Antibiotic-eluting scaffolds with responsive dual-release kinetics facilitate bone healing and eliminate S. aureus infection.

Osteomyelitis (OM) is a progressive, inflammatory infection of bone caused predominately by Staphylococcus aureus. Herein, we engineered an antibiotic-eluting collagen-hydroxyapatite scaffold capable of eliminating infection and facilitating bone healing. An iterative freeze-drying and chemical crosslinking approach was leveraged to modify antibiotic release kinetics, resulting in a layered dual-release system whereby an initial rapid release of antibiotic to clear infection was followed by a sustained controlled release to prevent reoccurrence of infection. We observed that the presence of microbial collagenase accelerated antibiotic release from the crosslinked layer of the scaffold, indicating that the material is responsive to microbial activity. As exemplar drugs, vancomycin and gentamicin-eluting scaffolds were demonstrated to be bactericidal, and supported osteogenesis in vitro. In a pilot murine model of OM, vancomycin-eluting scaffolds were observed to reduce S. aureus infection within the tibia. Finally, in a rabbit model of chronic OM, gentamicin-eluting scaffolds both facilitated radial bone defect healing and eliminated S. aureus infection. These results show that antibiotic-eluting collagen-hydroxyapatite scaffolds are a one-stage therapy for OM, which when implanted into infected bone defects simultaneously eradicate infection and facilitate bone tissue healing.

Tailored extracellular matrix-mimetic coating facilitates reendothelialization and tissue healing of cardiac occluders.

Minimally invasive transcatheter interventional therapy utilizing cardiac occluders represents the primary approach for addressing congenital heart defects and left atrial appendage (LAA) thrombosis. However, incomplete endothelialization and delayed tissue healing after occluder implantation collectively compromise clinical efficacy. In this study, we have customized a recombinant humanized collagen type I (rhCol I) and developed an rhCol I-based extracellular matrix (ECM)-mimetic coating. The innovative coating integrates metal-phenolic networks with anticoagulation and anti-inflammatory functions as a weak cross-linker, combining them with specifically engineered rhCol I that exhibits high cell adhesion activity and elicits a low inflammatory response. The amalgamation, driven by multiple forces, effectively serves to functionalize implantable materials, thereby responding positively to the microenvironment following occluder implantation. Experimental findings substantiate the coating's ability to sustain a prolonged anticoagulant effect, enhance the functionality of endothelial cells and cardiomyocyte, and modulate inflammatory responses by polarizing inflammatory cells into an anti-inflammatory phenotype. Notably, occluder implantation in a canine model confirms that the coating expedites reendothelialization process and promotes tissue healing. Collectively, this tailored ECM-mimetic coating presents a promising surface modification strategy for improving the clinical efficacy of cardiac occluders.

Ultrasound-responsive microfibers promoted infected wound healing with neuro-vascularization by segmented sonodynamic therapy and electrical stimulation.

Bacteria-infected wounds pose challenges to healing due to persistent infection and associated damage to nerves and vessels. Although sonodynamic therapy can help kill bacteria, it is limited by the residual oxidative stress, resulting in prolonged inflammation. To tackle these barriers, novel 4 octyl itaconate-coated Li-doped ZnO/PLLA piezoelectric composite microfibers are developed, offering a whole-course "targeted" treatment under ultrasound therapy. The inclusion of Li atoms causes the ZnO lattice distortion and increases the band gap, enhancing the piezoelectric and sonocatalytic properties of the composite microfibers, collaborated by an aligned PLLA conformation design. During the infection and inflammation stages, the piezoelectric microfibers exhibit spatiotemporal-dependent therapeutic effects, swiftly eliminating over 94.2 % of S. aureus within 15 min under sonodynamic therapy. Following this phase, the microfibers capture reactive oxygen species and aid macrophage reprogramming, restoring mitochondrial function, achieving homeostasis, and shortening inflammation cycles. As the wound progresses through the healing stages, bioactive Zn2+ and Li + ions are continuously released, improving cell recruitment, and the piezoelectrical stimulation enhances wound recovery with neuro-vascularization. Compared to commercially available dressings, our microfibers accelerate the closure of rat wounds (Φ = 15 mm) without scarring in 12 days. Overall, this "one stone, four birds" wound management strategy presents a promising avenue for infected wound therapy.

A dendritic cell-recruiting, antimicrobial blood clot hydrogel for melanoma recurrence prevention and infected wound management.

Surgical resection, the mainstay for melanoma treatment, faces challenges due to high tumor recurrence rates and complex postoperative wound healing. Chronic inflammation from residual disease and the risk of secondary infections impede healing. We introduce an innovative, injectable hydrogel system that integrates a multifaceted therapeutic approach. The hydrogel, crosslinked by calcium ions with sodium alginate, encapsulates a blood clot rich in dendritic cells (DCs) chemoattractants and melanoma cell-derived nanovesicles (NVs), functioning as a potent immunostimulant. This in situ recruitment strategy overcomes the limitations of subcutaneous tumor vaccine injections and more effectively achieves antitumor immunity. Additionally, the hydrogel incorporates Chlorella extracts, enhancing its antimicrobial properties to prevent wound infections and promote healing. One of the key findings of our research is the dual functionality of Chlorella extracts; they not only expedite the healing process of infected wounds but also increase the hydrogel's ability to stimulate an antitumor immune response. Given the patient-specific nature of the blood clot and NVs, our hydrogel system offers customizable solutions for individual postoperative requirements. This personalized approach is highlighted by our study, which demonstrates the synergistic impact of the composite hydrogel on preventing melanoma recurrence and hastening wound healing, potentially transforming postsurgical melanoma management.

NIR responsive scaffold with multistep shape memory and photothermal-chemodynamic properties for complex tissue defects repair and antibacterial therapy.

Complex tissue damage accompanying with bacterial infection challenges healthcare systems globally. Conventional tissue engineering scaffolds normally generate secondary implantation trauma, mismatched regeneration and infection risks. Herein, we developed an easily implanted scaffold with multistep shape memory and photothermal-chemodynamic properties to exactly match repair requirements of each part from the tissue defect by adjusting its morphology as needed meanwhile inhibiting bacterial infection on demand. Specifically, a thermal-induced shape memory scaffold was prepared using hydroxyethyl methacrylate and polyethylene glycol diacrylate, which was further combined with the photothermal agent iron tannate (FeTA) to produce NIR light-induced shape memory property. By varying ingredients ratios in each segment, this scaffold could perform a stepwise recovery under different NIR periods. This process facilitated implantation after shape fixing to avoid trauma caused by conventional methods and gradually filled irregular defects under NIR to perform suitable tissue regeneration. Moreover, FeTA also catalyzed Fenton reaction at bacterial infections with abundant H2O2, which produced excess ROS for chemodynamic antibacterial therapy. As expected, bacteriostatic rate was further enhanced by additional photothermal therapy under NIR. The in vitro and vivo results showed that our scaffold was able to perform high efficacy in both antibiosis, inflammation reduction and wound healing acceleration, indicating a promising candidate for the regeneration of complex tissue damage with bacterial infection.

Topical frankincense treatment for frostbite based on microcirculation improvements.

ETHNOPHARMACOLOGICAL RELEVANCE: The Chinese traditional medicine frankincense, which can promote blood circulation, is often used to treat skin lesions, including frostbite. AIM OF THE STUDY: To explore the properties of frankincense oil extract (FOE) and its active ingredients and their effect on frostbite wound recovery as an approach to understand the mechanism associated with microcirculation-improvement therapy. MATERIALS AND METHODS: The microcirculation-improving effects of FOE and its active ingredients were evaluated using liquid nitrogen-induced frostbite animal models. The rewarming capacity of FOE on the skin was determined through infrared detection, and frostbite wound healing was evaluated following haematoxylin and eosin (H&E) staining and fibre analysis. Moreover, related factors were examined to determine the anti-apoptotic, anti-inflammatory, and microcirculatory properties of FOE and its active ingredients on affected tissue in the context of frostbite. RESULTS: FOE and its active ingredients rapidly rewarmed wound tissue after frostbite by increasing the temperature. Moreover, these treatments improved wound healing and restored skin structure through collagen and elastin fibre remodelling. In addition, they exerted anti-apoptotic effects by decreasing the number of apoptotic cells, reducing caspase-3 expression, and eliciting anti-inflammatory effects by decreasing COX-2 and ß-catenin expression. They also improved microcirculatory disorders by decreasing HIF-1α expression and increasing CD31 expression. CONCLUSIONS: FOE and its active components can effectively treat frostbite by enhancing microcirculation, inhibiting the infiltration of inflammatory cells, decreasing cell apoptosis, and exerting antinociceptive effects. These findings highlight FOE as a new treatment option for frostbite, providing patients with an effective therapeutic strategy.

Exploring the wound healing potential of Lobostemon fruticosus using in vitro and in vivo bioassays.

ETHNOPHARMACOLOGICAL RELEVANCE: Lobostemon fruticosus (L.) H.Buek is a perennial and woody shrub of the Boraginaceae family, found in the Cape region of South Africa. The leaves and twigs are used to treat dermatological conditions such as wounds, burns, ringworm, erysipelas and eczema. Anti-inflammatory, antibacterial, antiviral and anti-proliferative activities of L. fruticosus have been reported. However, there is a void in research which reports on the wound healing properties of this plant. AIM OF THE STUDY: Aligned with the traditional use of L. fruticosus, our study aimed to use in vitro and in vivo bioassays to confirm the wound healing potential of the plant. MATERIALS AND METHODS: An aqueous methanol extract (80% v/v) of L. fruticosus was prepared using a sample collected from the Western Cape Province of South Africa and chromatographically profiled by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay was performed to determine the non-toxic concentrations of the extract for subsequent use in the in vitro scratch assay. Both the human keratinocyte (HaCaT) and fibroblast (BJ-5ta) cell lines were employed in the in vitro scratch assay. The in vivo caudal fin amputation assay was used to assess the wound healing potential of L. fruticosus, by monitoring fin regeneration in zebrafish larvae treated with the plant extract at various concentrations. RESULTS: Six major compounds were tentatively identified in the L. fruticosus extract namely; globoidnan A, globoidnan B, rutin, rabdosiin, sagerinic acid and rosmarinic acid. The potentially toxic pyrrolizidine alkaloids were also identified and quantitatively confirmed to be present at a low concentration of 119.58 ppm (m/m). Treatment of HaCaT and BJ-5ta cells with the plant extract in the scratch assay resulted in an increase in cell migration, which translates to accelerated wound closure. After 24 hr treatment with 100 µg/mL of extract, wound closure was recorded to be 91.1 ± 5.7% and 94.1 ± 1.3% for the HaCaT and BJ-5ta cells, respectively, while the untreated (medium) controls showed 72.3 ± 3.3% and 73.0 ± 4.3% for the two cell lines, respectively. Complete wound closure was observed between 24 and 36 hr, while the untreated control group did not achieve 100% wound closure by the end of the observation period (48 hr). In vivo, the crude extract at 100 µg/mL accelerated zebrafish caudal fin regeneration achieving 100.5 ± 3.8% regeneration compared to 68.3 ± 6.6% in the untreated control at two days post amputation. CONCLUSIONS: The study affirms the wound healing properties, as well as low toxicity of L. fruticosus using both in vitro and in vivo assays, which supports the traditional medicinal use. Other in vitro assays that target different mechanisms involved in wound healing should be investigated to support the current findings.

Programmed surface platform orchestrates anti-bacterial ability and time-sequential bone healing for implant-associated infection.

Implant-associated infection (IAI) has become an intractable challenge in clinic. The healing of IAI is a complex physiological process involving a series of spatiotemporal connected events. However, existing titanium-based implants in clinic suffer from poor antibacterial effect and single function. Herein, a versatile surface platform based on the presentation of sequential function is developed. Fabrication of titania nanotubes and poly-γ-glutamic acid (γ-PGA) achieves the efficient incorporation of silver ions (Ag+) and the pH-sensitive release in response to acidic bone infection microenvironment. The optimized PGA/Ag platform exhibits satisfactory biocompatibility and converts macrophages from pro-inflammatory M1 to pro-healing M2 phenotype during the subsequent healing stage, which creates a beneficial osteoimmune microenvironment and promotes angio/osteogenesis. Furthermore, the PGA/Ag platform mediates osteoblast/osteoclast coupling through inhibiting CCL3/CCR1 signaling. These biological effects synergistically improve osseointegration under bacterial infection in vivo, matching the healing process of IAI. Overall, the novel integrated PGA/Ag surface platform proposed in this study fulfills function cascades under pathological state and shows great potential in IAI therapy.

Corneal stromal structure replicating humanized hydrogel patch for sutureless repair of deep anterior-corneal defect.

A critical shortage of donor corneas exists worldwide. Hydrogel patches with a biological architecture and functions that simulate those of native corneas have garnered considerable attention. This study introduces a stromal structure replicating corneal patch (SRCP) composed of a decellularized cornea-templated nanotubular skeleton, recombinant human collagen, and methacrylated gelatin, exhibiting a similar ultrastructure and transmittance (above 80 %) to natural cornea. The SRCP is superior to the conventional recombinant human collagen patch in terms of biomechanical properties and resistance to enzymatic degradation. Additionally, SRCP promotes corneal epithelial and stromal cell migration while preventing the trans-differentiation of stromal cells into myofibroblasts. When applied to an ocular surface (37 °C), SRCP releases methacrylated gelatin, which robustly binds SRCP to the corneal stroma after activation by 405 nm light. Compared to gelatin-based photocurable hydrogel, the SRCP better supports the restoration of normal corneal curvature and withstands deformation under an elevated intraocular pressure (100 mmHg). In an in vivo deep anterior-corneal defect model, SRCP facilitated epithelial healing and vision recovery within 2 weeks, maintained graft structural stability, and inhibited stromal scarring at 4 weeks post-operation. The ideal performance of the SRCP makes it a promising humanized corneal equivalent for sutureless clinical applications.

Synergistic effects of thermally reduced graphene oxide/zinc oxide composite material on microbial infection for wound healing applications.

Infections originating from pathogenic microorganisms can significantly impede the natural wound-healing process. To address this obstacle, innovative bio-active nanomaterials have been developed to enhance antibacterial capabilities. This study focuses on the preparation of nanocomposites from thermally reduced graphene oxide and zinc oxide (TRGO/ZnO). The hydrothermal method was employed to synthesize these nanocomposites, and their physicochemical properties were comprehensively characterized using X-ray diffraction analysis (XRD), High-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FT-IR), Raman spectroscopy, UV-vis, and field-emission scanning electron microscopy (FE-SEM) techniques. Subsequently, the potential of TRGO/ZnO nanocomposites as bio-active materials against wound infection-causing bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, was evaluated. Furthermore, the investigated samples show disrupted bacterial biofilm formation. A reactive oxygen species (ROS) assay was conducted to investigate the mechanism of nanocomposite inhibition against bacteria and for further in-vivo determination of antimicrobial activity. The MTT assay was performed to ensure the safety and biocompatibility of nanocomposite. The results suggest that TRGO/ZnO nanocomposites have the potential to serve as effective bio-active nanomaterials for combating pathogenic microorganisms present in wounds.

Recurrence rates after healing in patients with neuroischemic diabetic foot ulcers healed with and without sucrose octasulfate-impregnated dressings: A 1-year comparative prospective study.

To compare recurrence rates after a 1-year follow-up period of healed neuroischemic diabetic foot ulcers after treatment with or without sucrose octasulfate impregnated dressing. A 1-year prospective study with two arms was conducted between April 2021 and April 2023 on 92 patients with healed neuroischemic diabetic foot ulcers. Patients were divided into two groups; the treatment group, that includes patients healed with a sucrose octasulfate-impregnated dressing, and the control group, which includes patients treated with other local treatments different from sucrose octasulfate-impregnated dressings. After healing, patients were prospectively followed up during 1-year and assessed monthly in the specialised outpatient clinics. The main outcome of the study was ulcer recurrence after wound healing within 1 year follow-up. Secondary outcomes were minor or major amputation and all causes of death. Fifty patients in the treatment group and 42 patients in the control group were included. Fourteen (28%) patients suffered from a reulceration event in the treatment group compared to 28 (66.7%) in the control group, p < 0.001. Time to recurrence in the treatment group was 10 (16.26-2.75) and 11.50 (30.75-5.25) weeks in the control group, p = 0.464. There were no observed differences in the minor amputation rates between the two groups: 15.2% (n = 7) in the treatment group and 7.1% (n = 3) in the control group (p = 0.362). Major amputations and death outcomes were exclusively observed in the treatment group. Specifically, four major amputations (8.7%) in the treatment group were complications arising from recurring events complicated by infection during the SARS-CoV-2 period. Seven patients died due to complications not related with local therapy. The relative risk of recurrence was 20.18 times higher in the control group compared with those treated with octasulfate dressing (p < 0.001). Treatment with sucrose octasulfate-impregnated dressings can decrease recurrence rates of neuroischaemic diabetic foot ulcers more effectively than neutral dressings. Besides, it may enhance the foot's clinical properties in patients with poor microcirculation, which could aid in preventing future recurrences.

Antimicrobial effects of a multimodal wound matrix against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in an in vitro and an in vivo porcine wound model.

Chronic non-healing wounds pose significant challenges due to an elevated inflammatory response caused in part by bacterial contamination (Physiol Rev. 2019;99:665). These wounds lead to billions being spent in the health care system worldwide (N Engl J Med. 2017;376:2367, Int J Pharm. 2014;463:119). We studied the in-vitro and in-vivo antimicrobial effects of a multimodal wound matrix (MWM) against two common wound pathogens, Methicillin-Resistant Staphylococcus aureus (MRSA USA300) and Pseudomonas aeruginosa ATCC 27312 (PA27312) (Int Wound J. 2019;16:634). The in-vitro study conducted was a zone of inhibition test with the two microbes at 104 Log CFU/mL inoculated on Tryptic soy agar with 5% sheep blood (TSAII) plates. Treatments used were MWM, Mupirocin (Positive control for MRSA), Silver Sulfadiazine (Positive Control for PA), Petrolatum and Sterile Saline (both serving as Negative Controls). Treatments were allowed to diffuse into the agar for 3 h and then were incubated for 24 h at 37°C. The in-vivo study utilized a deep dermal porcine wound model (22 × 22 × 3 mm) created on six animals. Three animals were inoculated with MRSA USA300 and the other three with PA27312 with each allowing a 72-h biofilm formation. After 72 h, baseline wounds were assessed for bacterial concentration and all remaining wounds were treated with either MWM alone, Silver Treatment or Untreated Control. Wounds were assessed on days 4, 8 and 12 after treatment application for microbiological analysis. In-vitro, MWM exhibited significant inhibition of MRSA USA300 and PA27312 growth when compared to negative controls (p ≤ 0.05). Likewise, in-vivo, the MWM-treated wounds exhibited a significant (p ≤ 0.05) bacterial reduction compared to all other treatment groups, especially on days 8 and 12 for both pathogens. MWM demonstrated promise in addressing colonized wounds with biofilms. Additional studies on MWM's benefits and comparisons with existing treatments are warranted to optimize wound care strategies (Adv Wound Care. 2021;10:281).

Evaluation of the efficacy of vacuum sealing drainage in combination with silver-containing dressings for the improvement of chronic refractory wounds.

PURPOSE: The aim of this study was to explore the clinical efficacy of vacuum sealing drainage in combination with silver-containing dressings for the treatment of chronic refractory wounds. METHODS: In this retrospective study, 80 patients with chronic refractory wounds who were treated in the hospital were retrospectively selected as the study objects. Based on the treatment modalities, the patients were divided into the study group (SG; n = 40, receiving vacuum sealing drainage combined with silver-containing dressings) and the control group (CG; n = 40, receiving vacuum sealing drainage alone). RESULTS: The total effective rate of the SG was 92.5%, significantly higher than the 75% in the CG. After treatment, the SG exhibited lower positive rates in bacterial culture, as well as decreased levels of C-reactive protein and erythrocyte sedimentation rate compared to the CG. Starting from the sixth day of treatment, the SG reported statistically significant lower pain intensity scores than the CG. Additionally, the SG exhibited significantly lower dimension scores in terms of scar thickness, color, tenderness, and vascular distribution compared to the CG. CONCLUSION: The combined application of vacuum sealing drainage and silver-containing dressings demonstrated a positive treatment efficacy for patients with chronic refractory wounds.

Magnesium metal-organic framework microneedles loaded with curcumin for accelerating oral ulcer healing.

Oral ulcers are a common oral mucosal disease that seriously affect the quality of life. Traditional drug treatments have shown unsatisfactory efficacy and potential adverse reactions. In this study, curcumin-loaded multifunctional magnesium metal-organic framework-embedded hyaluronic acid-soluble microneedles patches were developed to optimize treatment strategies for oral ulcers. This microneedles patch achieves efficient release of curcumin and Mg2+ in the ulcer through precisely targeted delivery and controllable release mechanism, significantly regulates inflammation, promotes cell migration and angiogenesis, and accelerates the ulcer healing process. At the same time, the synergistic effect of curcumin and gallic acid effectively alleviated oxidative stress, while the backplate ε-poly-L-lysine and needle tip Mg2+ jointly constructed an antibacterial barrier to effectively inhibit pathogens. Verification using an oral ulcer rat model showed that the microneedles patch exhibited excellent therapeutic effects. This not only opens up a new avenue for clinical oral treatment but also marks a breakthrough in nanobiomaterials science and drug delivery technology and heralds a broad prospect in the field of oral ulcer treatment in the future.

Effect of hyaluronic acid on palatal wound healing: A systematic review.

OBJECTIVES: To evaluate the efficacy of topically applied hyaluronic acid on wound healing (patient-reported outcomes and clinical healing) after a palatal autogenous gingival graft is harvested. MATERIALS AND METHODS: A systematic search was performed in April 2024 in eleven electronic databases. Two investigators independently screened the references for inclusion. Outcomes of interest included postoperative pain, analgesic consumption, complete epithelialization, and color match, which were synthesized using narrative synthesis. RESULTS: A total of 535 results were identified and eight articles were included in the systematic review. Hyaluronic acid use on the palatal donor site had a better response to healing and wound size compared to the control sites with no agent applied. Hyaluronic acid demonstrated a positive effect in the form of complete epithelialization, and color match, with improved patient-reported outcomes such as post-operative pain. CONCLUSION: Within the limitations of this systematic review, it can be concluded that hyaluronic acid shows a strong potential to improve patient-reported outcomes and clinical wound healing at the graft donor site on the palate. Future studies are required to clarify the optimal concentration, frequency of application, and synergistic effect when HA is combined with other interventions. CLINICAL RELEVANCE: Within the limitations of this systematic review, it can be concluded that hyaluronic acid shows a strong potential to improve patient-reported outcomes and clinical wound healing at the graft donor site on the palate. Future studies are required to clarify the optimal concentration, frequency of application, and synergistic effect when HA is combined with other interventions.

Composite microneedles loaded with Astragalus membranaceus polysaccharide nanoparticles promote wound healing by curbing the ROS/NF-κB pathway to regulate macrophage polarization.

The healing of chronic diabetic wounds remains a formidable challenge in modern times. In this study, a novel traditional Chinese medicine microneedle patch was designed based on the physiological characteristics of wounds, with properties including hemostasis, anti-inflammatory, antioxidant, antimicrobial, and induction of angiogenesis. Initially, white peony polysaccharide (BSP) with hemostatic properties and carboxymethyl chitosan (CMCS) with antimicrobial capabilities were used as materials for microneedle fabrication. To endow it with antimicrobial, procoagulant, and adhesive properties. Among them, loaded with ROS-sensitive nanoparticles of Astragalus polysaccharides (APS) based on effective components baicalein (Bai) and berberine (Ber) from Scutellaria baicalensis (SB) and Coptis chinensis (CC) drugs (APB@Ber). Together, they are constructed into multifunctional traditional Chinese medicine composite microneedles (C/B@APB@Ber). Bai and Ber synergistically exert anti-inflammatory and antimicrobial effects. Microneedle patches loaded with BSP and APS exhibited significant effects on cell proliferation and angiogenesis induction. The combination of composite polysaccharides enabled the microneedles to adhere stably to wounds and provide sufficient strength to penetrate the biofilm and induce dispersion. The combination of composite polysaccharides enabled the microneedles to adhere stably to wounds and provide sufficient strength to penetrate the biofilm and induce dispersion. Therefore, traditional Chinese medicine multifunctional microneedle patches offer potential medical value in promoting the healing of diabetic wounds.

Heterojunction functionalized sodium alginate/carboxylated cellulose nanocrystals film enhancing sterilization performance for wound healing.

In the realm of natural polysaccharides, hydrogen bonding is a prevalent feature, yet its role in enhancing photocatalytic antimicrobial properties has been underexplored. In this paper, heterojunctions formed by graphene oxide (GO) and ZIF-8 were locked in sodium alginate/ carboxylated cellulose nanocrystals via hydrogen bonding networks, designated as SCGZ. The SCGZ films exhibit superior photocatalytic performance compared to either ZIF-8 or heterojunctions. This enhancement is primarily due to two key factors: firstly, the hydrogen bonding network significantly enhances the transfer of protons and holes, thereby improving the separation efficiency of photo-generated carriers; secondly, the hydrogen bonding between the layers facilitates a more efficient charge transfer, which expedites the movement of electrons from ZIF-8 to GO upon illumination. In vitro studies demonstrated that the SCGZ films possess remarkable antibacterial capabilities, achieving 99.75 % and 99.61 % inhibition rates against S. aureus and E. coli, respectively. In vivo animal experiments have shown that SCGZ films can significantly accelerate the healing process of damaged tissues, with a healing efficiency of up to 90.5 %. This research provides additional insights into the development of natural polysaccharide-based multi­hydrogen bonded macromolecules with enhanced photocatalytic properties.

Crocin-1 laden thermosensitive chitosan-based hydrogel with smart anti-inflammatory performance for severe full-thickness burn wound therapeutics.

Burns are the fourth most common type of civilian trauma worldwide, and the management of severe irregular scald wounds remains a significant challenge. Herein, crocin-1 laden hydroxybutyl chitosan (CRO-HBC) thermosensitive hydrogel with smart anti-inflammatory performance was developed for accelerating full-thickness burn healing. The injectable and shape adaptability of the CRO-HBC gel make it a promising candidate for effectively filling scald wounds with irregular shapes, while simultaneously providing protection against external pathogens. The CRO-HBC gel network formed by hydrophobic interactions exhibited an initial burst release of crocin-1, followed by a gradual and sustained release over time. The excessive release of ROS and pro-inflammatory cytokines should be effectively regulated in the early stage of wound healing. The controlled release of crocin-1 from the CRO-HBC gel adequately addresses this requirement for wound healing. The CRO-HBC hydrogel also exhibited an excellent biocompatibility, an appropriate biodegradability, keratinocyte migration facilitation properties, and a reactive oxygen species scavenging capability. The composite CRO-HBC hydrogel intelligently mitigated inflammatory responses, promoted angiogenesis, and exhibited a commendable efficacy for tissue regeneration in a full-thickness scalding model. Overall, this innovative temperature-sensitive CRO-HBC injectable hydrogel dressing with smart anti-inflammatory performance has enormous potential for managing severe scald wounds.

Photothermal enhanced antibacterial chitosan-based polydopamine composite hydrogel for hemostasis and burn wound repairing.

Bleeding and bacterial infection are common problems associated with wound treatment, while effective blood clotting and vessel regeneration promotion are the primary considerations to design the wound dressing materials. This research presents a chitosan-based hydrogel with grafted quaternary ammonium and polyphosphate (QCSP hydrogel) as the antibacterial hemostatic dressing to achieve burn wound treatment. The tissue adhesion of the hydrogel sealed the blood flow and the polyphosphate grafted to the chitosan promoted the activation of coagulation factor V to enhance the hemostasis. At the same time, the grafted quaternary ammonium enhanced the antibacterial ability of the biodegradable hydrogel wound dressing. In addition, the polydopamine as a photothermal agent was composited into the hydrogel to enhance the antibacterial and reactive oxygen scavenging performance. The in vivo hemostasis experiment proved the polyphosphate enhanced the coagulation property. Moreover, this photothermal property of the composite hydrogel enhanced the burn wound repairing rate combined with the NIR stimulus. As a result, this hydrogel could have potential application in clinic as dressing material for hemostasis and infection prone would repairing.

PROTECTIVE EFFECT OF A NEW SUPEROXIDE-PRODUCING ENZYME COMPLEX FROM RASPBERRY IN RATS WITH THIRD-DEGREE THERMAL BURNS.

Thermal burns are the most common type of burn injuries. Medical treatment for burns is crucial, especially for third-degree burns and when a significant surface area of the body is affected. One of the most pressing issues in modern medicine is the search for new effective means to accelerate the healing of burn wounds. Oxygen radicals play a significant role in maintaining homeostasis, forming the body's resistance to infection, and ensuring the regeneration of organs and tissues. In this study, a superoxide (O2-)-producing enzyme (SPE) from raspberries was applied (topically to the skin, injected under the wound surface, with solution concentrations of 12.75% and 5%) after a third-degree thermal burn to determine its reparative effects on the skin. To assess the condition of the animals that had suffered burn injuries and the healing process, blood parameters were analyzed, and cytogenetic indices of bone marrow from the femur of the animals were studied: mitotic index, number of polyploid cells, and chromosomal aberrations. When analyzing hematological, cytogenetic, and histological parameters, significant differences were found between the «clean burn¼ groups and the groups in which SPE was used in different concentrations and methods of application. The use of SPE in both concentrations contributed to a reduction in the area of burn wounds compared to a «clean burn¼. The survival rate of animals for 30 days (before the end of the experiment) was 100% when using a 12.75% SPE solution and 50% when using a 5% SPE solution. The use of SPE led to significant differences in hematological parameters from the «clean burn¼ group throughout the entire duration of the experiment, showing a tendency to normalize the parameters. Under the influence of the 12.75% SPE solution, there was a tendency toward normalization of the mitotic index, along with a significant reduction in the percentage of polyploid cells and chromosomal aberrations, which may indicate its beneficial effects. This study found that a 12.75% SPE solution derived from raspberries was more effective and had healing properties on third-degree thermal burns, promoting rapid healing of the burn wound.