Search

Precise and efficient regulation of microglia is vital for ischemic stroke therapy and prognosis. The infiltration of neutrophils into the brain provides opportunities for regulatory drugs across the blood–brain barrier, while hindered by neutrophil extracellular traps (NETs) and targeted delivery of intracerebral drugs to microglia. This study reports an efficient neutrophil hijacking nanoplatform (referred to as APTS) for targeted A151 (a telomerase repeat sequence) delivery to microglia without the generation of NETs. In the middle cerebral artery occlusion (MCAO) mouse model, the delivery efficiency to ischemic stroke tissues increases by fourfold. APTS dramatically reduces the formation of NETs by 2.2‐fold via reprogramming NETosis to apoptosis in neutrophils via a reactive oxygen species scavenging‐mediated citrullinated histone 3 inhibition pathway. Noteworthy, A151 within neutrophils is repackaged into apoptotic bodies following the death pattern reprogramming, which, when engulfed by microglia, polarizes microglia to an anti‐inflammatory M2 phenotype. After four times treatment, the cerebral infarction area in the APTS group decreases by 5.1‐fold. Thus, APTS provides a feasible, efficient, and practical drug delivery approach for reshaping the immune microenvironment and treating brain disorders in the central nervous system. [ABSTRACT FROM AUTHOR]

Liver fibrosis is a progressive histological manifestation that happens in almost all chronic liver diseases. An unabated liver fibrosis may eventually develop into liver cirrhosis or hepatocellular carcinoma. Yet, the strategy for reversal of liver fibrosis is still limited. Herein, a biomimetic nano‐regulator (P‐ZIF8‐cirDNAzyme) is developed to affect both collagen synthesis and degradation in liver to remodel collagen microenvironment. It is found that Zn (II) interference can efficiently inhibit collagen synthesis in activated hepatic stellate cells (aHSC) by inactivating proline 4 hydroxylase and affecting many fibrosis‐related signaling pathways. Meanwhile, Zn (II)‐dependent circular DNAzymes (cirDNAzymes) are used to efficiently silence tissue inhibitors of metalloproteinase‐1, accelerating the degradation of collagen. They act in concert to recover the balance between collagen deposition and degradation. Additionally, ZIF‐8‐cirDNAzyme is coated by platelet membrane (PM) for precisely targeting aHSC via PM's inflammatory tropism and CD62p–CD44 interaction. In carbon tetrachloride‐induced fibrotic mice, P‐ZIF‐8‐cirDNAzyme shows a potent anti‐fibrotic effect, greatly reducing the expression of collagen by 73.12% and restoring liver function nearly to normal. This work proposes a prospective platform enabling ion interference and gene silencing, collectively acting in aHSC for reversal of liver fibrosis. [ABSTRACT FROM AUTHOR]

Despite the promise of tumor starvation therapies, they are often associated with nonspecific and incomplete energy blockade. Here, a novel paradigm of starvation therapy is proposed to synergize the "Zn2+ interference"‐mediated glycolysis inhibition and Zn2+‐activating GLUT1 (Glucose transporter 1) tumor specific depletion for systematic energy exhaustion. It is discovered that ZIF‐8 (zinc imidazolate metal–organic frameworks) can induce abrupt intracellular Zn2+ elevation preferentially in melanoma cells, and then achieve effective glycolysis blockade through "Zn2+ interference"‐triggered decrease of NAD+ and inactivation of GAPDH, making it a powerful tumor energy nanoinhibitor. Meanwhile, Zn2+‐activating DNAzymes for specifically cleaving GLUT1 mRNA is designed. This DNAzyme can only be activated under intracellular Zn2+ overloading, and then directionally cut off glucose supply, which further restrains the adaptive up‐regulation of glycolytic flux after glycolysis inhibition in tumors. Afterward, DNAzymes are loaded in ZIF‐8 concurrently tethered by hyaluronic acid (HA), constructing a "nanoenabled energy interrupter ". Such a rational design presents a preferential accumulation tendency to tumor sites due to the active CD44‐targeting mechanisms, specifically achieves remarkable systematic energy exhaustion in melanoma cells, and affords 80.8% in tumor growth suppression without systemic toxicity in vivo. This work verifies a fascinating therapeutic platform enabling ion interference‐inductive starvation strategy for effective tumor therapy. [ABSTRACT FROM AUTHOR]