Bifunctional bisphosphonate derivatives and platinum complexes with high affinity for bone hydroxyapatite

Area of Science:

• Medicinal Chemistry
• Inorganic Chemistry
• Cancer Research

Background:

• Platinum-based drugs are mainstays in cancer chemotherapy.
• Developing targeted drug delivery systems can improve efficacy and reduce side effects.
• Bisphosphonates are known for their bone-targeting capabilities.

Purpose of the Study:

• Synthesize novel platinum(II) complexes with bisphosphonate moieties.
• Evaluate the in vitro antitumor activity and bone affinity of these complexes.
• Identify potential bone-targeting anticancer agents.

Main Methods:

• Synthesis and characterization of ethylenediamine/1,3-propanediamine derivatives and their platinum(II) complexes.
• In vitro cytotoxicity assessment using WST-8 assay (CCK-8).
• Hydroxyapatite binding experiments and flow cytometry analysis.

Main Results:

• Synthesized platinum complexes (1-6) and platinum-free analogues (L1-L6).
• Complexes 1-6 exhibited higher in vitro antitumor activity than L1-L6, particularly against osteosarcoma (MG-63).
• Complexes 2, 3, and 6 demonstrated significantly higher hydroxyapatite binding affinity than cisplatin, comparable to zoledronate.

Conclusions:

• Novel platinum(II) complexes with bisphosphonate substituents show promising antitumor activity.
• Complex 2 is identified as a potential bone-targeting antitumor agent due to its cytotoxicity and bone affinity.
• Further in vivo studies are warranted for complex 2.