Search

Amplifying intracellular oxidative stress by organelle‐targeted reactive oxygen species (ROS) production combined with tumor cell‐specific gene disruption is a promising strategy for tumor treatment. However, due to the vulnerability of CRISPR/Cas9 ribonucleoproteins (RNPs) to ROS, co‐delivery of CRISPR/Cas9 RNPs and ROS generators to enhance the sensitivity of tumor cells to oxidative stress remains challenging. Herein, a cascade‐responsive "oxidative stress amplifier" (named DR‐TAF‐pHT/FA) is proposed, which can successively respond to cathepsin B, localized laser irradiation and ATP to generate ROS on the lysosomal membrane of tumor cells and release Cas9/sgNrf2 RNPs for efficient gene disruption. It is demonstrated that, under near infrared (NIR) irradiation, DR‐TAF‐pHT/FA achieves targeted rupture of lysosomal membranes, inducing significant intracellular oxidative stress. Meanwhile, due to the protective function of TAF coating (TA‐Fe3+ coordination self‐assembled networks), Cas9/sgNrf2 RNPs can safely escape into the cytoplasm and be released in response to ATP, further amplifying oxidative stress and promoting tumor cell apoptosis through efficient Nrf2 gene disruption. Treatment with DR‐TAF‐pHT/FA + NIR significantly improves tumor ablation efficiency and extends median survival time (over 70 days) in Hela xenograft models. This "oxidative stress amplifier" provides a new paradigm for multimodal and synergistic tumor therapy through precise lysosomal membrane bursting together with efficient Nrf2 gene disruption. [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]

Rainfall is one of the most significant natural factors for inducing landslides. The shallow saturated zone formed in slopes during rainfall is an important factor in inducing shallow landslides. In this paper, the characteristics and influencing factors of the saturated zone in soil slopes, and the relationship between the soil surface permeability coefficient and the rainfall intensity are analyzed. In this research, the equation that characterizes the rainfall intensity by the soil saturation is built based on the Mualem-van Genuchten model, which mathematically describes the soil water characteristics of unsaturated soils. Using this model, the target saturation of the slope surface during rainfall can be determined accurately, with an average deviation of − 0.008. Based on the equations, the innovative critical curve model of the rainfall intensity−time required to form the shallow saturated zone is established and calculated. The influence of the soil material, slope angle, rainfall intensity and antecedent rainfall on the critical curve for the shallow saturated zone is analyzed. The results indicate that for slopes of 30°~40°, it is easy for the shallow saturated zone to form, and the previous rainfall after more than 16 days has little impact on the critical curve. Furthermore, an innovative landslide prediction model, based on the critical curve for the shallow saturated zone and I-D modeling, is proposed to provide benchmarks for the prediction-specific characteristics of deep or shallow landslides, which is verified by the case of the Madiwan landslide. [ABSTRACT FROM AUTHOR]