Optogenetics can be used to modulate targeted neurons in vivo using visible light. Currently the visible light sources are surgically implanted into the brain tissue, but this harmful and invasive technique may be avoided if suitable scintillating nanoparticles can be inserted via injection. The particles could then be externally activated to provide the energy necessary to stimulate neuronal activity. The proposed nanoscintillators particles must meet a number of strict criteria if they can serve as local light sources to arouse neuromodulation. The particles need to be under 100nm, dispersible, and uniform. The phase, crystallinity, and dopant concentration must be optimized to absorb X-ray radiation and emit photons of the desired energy necessary to activate the selected neurons. We began a synthesis program to prepare suitable cerium doped gadolinium silicate nanoparticles using a modified core-shell technique. This produced several phases including Ce:Gd4.67(SiO4)3O (Ce:GSAP), Ce:Gd2SiO5 (Ce:GSO), and Ce:Gd2Si2O7, (Ce:GPS) nanoscinitillators. The silica core serves as both a template to ensure uniformity in size and shape, and can be manipulated to elicit different silicate phases. The chemistry leading to the various phases will be outlined. Photoluminescence and radioluminescence properties of the gadolinium silicate phases were studied to determine their potential for optogenetic application. The addition of lutetium into the gadolinium silicate nanoparticles was also investigated. The mixed gadolinium/lutetium materials could also be engineered to produce different silicate phases and showed enhanced light output under X-ray stimulation. This work led to a number of gadolinium silicate nanospheres that are attractive candidates for a less-invasive optogenetics. Initial exploration on other gadolinium containing nanoscintillators such as NaGdF4 and Gd2S2O will also be discussed.

Phase manipulation and luminescence studies of gadolinium silicate nanoparticles for application in neuromodulation

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.