Hematocompatibility and interaction of layered double hydroxide nanomaterials with plasma proteins

Layered double hydroxides (LDHs) have attracted increasing interest as advanced drug delivery nanomaterials with a high biocompatibility. In order to verify the feasibility of LDHs as an injectable nanocarrier, it is important to study the possible interactions of LDH nanomaterials with biological components in blood vessels. We have investigated the interaction between LDH materials and blood cells or plasma proteins. LDH nanomaterials were synthesized to have uniform size and morphology for reducing unintended interaction with bio substances and characterized with X-ray diffraction, electron microscopy and zeta potential analyses. The hemolytic effects of LDHs, evaluated with whole human blood and aqueous LDH suspension, did not show any significant leakage of hemoglobin in 30 min at high concentration. The possible protein adsorption and agglomeration by LDHs was checked by the fluorescence measurement utilizing plasma itself or individual plasma proteins such as human serum albumin, fibrinogen and gamma-immunoglobulin. The fluorescence of proteins was not significantly reduced by LDH treatment exhibiting the inertness of LDH nanomaterials in the blood plasma condition. The surface interaction between LDH nanomaterials and blood cells was visualized with optical microscopy and no significant morphological change nor reduction in numbers of blood cells were observed upon LDH treatment.