Spin-labeled ice binding compounds (IBCs) including ice binding proteins (IBPs) or antifreeze proteins (AFPs) and their analogs may carry paramagnetic centers for dynamic nuclear polarization (DNP), for enhancing nuclear magnetic resonance (NMR) signal intensities. Use of spin-labeled IBCs to perform DNP exploits the IBCs' ability to homogeneously distribute the paramagnetic centers in frozen water solution at low temperature, leading to high DNP efficiency. Other advantages of using spin-labeled IBCs include cryo-protecting biological samples; cryo-preserving relative positions and orientations of the spin labeling groups; selecting positions and orientations of spin labeling groups with freedom and without technical barriers to making multiple spin labels in an IBC; and enabling use of a solvent that is primarily water for DNP at low temperatures in view of the potentially high water solubilities of spin-labeled IBCs.

Disclosed herein are compounds (such as peptides or peptide mimetics) that bind to HIV RRE RNA. In some examples, the compounds inhibit (for example, decrease) binding of Rev to the RRE RNA. In some embodiments, the compounds include two moieties, each of which bind to one of the Rev binding sites in the RRE. In some examples, the moieties include peptides or small molecules. In some examples, the peptides include an arginine-rich motif. The RRE binding compounds may be further linked to a detectable label or cargo moiety. Also disclosed are methods of treating or inhibiting HIV including administering one or more of the disclosed compounds to a subject.

Disclosed herein are compounds (such as peptides or peptide mimetics) that bind to HIV RRE RNA. In some examples, the compounds inhibit (for example, decrease) binding of Rev to the RRE RNA. In some embodiments, the compounds include two moieties, each of which bind to one of the Rev binding sites in the RRE. In some examples, the moieties include peptides or small molecules. In some examples, the peptides include an arginine-rich motif. The RRE binding compounds may be further linked to a detectable label or cargo moiety. Also disclosed are methods of treating or inhibiting HIV including administering one or more of the disclosed compounds to a subject.

Disclosed herein are gelatin particles that have been crosslinked without using a crosslinking agent and are easily taken up by cells themselves, and a method for producing such gelatin particles. The gelatin particles are made of self-crosslinked gelatin and have a particle diameter of 0.010 m or more but 5.0 m or less. The gelatin particles can be produced by discharging droplets of a liquid containing melted gelatin into air in a heating tube or a drying chamber and drying the droplets to form the gelatin into particles under conditions where a difference between the temperature in the heating tube or the drying chamber and the temperature of the liquid is 235 C. or less and further by crosslinking the gelatin forming the particles.

Disclosed herein are gelatin particles that have been crosslinked without using a crosslinking agent and are easily taken up by cells themselves, and a method for producing such gelatin particles. The gelatin particles are made of self-crosslinked gelatin and have a particle diameter of 0.010 m or more but 5.0 m or less. The gelatin particles can be produced by discharging droplets of a liquid containing melted gelatin into air in a heating tube or a drying chamber and drying the droplets to form the gelatin into particles under conditions where a difference between the temperature in the heating tube or the drying chamber and the temperature of the liquid is 235 C. or less and further by crosslinking the gelatin forming the particles.

Provided herein are methods of enhancing in vivo efficacy of an active agent, comprising: administering to a subject an active agent that is coupled to a bioelastic polymer or elastin-like peptide, wherein the in vivo efficacy of the active agent is enhanced as compared to the same active agent when administered to the subject not coupled to (or not associated with) a bioelastic polymer or ELP.

Provided herein are methods of enhancing in vivo efficacy of an active agent, comprising: administering to a subject an active agent that is coupled to a bioelastic polymer or elastin-like peptide, wherein the in vivo efficacy of the active agent is enhanced as compared to the same active agent when administered to the subject not coupled to (or not associated with) a bioelastic polymer or ELP.

A composition for imaging a cell includes a first imaging probe and a second imaging probe that include respectively a first reporter moiety and a second reporter moiety. The first reporter moiety and the second reporter moiety form a signaling complex that produces a detectable signal when the first imaging probe and second imaging probe complex with first and second biomarkers of the cell.

A composition for imaging a cell includes a first imaging probe and a second imaging probe that include respectively a first reporter moiety and a second reporter moiety. The first reporter moiety and the second reporter moiety form a signaling complex that produces a detectable signal when the first imaging probe and second imaging probe complex with first and second biomarkers of the cell.

A contrast agent having a contrast protein have contrast properties and at least one targeting moiety, wherein the at least one targeting moiety is operatively linked to or incorporated within the contrast protein. Methods for targeting contrast agents and for preparing such agents are included.