Assembly of Emulsion-Based Cascade Vehicles for Combination Oxygen-Chemotherapy in Diabetic Wound Healing.

High blood glucose and insufficient angiogenesis in diabetic wounds prevent healing, often leading to amputation or death. To address this, a multifunctional emulsion loaded with simvastatin and stabilized by enzymes was synthesized using ultrasound-assisted emulsification. This emulsion promotes angiogenesis and reduces blood glucose levels. Glucose oxidase and catalase at the emulsion interface catalyze a glucose cascading response, lowering the glucose concentration at the diabetic wound site and improving the wound microenvironment. Simvastatin in the emulsion further promotes angiogenesis. The emulsion significantly accelerated wound healing in diabetic rats, offering a promising approach to diabetic wound management.

Metal-Phenolic Network-Coated Nanoparticles as Stabilizers for the Engineering of Pickering Emulsions with Bioactivity.

Pickering emulsions stabilized by functional nanoparticles (NPs) have received considerable attention for improving the physical stability and biological function of NPs. Herein, hydrophobic polyphenols were chosen as phenolic ligands to form metal-phenolic network (MPN) coatings on NPs (e.g., silica, polystyrene) mediated by the sono-Fenton reaction. The MPN coatings modulated the surface wettability and charges of NPs and achieved emulsification behavior for preparing Pickering emulsions with pH responsiveness and oxidation resistance. A series of polyphenols, including resveratrol, rutin, naringin, and curcumin, were used to form MPN coatings on NPs, which served as stabilizers for the engineering of functionalized oil-in-water (O/W) Pickering emulsions. This work provides a new avenue for the use of hydrophobic polyphenols to modulate NP emulsifiers, which broadens the application of polyphenols for constructing Pickering emulsions with antioxidant properties.

Dual-gradient enabled ultrafast biomimetic snapping of hydrogel materials.

The design of materials that can mimic the complex yet fast actuation phenomena in nature is important but challenging. Herein, we present a new paradigm for designing responsive hydrogel sheets that can exhibit ultrafast inverse snapping deformation. Dual-gradient structures of hydrogel sheets enable the accumulation of elastic energy in hydrogels by converting prestored energy and rapid reverse snapping (<1 s) to release the energy. By controlling the magnitude and location of energy prestored within the hydrogels, the snapping of hydrogel sheets can be programmed to achieve different structures and actuation behaviors. We have developed theoretical model to elucidate the crucial role of dual gradients and predict the snapping motion of various hydrogel materials. This new design principle provides guidance for fabricating actuation materials with applications in tissue engineering, soft robotics, and active medical implants.

MicroRNA-126/stromal cell-derived factor 1/C-X-C chemokine receptor type 7 signaling pathway promotes post-stroke angiogenesis of endothelial progenitor cell transplantation.

Stroke is the most common cause of mortality worldwide. Post-stroke angiogenesis is of great significance to the treatment of strokes. The aim of the present study was to investigate the mechanism underlying the angiogenesis-promoting effect of microRNA­126 (miR­126)­associated signaling pathways using a stroke model in vivo and a cell migration model in vitro. Bone marrow­derived endothelial progenitor cells (EPCs) were extracted and identified using a density gradient method. Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was performed to examine the expression levels of miR­126 and C­X­C chemokine receptor type 7 (CXCR7). Target genes of miR­126 were analyzed using TargetScan software version 7.1 (www.targetscan.org/). In addition, a reporter gene assay and RT­qPCR were performed to determine the target genes of miR­126. The effect of miR­126 on cell migration was examined using a cell migration model in vitro and a middle cerebral artery occlusion model of mice was established in vivo. The miR­126 antagomir­treated EPCs were infused into stroke mice. Microvessel density, nerve function score and infarction volume were assessed. Flow cytometric analysis indicated that cluster of differentiation (CD)34, CD133 and vascular endothelial growth factor receptor 2 were partly expressed on the cell surface of bone marrow­derived EPCs. In addition, the expression levels of Di­acetylated­low density lipoprotein and Ulex europaeus agglutinin 1 were positive. Stromal cell­derived factor 1 (SDF-1) was identified as a target gene of miR­126, which was confirmed by a reporter gene assay and RT­qPCR. Cell migration examination demonstrated that the neutralizing antibody of CXCR7 blocked miR­126 angomir­induced migration of EPCs. Microvessel density increased, while nerve function score and infarction volume decreased following infusion of miR-126 angomir­treated EPCs. Furthermore, miR­126 angomir improved the efficacy of EPC treatment. Thus, miR­126 improved the migration of EPCs via the miR­126/SDF­1/CXCR7 signaling pathway.