Nonclassical Modes to Inhibit β‐Hematin Crystallization

Abstract Biological crystallization is a fundamental process that underlies both normal physiological functions and pathological conditions. Traditionally, classical nucleation theory and classical crystal growth pathways have provided the framework for understanding biological crystallization and its regulation. Over the past two decades, extensive studies have revealed significant deviations from this paradigm. Nonclassical nucleation pathways, characterized by metastable intermediates such as prenucleation clusters, dense liquid droplets, and amorphous precursors, have emerged as a critical modification of the crystal formation mechanisms. These intermediates significantly influence nucleation dynamics and modulate crystal growth. Therefore, they offer new opportunities for designing inhibitors that target interactions with intermediates or unique mechanisms to suppress crystallization. Here, this study summarizes the mechanistic principles of nonclassical inhibition of β‐hematin crystallization, which is a detoxification process vital to the survival of malaria parasites living within human erythrocytes. The distinct modes of inhibition of four antimalarial drugs are examined across different stages of crystallization from pre‐nucleation, through nucleation, to crystal growth. Current challenges and future perspectives in leveraging nonclassical pathways for therapeutic applications are discussed, including the potential of combination therapies and the impact of pharmacokinetic parameters.