Gallium-modified gelatin nanoparticles loaded with quercetin promote skin wound healing via the regulation of bacterial proliferation and macrophage polarization

Piezoelectric-immunomodulatory electrospun membrane for enhanced repair of refractory wounds

The microenvironment and healing process of diabetic wounds are highly complex, necessitating the development of wound dressings that combine excellent biocompatibility, superior antibacterial properties, and immune-regulating capabilities. However, achieving this goal remains a significant challenge. In this study, a multifunctional electrospun dressing (polylactic acid@Ga, PLLA@Ga) was designed and fabricated by integrating sonodynamic therapy with gallium-doped mesoporous bioactive glass (Ga-MBG). Compared to pure PLLA materials, PLLA@Ga exhibited remarkable antibacterial effects in vitro and demonstrated effective anti-infection properties in vivo. These effects are primarily attributed to the release of Ga ions, which competitively replace iron, thereby disrupting iron-dependent bacterial enzymes and ultimately leading to bacterial death. Additionally, in vitro experiments showed that PLLA@Ga could promote macrophage polarization from the M1 to M2 phenotype, effectively modulating the immune microenvironment of diabetic infected wounds. In vivo wound healing experiments further revealed that PLLA@Ga significantly enhanced collagen deposition and angiogenesis, accelerating the healing process of infected diabetic wounds. Thus, the multifunctional electrospun dressing developed in this study holds great potential as a promising candidate for the treatment of diabetic wounds.

Collaboration in Contradiction: Self-Adaptive Synergistic ROS Generation and Scavenge Balancing Strategies Used for the Infected Wounds Treatment

The rational utilization of ROS is key to treating infected wounds. Exogenous ROS can destroy bacterial structures, quickly kill bacteria, and inhibit secondary infections. However, excess ROS at the wound will cause a secondary inflammatory response. Acute infections exacerbate this damage by increasing endogenous ROS, complicating the maintenance of ROS homeostasis. Therefore, regulating the balance of ROS production and scavenging in wounds has emerged as a promising strategy for wound treatment. Conventional ROS balancing platforms are mostly based on the " all for one" strategy of functional superposition and lack self-adaptability and integration. To subvert this conventional strategy, this study proposes a "one for all" self-adaptive integrated photodynamic therapy (PDT)-antioxidant model to actively regulate the ROS balance. A gelatin-hyaluronic acid hydrogel embedded with Se-modified cerium dioxide nanoparticles (Gel-HA-Se@CeO2 NPs) is designed for treating infected wounds. The Se@CeO2 NPs serve both as nanoenzymes and photosensitizers(PS). As nanoenzymes, they exhibit catalase and superoxide dismutase activities, converting hydrogen peroxide and superoxide anions into oxygen. As a PS, it synergizes with oxygen under NIR irradiation to rapidly produce singlet oxygen. Additionally, Se modification enhances the PDT effects by disrupting bacterial antioxidant systems. In vitro and in vivo experiments revealed that the ROS balance platform polarizes M1-type macrophages to M2-type macrophages, altering the wound microenvironment from proinflammatory to prohealing. RNA sequencing revealed that this hydrogel accelerated the reconstruction of the vascular network of the wound by activating the PI3K/AKT pathway and increasing VEGF secretion.This strategy is believed to be beneficial not only for infected wounds but also for treating other conditions that involve the regulation of reactive oxygen species, such as tumors and bacterial infections.

Loureirin B Accelerates Diabetic Wound Healing by Promoting TGFβ/Smad-Dependent Macrophage M2 Polarization: A Concerted Analytical Approach Through Single-Cell RNA Sequencing and Experimental Verification

Diabetic wound (DW) represent a significant clinical challenge and often fail to heal effectively. Loureirin B (LB), a flavonoid extracted from dragon's blood, has shown potential by influencing macrophage polarization and promoting wound healing. However, its mechanisms and efficacy in DW remain to be explored. This study employed single-cell RNA sequencing to analyze the classification of cells in diabetic foot ulcers and to identify the related mechanisms influenced by macrophages. Molecular docking was used to predict the interactions of LB with key proteins in the TGFβ/Smad signaling pathway. The effects of LB on macrophage polarization and wound healing were further validated through in vitro and in vivo experiments using a DW model. Single-cell analysis identified specific macrophage subtypes involved in the DW healing process and highlighted the role of the TGFβ/Smad pathway. Molecular docking suggested the potential action within the TGFβ/Smad pathway. In vitro studies showed that under high glucose conditions, LB promoted macrophage polarization from pro-inflammatory M1 to healing-promoting M2 and ECM production in fibroblasts by activating TGF-β/Smad signaling. In vivo, LB treatment enhanced wound healing rates in diabetic mice and promoted macrophage M2 polarization and fibroblast synthesis of ECM by activating TGF-β/Smad signaling. LB regulates macrophage M2 polarization and fibroblast synthesis of ECM by activating TGF-β/Smad signaling to promote DW healing. These findings suggest that LB could be a potential therapeutic agent for improving DW healing, emphasizing the need for further clinical studies to explore its efficacy and mechanisms in human subjects.

Engineering Ga-doped mesoporous bioactive glass-integrated PEEK implants for immunomodulatory and enhanced osseointegration effects

With the increasing aging population, the demand for orthopedic implants is also growing. Polyether ether ketone (PEEK) is considered a promising material for orthopedic implants due to its excellent biocompatibility. However, the lack of bioactivity and excessive immune response post-implantation often impair bone integration. Therefore, it is urgent to bio-functionalize PEEK-based implants to promote bone integration. This study employs a simple, economical, and feasible method to coat Ga-ion doped bioactive glass nanoparticles (Ga-MBGs) onto sulfonated PEEK surfaces, constructing a multifunctional PEEK-based orthopedic implant. The resulting bio-functionalized PEEK implants promote macrophage M2 phenotype polarization, thus fostering an anti-inflammatory immune microenvironment. Moreover, the direct osteogenic effect of Ga ions and the immuno-osteogenic effect through promoting macrophage M2 polarization enhance osteogenic differentiation potential in vitro and bone integration in vivo. A sequence of in vivo and in vitro experiments substantiates the essential and intricate function of this innovative orthopedic implants. in regulating normal bone immunity and metabolism. Overall, the application of Ga-MBGs provides a simple, economical, and effective method for developing multifunctional orthopedic implants. This surface bio-functionalized PEEK implant, capable of modulating immunity and bone metabolism, holds significant clinical application potential as an orthopedic implant.

Burn Wound Healing Activity of Hydroxyethylcellulose Gels with Different Water Extracts Obtained from Various Medicinal Plants in Pseudomonas aeruginosa-Infected Rabbits

Burn injuries represent a significant problem in clinical practice due to the high risk of infection and the prolonged healing process. Recently, more attention has been given to natural remedies such as water extracts of various medicinal plants, which possess anti-inflammatory and wound healing properties. The aim of this study is to evaluate the efficacy and safety of Satureja montana L. and other water extracts in a burn wound model. The study involved male Californian rabbits (n = 52) divided into eight groups. Burn wounds were modeled on the animals and subsequently treated with gels based on Satureja montana L. and other water extracts. The reparative potential of the epidermis (assessed by Ki-67 expression), the state of local immunity (measured by the number of CD-45 cells), and the anti-inflammatory role of mast cells (measured by tryptase levels) were evaluated. Bacteriological and morphological studies were conducted. The most pronounced bactericidal, reparative, and immunostimulatory effects were observed after the treatment using a gel mixture of water extracts from Satureja montana L., Salvia sclarea, Coriandrum sativum L., and Lavandula angustifolia in equal proportions (1:1:1:1). The other gels also demonstrated high efficacy in treating burn wounds, especially when using a strain of Pseudomonas aeruginosa resistant to several antibiotics. Immunohistochemical studies showed a significant increase in the number of Ki-67-positive cells in the basal layer of the epidermis and a decrease in the number of CD-45-positive cells, indicating improved proliferative activity and reduced inflammation. This study confirms the hypothesis that the use of water extract mixtures significantly enhances the reparative potential, improves the immune response in the treatment of burns, and promotes wound healing. These findings pave the way for further research and the application of complex phytotherapeutic agents, specifically water extracts of medicinal plants containing phenols and antioxidants in burn wound therapy.

The physiological phenomenon and regulation of macrophage polarization in diabetic wound

Macrophages play a crucial role in regulating wound healing, as they undergo a transition from the proinflammatory M1 phenotype to the proliferative M2 phenotype, ultimately contributing to a favorable outcome. However, in hyperglycemic and hyper-reactive oxygen species environments, the polarization of macrophages becomes dysregulated, hindering the transition from the inflammatory to proliferative phase and consequently delaying the wound healing process. Consequently, regulating macrophage polarization is often regarded as a potential target for the treatment of diabetic wounds. The role of macrophages in wound healing and the changes in macrophages in diabetic conditions were discussed in this review. After that, we provide a discussion of recent therapeutic strategies for diabetic wounds that utilize macrophage polarization. Furthermore, this review also provides a comprehensive summary of the efficacious treatment strategies aimed at enhancing diabetic wound healing through the regulation of macrophage polarization. By encompassing a thorough understanding of the fundamental principles and their practical implementation, the advancement of treatment strategies for diabetic wounds can be further facilitated.

Quercetin and Related Analogs as Therapeutics to Promote Tissue Repair

Quercetin is a polyphenol of the flavonoid class of secondary metabolites that is widely distributed in the plant kingdom. Quercetin has been found to exhibit potent bioactivity in the areas of wound healing, neuroprotection, and anti-aging research. Naturally found in highly glycosylated forms, aglycone quercetin has low solubility in aqueous environments, which has heavily limited its clinical applications. To improve the stability and bioavailability of quercetin, efforts have been made to chemically modify quercetin and related flavonoids so as to improve aqueous solubility while retaining bioactivity. In this review, we provide an updated overview of the biological properties of quercetin and proposed mechanisms of actions in the context of wound healing and aging. We also provide a description of recent developments in synthetic approaches to improve the solubility and stability of quercetin and related analogs for therapeutic applications. Further research in these areas is expected to enable translational applications to improve ocular wound healing and tissue repair.

Multifunctional Extracellular Matrix Hydrogel with Self-Healing Properties and Promoting Angiogenesis as an Immunoregulation Platform for Diabetic Wound Healing

Treating chronic wounds is a global challenge. In diabetes mellitus cases, long-time and excess inflammatory responses at the injury site may delay the healing of intractable wounds. Macrophage polarization (M1/M2 types) can be closely associated with inflammatory factor generation during wound healing. Quercetin (QCT) is an efficient agent against oxidation and fibrosis that promotes wound healing. It can also inhibit inflammatory responses by regulating M1-to-M2 macrophage polarization. However, its limited solubility, low bioavailability, and hydrophobicity are the main issues restricting its applicability in wound healing. The small intestinal submucosa (SIS) has also been widely studied for treating acute/chronic wounds. It is also being extensively researched as a suitable carrier for tissue regeneration. As an extracellular matrix, SIS can support angiogenesis, cell migration, and proliferation, offering growth factors involved in tissue formation signaling and assisting wound healing. We developed a series of promising biosafe novel diabetic wound repair hydrogel wound dressings with several effects, including self-healing properties, water absorption, and immunomodulatory effects. A full-thickness wound diabetic rat model was constructed for in vivo assessment of QCT@SIS hydrogel, in which hydrogels achieved a markedly increased wound repair rate. Their effect was determined by the promotion of the wound healing process, the thickness of granulation tissue, vascularization, and macrophage polarization during wound healing. At the same time, we injected the hydrogel subcutaneously into healthy rats to perform histological analyses of sections of the heart, spleen, liver, kidney, and lung. We then tested the biochemical index levels in serum to determine the biological safety of the QCT@SIS hydrogel. In this study, the developed SIS showed convergence of biological, mechanical, and wound-healing capabilities. Here, we focused on constructing a self-healing, water-absorbable, immunomodulatory, and biocompatible hydrogel as a synergistic treatment paradigm for diabetic wounds by gelling the SIS and loading QCT for slow drug release.