20. Hydrogels from Synthetic DNA
Dan Luo
Dan Luo, Biological and Environmental Engineering, and his research lab developed biocompatible, biogradable, inexpensive hydrogels—liquid-absorbing materials made from synthetic DNA—that can be used for biomedical applications, such as drug delivery or tissue engineering. Hydrogels are composed of long-chain molecules cross-linked to one another to create many small empty spaces that can absorb water or other liquids like a sponge. If the spaces are filled with a drug, the hydrogel can disperse the drug gradually as the structure biogrades. Research now under way may fill the spaces in the hydrogels with stem cells or tissue-growth factors for tissue engineering and tissue repair. These hydrogels are usually made from organic or inorganic polymers (molecules that form long chains), such as alginate from seaweed. Since high temperatures or harsh chemicals are not needed, the material to be encapsulated—whether proteins or live mammalian cells—can be introduced before the gel is formed. To test the effectiveness of the DNA hydrogels for delivering drugs, the researchers encapsulated porcine insulin and the anticancer drug Camptothecin and observed that the drugs were released in a controlled manner over time. When they encapsulated live cells in a gel, they discovered the cells were still alive three days later. To demonstrate that the hydrogels will hold their shape (for tissue engineering, for example), the researchers molded samples to spell “Cornell”!