Crystal Growth: Two main routes for the growth of crystalline species are either via molecule-by-molecule attachment to existing nuclei or via the addition of preformed metastable precursors, but do these mechanisms need to be mutually exclusive? Lupulescu and Rimer (p. 729 ; see the Perspective by Dandekar and Doherty ) developed an in situ atomic force microscopy (AFM) technique to study the crystallization of materials under extreme conditions of temperature (25° to 300°C) and alkalinity (up to a pH of 13). The growth of the zeolite silicalite-1 involved both the attachment of metastable precursors and of individual molecules.

Significance: Approximately 40% of the global population is at risk for malaria infection and 300–660 million clinical episodes of Plasmodium falciparum malaria occur annually. During the malaria parasite lifecycle in human erythrocytes, heme released during hemoglobin catabolism is detoxified by sequestration into crystals. Many of the common antimalarials are believed to suppress the parasite by inhibiting hematin crystallization. We present, to our knowledge, the first evidence of the molecular mechanisms of hematin crystallization and antimalarial drug action as crystal growth inhibitors. These findings enable the identification and optimization of functional moieties that bind to crystal surface sites, thus providing unique guidelines for the discovery of novel antimalarials to combat increased parasite resistance to current drugs.