Crystallization is widely used by synthetic chemists as a purification technique because it usually involves the expulsion of impurities. In this context, the efficient occlusion of guest nanoparticles within growing host crystals can be regarded as an interesting technical challenge. Indeed, although there are various reports of successful nanoparticle occlusion within inorganic crystals in the literature, robust design rules remain elusive. Herein, we report the synthesis of two pairs of sterically-stabilized diblock copolymer nanoparticles with identical compositions but varying particle size, morphology, stabilizer chain length and stabilizer chain surface density via polymerization-induced self-assembly (PISA). The mean degree of polymerization of the stabilizer chains dictates the spatial distribution of these model anionic nanoparticles within calcite (CaCO3): relatively short stabilizer chains merely result in near-surface occlusion, whereas sufficiently long stabilizer chains are essential to achieve uniform occlusion. This study reconciles the various conflicting literature reports of occluded nanoparticles being either confined to surface layers or uniformly occluded and hence provides important new insights regarding the criteria required for efficient nanoparticle occlusion within inorganic crystals.

Polymerization-induced self-assembly (PISA) mediated by reversible addition-fragmentation chain transfer (RAFT) polymerization offers ap latform technology for the efficient and versatile synthesis of well-defined sterically stabilized blockc opolymer nanoparticles.H erein we synthesizeaseries of such nanoparticles with tunable anionic charge density within the stabilizer chains,w hich are prepared via statistical copolymerization of anionic 2-(phosphonooxy)ethyl methacrylate (P) with non-ionic glycerol monomethacrylate (G). Systematic variation of the P/G molar ratio enables elucidation of the minimum number of phosphate groups per copolymer chain required to promote nanoparticle occlusion within amodel inorganic crystal (calcite). Moreover,the extent of nanoparticle occlusion correlates strongly with the phosphate content of the steric stabilizer chains.T his study is the first to examine the effect of systemically varying the anionic charge density of nanoparticles on their occlusion efficiency and sheds new light on maximizing the loading of guest nanoparticles within calcite host crystals.

The size control of nanomedicines for tumor diagnosis and therapy is of high importance, since it enables or disables deep and sufficient tumor penetration. Amphiphilic star-shaped block copolypept­(o)­ides offer substantial promise to precisely adjust the hydrophobic core and the hydrophilic corona, independent of each other, and therefore simultaneously control the size dimension in the interesting size range from 10 to 30 nm. To gain access to core–shell structures of such sizes, 3-arm and 6-arm PeptoStars, based on poly­(γ-tert-butyloxycarbonyl-l-glutamate)-b-polysarcosine (pGlu­(OtBu)-b-pSar), were prepared via controlled living ring-opening polymerization (ROP) of the corresponding N-carboxyanhydrides. Moreover, size exclusion chromatography (SEC) proves the presence of well-defined star shaped polymers with molecular weights from 38 to 88 kg/mol with low polymer dispersities of 1.16 to 1.23. By varying the α-helical peptide core and maintain a constant polysarcosine corona, hydrodynamic size analyses revealed the importance of using a sufficiently large and dense hydrophilic shielding corona to prevent aggregation of the hydrophobic core and obtain uniform-sized spherical-shaped particles with hydrodynamic diameters below 24 nm. Fluorescence correlation spectroscopy (FCS) additionally demonstrates the absence of protein adsorption in human plasma for 6-arm polypept­(o)­ide stars and thus confirms polysarcosine as stealthlike material.

Polymerization‐induced self‐assembly (PISA) mediated by reversible addition–fragmentation chain transfer (RAFT) polymerization offers a platform technology for the efficient and versatile synthesis of well‐defined sterically stabilized block copolymer nanoparticles. Herein we synthesize a series of such nanoparticles with tunable anionic charge density within the stabilizer chains, which are prepared via statistical copolymerization of anionic 2‐(phosphonooxy)ethyl methacrylate (P) with non‐ionic glycerol monomethacrylate (G). Systematic variation of the P/G molar ratio enables elucidation of the minimum number of phosphate groups per copolymer chain required to promote nanoparticle occlusion within a model inorganic crystal (calcite). Moreover, the extent of nanoparticle occlusion correlates strongly with the phosphate content of the steric stabilizer chains. This study is the first to examine the effect of systemically varying the anionic charge density of nanoparticles on their occlusion efficiency and sheds new light on maximizing the loading of guest nanoparticles within calcite host crystals.