Experimental study of bone differentiation and periapical bone repair induced by quercetin cyclodextrin inclusion complexes

Quercetin (Qc) is a natural flavonoid recognized for its diverse biological activities but is poorly soluble in water. Hydroxypropyl beta-cyclodextrin (HP-β-CD), a cyclodextrin analog, serves as a safe and efficient drug carrier by forming clathrates with therapeutic agents, enhancing their physicochemical and pharmacokinetic properties. This study reports the synthesis of inclusion complexes of HP-β-CD and Qc using ultrasonic magnetic stirring followed by lyophilization. These complexes were analyzed using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and UV–Vis spectroscopy (UV), Fourier-Transform Infrared spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR) to elucidate their structural and physicochemical properties. The findings validated the successful formation of clathrates between Qc and HP-β-CD, with the resulting inclusion complexes comprising Qc/HP-β-CD demonstrating markedly distinct spectral characteristics compared to unmodified Qc. Moreover, studies revealed a substantial enhancement in the anti-inflammatory and osteogenic activities of Qc upon encapsulation. These findings demonstrate that the Qc/HP-β-CD inclusion complexes markedly enhanced Qc bioavailability while amplifying its therapeutic efficacy in inflammation and bone regeneration.