The overactivated immune cells in the infectious lesion may lead to irreversible organ damages under severe infections. However, clinically used immunosuppressive anti‐inflammatory drugs will usually disturb immune homeostasis and conversely increase the risk of infections. Regulating the balance between anti‐inflammation and anti‐infection is thus critical in treating certain infectious diseases. Herein, considering that hydrogen peroxide (H₂O₂), myeloperoxidase (MPO), and neutrophils are upregulated in the inflammatory microenvironment and closely related to the severity of appendectomy patients, an inflammatory‐microenvironment‐responsive nanomedicine is designed by using poly(lactic‐co‐glycolic) acid (PLGA) nanoparticles to load chlorine E6 (Ce6), a photosensitizer, and luminal (Lum), a chemiluminescent agent. The obtained Lum/Ce6@PLGA nanoparticles, being non‐toxic within normal physiological environment, can generate cytotoxic single oxygen via bioluminescence resonance energy transfer (BRET) in the inflammatory microenvironment with upregulated H₂O₂ and MPO, simultaneously killing pathogens and excessive inflammatory immune cells in the lesion, without disturbing immune homeostasis. As evidenced in various clinically relevant bacterial infection models and virus‐induced pneumonia, Lum/Ce6@PLGA nanoparticles appeared to be rather effective in controlling both infection and inflammation, resulting in significantly improved animal survival. Therefore, the BRET‐based nanoparticles by simultaneously controlling infections and inflammation may be promising nano‐therapeutics for treatment of severe infectious diseases.

Drug delivery systems (DDS) with favorable serum stability, high intra-tumor accumulation and tumor specific drug release are highly desired for promoting chemotherapeutic efficacy.

Background: Neuroblastoma (NB), a type of solid tumor in children, has a poor prognosis. Few blood biomarkers can accurately predict the prognosis, including recurrence and survival, in children with NB. In this study, we found that the serum total cholesterol (Tchol) level was associated with the prognosis of patients through a retrospective study. Methods: Multivariate Cox regression model was used to identify the independent risk factors in the children with NB. Kaplan–Meier method was used to analyze the correlation between the common biomarkers, including the serum Tchol level, and the prognosis of the patients. ROC curves were used to predict the accuracy of the International Neuroblastoma Staging System (INSS) stage and Children’s Oncology Group (COG) risk stratification after adding the serum Tchol level. Results: Compared with the other patients, serum Tchol level was significantly increased in the relapsed and died patients (P < 0.05). Subsequently, serum Tchol level was found as an independent risk factor to affect the outcome of patients (P < 0.05). Finally, we added serum Tchol level into traditional stage and risk classification system to form the new INSS stage and COG risk classification system. It was found that the areas under the ROC curve (AUC) of recurrence-free survival in the new INSS stage and COG risk classification system were increased to 0.691 (95%CI: 0.535–0.847) and 0.748 (95%CI: 0.622–0.874), respectively. Moreover, the AUC areas of overall survival in the new INSS stage and COG risk classification system were increased to 0.722 (95%CI: 0.561–0.883) and 0.668 (95%CI: 0.496–0.819), respectively. Conclusion: We found that serum Tchol level, a clinical biomarker, is a risk factor for recurrence and death among the children with NB. The serum Tchol level could significantly increase the accuracy of the prediction for NB prognosis.

Sepsis, a life-threatening organ dysfunction induced by severe infection and uncontrolled host immune response, threatens the health of people all over the world. Herein, a type of nanoparticle formulation with simple components is synthesized by encapsulating monophosphoryl lipid A (MPLA), a TLR4 agonist, with poly(lactic-co-glycolic acid) (PLGA) nanoparticle. The obtained nanoparticles (MPLA@PLGA) could provide Escherichia coli (E. coli)-induced sepsis protection by regulating the immune system after sepsis challenge, including promoting the levels of various cytokines, boosting the percentage of natural killer cells and accelerating bacterial clearance. Notably, the survival mice pre-treated with these nanoparticles could resist repeated E. coli-induced sepsis. Our work therefore provides the great promise of MPLA@PLGA nanoparticles as a simple yet effective nano-drug for prevention and protection against E. coli-induced sepsis.