Self-Healing DNA-Based Reaction-Diffusion Patterns

We have developed a system for fabricating and perturbing self-healing oligonucleotide-based patterns in photolithographically-patterned hydrogels using electromagnetic radiation. Digital maskless photolithography combined with microfluidic handling provides the ability to construct soft materials of arbitrary shape at biologically relevant length scales of tens to hundreds of microns in a matter of seconds. We use this approach to first form self-healing linear and hill-shaped DNA-based gradients in poly(ethylene-glycol) diacrylate hydrogels. Undisturbed, these spatial patterns were stable over at least 24 hours. When patterns were perturbed in particular areas they reformed. The ability to grow and perturb gradients of biomolecules such as DNA may facilitate the study of cell populations in dynamic microenvironments, providing experimentalists control over where and when chemical cues are induced or inhibited at the microscale