🎯 Tumor-Targeting Vector

A tumor-targeting vector is a molecule or carrier used to deliver therapeutic agents (such as radionuclides, drugs, or nanoparticles) specifically to cancer cells by binding to tumor-associated antigens or receptors.

• High specificity for tumor markers
• Low affinity for healthy tissues
• Can be chemically linked to:
  • Alpha-emitting radionuclides (e.g., ^^225^^Ac, ^^213^^Bi)
  • Chemotherapeutic agents
  • Nanoparticles or liposomes

• Monoclonal antibodies (mAbs):
  • Recognize specific tumor antigens (e.g., HER2, EGFR)
  • High binding specificity
  • ⮕ Example: Trastuzumab

• Peptides:
  • Small and fast-clearing
  • Bind to receptors like somatostatin or substance P
  • ⮕ Example: DOTA-substance P used in glioblastoma TAT

• Aptamers:
  • DNA or RNA molecules folded into 3D shapes
  • Bind with high specificity to tumor markers

• Small molecules:
  • Chemically synthesized
  • Can target enzymes, transporters, or overexpressed receptors
  • ⮕ Example: PSMA ligands in prostate cancer

• Vectors are chelated or covalently linked to radionuclides
• Chelators like DOTA or NOTA are commonly used for stable binding
• Must retain binding ability after labeling

• Tumor specificity and minimal off-target binding
• Stable in circulation
• Compatible with chosen therapeutic agent
• Able to internalize (optional, but preferred for some radionuclides)

Tumor-targeting vectors are the precision delivery tools of modern oncology. When combined with alpha emitters, they form the basis of Targeted Alpha Therapy (TAT), enabling potent and selective destruction of tumor cells.