Hydrogels are commonly used inside the body to help in tissue regeneration and drug delivery. However, once inside, they can be challenging to control for optimal use. A team of researchers in the Department of Biomedical Engineering at Texas A&M University is developing a new way to manipulate the gel—by using light. Graduate student Patrick Lee and Dr. Akhilesh Gaharwar, associate professor, are developing a new class of hydrogels that can leverage light in a multitude of ways. Light is a particularly attractive source of energy as it can be confined to a predefined area as well as be finetuned by the time or intensity of light exposure. Their work was recently published in the journal Advanced Materials. Light-responsive hydrogels are an emerging class of materials used for developing noninvasive, noncontact, precise and controllable medical devices in a wide range of biomedical applications, including photothermal therapy, photodynamic therapy, drug delivery and regenerative medicine. Lee said light-responsive biomaterials are often used in biomedical applications; however, current light sources, such as ultraviolet light and visible light, cannot sufficiently penetrate the tissue to interact with the hydrogel. Instead, the team is researching near-infrared (NIR) light, which has a higher penetration depth. https://phys.org/news/2021-06-hydrogels-nanomaterials.html