Non-healing wound is a common complication of diabetic patients associated with high morbidity and mortality. Engineered therapeutic hydrogels have enviable advantages in tissue regeneration, however, they are suboptimal for the healing of diabetic wounds characterized by reactive oxygen species (ROS) accumulation and chronic hypoxia. Here, a unique biological metabolism-inspired hydrogel, for ameliorating this hostile diabetic microenvironment, is presented. Consisting of natural polymers (hydrazide modified hyaluronic acid and aldehyde modified hyaluronic acid) and a metal-organic frameworks derived catalase-mimic nanozyme (𝝐-polylysine coated mesoporous manganese cobalt oxide), the engineered nanozyme-reinforced hydrogels can not only capture the endogenous elevated ROS in diabetic wounds, but also synergistically produce oxygen through the ROS-driven oxygen production ability. These fascinating properties of hydrogels protect skin cells (e.g., keratinocytes, fibroblasts, and vascular endothelial cells) from ROS and hypoxia-mediated death and proliferation inhibition. Diabetic wounds treated with the nanozyme-reinforced hydrogels highlight the potential of inducing the macrophages polarization from pro-inflammatory phenotype (M1) to anti-inflammatory subtype (M2). The hydrogel dressings demonstrate a prominently accelerated healing rate as shown by alleviating the excessive inflammatory, inducing efficiently proliferation, re-epithelialization, collagen deposition, and neovascularization. This work provides an effective strategy based on nanozyme-reinforced hydrogel as a ROS-driven oxygenerator for enhancing diabetic wound healing.

We use the density matrix renormalization group method to study the interplay of the localized and itinerant behaviors in the one-dimensional Kondo-Heisenberg model. We find signatures of simultaneously localized and itinerant behaviors of the local spins and attribute this duality to their simultaneous entanglement within the spin chain and with conduction electrons due to incomplete hybridization. We propose a microscopic definition of the hybridization parameter that measures this "partial" itinerancy. Our results provide a microscopic support for the dual nature of f -electrons and the resulting two-fluid behavior widely observed in heavy electron materials.Coexistence of superconductivity with competing magnetic orders has been observed in many heavy electron superconductors 1 . This exotic phenomenon supports the dual (simultaneously itinerant and localized) nature of felectrons. A phenomenological formulation of this idea in a two-fluid model has provided a unified explanation for a variety of anomalous properties of heavy electron materials and yielded a number of surprising predictions including the universal logarithmic temperature scaling of the heavy electron density of states 2-7 . The two-fluid model provides a possible solution to the Kondo lattice problem and a simple framework for understanding the heavy electron physics 6 . It proposes two coexisting and competing quantum fluids in the normal state of heavy electron materials: a spin liquid of partially hybridized f -moments and a heavy electron liquid that emerges as a composite state of conduction electrons and magnetic fluctuations of the local moments due to collective hybridization. Similar two-fluid behavior has also been observed in the cuprate 8 and pnictide 9 superconductors. However, despite much effort 10-13 , a satisfactory microscopic theory of the two-fluid behavior has not been achieved. In particular, it is not clear what the duality exactly means microscopically, how the f -electrons can be simultaneously itinerant and localized and how one can measure this "partial" itinerancy.In this work, we study the interplay of the localized and itinerant behaviors in the one-dimensional (1D) Kondo-Heisenberg model using the density matrix renormalization group (DMRG) method [14][15][16] . The Kondo-Heisenberg model contains by definition two distinct components: the conduction electrons and the local spins. The DMRG method allows us to numerically calculate the momentum distribution of the conduction electrons and the correlation spectrum of the local spins and use these to track the detailed evolution of both components with varying Kondo coupling. A joint analysis of these quantities suggests that each local spin entangles simultaneously with other local spins and conduction electrons in the intermediate coupling regime, giving rise to signatures of emergent heavy electrons in a background of partially hybridized spins. This provides a natural basis for the dual behavior of f -electrons and the two-fluid physics observed in heavy electr...

The periosteum is a connective tissue membrane adhering to the surface of bone tissue that primarily provides nutrients and regulates osteogenesis during bone development and injury healing. However, building an artificial periosteum with good adhesion properties and satisfactory osteogenesis for bone defect repair remains a challenge, especially using three-dimensional (3D) bioprinting. In this study, dopamine was first grafted onto the molecular chain of gelatin using N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide to activate the carboxyl group and produce modified gelatin-dopamine (GelDA). Next, a methacrylated gelatin (GelMA), methacrylated silk fibroin (SilMA), GelDA, and graphene oxide (GO) nanosheet composite bioink loaded with bone marrow mesenchymal stem cells was prepared and used for bioprinting. The physicochemical properties, biocompatibility, and osteogenic roles of the bioink and 3D bioprinted artificial periosteum were then systematically evaluated. The results showed that the developed bioink showed good thermosensitivity and printability and could be used to build 3D bioprinted artificial periosteum with satisfactory cell viability and high adhesion. Finally, the 3D bioprinted artificial periosteum could effectively enhance osteogenesis both in vitro and in vivo. Thus, the developed 3D bioprinted artificial periosteum can prompt new bone formation and provides a promising strategy for bone defect repair.