Provided is a nanoparticulate composite with two layers. One of the layers comprises one or more metals, which are a paramagnetic metal, a ferromagnetic metal, or a superparamagnetic metal. This layer also contains one or more suitable dopants. The other layer comprises one or more metals of gadolinium, manganese (II), and iron (III), in the form of an oxide or a fluoride. This layer may contain one or more lanthanide dopants. The nanoparticulate composite may be used as a contrast agent, in particular in magnetic resonance imaging.

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.

Blood-brain barrier permeable peptide compositions that contain variable antigen binding domains from camelid and/or shark heavy-chain only single-domain antibodies are described. The variable antigen binding domains of the peptide compositions bind to therapeutic and diagnostic biomarkers in the central nervous system, such as the amyloid-beta peptide biomarker for Alzheimer's disease. The peptide compositions contain constant domains from human IgG, camelid IgG, and/or shark IgNAR. The peptide compositions include heavy-chain only single-domain antibodies and compositions with one or more variable antigen binding domain bound to one or more constant domains.

Provided are a nanophosphor and a silica composite including the nanophosphor. The nanophosphor has a core/first shell/second shell structure or a core/first shell/second shell/third shell structure, wherein the core includes a Yb.sup.3+-doped fluoride-based nanoparticle, the first shell is an up-conversion shell including a Yb.sup.3+ and Tm.sup.3+-codoped fluoride-based crystalline composition, the second shell is a fluoride-based emission shell, and the third shell is an outermost crystalline shell.

Provided is a nanophosphor having a core/double shell structure, the nanophosphor including a upconversion core including a Yb.sup.3+, Ho.sup.3+, and Ce.sup.3+ co-doped fluoride-based nanophosphor represented by Formula 1; a first shell surrounding at least a portion of the upconversion core, and comprising a Nd.sup.3+ and Yb.sup.3+ co-doped fluoride-based crystalline composition represented by Formula 2; and a second shell surrounding at least a portion of the first shell, and having paramagnetic properties represented by Formula 3.

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.

Disclosed are monoacylated Toll-like receptor 2 ligands which can be used in both the development of targeted agents for the imaging and treatment of pancreatic cancer as well as other cancers, and as an adjuvant for cancer immunotherapy. The monoacylated compounds disclosed herein have a higher binding affinity for TLR2 relative to a known potent diacylated agonists, but only the bioactivity. Competition of the monoacylated compound with the diacylated compound for binding TLR2 was confirmed. Hence, the reported monoacylated compounds are inhibitors/antagonists of TLR2 activation.

Blood-brain barrier permeable peptide compositions that contain variable antigen binding domains from camelid and/or shark heavy-chain only single-domain antibodies are described. The variable antigen binding domains of the peptide compositions bind to therapeutic and diagnostic biomarkers in the central nervous system, such as the amyloid-beta peptide biomarker for Alzheimer's disease. The peptide compositions contain constant domains from human IgG, camelid IgG, and/or shark IgNAR. The peptide compositions include heavy-chain only single-domain antibodies and compositions with one or more variable antigen binding domain bound to one or more constant domains.