Sequential ultrasound-driven dynamic control of macrophage polarization combined with hydrogel for mechano-chemical synergistic tissue repair

Abstract

Precise regulation of macrophage fate is crucial for effective management of inflammation. However, conventional biochemical strategies often suffer from limitations in safety and efficiency, necessitating the development of more effective and controllable alternatives. In this study, we develop an ultrasound-engineered cell culture device capable of delivering finely tuned ultrasonic mechanical stimulation and demonstrate for the first time that ultrasound can remotely and dynamically modulate macrophage phenotypic fate. Our results demonstrate that ultrasound stimulation not only induces flexible transitions between macrophage subtypes but also exhibits superior immunomodulatory performance in induction efficiency, dynamic responsiveness, and spatio-temporal controllability compared to classical biochemical methods. Transcriptome sequencing reveals that ultrasound directionally polarizes M2a macrophages via activation of the integrin αXβ2/TGF-β/c-Fos/IL-10 pathway. Based on the programmable dynamic control of macrophage phenotype, we propose “sequential ultrasound therapy” and combine it with metformin hydrogel with controlled-release function to construct a physicochemically coordinated “inflammatory switch and angiogenesis promotion” therapeutic platform, exhibiting superior inflammatory repair effects than single treatment for in vivo diabetic wounds and myocardial infarction models. Overall, this study not only advances the mechanistic understanding of ultrasound in tissue repair but also proposes a remote, non-invasive ultrasound immunotherapy paradigm with clinical translation potential.