Layered zirconium phosphonate with inorganic-organic hybrid structure: Preparation and its assembly with DNA

An aminoethoxy-functionalized zirconium phosphonate (Zr(O3POCH2CH2NH2)(2)center dot 3H(2)O), abbreviated as ZrRP (R=OCH2CH2NH2); with layered structure has been synthesized. This layered compound possesses the characteristic of inorganic-organic hybrid, due to the covalently linked aminoethoxy in the host layer. The anion exchanged property of this zirconium phosphonate is suitable for the direct intercalation of negatively charged DNA, which is different from these reported zirconium phosphates or zirconium phosphonates. As a precursor, this prepared zirconium phosphonate was utilized to fabricate a novel DNA/ZrRP binary hybrid via a delamination-reassembly procedure. The release behavior of DNA from the DNA/ZrRP composite was investigated at different medium pH, because the combination between zirconium phosphonate sheets and DNA was pH-dependent sensitively. Moreover, the helical conformation of DNA was almost retained after the intercalation and release process. These properties of the DNA/ZrRP composite suggested the potential application of layered zirconium phosphonate as a non-viral vector in gene delivery. (C) 2014 Elsevier Inc. All rights reserved.