Registered charity number: 207890 www.rsc.org/MaterialsB As featured in: See Won San Choi, Ha-Jin Lee et al., J. Mater. Chem. B, 2015, 3, 1001. Showcasing collaborative research from the Western Seoul Center, Korea Basic Science Institute and the Department of Chemical and Biological Engineering, Hanbat National University in Korea. Title: Polyelectrolyte-mediated hierarchical mesoporous calcium silicates: a platform for drug delivery carrier with ultrahigh loading capacity and controlled release behaviour Mesoporous calcium silicate hydrates (PAH-CS) with a large speciļ¬c surface area and pore volume have been developed by a poly(allylamine hydrochloride)-assisted synthetic method. The very high cationic charge of PAH-CS due to an excess of Ca 2+ and NH 3 + existing on its surface resulted in an extremely high loading capacity for anionic drugs and proteins.