Elasticity in Macrophage‐Synthesized Biocrystals

Abstract

Supramolecular crystalline assembly constitutes a rational approach to bioengineer intracellular structures. Here, biocrystals of clofazimine (CFZ) that form in vivo within macrophages were measured to have marked curvature. Isolated crystals, however, showed reduced curvature suggesting that intracellular forces bend these drug crystals. Consistent with the ability of biocrystals to elastically deform, the inherent crystal structure of the principal molecular component of the biocrystals—the hydrochloride salt of CFZ (CFZ‐HCl)—has a corrugated packing along the (001) face and weak dispersive bonding in multiple directions. These characteristics were previously found to be linked to the elasticity of other organic crystals. Internal stress in bent CFZ‐HCl led to photoelastic effects on the azimuthal orientation of polarized light transmittance. We propose that elastic, intracellular crystals can serve as templates to construct functional microdevices with different applications.Clofazimine hydrochloride (CFZ‐HCl) crystals, the primary component of CFZ‐associated biocrystals that intracellularly crystallize in macrophage cells exhibit elastic behavior. The multi‐directional interactions established via the salt‐associated chloride and corrugated packing in the crystal structure of CFZ‐HCl allow for the crystal’s elasticity.