Disclosed are methods for imaging lumen-forming structures such as blood vessels using near-infrared fluorescence in the NIR-II region of 1000-1700 nm. The fluorescence is created by excitation of solubilized nano-structures that are delivered to the structures, such as carbon nanotubes, quantum dots or organic molecular fluorophores attached to hydrophilic polymers. These nanostructures fluoresce in the NIR-II region when illuminated through the skin and tissues. Fine anatomical vessel resolution down to 30 m and high temporal resolution up to 5-10 frames per second is obtained for small-vessel imaging with up to 1 cm penetration depth in mouse hind limb, which compares favorably to tomographic imaging modalities such as CT and MRI with much higher spatial and temporal resolution, and compares favorably to scanning microscopic imaging techniques with much deeper penetration.

Polymers, monomers, chromophoric polymer dots and related methods are provided. Highly fluorescent chromophoric polymer dots with narrow-band emissions are provided. Methods for synthesizing the chromophoric polymers, preparation methods for forming the chromophoric polymer dots, and biological applications using the unique properties of narrow-band emissions are also provided.

The invention provides novel biocompatible upconversion nanoparticle (UCNP) that comprises a core of cubic nanocrystals (e.g., comprising -Na Ln.sub.a, Ln.sub.b Ln.sub.c F.sub.4) and an epitaxial shell (e.g., formed from CaF.sub.2; wherein Ln.sub.b is Yb), and related methods of preparation and uses thereof.

The invention relates to novel luminescent compositions of matter containing two fluorophores (sensitizers), synthetic methods for making the compositions, macromolecular conjugates of the compositions, and the use of the compositions and their conjugates in various methods of detection. The invention also provides kits containing the compositions and their conjugates for use in the methods of detection.

Microfluidic organ-on-a-chip devices have been developed with the aim to replicate human tissues in vitro. However, there is no option to quantitatively monitor biological processes that take place within the chip, over time. Destructive methods in order to analyze, tissue formation, gene expression, protein secretion etc. require the harvest of the tissue at a certain time point. Described herein are methods and compositions for non-destructive molecular imaging methods and systems in order to quantitatively monitor specific biological processes, over time, within the chip, without the need to harvest.

Polymers, monomers, chromophoric polymer dots and related methods are provided. Highly fluorescent chromophoric polymer dots with narrow-band emissions are provided. Methods for synthesizing the chromophoric polymers, preparation methods for forming the chromophoric polymer dots, and biological applications using the unique properties of narrow-band emissions are also provided.

The disclosure features methods that include: administering to a subject a composition that includes particles, where each one of the particles features at least one targeting group that binds to a structural entity in the subject and at least one reacting group that reacts chemically with a reactive oxygen species in the subject, and where the particle emits luminescence when the reaction occurs; detecting the luminescence emission from the particles; and displaying an image of the subject showing locations of at least some reactive oxygen species in the subject based on the detected luminescence.

This invention is in the field of fluorescence imaging and relates to a new near infrared (NIR) reactive oxygen species (ROS) sensor designed with controlled fluorescence on-off switching mechanism.

Microfluidic organ-on-a-chip devices have been developed with the aim to replicate human tissues in vitro. However, there is no option to quantitatively monitor biological processes that take place within the chip, over time. Destructive methods in order to analyze, tissue formation, gene expression, protein secretion etc. require the harvest of the tissue at a certain time point. Described herein are methods and compositions for non-destructive molecular imaging methods and systems in order to quantitatively monitor specific biological processes, over time, within the chip, without the need to harvest.

The invention provides novel biocompatible upconversion nanoparticle (UCNP) that comprises a core of cubic nanocrystals (e.g., comprising -Na Ln.sub.a, Ln.sub.b Ln.sub.c F.sub.4) and an epitaxial shell (e.g., formed from CaF.sub.2; wherein Ln.sub.b is Yb), and related methods of preparation and uses thereof.