Latest ArticlesSevere traumatic bone healing relies on the involvement of growth factors. However, excessive supplementation of growth factors can lead to ectopic ossification and inflammation. In this study, utilizing the neural regulatory mechanism of bone regeneration, we have developed a multifunctional three dimensions (3D) printed scaffold containing both vasoactive intestinal peptide (VIP) and nerve growth factor (NGF) as an effective new method for achieving bone defect regeneration. The scaffold is provided by a controlled biodegradable and biomechanically matched poly(lactide-ethylene glycol-trimethylene carbonate) (PLTG), providing long-term support for the bone healing cycle. Factor loading is provided by peptide fiber-reinforced biomimetic antimicrobial extracellular matrix (ECM) (B-ECM) hydrogels with different release kinetics, the hydrogel guides rapid bone growth and resists bacterial infection at the early stage of healing. Physical and chemical characterization indicates that the scaffold has good structural stability and mechanical properties, providing an ideal 3D microenvironment for bone reconstruction. In the skull defect model, compared to releasing VIP or NGF alone, this drug delivery system can simulate a natural healing cascade of controllable release factors, significantly accelerating nerve/vascular bone regeneration. In conclusion, this study provides a promising strategy for implanting materials to repair bone defects by utilizing neuroregulatory mechanisms during bone regeneration.
Acute lung injury (ALI) is a serious clinical condition with a high mortality rate. Oxidative stress and inflammatory responses play pivotal roles in the pathogenesis of ALI. ONOO− is a key mediator that exacerbates oxidative damage and microvascular permeability in ALI. Accurate detection of ONOO− would facilitate early diagnosis and intervention in ALI. Near-infrared fluorescence (NIRF) probes offer new solutions due to their sensitivity, depth of tissue penetration, and imaging capabilities. However, the developed ONOO− fluorescent probes face problems such as interference from other reactive oxygen species and easy intracellular diffusion. To address these issues, we introduced an innovative self-immobilizing NIRF probe, DCI2F-OTf, which was capable of monitoring ONOO− in vitro and in vivo. Importantly, leveraging the high reactivity of the methylene quinone (QM) intermediate, DCI2F-OTf was able to covalently label proteins in the presence of ONOO−, enabling in situ imaging. In mice models of ALI, DCI2F-OTf enabled real-time imaging of ONOO− levels and found that ONOO− was tightly correlated with the progression of ALI. Our findings demonstrated that DCI2F-OTf was a promising chemical tool for the detection of ONOO−, which could help to gain insight into the pathogenesis of ALI and monitor treatment efficacy.
D-D'-A type aza-borondipyrromethenes (aza-BODIPYs) were prepared by Suzuki cross-coupling reaction. Photothermal conversion efficiency of self-assemble aza-BODIPY-based nanoparticles (DA-azaBDP-NPs) with NIR-II emission (λem = 1065 nm) was 37.2% under near infrared (NIR) irradiation, and the outstanding cytotoxicity was triggered by coexistence of DA-azaBDP-NPs and the NIR irradiation, with the decrease of glioblastoma migration and the inhibition of glioblastoma proliferation. DA-azaBDP-NPs could promote glioblastoma autophagy and accelerate the process of cell death. The photothermal therapy (PTT) of DA-azaBDP-NPs can effectively induce glioblastoma death by apoptosis under the NIR irradiation, which is highly promising to be applied in vivo experiments of brain.
A computer-assisted chemical investigation of an intriguing photoreaction of norditerpenoids (3‒7) has been first reported, leading to not only their biomimetic conversion, but also the generation of several new products with uncommon 4,14-dioxabicyclo[10.2.1]pentadecane scaffold (8, 9, 12‒14). In bioassay, compounds 10 and 15 exhibited significant stimulation of GLP-1 secretion. This study has given an insight for the application of computational methods on the late-stage skeleton transformation of complex natural products towards new bioactive compounds.
Biomolecular condensates, also known as membraneless organelles, play a crucial role in cellular organization by concentrating or sequestering biomolecules. Despite their importance, synthetically mimicking these organelles using non-peptidic small organic molecules has posed a significant challenge. The present study reports the discovery of D008, a self-assembling small molecule that sequesters a unique subset of RNA-binding proteins. Analysis and screening of a comprehensive collection of approximately 1 million compounds in the Chinese National Compound Library (Shanghai) identified 44 self-assembling small molecules in aqueous solutions. Subsequent screening of the focused library, coupled with proteome analysis, led to the discovery of D008 as a small organic molecule with the ability to condensate a specific subset of RNA-binding proteins. In vitro experiments demonstrated that the D008-induced sequestration of RNA-binding proteins impeded mRNA translation. D008 may offer a unique opportunity for studying the condensations of RNA-binding proteins and for developing an unprecedented class of small molecules that control gene expression.
Insufficient endogenous H2O2 for generation of hydroxyl radicals (•OH) has strikingly compromised anti-tumor benefits of ferroptosis. Herein, we develop a H2O2 self-supplying nanoparticle based on a pH-responsive lipopeptide C18-pHis10. Inspired by the coordinate pattern of hemoglobin binding heme, Fe2+ and tetrakis(4-carboxyphenyl)porphyrin (TCPP) were delicately encapsulated by formation of coordination compounds with His. Ascorbgyl palmitate (AscP) was also incorporated into the nanoparticles for generation of H2O2 by reduction 1O2 produced from TCPP, meanwhile prevented Fe2+ from being oxidized. The protonation of pHis in acidic endo-lysosome induced the breakage of Fe2+/His/TCPP coordinate interactions, leading to accelerated release of payloads and the following escape to cytoplasm. Upon laser irradiation, TCPP produces excessive 1O2 followed by conversion to H2O2 in the presence of AscP, which is further catalyzed to lethal •OH by Fe2+ via Fenton reaction. The self-supplying H2O2 was found to result significantly higher accumulation of lipid peroxides and more effective tumor inhibition. Overall, this work sheds new a light on H2O2 self-supplying strategy to enhance ferroptosis by taking advantage of 1O2 generated by photodynamic therapy (PDT).
Postoperative recurrence and metastasis are still the main challenges of cancer therapy. Tumor vaccines that induce potent and long-lasting immune activation have great potential for postoperative cancer therapy. However, the clinical effects of therapeutic tumor vaccines are unsatisfactory due to immune escape caused by the lack of immunogenicity after surgery and the local fibrosis barrier of the tumor which limits effector T cell infiltration. To overcome these challenges, we developed an injectable hydrogel-based tumor vaccine, RATG, which contains whole tumor cell lysates (TCL), Toll-like receptor (TLR) 7/8 agonist imiquimod (R837) and an antifibrotic drug ARV-825. TCL and R837 were loaded onto the hydrogel to achieve a powerful reservoir of antigens and adjuvants that induced potent and lasting immune activation. More importantly, ARV-825 could be slowly and sustainably released in the tumor resection cavity to downregulate α-smooth muscle actin (α-SMA) and collagen levels, disintegrate fibrosis barriers and promote T cell infiltration after immune activation to reduce immune escape. In addition, ARV-825 also directly acted on the remaining tumor cells to degrade bromodomain-containing protein 4 (BRD4) which is a critical epigenetic reader overexpressed in tumor cells, inhibiting tumor cell migration and invasion. Therefore, our injectable hydrogel created a powerful immune niche in postoperative tumor resection cavity, significantly enhancing the efficacy of tumor vaccines. Our strategy potently activates the immune system and disintegrates the fibrotic barrier of residual tumors with immune microenvironment remodeling in situ, showing anti-recurrence and anti-metastatic effects, and provides a new paradigm for postoperative treatment of tumors.
Cu-based metal-organic frameworks (MOFs) are widely employed in CO2 reduction reactions (CO2RR). Mostly, the in-situ reconstructed derivatives such as Cu or Cu oxides during CO2RR are regarded as the catalytic active center for the formation of catalytic products. However, in many cases, the pristine MOFs still exist during the catalytic process, the key role of these pristine MOFs is often ignored in revealing the catalytic mechanism. Here, we designed two Cu(imidazole) with different coordination environments, namely CuN2 and Cu2N4 for CO2RR. The structures of the two MOFs were still remained after the catalytic reaction. We discovered that the pristine MOFs served as activation catalysts for converting CO2 into CO. Sequentially, the Cu-based derivatives, in the two cases, Cu(111) converted the CO into C2+ products. The CuN2 with more exposed Cu-N centers showed a higher FECO and a higher final FEC2+ than Cu2N4. This auto-tandem catalytic mechanism was supported by electrocatalytic performance, TPD-CO, HRTEM, SAED, XPS, in-situ XANES and XES and DFT computation. The auto-tandem catalytic mechanism provides a new route to design Cu-based MOF electrocatalysts for high product selectivity in CO2RR.
Two-dimensional (2D) transition metal sulfides (TMDs) are emerging and highly well received 2D materials, which are considered as an ideal 2D platform for studying various electronic properties and potential applications due to their chemical diversity. Converting 2D TMDs into one-dimensional (1D) TMDs nanotubes can not only retain some advantages of 2D nanosheets but also providing a unique direction to explore the novel properties of TMDs materials in the 1D limit. However, the controllable preparation of high-quality nanotubes remains a major challenge. It is very necessary to review the advanced development of one-dimensional transition metal dichalcogenide nanotubes from preparation to application. Here, we first summarize a series of bottom-up synthesis methods of 1D TMDs, such as template growth and metal catalyzed method. Then, top-down synthesis methods are summarized, which included self-curing and stacking of TMDs nanosheets. In addition, we discuss some key applications that utilize the properties of 1D-TMDs nanotubes in the areas of catalyst preparation, energy storage, and electronic devices. Last but not least, we prospect the preparation methods of high-quality 1D-TMDs nanotubes, which will lay a foundation for the synthesis of high-performance optoelectronic devices, catalysts, and energy storage components
Metal-organic frameworks (MOFs) provide great prospective in the photodegradation of pollutants. Nevertheless, the poor separation and recovery hamper their pilot- or industrial-scare applications because of their microcrystalline features. Herein, this challenge can be tackled by integrating Cu-MOFs into an alginate substrate to offer environmentally friendly, sustainable, facile separation, and high-performance MOF-based hydrogel photocatalysis platforms. The CuII-MOF 1 and CuI-MOF 2 were initially synthesized through a direct diffusion and single-crystal to single-crystal (SCSC) transformation method, respectively, and after the immobilization into alginate, more effective pollutant decontamination was achieved via the synergistic effect of the adsorption feature of hydrogel and in situ photodegradation of Cu-MOFs. Specifically, Cu-MOF-alginate composites present an improved and nearly completed Cr(VI) elimination at a short time of 15–25 min. Additionally, the congo red (CR) decolorization can be effectively enhanced in the presence of Cr(VI), and 1-alginate showed superior simultaneous decontamination efficiency of CR and Cr(VI) with 99% and 78%, respectively. Furthermore, Cu-MOF-alginate composites can maintain a high pollutant removal after over 10 continuous cycles (95% for Cr(VI) after 14 runs, and 90% for CR after 10 runs). Moreover, the Cr(VI)/CR degradation mechanism for Cu-MOF-alginate composite was investigated.