Now, 3D printed smart gel for targeted drug delivery

Scientists have 3D printed a smart gel that could lead to the development of "living" structures in human organs and tissues, soft robots and targeted drug delivery.
The approach involves printing a 3D object with a hydrogel (water-containing gel) that changes shape over time when temperatures change, said Howon Lee, assistant professor at Rutgers University in the US.
The study, published in the journal Scientific Reports, demonstrated fast, scalable, high-resolution 3D printing of hydrogels, which remain solid and retain their shape despite containing water.
Hydrogels are everywhere in our lives, including in contact lenses, diapers and the human body.
The smart gel could provide structural rigidity in organs such as the lungs, and can contain small molecules like water or drugs to be transported in the body and released.

It could also create a new area of soft robotics, and enable new applications in flexible sensors and actuators, biomedical devices and platforms or scaffolds for cells to grow, Lee said.

"The full potential of this smart hydrogel has not been unleashed until now," said Lee.
"We added another dimension to it, and this is the first time anybody has done it on this scale. They are flexible, shape-morphing materials. I like to call them smart materials," Lee said.
Engineers worked with a hydrogel that has been used for decades in devices that generate motion and biomedical applications such as scaffolds for cells to grow on.

However, hydrogel manufacturing has relied heavily on conventional, two-dimensional methods such as molding and lithography.
The researchers used a lithography-based technique that is fast, inexpensive and can print a wide range of materials into a 3D shape.
It involves printing layers of a special resin to build a 3D object.
The resin consists of the hydrogel, a chemical that acts as a binder, another chemical that facilitates bonding when light hits it and a dye that controls light penetration.