Shibo Xu,Linna Chang,Xingjun Zhao,Yanan Hu,Yiyi Lin,Zhenhua Chen,Xiuli Ren,Xifan Mei
Osteoarthritis (OA), a widespread degenerative disease characterized by cartilage destruction, has emerged as a public health challenge in the current aging society. In addition to applied steroids and surgery, near-infrared (NIR) sensitive nano-enzyme for the treatment of osteoarthritis through mitochondrial repair and cartilage protection is attractive and promising. In this study, a NIR sensitive multifunctional heterostructure (EGCG (Epigallocatechin gallate) decorated Au-Ag nano-jars ( [email protected] )) was introduced as an enzyme-sensitive active nanoplatform for the treatment of osteoarthritis. Molecular biology results indicated that [email protected] possesses intrinsic properties of anti-oxidative stress and was able to reduce the apoptosis rate of chondrocytes by 83.3%. The area of the intra-articular joint cavity injected with [email protected] can be elevated to 46.6 °C under NIR to promote the release of EGCG further to induce cartilage regeneration. X-ray radiography and section staining showed that [email protected] reduced cartilage damage and decreased OARSI scores by approximately 52% after 8 weeks of treatment in a surgically induced OA model. The results demonstrated that this multifunctional enzyme-like nanoplatform with a synergistic NIR sensitive property to facilitate cartilage migration and regeneration repair provides a promising OA treatment strategy. Statement of significance 1. NIR-sensitive nano-enzyme is gaining much attention in the field of biomedical materials . 2. EGCG decorated Au-Ag nano-heterostructures were utilized as NIR-sensitive nano-enzymes for the treatment of osteoarthritis through mitochondrial repair and cartilage protection. 3. The obtained multifunctional Au-Ag nano-heterostructures are promising for osteoarthritis treatment.
We aimed to explore the effects of emodin on the energy metabolism of myocardial cells in rats with post-myocardial infarction (MI) heart failure (HF) and the extracellular signal-regulated kinase (ERK) pathway. The model of MI was established by ligation of the left anterior descending branch. After 4 weeks, the rats with left ventricular ejection fraction (LVEF) of ≤45% were used aspost-MI HF model animals and randomly divided into model, low-dose, middle-dose, high-dose and control groups (n=10). Low-, middle- and high-dose groups were gavaged with 20 mg/kg, 40 mg/kg and 60 mg/kg emodin daily, respectively. After administration for 14 d, the changes in LVEF, left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD) and interventricular septum thickness (IVS) were analyzed. The apoptosis rate of myocardial cells was detected by TUNEL staining. The levels of serum cardiac troponin I (cTnI) and peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1) were determined using ELISA, and the expressions of mitochondrial respiratory chain complex I protein and phosphorylated-ERK (p-ERK) in myocardial tissues were determined by Western blotting. Compared with model group, LVEDD, LVESD, apoptosis rate of myocardial cells, levels of serum cTnI and PGC-1, and expressions of complex I and p-ERK in myocardial tissues significantly decreased, while LVEF and IVS increased in low-dose, middle-dose, high-dose and control groups (P<0.05). The changes in the above indices were significantly dependent on the dose of emodin (P<0.05).Emodin can significantly relieve post-MI HF, reduce the apoptosis rate of myocardial tissues, and ameliorate the cardiac function of rats.