Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A-X-B-C)-M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A-X-B-C)-M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A-X-B-C)n-M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutatmates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A-X-B-C)-M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: A method and system are provided for detection of localized hydrogen peroxide within tissue by introducing a catalase-containing material into at location of interest, positioning an ultrasound transducer over the location, and generating an ultrasound image to detect microbubbles, where the presence of microbubbles indicate the presence of localized hydrogen peroxide. The catalase-coated surface may be the inner surface of a microtube, on the surface of or incorporated within a nanosphere or microsphere, or an implantable device.

Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A-X-B-C)-M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: A method and system are provided for detection of localized hydrogen peroxide within tissue by introducing a catalase-containing material into at location of interest, positioning an ultrasound transducer over the location, and generating an ultrasound image to detect microbubbles, where the presence of microbubbles indicate the presence of localized hydrogen peroxide. The catalase-coated surface may be the inner surface of a microtube, on the surface of or incorporated within a nanosphere or micro sphere, or an implantable device.

Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A—X—B—C)n—M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: Disclosed herein, in certain embodiments, is a selective transport molecule with increased in vivo circulation. In some embodiments, a selective transport molecule disclosed herein has the formula (A-X-B-C)-M, wherein C is a cargo moiety; A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and M is a macromolecular carrier.

Abstract: A generic structure for the peptides of the present invention includes A-X-B-C, where C is a cargo moiety, the B portion includes basic amino acids, X is a cleavable linker sequence, and the A portion includes acidic amino acids. The intact structure is not significantly taken up by cells; however, upon extracellular cleavage of X, the B-C portion is taken up, delivering the cargo to targeted cells. Cargo may be, for example, a contrast agent for diagnostic imaging, a chemotherapeutic drug, or a radiation-sensitizer for therapy. X may be cleaved extracellularly or intracellularly. The molecules of the present inventnon may be linear, cyclic, branched, or have a mixed structure.