The regeneration of diabetic bone defects remains challenging as the innate healing process is impaired by glucose fluctuation, reactive oxygen species (ROS), and overexpression of proteinases (such as matrix metalloproteinases, MMPs). A “diagnostic” and therapeutic dual‐logic‐based hydrogel for diabetic bone regeneration is therefore developed through the design of a double‐network hydrogel consisting of phenylboronic‐acid‐crosslinked poly(vinyl alcohol) and gelatin colloids. It exhibits a “diagnostic” logic to interpret pathological cues (glucose fluctuation, ROS, MMPs) and determines when to release drug in a diabetic microenvironment and a therapeutic logic to program different cargo release to match immune‐osteo cascade for better tissue regeneration. The hydrogel is also shown to be mechanically adaptable to the local complexity at the bone defect. Furthermore, the underlying therapeutic mechanism is elucidated, whereby the logic‐based cargo release enables the regulation of macrophage polarization by remodeling the mitochondria‐related antioxidative system, resulting in enhanced osteogenesis in diabetic bone defects. This study provides critical insight into the design and biological mechanism of dual‐logic‐based tissue‐engineering strategies for diabetic bone regeneration.

Risk of implant failure increases profoundly in patients with pre‐existing conditions (e.g., diabetes). Current therapies adopt a one‐sided focus on the direct antibacterial properties of biomaterials and osteogenesis stimulation. However, in this study it is demonstrated that a “chain armor” structure (Ce‐TA) that mainly targets the regulation of the local pathological microenvironment, provides a novel solution to scavenge reactive oxygen species (ROS) by simulating superoxide dismutase and catalase and significantly improving osteointegration under diabetic conditions. Ce‐TA based on a metal phenolic network biological functional interface is successfully constructed. Ce‐TA, an ultrathin armor structure, is biocompatible and facile. Through in vitro assays it is demonstrated that Ce‐TA reshapes the diabetic microenvironment into a regenerative one in a microenvironment‐responsive manner, where Ce‐TA regulates hypoxia‐inducible factor 1α (HIF‐1α) activity by reducing the level of mitochondrial ROS, and effectively alleviates mitochondrial dysfunction and reprogrammes macrophages to a pro‐healing state. Furthermore, it is confirmed that Ce‐TA shows excellent therapeutic effects on the reducing postoperative infection and enhances osteointegration of intra‐osseous implants in diabetic rat models. The proposed strategy opens up a promising opportunity for repurposing metals with intrinsic enzyme‐like activity for the goal of enhancing the osteointegration of devices with orthopedic and dental applications among diabetic patients.

The regeneration of bone defects in patients with diabetes mellitus (DM) is remarkably impaired by hyperglycemia and over-expressed proinflammatory cytokines, proteinases (such as matrix metalloproteinases, MMPs), etc. In view of the fact that exosomes represent a promising nanomaterial, herein, we reported the excellent capacity of stem cells from apical papilla-derived exosomes (SCAP-Exo) to facilitate angiogenesis and osteogenesis whether in normal or diabetic conditions in vitro. Then, a bioresponsive polyethylene glycol (PEG)/DNA hybrid hydrogel was developed to support a controllable release of SCAP-Exo for diabetic bone defects. This system could be triggered by the elevated pathological cue (MMP-9) in response to the dynamic diabetic microenvironment. It was further confirmed that the administration of the injectable SCAP-Exo-loaded PEG/DNA hybrid hydrogel into the mandibular bone defect of diabetic rats demonstrated a great therapeutic effect on promoting vascularized bone regeneration. In addition, the miRNA sequencing suggested that the mechanism of dual-functional SCAP-Exo might be related to highly expressed miRNA-126-5p and miRNA-150-5p. Consequently, our study provides valuable insights into the design of promising bioresponsive exosome-delivery systems to improve bone regeneration in diabetic patients.

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Periodontitis is a widespread oral disease characterized by continuous inflammation of the periodontal tissue and an irreversible alveolar bone loss, which eventually leads to tooth loss. Four-octyl itaconate (4-OI) is a cell-permeable itaconate derivative and has been recognized as a promising therapeutic target for the treatment of inflammatory diseases. Here, we explored, for the first time, the protective effect of 4-OI on inhibiting periodontal destruction, ameliorating local inflammation, and the underlying mechanism in periodontitis. Here we showed that 4-OI treatment ameliorates inflammation induced by lipopolysaccharide in the periodontal microenvironment. 4-OI can also significantly alleviate inflammation and alveolar bone loss via Nrf2 activation as observed on samples from experimental periodontitis in the C57BL/6 mice. This was further confirmed as silencing Nrf2 blocked the antioxidant effect of 4-OI by downregulating the expression of downstream antioxidant enzymes. Additionally, molecular docking simulation indicated the possible mechanism under Nrf2 activation. Also, in Nrf2−/− mice, 4-OI treatment did not protect against alveolar bone dysfunction due to induced periodontitis, which underlined the importance of the Nrf2 in 4-OI mediated periodontitis treatment. Our results indicated that 4-OI attenuates inflammation and oxidative stress via disassociation of KEAP1-Nrf2 and activation of Nrf2 signaling cascade. Taken together, local administration of 4-OI offers clinical potential to inhibit periodontal destruction, ameliorate local inflammation for more predictable periodontitis.

BackgroundDoxorubicin (DOX) is one of the most effective chemotherapeutic agents available; however, its use is limited by the risk of serious cardiotoxicity. Danshensu (DSS), an active ingredient in Salvia miltiorrhiza, has multiple cardioprotective effects, but the effect of DSS on DOX-induced cardiotoxicity has not been reported.ObjectivesPredicting the targets of DOX-induced cardiotoxicity and validating the protective effects and mechanisms of DSS.Methods(1) Using methods based on network pharmacology, DOX-induced cardiotoxicity was analyzed by data analysis, target prediction, PPI network construction and GO analysis. (2) The cardiotoxicity model was established by continuous intraperitoneal injection of 15 mg/kg of DOX into mice for 4 days and the protective effects and mechanism were evaluated by treatment with DSS.ResultsThe network pharmacology results indicate that CAT, SOD, GPX1, IL-6, TNF, BAX, BCL-2, and CASP3 play an important role in this process, and Keap1 is the main target of DOX-induced cardiac oxidative stress. Then, based on the relationship between Keap1 and Nrf2, the Keap1-Nrf2/NQO1 pathway was confirmed by animal experiments. In the animal experiments, by testing the above indicators, we found that DSS effectively reduced oxidative stress, inflammation, and apoptosis in the damaged heart, and significantly alleviated the prolonged QTc interval caused by DOX. Moreover, compared with the DOX group, DSS elevated Keap1 content and inhibited Nrf2, HO-1, and NQO1.ConclusionThe results of network pharmacology studies indicated that Keap1-Nrf2/NQO1 is an important pathway leading to DOX-induced cardiotoxicity, and the results of animal experiments showed that DSS could effectively exert anti-oxidative stress, anti-inflammatory and anti-apoptotic therapeutic effects on DOX-induced cardiotoxicity by regulating the expression of Keap1-Nrf2/NQO1.

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