Abstract: Peptides that are stable to denaturation and degradation by reducing agents, proteases, temperature, and low pH environments are disclosed. Pharmaceutical compositions and uses for peptides, peptide-active agent conjugates, and peptide-detectable agent conjugates comprising such peptides are also disclosed. Peptide compositions, peptide conjugate compositions, and pharmaceutical compositions can be formulated for various routes of delivery, such as oral delivery, and for deliver to various compartments of the body. Peptides of this disclosure are stable and display enhanced pharmacokinetics after such delivery.

Abstract: Peptides that home, migrate to, distribute to, accumulate in, are directed to, and/or bind to tumors, cancerous tissues and cells thereof are disclosed. Pharmaceutical compositions and uses for peptides, peptide-active agent complexes comprising such peptides, or peptide-detectable agent complexes comprising such peptides are additionally disclosed. Such compositions can be formulated for targeted or untargeted delivery of a drug to a target region, tissue, structure or cell. Targeted compositions of the disclosure can deliver peptide, peptide-active agent complexes, or peptide-detectable agent complexes to target regions, tissues, structures or cells targeted by the peptide.