Sol-gel chemistry with organoalkoxysilane precursors combines the synthetic accessibility of silica with organic functionality encoded covalently into the framework. In this talk I will highlight how templated synthesis can exploit this chemistry across a wide range of length scales to give morphologically well-defined nanoparticles that respond to stimuli, are multifunctional by design, and address biomedical needs such as drug delivery, prodrug activation and imaging.
The first part concerns organosilica nanocages prepared with control over size and shape in the range of tens of nanometers.[1] Disulfide bridges built into the framework render these objects degradable in the presence of reducing agents, while their porous shell and hollow interior allow bioactive molecules to be captured and released on demand for targeted delivery. Beyond biomedical use, the same combination of a confined interior and degradability on demand provides an environment in which to study fundamental processes, including the control of dynamic supramolecular aggregation inside living cells.[2]
The second part moves to molecular precision in nanomaterials. A sustainable emulsion route converts commercial organoalkoxysilanes bearing amino groups into cubic polyamine silsesquioxanes that are stable in water, monodisperse and ultrasmall (below 5 nm), and that carry a defined number of functional groups.[3] These biocompatible nanomaterials can be engineered to act as aminocatalysts that are switched on by a chemical stimulus, and this reactivity has been exploited for metal-free prodrug activation. The same polyamine arms coordinate several metal ions per cage, opening a route to radiolabeled tracers for imaging.
The talk closes with perspectives on the design of precision nanotheranostics and on the challenges that remain.
References:
[1] ACS Nano 2021, 15, 9701-9716
[2] J. Am. Chem. Soc 2021, 143, 7681-7687
[3] Angew. Chem. Int. Ed 2026, 65, e8446184