A Topologically Engineered Gold Island for Programmed In Vivo Stem Cell Manipulation.

Even a well-designed system can only control stem cell adhesion, release, and differentiation, while other cell manipulations such as in situ labeling and retention in target tissues, are difficult to achieve in the same system. Herein, native ligand cluster-mimicking islands, composed of topologically engineered ligand, anchoring point AuNP, nuclease mimetics Ce IV complexes and magnetic core Fe 3 O 4 , are designed to facilitate comprehensive cell manipulations in a programmable manner. Three islands with different amounts of AuNPs are constructed, which means tunable interligand spacing within a cluster. These nanostructures are chemically coupled to a substrate using DNA tethers. Under a tissue-penetrative magnetic field, this integrated system promotes stem cell adhesion, proliferation, mechanosensing, differentiation, detachment, in situ effective magnetic labeling and retention both in vitro and in vivo, offering fascinating opportunities for a biomimetic matrix in regenerative medicine.