Wound-Healing and Antibacterial Activity of the Quercetin-4-Formyl Phenyl Boronic Acid Complex against Bacterial Pathogens of Diabetic Foot Ulcer

Quercetin@β-Cyclodextrin Conjugated Keratin/Polyurethane Biocomposite Mats for Infected Diabetic Wound Healing

Chronic diabetic wounds suffer from severe complications caused by long-term high levels of oxidative stress and bacterial infection. Quercetin (Que) has excellent anti-inflammatory, antioxidant, and antibacterial activity, making it a promising drug to address the above issues. To exploit the benefits of Que in a more effective and sustained way to treat diabetic wounds, carboxymethyl β-cyclodextrin (CMCD) was synthesized and conjugated to keratin, then complexed with Que to form Que@Ker-CMCD inclusion, followed by electrospinning with polyurethane (PU) to afford Que@Ker-CMCD/PU mats. The approach significantly enhanced water solubility, bioavailability, and sustained release of Que. Crucially, these mats exhibited robust antioxidant and antibacterial activities. Moreover, the mats fostered an environment conducive to cell proliferation, migration, angiogenesis, and re-epithelialization, pivotal processes in wound healing and remodeling. Consequently, a marked acceleration in remodeling chronic diabetic wounds was observed. In conclusion, this study introduces a novel therapeutic strategy that not only harnesses the multifaceted benefits of Que but also enhances its delivery and performance, offering a promising avenue for the effective treatment of chronic diabetic wounds.

ROS responsive conductive microspheres loaded with salvianolic acid B as adipose derived stem cell carriers for acute myocardial infarction treatment

Stem cell therapy is currently the most promising strategy for the treatment of myocardial infarction. However, the development of injectable cell carriers that can scavenge reactive oxygen species (ROS) in the infarct zone to improve transplanted cell survival remains a challenge. Here, we developed a ROS responsive conductive microsphere based on chitosan (CS) and dextran (DEX) with 4-formylphenylboronic acid (4-FPBA) as a cross-linking agent and the addition of graphite oxide (GO) and the anti-inflammatory agent salvianolic acid B (SalB), as a cell delivery carrier for myocardial infarction. These microspheres were crosslinked by dual dynamic networks of Schiff base and phenylborate bonds. The relationship between CS concentration and microsphere particle size, as well as the biocompatibility, ROS responsiveness, anti-inflammatory properties, and effects on myogenic differentiation of H9C2 cells were fully investigated. The microspheres exhibit good biocompatibility, proliferation promoting, differentiation promoting, antioxidant, and anti-inflammatory properties. When applied to mice myocardial infarction models, the ROS responsive conductive microspheres loaded with SalB and adipose derived stem cells (ADSC) exhibited excellent in vivo repair ability. In addition, they reduced myocardial fibrosis and promoted ventricular wall regeneration by promoting the expression of Connexin 43 (Cx43) and CD31, ultimately reshaping the infarcted myocardium, suggesting their great potential as cell delivery carriers for myocardial infarction treatment.

Antibacterial, Antibiofilm, and Wound Healing Activities of Rutin and Quercetin and Their Interaction with Gentamicin on Excision Wounds in Diabetic Mice

Phytochemicals are effective and are gaining attention in fighting against drug-resistant bacterial strains. In the present study, rutin and quercetin were tested for antibacterial, antibiofilm, and wound healing activities on excision wounds infected with MDR-P. aeruginosa in diabetic mice. Antibacterial and antibiofilm activities were studied in vitro using broth dilution assay and crystal violet assay, respectively. These phytochemicals were tested alone for wound-healing activities at different concentrations (0.5% and 1% in ointment base) and in combination with gentamicin to evaluate any additive effects. Rutin and quercetin demonstrated effectiveness against MDR-P. aeruginosa at higher concentrations. Both phytochemicals inhibited biofilm formation in vitro and contributed to the healing of diabetic wounds by eradicating biofilm in the wounded tissue. Rutin at a low concentration (0.5%) had a lesser effect on reducing the epithelization period and regeneration of the epithelial layer compared to quercetin. When combined with gentamicin, quercetin (1%) displayed the maximum effect on epithelium regeneration, followed by rutin (1%) in combination with gentamicin. Both phytochemicals were found to be more effective in controlling biofilm and wound-healing activities when used as an additive with gentamicin. The study supports the traditional use of phytochemicals with antibacterial, antibiofilm, and wound-healing activities in managing diabetic infections.

Boron-containing compounds as labels, drugs, and theranostic agents for diabetes and its complications

Diabetes is a disease with a high global burden. Current strategies have failed to limit the advancement and impact of the disease. Successful early diagnosis and treatment will require the development of new agents. In this sense, boron-containing compounds have been reported as agents with the ability to reduce glycemia and lipidemia. They have also been used for labeling and measuring carbohydrates and other molecules linked to the initial stages of diabetes and its progression. In addition, certain boron compounds bind to molecules related to diabetes development and their biological activity in the regulation of elevated glycemia. Finally, it should be noted that some boron compounds appear to exert beneficial effects on diabetes complications such as accelerating wound healing while ameliorating pain in diabetic patients.

Dual Drug-Loaded Coaxial Nanofiber Dressings for the Treatment of Diabetic Foot Ulcer

Introduction

Diabetes mellitus is frequently associated with foot ulcers, which pose significant health risks and complications. Impaired wound healing in diabetic patients is attributed to multiple factors, including hyperglycemia, neuropathy, chronic inflammation, oxidative damage, and decreased vascularization.

Rationale

To address these challenges, this project aims to develop bioactive, fast-dissolving nanofiber dressings composed of polyvinylpyrrolidone loaded with a combination of an antibiotic (moxifloxacin or fusidic acid) and anti-inflammatory drug (pirfenidone) using electrospinning technique to prevent the bacterial growth, reduce inflammation, and expedite wound healing in diabetic wounds.

Results

The fabricated drug-loaded fibers exhibited diameters of 443 ± 67 nm for moxifloxacin/pirfenidone nanofibers and 488 ± 92 nm for fusidic acid/pirfenidone nanofibers. The encapsulation efficiency, drug loading and drug release studies for the moxifloxacin/pirfenidone nanofibers were found to be 70 ± 3% and 20 ± 1 µg/mg, respectively, for moxifloxacin, and 96 ± 6% and 28 ± 2 µg/mg, respectively, for pirfenidone, with a complete release of both drugs within 24 hours, whereas the fusidic acid/pirfenidone nanofibers were found to be 95 ± 6% and 28 ± 2 µg/mg, respectively, for fusidic acid and 102 ± 5% and 30 ± 2 µg/mg, respectively, for pirfenidone, with a release rate of 66% for fusidic acid and 80%, for pirfenidone after 24 hours. The efficacy of the prepared nanofiber formulations in accelerating wound healing was evaluated using an induced diabetic rat model. All tested formulations showed an earlier complete closure of the wound compared to the controls, which was also supported by the histopathological assessment. Notably, the combination of fusidic acid and pirfenidone nanofibers demonstrated wound healing acceleration on day 8, earlier than all tested groups.

Conclusion

These findings highlight the potential of the drug-loaded nanofibrous system as a promising medicated wound dressing for diabetic foot applications.

Accelerated full-thickness skin wound tissue regeneration by self-crosslinked chitosan hydrogel films reinforced by oxidized CNC-AgNPs stabilized Pickering emulsion for quercetin delivery

BACKGROUND

The non-toxic self-crosslinked hydrogel films designed from biocompatible materials allow for controlled drug release and have gathered remarkable attention from healthcare professionals as wound dressing materials. Thus, in the current study the chitosan (CS) film is infused with oil-in-water Pickering emulsion (PE) loaded with bioactive compound quercetin (Qu) and stabilized by dialdehyde cellulose nanocrystal-silver nanoparticles (DCNC-AgNPs). The DCNC-AgNPs play a dual role in stabilizing PE and are involved in the self-crosslinking with CS films. Also, this film could combine the advantage of the controlled release and synergistic wound-healing effect of Qu and AgNPs.

RESULTS

The DCNC-AgNPs were synthesized using sodium periodate oxidation of CNC. The DCNC-AgNPs were used to stabilize oil-in-water PE loaded with Qu in its oil phase by high speed homogenization. Stable PEs were prepared by 20% v/v oil: water ratio with maximum encapsulation of Qu in the oil phase. The Qu-loaded PE was then added to CS solution (50% v/v) to prepare self-crosslinked films (CS-PE-Qu). After grafting CS films with PE, the surface and cross-sectional SEM images show an inter-penetrated network within the matrix between DCNC and CS due to the formation of a Schiff base bond between the reactive aldehyde groups of DCNC-AgNPs and amino groups of CS. Further, the addition of glycerol influenced the extensibility, swelling ratio, and drug release of the films. The fabricated CS-PE-Qu films were analyzed for their wound healing and tissue regeneration potential using cell scratch assay and full-thickness excisional skin wound model in mice. The as-fabricated CS-PE-Qu films showed great biocompatibility, increased HaCat cell migration, and promoted collagen synthesis in HDFa cells. In addition, the CS-PE-Qu films exhibited non-hemolysis and improved wound closure rate in mice compared to CS, CS-Qu, and CS-blank PE. The H&E staining of the wounded skin tissue indicated the wounded tissue regeneration in CS-PE-Qu films treated mice.

CONCLUSION

Results obtained here confirm the wound healing benefits of CS-PE-Qu films and project them as promising biocompatible material and well suited for full-thickness wound healing in clinical applications.

Quercetin and its derivatives for wound healing in rats/mice: Evidence from animal studies and insight into molecular mechanisms

Aimed to clarify the effect of quercetin and its derivatives on wound healing in animal experiments. PubMed, Embase, Science Direct, Web of Science, SinoMed, Vip Journal Integration Platform, China National Knowledge Infrastructure and WanFang databases were searched for animal experiments investigating the effect of quercetin and its derivatives on wound healing to April 2023. The Review Manager 5.4 software was used to conduct meta-analysis. Eighteen studies were enrolled in this article. According to the SYRCLE's RoB tool assessment, these studies exposed relatively low methodological quality. It was shown that animals with cutaneous wound receiving quercetin had faster wound healing in wound closure (%) than the control group. Moreover, the difference in efficacy gradually emerged after third day (WMD = 7.13 [5.52, 8.74]), with a peak reached on the tenth day after wounding (WMD = 19.78 [17.82, 21.74]). Subgroup analysis revealed that quercetin for wound closure (%) was independent of the types of rats and mice, wound area and with or without diabetes. Clear conclusion was also shown regarding the external application of quercetin for wound healing (WMD = 17.77 [11.11, 24.43]). A significant reduction in the distribution of inflammatory cells occurred in the quercetin group. Quercetin could increase blood vessel density (WMD = 1.85 [0.68, -3.02]), fibroblast distribution and collagen fraction. Biochemical indicators, including IL-1β, IL-10, TNF-α, TGF-β, vascular endothelial growth factor (VEGF), hydroxyproline and alpha-smooth muscle actin (α-SMA), had the consistent results. Quercetin and its derivatives could promote the recovery of cutaneous wound in animals, through inhibiting inflammatory response and accelerating angiogenesis, proliferation of fibroblast and collagen deposition.

The effect of the boron-based gel on the treatment of diabetic foot ulcers: A prospective, randomized controlled trial

BACKGROUND

Chronic ulcers represent impaired healing capacity with high mortality in the elderly or patients with systemic disorders such as diabetes. Boron is an effective agent in wound healing by promoting cell migration and proliferation and reducing inflammation in the wound area. This study aimed to evaluate the therapeutic effect of a sodium pentaborate-based topical formulation compared to control on the treatment of diabetic foot ulcers.

METHODS

A prospective, double-blind, randomized controlled trial was conducted to apply randomly the topical sodium pentaborate 3% gel or topical conventional remedy (control) by patients diagnosed with diabetic foot ulcers. The 171 eligible participants aged 18-75 years received the allocated medicines twice a day for a month with an allocation ratio of 3:1. Twenty-five days and two months after the end of the trial, participants were reinvestigated for their ulcer condition and any recurrence. Wagner's classification of diabetic foot ulcers was applied to this purpose (0-5).

RESULTS

161 participants (57 females, 104 males; mean age: 59.37) completed this study. After the intervention, most participants in the intervention group had a lower ulcer grade than the control group (adjusted mean difference (95% CI): - 0.91 (-1.1 to -0.73); p < 0.001). Moreover, most participants in the intervention group (n = 109 (90.8%)) were treated at a higher rate than the control group (n = 5 (12.2%)) after intervention (adjusted odds ratio (95% CI): 0.008 (0.002-0.029); p < 0.001). There was no case of recurrence in the intervention group while its rate was (n = 2 (40%)) in the control group (p < 0.001).

CONCLUSION

The present study suggests that topical sodium pentaborate gel may help treat and decrease the grade of diabetic foot ulcers and prevent the recurrence of diabetic foot ulcers.

New Hydrogels Nanocomposites Based on Chitosan, 2-Formylphenylboronic Acid, and ZnO Nanoparticles as Promising Disinfectants for Duodenoscopes Reprocessing

New hydrogels nanocomposites, based on iminoboronate hydrogels and ZnO nanoparticles (ZnO-NPs), were obtained and characterised in order to develop a new class of disinfectants able to fight the nosocomial infections produced by duodenoscopes investigation procedures. The formation of the imine linkages between chitosan and the aldehyde was demonstrated using NMR and FTIR spectroscopy, while the supramolecular architecture of the developed systems was evaluated via wide-angle X-ray diffraction and polarised optical microscopy. The morphological characterisation of the systems via scanning electron microscopy revealed the highly porous structure of the materials, in which no ZnO agglomeration could be observed, indicating the very fine and homogenous encapsulation of the nanoparticles into the hydrogels. The newly synthetised hydrogels nanocomposites was proven to have synergistic antimicrobial properties, being very efficient as disinfectants against reference strains as: Enterococcus faecalis, Klebsiella pneumoniae, and Candida albicans.

Flavonoids as Potential Wound-Healing Molecules: Emphasis on Pathways Perspective

Wounds are considered to be a serious problem that affects the healthcare sector in many countries, primarily due to diabetes and obesity. Wounds become worse because of unhealthy lifestyles and habits. Wound healing is a complicated physiological process that is essential for restoring the epithelial barrier after an injury. Numerous studies have reported that flavonoids possess wound-healing properties due to their well-acclaimed anti-inflammatory, angiogenesis, re-epithelialization, and antioxidant effects. They have been shown to be able to act on the wound-healing process via expression of biomarkers respective to the pathways that mainly include Wnt/β-catenin, Hippo, Transforming Growth Factor-beta (TGF-β), Hedgehog, c-Jun N-Terminal Kinase (JNK), NF-E2-related factor 2/antioxidant responsive element (Nrf2/ARE), Nuclear Factor Kappa B (NF-κB), MAPK/ERK, Ras/Raf/MEK/ERK, phosphatidylinositol 3-kinase (PI3K)/Akt, Nitric oxide (NO) pathways, etc. Hence, we have compiled existing evidence on the manipulation of flavonoids towards achieving skin wound healing, together with current limitations and future perspectives in support of these polyphenolic compounds as safe wound-healing agents, in this review.

Beneficial Effects of a Blended Fibroin/Aloe Gel Extract Film on the Biomolecular Mechanism(s) via the MAPK/ERK Pathway Relating to Diabetic Wound Healing

In diabetic patients, the process of wound healing is usually delayed or impaired. A diabetic environment could be associated with dermal fibroblast dysfunction, reduced angiogenesis, the release of excessive proinflammatory cytokines, and senescence features. Alternative therapeutic treatments using natural products are highly demanded for their high potential of bioactive activity in skin repair. Two natural extracts were combined to develop fibroin/aloe gel wound dressing. Our previous studies revealed that the prepared film enhances the healing rate of diabetic foot ulcers (DFUs). Moreover, we aimed to explore its biological effects and underlying biomolecular mechanisms on normal dermal, diabetic dermal, and diabetic wound fibroblasts. Cell culture experiments showed that the γ-irradiated blended fibroin/aloe gel extract film promotes skin wound healing by enhancing cell proliferation and migration, vascular epidermal growth factor (VEGF) secretion, and cell senescence prevention. Its action was mainly linked to the activation of the mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway known to regulate various cellular activities, including proliferation. Therefore, the findings of this study confirm and support our previous data. The blended fibroin/aloe gel extract film displays a biological behavior with favorable properties for delayed wound healing and can be considered as a promising therapeutic approach in the treatment of diabetic nonhealing ulcers.

Herbal Products and Their Active Constituents for Diabetic Wound Healing-Preclinical and Clinical Studies: A Systematic Review

The purpose of this review is to provide verified data on the current knowledge acquired in preclinical and clinical studies regarding topically used herbal products and their active constituents (formulations and dressings) with diabetic wound healing activity. Moreover, herbal products and their active constituents used for diabetic wound infections, and various cellular and molecular mechanisms of their actions will also be described. The electronic databases were searched for articles published from 2012 to 2022. Publications with oral or systemic administration of herbal products in diabetic wound healing, published before 2012, available only as an abstract, or in languages other than English were excluded from the study. The 59 articles comparing topically used herbal products in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. Herbal products through different mechanisms of action, including antimicrobial, anti-inflammatory, antioxidant activity, stimulation of angiogenesis, production of cytokines and growth factors, keratinocytes, and fibroblast migration and proliferation may be considered as an important support during conventional therapy or even as a substitute for synthetic drugs used for diabetic wound treatment.