Agents and methods for imaging a cell and/or a portion of tissue characterized by fibrosis, as well as to agents and methods for determining and/or diagnosing fibrotic diseases are disclosed herein. Also disclosed herein are polymer conjugates that can include a detectable label, a retinoid and a polymer. The polymer conjugates can be used to image a portion of tissue, deliver a detectable label to a portion of tissue or a cell and/or diagnosis a condition or disease.
