Beta (TGF-β) pathway, it also plays important roles in cell proliferation. Thus, induction of excess (or otherwise external) BMP2 may lead to undesirable tissue behavior in mammalian systems.

Documented adverse effects of recombinant human BMP2 used in spinal fusion therapy include cyst-like bony formations and soft swelling with hematomas. Further research using mice with spine defects as test subjects indicates that occurrence and severity of said adverse effects increases with BMP2 dosage. Though we have selected BMP2 for its documented properties of retarding the growth of and induction of cell death in colon carcinoma cells, BMP2 receptor transcription has been found up-regulated in other cancer cell types, including pancreatic cancer. Thus, confined delivery of the chemokine becomes critical.