Anticancer evaluation and drug delivery of new palladium(II) complexes based on the chelate of alendronate onto hydroxyapatite nanoparticles

Abstract Bisphosphonates represent a significant subclass of phosphonates, organophosphorus compounds. Nitrogenous bisphosphonates have been used in the treatment of bone-related disease including osteoporosis and cancer therapies. The new palladium(II)-alendronate (H 2 Ald), {[Pd(Ald)(H 2 O) 2 ] and [Pd 2 (bpy) 2 (Ald-2H)]} complexes were synthesized and characterized using IR, NMR ( 1 H, 13 C, 31 P), UV–visible, mass spectra, elemental analysis, molar conductivity and thermal measurements. The anticancer activity of [Pd(Ald)(H 2 O) 2 ] and [Pd 2 (bpy) 2 (Ald-2H)] were tested against the human prostate (DU 145) and breast (MDA-MB231) cancer cell lines, the later complex showed promising results compared to the market drug cisplatin . Moreover, the complex [Pd 2 (bpy) 2 (Ald-2H)] has apparent affinity for hydroxyapatite nanoparticles (HAnp), which is the main constituent of bone tissue. Thus, the physicochemical characteristics, in vitro release of [Pd 2 (bpy) 2 (Ald-2H)] from HAnp were evaluated using UV-visible spectroscopy. The [Pd 2 (bpy) 2 (Ald-2H)] encapsulation efficiency was found to be 96.83%, while the released 85.2 up to 10 days at the physiological pH 7.4.