Provided herein are compositions, systems, kits, and methods for treating nervous system injuries caused by trauma or neurodegeneration or aging in a subject by administering a CSPG or SOCS3 reduction peptide (CRP and SRP respectively), or a nucleic acid sequence encoding the CRP or SRP, wherein both the CRP and SRP comprise a cell membrane penetrating domain, and a lysosome targeting domain, and the CRP further comprises a chondroitin sulfate proteoglycan (CSPG) binding domain, and the SRP further comprises a suppressor of cytokine signaling-3 (SOCS3) binding domain.

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.

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.

The present disclosure provides peptoid-based chelating ligands, corresponding cyclic peptoids, and methods of making thereof. Functional groups may be tailored for high metal binding affinity and selectivity. The side chains of a cyclic peptoid according to the present disclosure may be selected based on, for example, high affinity for actinide or other metal ions, selectivity for actinide or other metal ions, the ability to recover a metal once it is bound to the peptoid, and whether the overall peptoid should be hydrophobic or hydrophilic. Unlike siderophores, peptoid-based chelating ligands of the present disclosure are not readily hydrolyzed under physiological conditions. Therefore, peptoid-based chelating ligands may be, for example, used to treat actinide (e.g., iron and lead) poisoning in vivo. Moreover, peptoid-based chelating ligands of the present disclosure may be used for medical imaging, chelation therapy, drug delivery, and separation technologies, for example.

Targeted molecular imaging agents (TMIAs) are derived from coupling together pre-formed amino acids with imaging agents attached to their side chains. These peptide-based imaging agents may synthesized from a single or multiple preformed amino acids containing multi-modal, multi-chelated metal, multi-dye imaging agents, or combinations of these, on the side chains of resultant peptides. These imaging amino acids or peptides may be conjugated directly, or activated, or attached to linkers to which targeting groups, such as peptides, proteins, antibodies, aptamers, or small molecule inhibitors, may be conjugated in the final steps of the synthesis to form a wide variety of TMIAs.

Targeted molecular imaging agents (TMIAs) are derived from coupling together pre-formed amino acids with imaging agents attached to their side chains. These peptide-based imaging agents may synthesized from a single or multiple preformed amino acids containing multi-modal, multi-chelated metal, multi-dye imaging agents, or combinations of these, on the side chains of resultant peptides. These imaging amino acids or peptides may be conjugated directly, or activated, or attached to linkers to which targeting groups, such as peptides, proteins, antibodies, aptamers, or small molecule inhibitors, may be conjugated in the final steps of the synthesis to form a wide variety of TMIAs.

The present disclosure provides an isolated, engineered or non-naturally occurring protein comprising an antibody light chain variable domain (V.sub.L) which may comprise at least one negatively charged amino acid positioned between residues 49 to 56 according to the numbering system of Kabat, the protein capable of binding specifically to an antigen.

The present disclosure provides an isolated, engineered or non-naturally occurring protein comprising an antibody light chain variable domain (V.sub.L) which may comprise at least one negatively charged amino acid positioned between residues 49 to 56 according to the numbering system of Kabat, the protein capable of binding specifically to an antigen.

Provided are macrocyclic compounds and compounds with two or more macrocyclic groups, iron coordinated macro-cyclic compounds, and iron coordinated compounds with two or more macrocyclic groups. The iron is high-spin iron(III). The iron coordinated compounds may exhibit a negative redox potential (e.g., relative to a normal hydrogen electrode at a biologically relevant pH, for example, a pH of 6.5-7.5). The compounds can be used as MRI contrast agents.

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.