Latest ArticlesPostoperative 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.
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.
Singlet oxygen (1O2), as the primary reactive oxygen species in photodynamic therapy, can effectively induce excessive oxidative stress to ablate tumors and kill germs in clinical treatment. However, monitoring endogenous 1O2 is greatly challenging due to its extremely short lifetime and high reactivity in biological condition. Herein, we report an ultra-high signal-to-ratio near-infrared chemiluminescent probe (DCM-Cy) for the precise detection of endogenous 1O2 during photodynamic therapy (PDT). The methoxy moiety was removed from enolether unit in DCM-Cy to suppress the potential self-photooxidation reaction, thus greatly eliminating the photoinduced background signals during PDT. Additionally, the compact cyclobutane modification of DCM-Cy resulted in a significant 6-fold increase in cell permeability compared to conventional adamantane-dioxane probes. Therefore, our "step-by-step" strategy for DCM-Cy addressed the limitations of traditional chemiluminescent (CL) probes for 1O2, enabling effectively tracking of endogenous 1O2 level changes in living cells, pathogenic bacteria and mice in PDT.
Designing advanced hydrogels with controlled mechanical properties, drug delivery manner and multifunctional properties will be beneficial for biomedical applications. However, the further development of hydrogel is limited due to its poor mechanical property and structural diversity. Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties. Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel, but also expand the functionality of hydrogel. Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods. In this review, we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities. In addition, further development and application prospects of the micelle-hydrogels composites have also been addressed.
Constructing multi-dimensional hydrogen bond (H-bond) regulated single-molecule systems with multi-emission remains a challenge. Herein, we report the design of a new excited-state intramolecular proton transfer (ESIPT) featured chromophore (HBT-DPI) that shows flexible emission tunability via the multi-dimensional regulation of intra- and intermolecular H-bonds. The feature of switchable intramolecular H-bonds is induced via incorporating several hydrogen bond acceptors and donors into one single HBT-DPI molecule, allowing the "turn on/off" of ESIPT process by forming isomers with distinct intramolecular H-bonds configurations. In response to different external H-bonding environments, the obtained four types of crystal/cocrystals vary in the contents of isomers and the molecular packing modes, which are mainly guided by the intermolecular H-bonds, exhibiting non-emissive features or emissions ranging from green to orange. Utilizing the feature of intermolecular H-bond guided molecular packing, we demonstrate the utility of this fluorescent material for visualizing hydrophobic/hydrophilic areas on large-scale heterogeneous surfaces of modified poly(1,1-difluoroethylene) (PVDF) membranes and quantitatively estimating the surface hydrophobicity, providing a new approach for hydrophobicity/hydrophilicity monitoring and measurement. Overall, this study represents a new design strategy for constructing multi-dimensional hydrogen bond regulated ESIPT-based fluorescent materials that enable multiple emissions and unique applications.
Glioma is a severe malignant brain tumor marked by an exceedingly dire prognosis and elevated incidence of recurrence. The resilience of such tumors to chemotherapeutic agents, coupled with the formidable obstacle the blood-brain barrier (BBB) presents to most pharmacological interventions are major challenges in anti-glioma therapy. In an endeavor to surmount these impediments, we have synergized pH-sensitive nanoparticles carrying doxorubicin and apatinib to amplify the anti-neoplastic efficacy with cyclic arginine–glycine–aspartate acid (cRGD) modification. In this study, we found that the combination of doxorubicin (DOX) and apatinib (AP) showed a significant synergistic effect, achieved through cytotoxicity and induction of apoptosis, which might be due to the increased intracellular uptake of DOX following AP treatment. Besides, polycaprolactone-polyethylene glycol-cRGD (PCL-PEG-cRGD) drug carrier could cross the BBB by its targeting ability, and then deliver the drug to the glioma site via pH-responsive release, increasing the concentration of the drugs in the tumor. Meanwhile, DOX/AP-loaded PCL-PEG-cRGD nanoparticles effectively inhibited cell proliferation, enhanced glioma cell apoptosis, and retarded tumor growth in vivo. These results collectively identified DOX/AP-loaded PCL-PEG-cRGD nanoparticles as a promising therapeutic candidate for the treatment of glioma.
Diabetic kidney disease (DKD) is recognized as a severe complication in the development of diabetes mellitus (DM), posing a significant burden for global health. Major characteristics of DKD kidneys include tubulointerstitial oxidative stress, inflammation, excessive extracellular matrix deposition, and progressing renal fibrosis. However, current treatment options are limited and cannot offer enough efficacy, thus urgently requiring novel therapeutic approaches. Tetrahedral framework nucleic acids (tFNAs) are a novel type of self-assembled DNA nanomaterial with excellent structural stability, biocompatibility, tailorable functionality, and regulatory effects on cellular behaviors. In this study, we established an in vitro high glucose (HG)-induced human renal tubular epithelial cells (HK-2 cells) pro-fibrogenic model and explored the antioxidative, anti-inflammatory, and antifibrotic capacity of tFNAs and the potential molecular mechanisms. tFNAs not only effectively alleviated oxidative stress through reactive oxygen species (ROS)-scavenging and activating the serine and threonine kinase (Akt)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway but also inhibited the production of pro-inflammatory factors such as tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in diabetic HK-2 cells. Additionally, tFNAs significantly downregulated the expression of Collagen I and α-smooth muscle actin (α-SMA), two representative biomarkers of pro-fibrogenic myofibroblasts in the renal tubular epithelial-mesenchymal transition (EMT). Furthermore, we found that tFNAs exerted this function by inhibiting the Wnt/β-catenin signaling pathway, preventing the occurrence of EMT and fibrosis. The findings of this study demonstrated that tFNAs are naturally endowed with great potential to prevent fibrosis progress in DKD kidneys and can be further combined with emerging pharmacotherapies, providing a secure and efficient drug delivery strategy for future DKD therapy.
Diseases associated with bacterial infection, especially those caused by gram-negative bacteria, have been posing a serious threat to human health. Photodynamic therapy based on aggregation-induced emission (AIE) photosensitizer have recently emerged and provided a promising approach for bacterial discrimination and efficient photodynamic antimicrobial applications. However, they often suffer from the shorter excitation wavelength and lower molar extinction coefficients in the visible region, severely limiting their further applications. Herein, three novel BF2-curcuminoid-based AIE photosensitizers, TBBC, TBC and TBBC-C8, have been rationally designed and successfully developed, in which OCH3- and OC8H17-substituted tetraphenylethene (TPE) groups serve as both electron donor (D) and AIE active moieties, BF2bdk group functions as electron acceptor (A), and styrene (or ethylene) group as π-bridge in this D-π-A-π-D system, respectively. As expected, these resulting BF2-curcuminoids presented solvent-dependent photophysical properties with large molar extinction coefficients in solutions and excellent AIE properties. Notably, TBBC showed an effective singlet oxygen generation efficiency thanks to the smaller singlet-triplet energy gap (ΔEST), and remarkable photostability under green light exposure at 530 nm (8.9 mW/cm2). More importantly, TBBC was demonstrated effectiveness in selective staining and photodynamic killing of Escherichia coli (E. coli) in vitro probably due to its optimal molecular size compared with TBC and TBBC-C8. Therefore, TBBC will have great potential as a novel AIE photosensitizer to apply in the discrimination and selective sterilization between Gram-positive and Gram-negative bacteria.
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).
Severe 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.