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Refractory diabetic wounds are a devastating and rapidly growing clinical problem, which is associated with high incidence rates, mortality, and recurrence rates. Therapeutic angiogenesis in wound tissues is essential to the healing of diabetic wounds. However, the presence of excessive oxidative stress in diabetic wounds hinders angiogenesis, and conventional anti-oxidative approaches are inefficient to compensate for the systematically impaired angiogenesis. Here, a multifunctional supramolecular hyaluronic acid hydrogel dressing for diabetic wounds is successfully designed and constructed (GHPM). The GHPM hydrogel features outstanding properties, including excellent tissue adhesion, antibacterial ability, conductivity, and antioxidant properties. Based on the dynamic crosslinking structure, the GHPM hydrogel also presents adequate injectable and self-healing capabilities, which play a vital role in covering irregular or deep wounds. Additionally, diabetic wounds treated with GHPM hydrogel showed a significant acceleration of wound closure by preventing wound infection, reducing oxidative stress, and accelerating collagen deposition. More interestingly, the combination of electrical stimulation and GHPM hydrogel can effectively promote angiogenesis and neurogenesis, further accelerating diabetic wound healing in an all-around way. This advanced collaborative strategy opens a new avenue in treating diabetic wounds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Osteosarcoma is difficult to be resected through surgical operations without damage to the bone matrix, while chemotherapy and radiotherapy induce inevitable systemic injury. It is still a major challenge to develop a novel treatment suitable for the complex anatomical structure of the bone. Herein, inspired by lotus seedpods, injectable hydrogels with long-term retention for synergistic osteosarcoma treatment were developed. Gold nanoclusters (GNCs) with strong fluorescence (FL) and computed tomography (CT) imaging effects represented the lotus seeds. The oxidized hyaluronic acid (HA-ALD) chain resembled the stem. HA-ALD and GNCs form crosslinking-assembled hydrogels abbreviated as HG-CAHs through dynamic amide bonds. Compared with DNA-, pH-, and light-mediated assembly, this in situ method induces enhanced photothermal therapy (PTT) ability, ensures high biocompatibility, and retains the imaging function of GNCs, which contribute to lighting up osteosarcoma persistently for further diagnosis and treatment. In addition, the HG-CAHs with outstanding mechanical properties are similar to the lotus seedpods with supportive force and a typical porous structure. They are favorable for the local pH- and near-infrared (NIR)-responsive release of doxorubicin (Dox) owing to the acidic osteosarcoma microenvironment and the Brownian movement. The HG-CAHs ablate osteosarcoma efficiently and reduce metabolic toxicity significantly, which will aid in the development of a new generation of osteosarcoma treatments.

The treatment of large segmental bone defects and complex types of fractures caused by trauma, inflammation, or tumor resection is still a challenge in the field of orthopedics. Various natural or synthetic biological materials used in clinical applications cannot fully replicate the structure and performance of raw bone. This highlights how to endow materials with multiple functions and biological properties, which is a problem that needs to be solved in practical applications. Hydrogels with outstanding biocompatibility, for their casting into any shape, size, or form, are suitable for different forms of bone defects. Therefore, they have been used in regenerative medicine more widely. In this review, versatile hydrogels are compounded with nanoparticles of different dimensions, and many desirable features of these materials in bone regeneration are introduced, including drug delivery, cell factor vehicle, cell scaffolds, which have potential in bone regeneration applications. The combination of hydrogels and nanoparticles of different dimensions encourages better filling of bone defect areas and has higher adaptability. This is due to the minimally invasive properties of the material and ability to match irregular defects. These biological characteristics make composite hydrogels with different dimensional nanoparticles become one of the most attractive options for bone regeneration materials., (© 2021 Wiley-VCH GmbH.)

Diabetic foot ulcers (DFUs) are hard-healing chronic wounds and susceptible to bacterial infection. Conventional hydrogel dressings easily lose water at high temperature or freeze at low temperature, making them unsuitable for long-term use or in extreme environments. Herein, a temperature-tolerant (-20 to 60 °C) antibacterial hydrogel dressing is fabricated by the assembly of polyacrylamide, gelatin, and ε-polylysine. Owing to the water/glycerin (Gly) binary solvent system, the resultant hydrogel (G-PAGL) displayed good heat resistance and antifreezing properties. Within the wide temperature range (-20 to 60 °C), all the desirable features of the hydrogel, including superstretchability (>1400%), enduring water retention, adhesiveness, and persistent antibacterial property, are quite stable. Remarkably, the hydrogel wound dressing displayed lasting and broad antibacterial activity against Gram-positive and Gram-negative bacteria. Satisfactorily, the double-network (DN) G-PAGL hydrogel dressing could effectively promote the healing of DFUs by accelerating collagen deposition, promoting angiogenesis, and inhibiting bacterial breed. As far as we know, this is the first time that the extensive temperature-tolerant DN hydrogel with antibacterial ability is developed to use as DFU wound dressing. The G-PAGL hydrogel provides more choices for DFU wound dressings that could be used in extreme environments.