Optogenetics is a promising new field of research that may lead to new treatment options for a variety of conditions. At its root, optogenetics involves introducing optically sensitive cells into an animal that produce desired proteins in response to light stimulation. While the possibilities of this technology are nearly endless, a major hurdle in making it practical is being able to deliver light to the cells, since usually tissue is in the way. Now researchers at Massachusetts General Hospital report developing a new hydrogel implant that can be used to both shine light and sense its presence deep within the body.
The light-guiding hydrogel provides a foundation for cellular growth and can be used to ferry in the genetically engineered cells as well during implantation. To demonstrate the scaffold’s potential for regulating internal body chemistry, the team implanted the device into mice and were able to control the release of glucagon-like peptide-1 (GLP-1), a protein involved in glucose metabolism, using externally delivered blue light.
From the study abstract in Nature Photonics:
Hydrogel patches containing cells were implanted in awake, freely moving mice for several days and shown to offer long-term transparency, biocompatibility, cell viability and light-guiding properties (loss of <1 dB cm−1). Using optogenetic, glucagon-like peptide-1 secreting cells, we conducted light-controlled therapy using the hydrogel in a mouse model with diabetes and obtained improved glucose homeostasis. Furthermore, real-time optical readout of encapsulated heat-shock-protein-coupled fluorescent reporter cells made it possible to measure the nanotoxicity of cadmium-based bare and shelled quantum dots (CdTe; CdSe/ZnS) in vivo.