Synthesis of a novel dexamethasone intercalated layered double hydroxide nanohybrids and their deposition on anodized titanium nanotubes for drug delivery purposes.

Abstract Dexamethasone, an anti-inflammatory drug, was intercalated in both Zn/Al-NO 3 and Zn/Al-CO 3 layered double hydroxides with three different LDH/DEXA molar ratios through ion-exchange technique. Then the maximum added drug nanohybrid (NL-1D) deposited into nanotubes of anodized titanium (ATS-NL-1D). The X-ray diffraction (XRD) demonstrated that dexamethasone anions are accommodated within the interlayer space of Zn/Al-NO 3 LDHs, with the d spacing of 8.9 Å which became 21.215 Å after intercalation (NL-1D). However, it confirmed that dexamethasone anions only settled on the surface of Zn/Al-CO 3 LDHs and we only demonstrated Zn/Al-CO 3 data to prove that drug anions never intercalated into the interlayer space of these LDHs. The Fourier transform infrared spectroscopy (FTIR) also supported the formation of Zn/Al-NO 3 LDHs and confirmed unsuccessful intercalation of the drug in Zn/Al-CO 3 LDHs, therefore we continued our work with Zn/Al-NO 3 LDHs. Thermal analysis (STA) showed that nanohybrids are more thermally stable than the drug alone. Furthermore, it demonstrated that dexamethasone loading for NL-1D was around 12%. In-vitro release study of LDH-DEXA nanohybrids suggested a considerable reduction in release rate due to the incarceration of drug molecules inside nanohybrids. Release rate showed even more reduction from ATS-NL-1D, because of entanglement of nanohybrid particles inside nanotubes of anodized titanium which justified the anodization process for implant application. Cell adhesion and viability studies revealed that ATS-NL-1D not only wasn't toxic but also the osteoblast cells viability was more than 80% on these sheets. All in all, this work demonstrated that ATS-NL-1D is a suitable candidate for bone implant applications. Graphical abstract fx1 Highlights • Intercalation expanded the interlayer spacing of nitrate LDHs from 8.9 Å to 21.215 Å. • Amount of drug in nitrate layered double hydroxide was estimated to be 12%. • Nanohybrid deposition on anodized titanium decreased the release time. • Osteoblast cell viability was more than 80% on samples with great cell adhesion. [ABSTRACT FROM AUTHOR]