Abstract: An imaging system for cell-based therapies is provided. The imagining system includes one or more optical tags configured for insertion into a cell or biological tissue, an excitation light source configured to illuminate the one or more optical tags; a detector configured to measure optical emission of the one or more optical tags; an imaging subsystem configured to determine a three-dimensional location of each of the one or more optical tags in the cell or biological tissue; and a controller in electrical communication with the excitation light source, the detector, and the imaging subsystem. Each of the one or more optical tags has a contrasting feature and includes a fluorescent material. The contrasting feature may be defined by at least one of a refractive index, shape, color, and laser emission of each optical tag of the one or more optical tags.

Abstract: Provided are compositions that include polymeric fibers and microspheres entrapped within the fibers, the compositions being capable of controlled delivery of one or more agents while also maintaining their structural properties. Also provided are related methods of fabricating these compositions and methods of utilizing the compositions to deliver agents to a subject.