Fig. 1. Schematic illustration of magneto-catalytic theranostics.

a Schematic of an encABC and its biomimetic mineralized procedure. The inner cores of encapsulin-produced magnetic iron oxide nanocomposites (eMIONs) have the optimal size for magnetic hyperthermia induction and consist of FeO subdomain-containing Fe₃O₄, with ~100% crystallinity, and have remnant magnetization, thus achieving prominent magnetic-heat induction in an alternative magnetic field (AMF). Moreover, eMIONs are great catalase-like nanozymes that can be utilized for catalytic therapy. b eMIONs accumulated in tumor sites and suppressed tumor growth effectively, as monitored by multimodality imaging. eMIONs retained in the tumor region augmented oxygen production to modulate the tumor microenvironment, decrease HIF-1α, and VEGF expression. Then, at an optimal time point, AMF not only induced MHT but also improved the catalytic efficacy, resulting in a magneto-catalytic therapy (MCT).