Chiral Skeletons of Mesoporous Silica Nanospheres to Mitigate Alzheimer's β-Amyloid Aggregation.

Chiral mesoporous silica (mSiO) nanomaterials have gained significant attention during the past two decades. Most of them show a topologically characteristic helix; however, little attention has been paid to the molecular-scale chirality of mSiO frameworks. Herein, we report a chiral amide-gel-directed synthesis strategy for the fabrication of chiral mSiO nanospheres with molecular-scale-like chirality in the silicate skeletons. The functionalization of micelles with the chiral amide gels via electrostatic interactions realizes the growth of molecular configuration chiral silica sols. Subsequent modular self-assembly results in the formation of dendritic large mesoporous silica nanospheres with molecular chirality of the silica frameworks. As a result, the resultant chiral mSiO nanospheres show abundant large mesopores (∼10.1 nm), high pore volumes (∼1.8 cm·g), high surface areas (∼525 m·g), and evident CD activity. The successful transfer of the chirality from the chiral amide gels to composited micelles and further to asymmetric silica polymeric frameworks based on modular self-assembly leads to the presence of molecular chirality in the final products. The chiral mSiO frameworks display a good chiral stability after a high-temperature calcination (even up to 1000 °C). The chiral mSiO can impart a notable decline in β-amyloid protein (Aβ42) aggregation formation up to 79%, leading to significant mitigation of Aβ42-induced cytotoxicity on the human neuroblastoma line SH-ST5Y cells . This finding opens a new avenue to construct the molecular chirality configuration in nanomaterials for optical and biomedical applications.