Abstract: The present application provides compositions and methods for determining a disease or condition in a subject. The method comprises contacting a body fluid with a molecule comprising a reporter thereof and the reported is cleaved by an agent in the body fluid. Diseases and conditions that can be determined by the method are also described.

Abstract: A nanoparticle activity sensor containing a reporter and at least one tuning domain that modifies a distribution or residence time of the activity sensor when administered to a patient. When administered to the patient, the activity sensor enters cells or tissue where it is cleaved by enzymes specific to a physiological state such as a disease to release a detectable analyte. The tuning domains include molecular structures that modulate distribution or decay by protecting the particle from premature cleavage and indiscriminate hydrolysis, shielding the particle from immune detection and clearance, or by targeting the particle to specific tissue, bodily fluids, or cell types.

Abstract: The present application provides compositions and methods for determining a disease or condition in a subject. The method comprises contacting a body fluid with a molecule comprising a reporter thereof and the reported is cleaved by an agent in the body fluid. Diseases and conditions that can be determined by the method are also described.

Abstract: Methods and compositions for screening or diagnosis of liver disease are provided. The results may also indicate course and efficacy of treatment. The composition includes an activity sensor and a reporter releasably attached to the activity sensor. The method includes detecting the presence and/or amount of a reporter. The reporter is released from an activity sensor in the presence of diseased liver tissue but remains attached to the activity sensor in healthy tissue. The presence and/or amount of the reporter are used to characterize the liver disease. The liver disease may be nonalcoholic steatohepatitis (NASH) and results may further indicate staging of NASH.