Targetingpeptiden

Targetingpeptiden are short amino acid sequences that confer specificity to biological targets, enabling selective delivery of therapeutic cargos or imaging agents. By binding to receptors, transporters, or membrane components associated with particular cell types, tissues, or organelles, these peptides help concentrate active compounds at the desired site while reducing exposure elsewhere.

Mechanisms and classes vary. Receptor-targeting peptides bind cell-surface receptors overexpressed in diseased tissues and can trigger receptor-mediated endocytosis. Cell-penetrating peptides facilitate translocation across membranes, often carrying cargo inside cells. Organelle-targeting peptides direct cargos to mitochondria, nuclei, or other compartments via intracellular transport machinery. Well-known examples include RGD motifs targeting integrins, LyP-1 for tumor vasculature, and mitochondrial targeting sequences.

Applications span drug delivery and diagnostics. Targetingpeptiden are used to enhance delivery of chemotherapeutics, siRNA, or gene-editing components, and to improve the contrast and specificity of imaging agents. In nanomedicine, peptides are commonly attached to liposomes, polymeric nanoparticles, or dendritic structures to improve localization in tumors or inflamed tissues. They are studied across oncology, neurology, infectious disease, and vascular disorders.

Design and practical considerations are central to their use. Successful targeting requires balancing affinity, specificity, and stability while minimizing immunogenicity and unfavorable pharmacokinetics. Conjugation strategies include covalent linking or genetic fusion, and cleavable linkers may release cargo upon reaching the target. Challenges include heterogeneous target expression, off-target binding, proteolysis, and endosomal entrapment, which can limit efficacy. See also peptide targeting and ligand-receptor interactions for related concepts.