Lanthanide containing compounds for therapeutic care in bone resorption disorders

Area of Science:

• Inorganic Chemistry
• Medicinal Chemistry
• Biochemistry

Background:

• Lanthanide ions (Ln(III)) mimic calcium ions (Ca(II)) and influence bone remodeling.
• Disrupting bone remodeling offers a therapeutic strategy for bone density disorders, including osteoporosis.
• Development of orally active agents is crucial for managing these conditions.

Purpose of the Study:

• To synthesize and characterize novel lanthanide complexes for potential oral treatment of bone density disorders.
• To evaluate the biological activity, including cytotoxicity, cell uptake, and hydroxyapatite binding, of these complexes.

Main Methods:

• Synthesis and characterization of lanthanide(III) complexes (LnL3) with pyrone and pyridinone ligands.
• In vitro studies: Cytotoxicity assays, Caco-2 cell uptake and bidirectional transport, and hydroxyapatite (HA) binding assays.
• Quantification of lanthanide ions using ICP-MS and proligand using UV-vis spectrophotometry.

Main Results:

• LnL3 complexes exhibited significantly lower cytotoxicity compared to cisplatin (IC50 values at least 6 times greater).
• All complexes demonstrated high hydroxyapatite binding capacity (>= 98%) and moderate permeability coefficients.
• La(dpp)3 emerged as the lead compound, showing the highest cell uptake (9.07 +/- 2.33%) and apparent permeability (Papp) (3.54 +/- 2.86 x 10(-6) cm s(-1)).

Conclusions:

• The synthesized lanthanide complexes are potential candidates for treating bone density disorders.
• La(dpp)3 shows particular promise as an orally active agent due to its favorable biological properties.
• Further investigation into these lanthanide complexes could lead to new therapeutic strategies for osteoporosis.