Ceramic nanovector based on layered double hydroxide: attributes, physiologically relevant compositions and surface activation

Since 2001, intercalated or biohybridised ceramics based on layered double (M2+,M3+) hydroxide nanoparticles (LDHN) have been evaluated as a passive vector for drug and non-viral gene delivery. This paper identifies the attributes of LDHN as a passive delivery platform, judiciously selects and discusses issues in synthesis of physiologically relevant compositions, and demonstrates surface activation of (Mg2+,Al3+) LDHN; the latter a critical first step in the surface functionalisation process for active targeting. After a description of the layered double hydroxide (LDH) structure and unique attributes of LDHN as a passive platform, the advantages and issues of a robust LDHN surface functionalisation process for active targeting are identified. Next, the judicious selection of physiological relevant (Mg2+,Fe3+) and (Zn2+,Fe3+) LDH compositions is made, and their synthesis by precipitation and potential difficulties are discussed. Finally, the surface activation of (Mg2+,Al3+) LDHN is demonstrated by a bimolecular, nucleophilic substitution type reaction using acryloyl chloride.