Living therapeutic materials are soft medical devices that are being developed for long-term sustained drug release. They are made of biocompatible hydrogels containing microbes that are genetically engineered to produce and release drugs. The hydrogels protect the microbes from harsh conditions within the host and provide a controlled environment for them to function in a predictable manner. Additionally, the hydrogels also securely contain the genetically engineered microbes and prevent their release within the body or into the environment.

I will share our work on developing remote-controlled living therapeutic materials, in which probiotic bacteria are genetically engineered to sense external stimuli and secrete a variety of biopharmaceuticals in response. Specifically, we have engineered protibiotic E. coli and lactobacilli to sense external stimuli like light, heat, and food-grade small-molecules and, in response, secrete immunomodulatory, anti-microbial, and regenerative biomolecules. Through this, we can achieve on-demand control over drug release profiles to address diseases with recurring symptoms and to reduce the possibility of drug resistance or off-target effects. Furthremore, apart from controlling the bacteria through genetic programming, several aspects of their performance can also be influenced by tuning the mechanical properties of their encapsulating matrix. We have shown how growth, metabolism, drug production rates, and biocontainment of the bacteria can be altered in materials with different viscoelastic and cross-linking features. The resulting biocompatibility and activity of these remote-controlled living therapeutic materials has been demonstrated with cell- and tissue-culture models. Thus, I will share the advances we have made and challenges we faced in developing these next generation materials for creating smart and sustainable therapeutic solutions.