An injectable anti-microbial and adhesive hydrogel for the effective noncompressible visceral hemostasis and wound repair

Control of drug release from cotton fabric by nanofibrous mat

A drug delivery system (DDSs) was developed in the present study based on textile substrates as drug carriers and electrospun nanofibers as a controller of release rate. Three types of drugs consisting of ciprofloxacin (CIP), clotrimazole (CLO), and benzalkonium chloride (BEN) were loaded into the cover glass (CG) and cotton fabrics (CF1 and CF2) separately. Then, the drug-loaded substrates were coated with polycaprolactone (PCL) and polycaprolactone/gelatin (PCL/Gel) nanofibers with various thicknesses. The morphology and hydrophilicity of the electrospun nanofibers and the release profile of drug-loaded samples were investigated. FTIR, XRD, and in vitro biodegradability analysis were analyzed to characterize the drug delivery system. A morphological study of electrospun fibers showed the mean diameter of the PCL and PCL/Gel nanofibers 127 ± 25 and 178 ± 38 nm, respectively. The drug delivery assay revealed that various factors affect the rate of drug releases, such as the type of drug, the type of drug carrier, and the thickness of the covered nanofibers. The study highlights the ability of drugs to load substrates with coated nanofibers as controlled drug delivery systems. In conclusion, it is shown that the obtained samples are excellent candidates for future wound dressing applications.

Tungsten disulfide nanoflowers with multi-nanoenzyme activities for the treatment of acute liver injury

In this study, polyvinyl pyrrolidone modified tungsten disulfide (WS₂-PVP) nanoflower was synthesized using a simple and effective one-pot method. Owing to the surface polyvinyl pyrrolidone (PVP) modification, WS₂-PVP nanoflowers showed excellent colloidal stability in different circumstances, which can be well dispersed in water, saline, and cell culture medium. Meanwhile, the WS₂-PVP nanoflowers have a good biocompatibility both in vitro and in vivo. Further studies confirmed that the WS₂-PVP nanoflowers have the ability of simulating catalase, superoxide dismutase and glutathione peroxidase enzymes and scavenging reactive oxygen species (ROS). Therefore, WS₂-PVP nanoflowers were used to treat reactive oxygen species-related diseases, which showed the cell protection effect and significantly improved the treatment results of acute liver injury on mice. We hope that our findings will facilitate the development of nanomaterials with multiple enzymatic mimicking properties and further clinical application of tungsten-based ROS scavengers in biomedical therapy and research.

Degradation of methylene blue through Fenton-like reaction catalyzed by MoS2-doped sodium alginate/Fe hydrogel

In this study, a low-cost and high-performance MoS₂/sodium alginate (SA)/Fe (MSF) hydrogel catalyst was prepared. It was found that the MSF hydrogel could efficiently catalyze the degradation of methylene blue (MB) through the Fenton reaction without the addition of Fe²⁺. The reaction was initiated by Fe²⁺ which was derived from the cyclic redox reaction between MoS₂ and Fe³⁺ and produced large quantities of ·OH to degrade the MB. The effect of MoS₂ concentration, FeCl₃·6H₂O concentration, H₂O₂ dosage, solution pH, and light on the degradation was systematically studied. The MoS₂ concentration of 0.5 mg/ mL, FeCl₃·6H₂O concentration of 0.25 g/mL, 50 μL H₂O₂, and the pH of 4.0 were the optimized parameters. Moreover, it was found that the MB degraded faster under the infrared radiation. The MB removal rate reached as high as 98% within 15 min in the presence of a low concentration of H₂O₂ and the procedure could be repeated 5 times. The MSF hydrogel provided an effective and simple strategy for the sustainable degradation of organic pollutants in wastewater.

Synthetic and Biodegradable Molybdenum (IV) Diselenide Triggers the Cascade Photo- and Immunotherapy of Tumor

In this study, a polyvinylpyrrolidone (PVP)-decorated MoSe₂ (MoSe₂ -PVP) nanoparticle with excellent photothermal transforming ability and chlorin E6 (Ce6) loading capacity is designed for combined tumor photothermal therapy (PTT), tumor photodynamic therapy (PDT), and immunotherapy. The light-to-heat conversion efficiency under irradiation with an 808 nm near-infrared laser is as high as 59.28%. The MoSe₂ -PVP NPs could function as an artificial catalase and catalyze the decomposition of H₂ O₂ . Their catalytic activity and thermal durability are higher than the native catalase, which relieve the tumor hypoxia status and sensitize the tumor PDT. The data show that the synthetic MoSe₂ -PVP is biodegradable, owing to the oxidation of the Mo⁴⁺ to Mo⁶⁺ . Moreover, its degradation products could increase the proportion of mature dendritic cells and CD8⁺ thymus (T) cells and promote the infiltration of active CD8⁺ T cells in tumors. The immune checkpoint inhibitor, programmed cell death protein 1 monoclonal antibody is combined with MoSe₂ -PVP and it is found that its degradation product could efficiently change the immune microenvironment of the tumor.

Development of PVA-based microsphere as a potential embolization agent

The development of tissue adhesive embolization microspheres with imaging ability is one of the important methods to improve the efficacy of interventional embolization. This study reported the synthesis of iodine (I)-polyvinyl alcohol (PVA)@polydopamine (PDA) microspheres to achieve the computed tomography image, drug loading and controlled release, and the enhanced embolization of liver portal vein. The I-PVA@PDA microspheres with a diameter of 147.9 μm showed an excellent computed tomography imaging ability. Moreover, the introduction of PDA endowed the I-PVA@PDA microspheres with tissue adhesive ability and therefore the in vivo embolization effect was improved. The in vivo embolization results showed that focal necrosis of hepatocytes with necrotic cell fragments and inflammatory cell infiltration was observed in the liver tissue, proving that the I-PVA@PDA microspheres have an enhanced embolization effect than PVA particles. The I-PVA@PDA microspheres were further used to deliver and release of chemotherapeutic drugs (5-fluorouracil), which displayed an initial fast release (release amount: 29.74%) in the first 24 h and then a sustained release of 34.48% within 72 h. Moreover, as a universal platform, the PVA@PDA microspheres could combine with other imaging agents like Bi2S3, thus holding a great potential in the interventional treatment of different diseases.

All-in-one theranostic nano-platform based on polymer nanoparticles for BRET/FRET-initiated bioluminescence imaging and synergistically anti-inflammatory therapy for ulcerative colitis

Background

Ulcerative colitis (UC), a subtype of inflammatory bowel disease (IBD), has evolved into a global burden given its high incidence. There is a clinical need to create better diagnostic and therapeutic approaches to UC.

Results

We fabricated P-selectin binding peptide-decorated poly lactic-co-glycolic acid (PBP-PLGA-NP) doped with two lipophilic dyes, DiL and DiD. Meanwhile, two low-toxic anti-inflammatory natural products (betulinic acid [BA] and resveratrol [Res]) were co-loaded in the PBP-PLGA-NP system. The BA/Res-loaded NPs had an average size of around 164.18 nm with a negative zeta potential (− 25.46 mV). Entrapment efficiencies of BA and Res were 74.54% and 52.33%, respectively, and presented a sustained drug release profile. Further, the resulting PBP-PLGA-NP could be internalized by RAW 264.7 cells and Colon-26 cells efficiently in vitro and preferentially localized to the inflamed colon. When intravenously injected with luminol, MPO-dependent bioluminescence imaging to visualize tissue inflammation was activated by the bioluminescence and fluorescence resonance energy transfer (BRET-FRET) effect. Importantly, injected NPs could remarkably alleviate UC symptoms yet maintain intestinal microbiota homeostasis without inducing organ injuries in the mice models of colitis.

Conclusions

This theranostic nano-platform not only serves as a therapeutic system for UC but also as a non-invasive and highly-sensitive approach for accurately visualizing inflammation.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01299-8.

Nanofiber/hydrogel core-shell scaffolds with three-dimensional multilayer patterned structure for accelerating diabetic wound healing

Impaired angiogenesis is one of the predominant reasons for non-healing diabetic wounds. Herein, a nanofiber/hydrogel core–shell scaffold with three-dimensional (3D) multilayer patterned structure (3D-PT-P/GM) was introduced for promoting diabetic wound healing with improved angiogenesis. The results showed that the 3D-PT-P/GM scaffolds possessed multilayered structure with interlayer spacing of about 15–80 μm, and the hexagonal micropatterned structures were uniformly distributed on the surface of each layer. The nanofibers in the scaffold exhibited distinct core–shell structures with Gelatin methacryloyl (GelMA) hydrogel as the shell and Poly (d, l-lactic acid) (PDLLA) as the core. The results showed that the porosity, water retention time and water vapor permeability of the 3D-PT-P/GM scaffolds increased to 1.6 times, 21 times, and 1.9 times than that of the two-dimensional (2D) PDLLA nanofibrous scaffolds, respectively. The in vitro studies showed that the 3D-PT-P/GM scaffolds could significantly promote cell adhesion, proliferation, infiltration and migration throughout the scaffolds, and the expression of cellular communication protein-related genes, as well as angiogenesis-related genes in the same group, was remarkably upregulated. The in vivo results further demonstrated that the 3D-PT-P/GM scaffolds could not only effectively absorb exudate and provide a moist environment for the wound sites, but also significantly promote the formation of a 3D network of capillaries. As a result, the healing of diabetic wounds was accelerated with enhanced angiogenesis, granulation tissue formation, and collagen deposition. These results indicate that nanofiber/hydrogel core–shell scaffolds with 3D multilayer patterned structures could provide a new strategy for facilitating chronic wound healing.