Macrophage-T cell hybrid membrane-camouflaged biomimetic nanoparticles ameliorate autoimmune myocarditis via suppressing macrophage pyroptosis by target gene silencing

Abstract Background Current management of myocarditis mainly relies on conventional approaches and immunosuppressive therapies. However, these strategies often yield limited efficacy. Our previous research revealed the pivotal role of macrophage pyroptosis in myocarditis pathogenesis. Therefore, targeted intervention to inhibit macrophage pyroptosis may provide new insights into myocarditis treatment. Purpose We previously identified interferon regulatory factor 1 (IRF1) as the key modulator of macrophage pyroptosis in myocarditis. In this study, we synthesized a nano-delivery platform consisting of a macrophage-T cell hybrid membrane-coated zeolitic imidazolate framework-8 (ZIF-8) encapsulating IRF1-small interfering RNA (siRNA@ZIF@HM). We aimed to evaluate its targeting capability and therapeutic efficacy for macrophage pyroptosis in myocarditis. Methods The fabrication of siRNA@ZIF@HM was validated using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cellular uptake, cytotoxicity, endolysosome escape, IRF1 silencing, and anti-pyroptotic effect were assessed using mouse bone marrow-derived macrophages and the mouse macrophage cell line J774A.1 and RAW264.7. An experimental autoimmune myocarditis (EAM) mouse model was induced in Balb/c mice for in vivo investigations. Pharmacokinetics and targeting capability were determined with ex vivo fluorescence imaging and immunofluorescence staining. Subsequently, mice were randomly allocated into control, EAM + siRNA, EAM + siRNA@ZIF, and EAM + siRNA@ZIF@HM groups to assess the therapeutic efficacy. Additionally, the biodistribution and biosafety of siRNA@ZIF@HM were also evaluated. Results TEM, DLS, and element mapping confirmed the successful fabrication of siRNA@ZIF@HM, with a diameter of approximately 130 nm. The nanoparticle exhibited pH responsiveness and membrane markers of macrophage and T lymphocytes (Figure 1). It demonstrated high targeting specificity for pro-inflammatory macrophages and myocarditis. Immunofluorescence microscopy revealed successful endolysosome escape of IRF1-siRNA in macrophages. Consequently, the nanoparticle significantly silenced IRF1 protein expression and suppressed macrophage pyroptosis both in vivo and in vitro, resulting in the amelioration of autoimmune myocarditis (Figure 2). Furthermore, the nanoparticle showed good biocompatibility with no significant changes observed in other organs. Conclusions The pH-responsive, macrophage-T cell hybrid membrane-coated biomimetic nanoparticle demonstrates promising capability for targeted siRNA delivery to myocardial inflammation sites, particularly pro-inflammatory macrophages. Additionally, targeting IRF1-mediated macrophage pyroptosis represents a potential therapeutic strategy for myocarditis treatment.Figure 1Figure 2