Disclosed is a method of non-invasive infrared imaging, comprising (a) administering a composition containing infrared-emitting particles which contain rare earth elements that emit in the short-wavelength infrared (SWIR) spectrum, where the particles are encapsulated with a biocompatible matrix to form downconverting encapsulated particles; and (b) irradiating with infrared radiation, where both excitation and emission spectra of the encapsulated particles are in the infrared region. Analogous methods of image-guided biomedical intervention, and drug tracking and delivery are also disclosed. Also disclosed is a composition for biomedical applications, containing infrared-emitting particles which contain rare earth-elements that emit in the short-wavelength infrared (SWIR) spectrum, where the particles are encapsulated with a biocompatible matrix to form downconverting encapsulated particles.

A method of detecting migration of tumor cells is provided by implanting in a region of tumor cells one or more implants having a matrix material of a biocompatible and biodegradable polymer, and a plurality of nanoparticles dispersed within the matrix material and functionalized to bind tumor cells. Nanoparticles bound to the tumor cells that have migrated out of the region can be detected by various imaging modalities. The implant can be in the shape of a brachytherapy spacer or radiotherapy fiducial maker or can be a coating on a brachytherapy spacer or fiducial marker. A method of treating cancer is provided by implanting one or more brachytherapy spacers or fiducial markers including the matrix material and an anti-cancer therapeutic agent dispersed within the matrix material.

The present disclosure relates to an upconversion nanoparticle, which is represented by the following Chemical Formula 1 and comprises a nanoparticle doped with lanthanide ion:

Li.sub.3ZrF.sub.7:Ln.sup.3+[Chemical Formula 1]

where Ln is a lanthanide element selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof.

Polymer nanoparticles and related methods are provided. The polymer particles can include polymer dots having a coating including a polyelectrolyte polymer. Methods of making and using the polymer nanoparticles are also provided.

A process for ultrasensitive in vitro detection and/or quantification of a substance of interest in a sample is performed by detecting the luminescence emission by photoluminescent inorganic nanoparticles. The process includes (i) use of photoluminescent particles comprising a photoluminescent inorganic nanoparticle consisting of a crystalline matrix having at least 10.sup.3 rare-earth ions, and coupled to a targeting agent for the substance to be analyzed, under conditions conducive to their association with the sample substance to be analyzed; (ii) exciting the rare-earth ions of the particles by an illumination device having a power of at least 50 mW and an excitation intensity of at least 1 W/cm.sup.2; (iii) detecting the luminescence emission by the particles after single-photon absorption; and (iv) determining the presence and/or concentration of the substance by interpreting said luminescence measurement. This process can be used for in vitro diagnostic purposes and as an in vitro diagnostic kit.

A functionalised particle, wherein the particle has a first optical spectral signature in a first structural configuration of the particle and a second optical spectral signature in a second structural configuration of the particle.

Described herein are flash nanoprecipitation methods capable of encapsulating hydrophobic molecules, hydrophilic molecules, bioactive protein therapeutics, or other target molecules in amphiphilic copolymer nanocarriers.

A method of exciting an organic salt in a cell is provided. The method includes contacting the cell with a composition including the organic salt, the organic salt having a photoactive ion and a counterion. The cell uptakes the organic salt, the organic salt is substantially free of a coating within the cell, and the organic salt is non-toxic to the cell in the dark. The method also includes exposing the cell to light having a first wavelength, wherein the organic salt absorbs the light having the first wavelength and the photoactive ion becomes excited.

A composition includes a plurality of gold nanoparticles each having at least one surface. The gold nanoparticles have an average length of at least about 90 nm and an average width of at least about 25 nm.

Disclosed herein, inter alia, are compositions and methods of modulating macrophage activity. Provided is a method of treating a disease (e.g., a macrophage-associated disease, autoimmune disease, inflammatory disease, or a cancer of an organ in the intraperitoneal cavity), the method including intraperitoneally administering to a subject in need thereof a therapeutically effective amount of a nanoparticle composition or pharmaceutical composition. Provided is a silica nanoparticle non-covalently bound to a plurality of nucleic acids, wherein the silica nanoparticle has a net positive charge in the absence of the plurality of nucleic acids. Provided is a pharmaceutical composition including a nanoparticle composition as described herein, and a pharmaceutically acceptable excipient.