A new type of DNA-based artificial extracellular matrix permits the tuning of cellular morphology for tissue engineering, researchers at Harvard University report (J. Am. Chem. Soc., DOI: 10.1021/ja105431h). Faisal A. Aldaye, Pamela A. Silver, and coworkers constructed a hybrid DNA/protein matrix from a DNA ribbon decorated with a segment from human fibronectin, a protein involved in cell adhesion. They found that human cervical cancer cells efficiently attached to the hybrid matrix but not to control matrices made with only the DNA or the protein segments. In addition, cells adhered to the DNA/fibronectin matrix faster than to control matrices made of either polylysine or intact fibronectin, and 90% of the cells withstood the application of a large detachment force. Only 4% of cells attached to the DNA/protein matrix died within 48 hours, whereas most of the cells attached to a DNA-only matrix died, suggesting that the protein portion is necessary for cell survival. The incorporation of single-stranded segments into the double-stranded DNA changed both the stiffness of the matrix and the morphology of cells growing on the matrix, the researchers note.