Mechanical Wind Research Articles

Glucose-responsive carboxymethyl chitosan/ sodium alginate film protects against mechanical wound on postharvest blueberry

Fresh fruits and vegetables, particularly berries, are highly susceptible to mechanical damage, which results in nutrient loss, reduced quality, and increased decay from microbial infections, ultimately leading to significant losses. Here, a biodegradable polysaccharide film was employed to encapsulate glucose oxidase (Gox), thereby creating a glucose/wounding-responsive active package that reduced fruit respiration, promoted healing and protected blueberry wounds from mold infection. The combination of carboxymethyl chitosan and sodium alginate resulted in the formation of the polysaccharides film CSF that effectively restricted the permeation of oxygen, water, and carbon dioxide around the surface of the fruit. The encapsulation of Gox in the CSF film (CSFG) reduced glucose levels through enzymatic reaction in surface wounds of the fruit, thereby competing for glucose to establish a starvation-like microenvironment for the pathogenic fungus Botrytis cinerea. The enzymatic reaction also facilitated the production of hydrogen peroxide, which functioned as a fungicide that inhibits the growth of B. cinerea and served as a secondary messenger in fruit immunity. The CSFG film increased beta-glucanase activity, and decreased lipid peroxidation in wounds of blueberries. Therefore, this glucose-responsive CSFG barrier significantly reduced the decay rates of gray mold, caused by B. cinerea in wounded blueberries, by 66.7% compared to the control at 6 d of storage. Taken together, the glucose-responsive active packaging film provides an alternative package for safeguarding blueberries against mechanical damage.

Withdrawal: Conductive Hydrogel Dressing With High Mechanical Strength for Joint Wound Healing.

Hydrogel wound dressing can accelerate angiogenesis to achieve rapid wound healing, but traditional hydrogel dressings are difficult to meet the repair of joint sites due to their low mechanical strength. Therefore, we constructed the gel system by designing the chemical-physical interpenetrating network structure to achieve high strength and high toughness of the hydrogel. The high-strength double-network hydrogels were synthesized by simple free radical polymerization and low-temperature physicochemical cross-linking in our experiments. The suspension was obtained by green reduction of graphene oxide with carboxymethyl chitosan, followed by the introduction of acrylamide (AM) to form a covalent cross-linked network, which was immersed in ferric chloride solution to form metal ligand bonds, and finally the chemical-physical dual cross-linked network hydrogel wound dressing was prepared. Here, reduced graphene oxide can enhance electrical conductivity and excellent near-infrared photothermal effect to the hydrogel. The cell viability of this novel wound dressing was above 90.0%, its hemolysis rate was below 2.0%, and the electrical conductivity could reach (6.89 ± 0.07 (mS/cm)). In addition, the stress-strain curve demonstrated that the double cross-linked network hydrogel could reach a stress of more than 0.8MPa at 82.0% strain, and the cyclic compression experiment shows that it can still recover its original shape after five times of repeated compression. This work can provide a reference for the exploitation of high mechanical strength hydrogel wound dressings with good electrical conductivity and near-infrared photothermal effect. This article is protected by copyright. All rights reserved.

Tissue-adhesive, stretchable and compressible physical double-crosslinked microgel-integrated hydrogels for dynamic wound care

Integrated wound care through sequentially promoting hemostasis, sealing, and healing holds great promise in clinical practice. However, it remains challenging for regular bioadhesives to achieve integrated care of dynamic wounds due to the difficulties in adapting to dynamic mechanical and wet wound environments. Herein, we reported a type of dehydrated, physical double crosslinked microgels (DPDMs) which were capable of in situ forming highly stretchable, compressible and tissue-adhesive hydrogels for integrated care of dynamic wounds. The DPDMs were designed by the rational integration of the reversible crosslinks and double crosslinks into micronized gels. The reversible physical crosslinks enabled the DPDMs to integrate together, and the double crosslinked characteristics further strengthen the formed macroscopical networks (DPDM-Gels). We demonstrated that the DPDM-Gels simultaneously possess outstanding tensile (∼940 kJ/m3) and compressive (∼270 kJ/m3) toughness, commercial bioadhesives-comparable tissue-adhesive strength, together with stable performance under hundreds of deformations. In vivo results further revealed that the DPDM-Gels could effectively stop bleeding in various bleeding models, even in an actual dynamic environment, and enable the integrated care of dynamic skin wounds. On the basis of the remarkable mechanical and appropriate adhesive properties, together with impressive integrated care capacities, the DPDM-Gels may provide a new approach for the smart care of dynamic wounds. Statement of significanceIntegrated care of dynamic wounds holds great significance in clinical practice. However, the dynamic and wet wound environments pose great challenges for existing hydrogels to achieve it. This work developed robust adhesive hydrogels for integrated care of dynamic wounds by designing dehydrated, physical double crosslinked microgels (DPDMs). The reversible and double crosslinks enabled DPDMs to integrate into macroscopic hydrogels with high mechanical properties, appropriate adhesive strength and stable performance under hundreds of external deformations. Upon application at the injury site, DPDM-Gels efficiently stopped bleeding, even in an actual dynamic environment and showed effectiveness in integrated care of dynamic wounds. With the fascinating properties, DPDMs may become an effective tool for smart wound care.

A multifunctional thermosensitive hydrogel based on phototherapy for promoting the healing of dental extraction wounds.

Post-extraction wound infections are a common complication of dental extractions. More specifically, infection in the alveolar socket after tooth extraction accelerates the resorption and destruction of the alveolar bone, and ultimately affects the final restoration results. Currently, the main clinical treatment approaches applied to the socket after tooth extraction include mechanical wound debridement, chemical rinses (e.g., chlorhexidine), filling of the extraction socket with absorbent gelatin sponges, and the systemic application of antibiotics. However, these traditional treatment modalities have some limitations and their therapeutic effects are unsatisfactory. In this study, a phototherapeutic temperature-sensitive hydrogel material was constructed for injection using a tea polyphenol (TP)-modified poly-N-isopropylacrylamide (PNIPAM) hydrogel skeleton loaded with the photosensitiser indocyanine green (ICG). The resulting PNIPAM-TP/ICG system exhibited an excellent injectability and temperature-sensitive properties. In addition, it stopped haemorrhaging and acted as a wound astringent. The hydrogel steadily released ICG into the oral environment to exert photothermal/photodynamic effects along with synergistic antibacterial and anti-inflammatory properties when combined with tea polyphenols. In vivo experiments demonstrated that the application of PNIPAM-TP/ICG to infected dental extraction wounds in rats rapidly stopped the bleeding and accelerated wound healing. Overall, this study describes a drug-loaded, temperature-sensitive hydrogel for the treatment of open wound infections, and shows promise as a reference for the treatment of tooth extraction wounds.

Incidence and risk factors of postoperative delirium following hepatic resection: a retrospective national inpatient sample database study

BackgroundPostoperative delirium (POD) is a common complication after major surgery and can cause a variety of adverse effects. However, no large-scale national database was used to assess the occurrence and factors associated with postoperative delirium (POD) following hepatic resection.MethodsPatients who underwent hepatic resection from 2015 to 2019 were screened using the International Classification of Diseases (ICD) 10th edition clinical modification code from the National Inpatient Sample (NIS) Database. Peri-operative factors associated with delirium were screened and underwent statistical analysis to identify independent predictors for delirium following hepatic resection.ResultsA total of 80,070 patients underwent hepatic resection over a five-year period from 2015 to 2019. The overall occurrence of POD after hepatic resection was 1.46% (1039 cases), with a slight upward trend every year. The incidence of elective admission was 6.66% lower (88.60% vs. 81.94%) than that of patients without POD after hepatic resection and 2.34% (45.53% vs. 43.19%) higher than that of patients without POD in teaching hospitals (P < 0.001). In addition, POD patients were 6 years older (67 vs. 61 years) and comprised 9.27% (56.69% vs. 47.42%) more male patients (P < 0.001) compared to the unaffected population. In addition, the occurrence of POD was associated with longer hospitalization duration (13 vs. 5 days; P < 0.001), higher total cost ($1,481,89 vs. $683,90; P < 0.001), and higher in-hospital mortality (12.61% vs. 4.11%; P < 0.001). Multivariate logistic regression identified hepatic resection-independent risk factors for POD, including non-elective hospital admission, teaching hospital, older age, male sex, depression, fluid and electrolyte disorders, coagulopathy, other neurological disorders, psychoses, and weight loss. In addition, the POD after hepatic resection has been associated with sepsis, dementia, urinary retention, gastrointestinal complications, acute renal failure, pneumonia, continuous invasive mechanical ventilation, blood transfusion, respiratory failure, and wound dehiscence / non-healing.ConclusionAlthough the occurrence of POD after hepatic resection is relatively low, it is beneficial to investigate factors predisposing to POD to allow optimal care management and improve the outcomes of this patient population.

How effective is simple mechanical wound debridement in reducing bacterial colonisation? Results of a prospective clinical study.

Bacteria in wounds can lead to stagnation of wound healing as well as to local or even systemic wound infections up to potentially lethal sepsis. Consequently, the bacterial load should be reduced as part of wound treatment. Therefore, the efficacy of simple mechanical wound debridement should be investigated in terms of reducing bacterial colonisation. Patients with acute or chronic wounds were assessed for bacterial colonisation with a fluorescence camera before and after mechanical wound debridement with sterile cotton pads. If bacterial colonisation persisted, a second, targeted wound debridement was performed. A total of 151 patients, 68 (45.0%) men and 83 (55.0%) women were included in this study. The male mean age was 71.0 years and the female 65.1 years. By establishing a new analysis method for the image files, we could document that the bacterial colonised areas were distributed 21.9% on the wound surfaces, 60.5% on the wound edges (up to 0.5 cm) and 17.6% on the wound surroundings (up to 1.5 cm). One mechanical debridement achieved a significant reduction of bacterial colonised areas by an average of 29.6% in the wounds, 18.9% in the wound edges and 11.8% in the wound surroundings and was increased by performing it a second time. It has been shown that even a simple mechanical debridement with cotton pads can significantly reduce bacterial colonisation without relevant side effects. In particular, the wound edges were the areas that were often most contaminated with bacteria and should be included in the debridement with special attention. Since bacteria remain in wounds after mechanical debridement, it cannot replace antimicrobial therapy strategies, but offer a complementary strategy to improve wound care. Thus, it could be shown that simple mechanical debridement is effective in reducing bacterial load and should be integrated into a therapeutic approach to wounds whenever appropriate.

Suture Materials: A Perio Perspective

Sutures are natural or synthetic biomaterial devices used to connect blood vessels and align tissues [1]. Its primary function is to reunite and secure tissues after separation due to surgery or trauma. The purposes of wound closure include erasing the dead space, regular distribution of tension along the deep suture lines, keeping the tractile strength across the wound until the tissue tractile strength is sufficient and aiming to approximate the epithelial portion of the closure. Sutures are the most commonly used material for mechanical wound closure, even though there are other methods like staples, tape, and adhesive [2].

Role of mechanotransduction on decision making for treatment of chronic wounds

AbstractThe objective of this study is to take an initial step to determine and interpret the extents to which biophysical wound dressing properties impact mechanotransduction within a wound tissue. Current experimental techniques make it challenging to investigate many of the complexities of the wound healing process. Thus, the purpose of this study is to begin with computational models and theoretical descriptions that propose predictions and explanations of the role of various mechanical wound dressing characteristics on mechanotransduction in wound tissues. Three‐dimensional models of wound tissue and wound dressings have been developed to analyze how von Mises stresses are distributed within the tissue models. Our results show that shorter ellipsoid dressings lead to highest stresses within the wound tissue where dressing's thickness and stiffness don't show a significant impact. When using a rectangular dressing, shorter, softer, thinner ones lead to high stress transmission to a wound tissue.

Hemostatic Tranexamic Acid-Induced Fast Gelation and Mechanical Reinforcement of Polydimethylacrylamide/Carboxymethyl Chitosan Hydrogel for Hemostasis and Wound Healing.

The combinational properties with excellent mechanical properties, adhesive performance, hemostatic ability, antibacterial action, and wound healing efficacy are highly desirable for injectable hydrogels' practical applications in hemorrhage control and wound closure, but designing one single hydrogel system integrating with such properties is still difficult. Herein, a simplified yet straightforward strategy is proposed to prepare an injectable and robust poly(N,N-dimethylacrylamide) (PDMAA)/carboxymethyl chitosan (CMCS) hydrogel induced by tranexamic acid (TXA). TXA not only promotes the rapid generation of free radicals but also introduces multiple hydrogen bonds into the hydrogel network. Moreover, as a common clinical hemostatic drug, TXA itself has excellent hemostatic effects. In addition, CMCS imparts sterilization and hemostasis effects to the hydrogel, thereby promoting wound healing. Besides, the amino and carboxyl groups on TXA molecules and the hydroxyl, amino, and carboxyl groups on CMCS molecules can form multiple hydrogen bonds with wet biological tissues, leading to good wet tissue adhesion of the hydrogel. As a result, the hydrogel with excellent mechanical properties (up to 1.83 MPa at 90% compression strain), adhesion performance (up to 18.7 kPa adhesion strength to porcine skin tissue), biocompatibility, hemostatic ability, antibacterial activity, and wound healing properties can be fabricated within several minutes. These combinational advantages enable the hydrogel to efficiently stop hemorrhage (blood loss amount: 110 mg; hemostasis time: 25 s) and promote the wound healing process (wound closure rate at 2 weeks: 83%), which can be verified using rat models of liver bleeding and infected full thickness skin defect. Overall, this facile strategy to design a hydrogel incorporating such unique advantages will greatly advance the hydrogel's clinical application in rapid hemostasis and wound healing.

IMPROVING SURGICAL STRATEGIES FOR TREATING EXTENSIVE SOFT TISSUE WOUNDS RESULTING FROM MINE AND EXPLOSIVE TRAUMA

Introduction.Since February 24, 2022, a primary focus of surgical care in Ukraine has been to provide assistance to citizens affected by Russian aggression. A significant proportion of wounds and injuries sustained in this context involves mine-explosive wounds, manifesting as soft tissue damage in the form of lacerations, shrapnel injuries, and wounds of varying degrees of contamination and size.&#x0D; The widespread adoption of Vacuum-Assisted Closure (VAC) therapy for wounds characterized by extensive muscle and skin defects involves the localized application of negative pressure to damaged tissues. Typically, this precedes planned autodermoplasty, which, despite being a scheduled intervention, follows urgent surgical corrections. These interventions offer a distinct opportunity for individuals with substantial soft tissue injuries— and, as evidenced by experience, not limited to them— to restore their pre-injury quality of life.&#x0D; The aim of this study is to enhance the quality of life for individuals affected by mine-explosive injuries and extensive soft tissue wounds.&#x0D; Materials and methods. The outcomes of surgical treatment of 57 civilian victims afflicted by landmine-explosive wounds and extensive soft tissue injuries were examined. These individuals underwent treatment at the Surgical Department of the Regional Clinical Hospital" during the period 2022 – 2023. Among the cohort, 34 were women, constituting 59%, while 23 were men, representing 41%, the ages of the patients ranged from 34 to 74 years.&#x0D; Results and discussion. All 57 patients initially underwent surgical treatment of wounds, involving the removal of foreign bodies if present, necrectomy, and subsequent application of the second-stage Vacuum-Assisted Closure (VAC) therapy. The VAC therapy was used to cleanse the wounds and reduce their surface area. Continuous VAC therapy was administered at a negative pressure ranging from 50 mmHg (on the anterior abdominal wall and the back surface of the chest) to 110 mmHg (on tissues of the lower extremities). The replacement of the VAC dressing occurred every 3-5 days, contingent upon the quantity and quality of the exudate, with typically 2-3 changes required. The third stage involved the application of free autodermoplasty utilizing a perforated skin flap. Mechanical wound treatment was performed iteratively until the level of "bloody dew" was reached.&#x0D; We suggest that all these stages are essential for achieving favorable treatment outcomes, irrespective of any severe accompanying pathology that may arise. Indeed, comorbidity stands out as a defining factor that distinguishes the civilian population qualitatively from the military category.&#x0D; Conclusions. The application of Vacuum-Assisted Closure (VAC) therapy followed by autodermoplasty in the management of extensive soft tissue injuries caused by mine-explosive incidents significantly enhances the efficacy of surgical treatment and reduces the period of patient incapacitation, presenting clear economic benefits. Autodermoplasty, in particular, holds a commendable position within the realm of reconstructive surgery for mine and explosive wounds. Within this context, autodermoplasty emerges as a surgical intervention that not only yields positive aesthetic outcomes but also facilitates an accelerated adaptation of the affected body part. This, in turn, contributes to an improved quality of life for victims of mine-explosive trauma grappling with substantial soft tissue damage.

Fabrication and characterization of high molecular mass tmpe-based polyurethane wound dressing materials containing allantoin and gentamicin by electrospinning

In this study, biocompatible, antibacterial and high mechanical strength polyurethane-based wound dressing materials were prepared by using the electrospinning technique. In addition, allantoin and gentamicin which will contribute to wound healing, were incorporated into these fiber materials. Polyurethane structures containing trimethylolpropane ethoxylate (TMPE) with 2 different molecular weights were synthesized. TMPE-based polyurethanes/polycaprolactone (1:3) blends were also prepared by adding 1% gentamicin and 10% allantoin and they were knitted by the electrospinning method and turned into a wound dressing material. After this stage, chemical structure, morphological, thermal and mechanical properties, flexibility, antibacterial effect, in vitro biocompatibility, cell adhesion tests, allantoin release level, and biodegradability of the prepared wound dressing materials were performed. The prepared fiber materials exhibited antibacterial properties and 80% cell viability, approximately. In addition, the obtained wound dressing materials showed high mechanical strength and ideal gas permeability. For this reason, it offers an ideal alternative for closing wounds.

Understanding factors that impact the length of stay after total hip arthroplasty – A national in-patient sample-based study

BackgroundTotal hip arthroplasty (THA) is increasingly used every year; however, there is currently limited information on factors that impact the length of stay (LOS) following the procedure. Longer LOS following THA is met with an increase in the cost of care, necessitating studies to identify factors that may impact LOS. MethodsIn this retrospective study, we used the Nationwide Inpatient Sample (NIS) database from 2016 to 2019 to analyze the preoperative comorbidities and postoperative complications that impact the LOS following THA. We divided our cohort into patients with a LOS greater than two days, and patients with a LOS less than two days. ResultsA total of 367,890 patients were identified in the NIS database who underwent THA during the study period. Of this cohort, 112,288 (30.52%) patients were identified as having a LOS greater than two days, while the remaining 255,602 (69.48%) patients were patients who had a LOS less than two days. Multivariate analysis demonstrated several pre-operative factors, such as diabetes, systemic lupus erythematosus, organ transplant, dialysis, the human immunodeficiency virus, chronic kidney disease, and Parkinson's disease, were independently associated with a higher risk of a LOS greater than two days. The subsequent multivariate analysis for post-operative variables demonstrated that acute renal failure, myocardial infarction, blood loss anemia, blood transfusion, pulmonary embolism, deep vein thrombosis, periprosthetic fracture, periprosthetic mechanical complications, periprosthetic infections, and wound dehiscence were all independently associated with a higher risk of a LOS greater than two days. ConclusionsSeveral pre-operative comorbidities and postoperative complications were found to increase the likelihood of a LOS greater than two days. In addition, the group with a LOS greater than two days incurred a higher cost of care. This information is useful for providers to make informed decisions regarding patient care and resource utilization for patients undergoing THA, potentially reducing LOS.

Low temperature, mechanical wound, and exogenous salicylic acid (SA) can stimulate the SA signaling molecule as well as its downstream pathway and the formation of fruiting bodies in Flammulina filiformis.

Low temperature (LT) and mechanical wound (MW), as two common physics methods, have been empirically used in production to stimulate the primordia formation of Flammulina filiformis, which is typically produced using the industrial production mode. However, the detailed effect on the fruiting body formation and important endogenous hormones and signaling pathways in this process is poorly understood. In this study, LT, MW, their combination, i.e., MW + LT, and low concentration of SA (0.1 mM SA) treatments were applied to the physiologically mature mycelia of F. filiformis. The results showed that the primordia under the four treatments began to appear on the 5th-6th days compared with the 12th day in the control (no treatment). The MW + LT treatment produced the largest number of primordia (1,859 per bottle), followed by MW (757), SA (141), and LT (22), compared with 47 per bottle in the control. The HPLC results showed that the average contents of endogenous SA were significantly increased by 1.3 to 2.6 times under four treatments. A total of 11 SA signaling genes were identified in the F. filiformis genome, including 4 NPR genes (FfNpr1-4), 5 TGA genes (FfTga1-5), and 2 PR genes (FfPr1-2). FfNpr3 with complete conserved domains (ANK and BTB/POZ) showed significantly upregulated expression under all four above treatments, while FfNpr1/2/4 with one domain showed significantly upregulated response expression under the partial treatment of all four treatments. FfTga1-5 and FfPr1-2 showed 1.6-fold to 8.5-fold significant upregulation with varying degrees in response to four treatments. The results suggested that there was a correlation between "low temperature/mechanical wound-SA signal-fruiting body formation", and it will help researchers to understand the role of SA hormone and SA signaling pathway genes in the formation of fruiting bodies in fungi.

Mechanical properties and wound healing potential of bacterial cellulose-xyloglucan-dextran hydrogels

Bacterial cellulose (BC) is a promising material for use as an artificial skin in wound healing application, however, its applications are limited due to its poor malleability. Incorporating non-cellulosic polysaccharides such as dextran and xyloglucan (XG) may enhance its respective wound healing and malleability. This study presents a novel in situ biopreparation method to produce BC-based hybrid hydrogels containing dextran (BC-D) and xyloglucan-dextran (BC-XG-D) with unique mechanical and rheological properties. Structural analysis revealed that dextran of different sizes (10 k, 70 k and 2 M of Mw) form micron-sized particles by loosely binding to cellulosic fibres. The addition of xyloglucan resulted acts as a lubricant in mechanical testing. The BC-XG-D hybrid hydrogels showed a reduced Young's modulus of 4 MPa and a higher maximum tensile strain of 53 % compared to native BC. Moreover, they displayed less plastic but more viscous behaviour under large shear strain deformation. The wound healing animal model experiments demonstrated that the BC-XG-D hybrid hydrogels promoted wound healing process and skin maturation. Overall, these findings contribute to the development of functional BC-based medical materials with desired mechanical and rheological properties that have the potential to accelerate wound healing.

Abstract P2012: Development Of An In Vitro Assay To Model Loss Of Neighbor At The Infarct Border Zone

The borderzone (BZ) of the infarcted heart separates poorly-perfused areas of cell death from well-perfused territories of comparatively normal myocardium. The BZ after myocardial infarction is of key importance for the remodeling process that drives heart failure and sudden cardiac death. We recently defined the transcriptional features of the infarct borderzone using single cell RNA-Seq and spatial transcriptomics which revealed prominent upregulation of mechanotransduction transcriptional programs. A similar transcriptional response was inducible by needle trauma alone. To explain these results, we proposed the “Loss of Neighbor” (LON) Hypothesis, where surviving cells neighboring the infarct experience mechanical instability due to the highly asymmetric loss of load, leading to cell signal activation. Here, we develop and validate an in vitro model of loss of neighbor using a mechanical scratch assay to model the biology of the infarct borderzone. We cultured neonatal rat cardiomyocytes and cardiac fibroblasts and subjected them to mechanical “scratch” injury. To evaluate how the mechanical wound altered gene expression, we performed qPCR for genes expressed by cardiomyocytes in the remote zone and the borderzone using RNA isolated from cells with or without exposure to mechanical scratch injury. Compared to non-scratched cultures, scratched cells significantly upregulated BZ-specific genes such as Ankrd1, Nppa, Flnc, and Xirp2 . In addition, scratched cells significantly upregulated expression of interferon-stimulated genes (ISGs) compared to non-scratched cells or scratched cells exposed to anti-IFNAR Ab. This suggests that the interferon-inducible cell (IFNIC) response observed at the infarct borderzone in vivo can be induced by in vitro cardiomyocyte LON. Taken together, our results suggest that the mechanical scratch assay in vitro captures key elements of the transcriptional borderzone in vivo . Overall, this model can guide further elucidation of the transcriptional program states during cardiac remodeling.

Use of disposable negative pressure wound therapy in 16 podiatry clinic patients with chronic wounds

BACKGROUND: Disposable mechanical negative pressure wound therapy (dNPWT) can help manage lower extremity wounds in the outpatient clinic. PURPOSE: We assessed dNPWT use in 16 patients at a podiatry clinic. METHODS: Patients were treated between October 31, 2019 and December 16, 2021. All patients received dNPWT with dressing changes every 2 to 3 days. Demographics, baseline wound and subsequent wound visit data, and treatments were recorded. Wound healing outcomes were assessed. RESULTS: Average patient age was 59.6 ± 8.9 years old. Patient comorbidities included poor nutritional status, diabetes, and hypertension. Wound types consisted of 6 diabetic foot ulcers, 9 surgical wounds, and 1 pressure injury. At baseline, the average wound age was 15.6 weeks, average area was 5.5 cm2, and average volume was 3.3 cm3. The average time from presentation to end of dNPWT was 45.5 days. In this timeframe, wounds improved in granulation tissue amount (81%), reduced in area (63%), and reduced in volume (69%). By the end of treatment, a majority of patients (88%) displayed 76% to 100% wound bed coverage with healthy granulation tissue. The remaining 12% showed &lt;76% coverage with granulation tissue. CONCLUSIONS: In this retrospective study, 14 of 16 patients displayed improvement in wound area, volume, and granulation tissue amount during dNPWT treatment.

Microgel Assembly Powder Improves Acute Hemostasis, Antibacterial, and Wound Healing via In Situ Co‐Assembly of Erythrocyte and Microgel

AbstractRapid and effective hemostasis on irregular‐shaped non‐compressible bleeding wounds is still one of the key challenges in clinical practice. Herein, a novel multi‐functional microgel assembly powder (MAP) composed of oxidized dextran/methacrylate gelatin (ODex/GelMA) microgel powder and long‐chain alkyl quaternized chitosan (LQCS) crosslinker powder is reported for acute hemostasis, antibacterial, and wound healing. When MAP is applied onto bleeding wounds, porous ODex/GelMA microgel powder immediately absorbs massive liquid in blood whilst LQCS induces in situ co‐assembly of erythrocytes and microgels. In other words, MAP combines the merits of hemostatic powders and hemostatic hydrogels, that is, the excellent hemostasis performance of MAP is originated from not only the high fluid uptake ratio/rate that causes the aggregation of coagulation factors and erythrocytes, but also the formation of erythrocytes‐involved hydrogel‐like microgel assembly that dramatically improves the mechanical strength, tissue adhesion and wound sealing performance in blood compared with those in PBS. In addition, MAP also exhibits excellent antibacterial ability, and promotes the wound healing in bacterial‐infected full‐thickness skin wounds. The fantastic features of MAP including low cost, easy synthesis and usage, excellent hemostasis on irregular‐shaped, non‐compressible bleeding wounds, outstanding antibacterial and wound healing, good cytocompatibility, make it a promising hemostatic material and wound dressing.

Qualitative study on diabetic cutaneous wound healing with radiation crosslinked bilayer collagen scaffold in rat model

Diabetes may leave patients more prone to skin problems, and minor skin conditions can more easily turn into serious damage to the extracellular matrix, which further impairs the skin's mechanical properties and delays wound healing. Therefore, the aim of the work is to develop extracellular matrix substitution to remodel the mechanical properties of diabetic cutaneous wound and thus accelerate diabetic wound healing. A green fabrication approach was used to prepare radiation crosslinked bilayer collagen scaffold from collagen dispersion. The morphological, mechanical and swelling characteristics of radiation crosslinked bilayer collagen scaffold were assessed to be suitable for cutaneous wound remodeling. The feasibility of radiation crosslinked bilayer collagen scaffold was performed on full-skin defect of streptozotocin-induced diabetic rats. The tissue specimens were harvested after 7, 14, and 21 days. Histopathological analysis showed that radiation crosslinked bilayer collagen scaffold has beneficial effects on inducing skin regeneration and remodeling in diabetic rats. In addition, immunohistochemical staining further revealed that the radiation crosslinked bilayer collagen scaffold could not only significantly accelerate the diabetic wound healing, but also promote angiogenesis factor (CD31) production. Vascularization was observed as early as day 7. The work expands the therapeutic ideas for cutaneous wound healing in diabetes.

First Report of Neopestalotiopsis clavispora Causing Postharvest Fruit Rot on Actinidia arguta in Liaoning Province, China.

Actinidia arguta, commonly called hardy kiwifruit or kiwiberry, is a perennial vine of Actinidiaceae Actinidia genus. Understanding the main pathogens that cause the fruit rot of A. arguta during storage is of great significance for finding strategies to prevent fruit rot. In September 2020, the A. arguta (Sieb.et Zucc.) Planch. ex Miq. LD133 was harvested from a farm in Dandong City, Liaoning Province, China (40°31'N, 124°20'E). After being stored at room temperature for about a week, the fruit rotted (no mechanical damage or wound). Initial symptoms were localized irregular spots, which then became soft and the spots connected into large, flaky, light brown lesions. Later symptoms were dark brown lesions and rot that affect the entire fruit. The strain that shows the same morphology as observed in the four decaying tissues was isolated on PDA. The strain was white, edge irregular and surface wavy, and the reverse side was pale yellow (Fig. S1A). The black viscous acervuli appeared on the surface of the mycelium after 7 to 10 days at 25℃ with 12 hours photoperiod. Conidia were fusiform to ellipsoid, straight to slightly curved, 5.7×25.9 µm (width × length), n=30, with five versicolor cells (three brown median cells, two hyaline cells on apical and basal). The apical cell generally contains one to four appendages on conidia (Fig. S1B). For identify the selected strains, three genetic regions (ITS, TUB and TEF 1-α) were used for amplification and sequencing. These sequences of pathogen shared 98 to 100% homology with Neopestalotiopsis clavispora. Then, a phylogenetic tree was constructed by the Bayesian algorithm using PhyloSuite (v1.2.2) (Zhang et al. 2020). Based on the morphological and molecular characterization, the pathogen was identified as Neopestalotiopsis clavispora (Chamorro et al. 2016). Next, pathogenicity of the screened strains was determined by wound inoculation method. Ripe healthy fruits are immersed in 1% NaClO, rinsed twice with sterile water. A sterile needle was used to penetrate 1-2mm of peel, and then inoculate hyphae (about 5mm in length, 1mm in diameter), and 10 µL of sterile water as a control. The treated fruits are stored in an artificial climate chamber (22°C, 70% relative humidity with 12 hours photoperiod). The inoculated fruit began to show signs of rot on the second day, and after 6 days, lesions similar to those found during storage of the pathogenic isolated fruit appeared. Similarly, 10 µL (106 conidia/mL) conidial suspension exhibited decay symptoms. Compared with conidial suspension as inoculum, hyphae has shorter incubation period and stronger pathogenicity to fruit (Fig. S2). The pathogen was re-isolated from these infected fruits and identified as N. clavispora, thus fulfilling Koch's postulates. N. clavispora has been reported causing root and crown rot on strawberry in Spain, Argentina, Uruguay and Italy (Chamorro et al. 2016; Gilardi et al. 2019; Machin et al. 2019; Obregon et al. 2018), and as a pathogen on blueberry in Spain and Korea (Borrero et al. 2018; Lee et al. 2019), and causing leaf spot on macadamia in Brazil (Santos et al. 2019), and causing leaf spot on Syzygium cumini in India (Banerjee and Rana 2020). However, to our knowledge, this is the first report of Neopestalotiopsis clavispora causing postharvest fruit rot of A. argute in the worldwide. The identification of the pathogen is of great significance for conducting research on A. argute fruit preservation to prolong its shelf life and improve its merchantability.

A Novel Dual Electrical and Dual Mechanical Wound Field Flux Switching Generator for Co-Rotating and Counter-Rotating Wind Turbine Applications

A Novel Dual Electrical and Dual Mechanical Wound Field Flux Switching Generator for Co-Rotating and Counter-Rotating Wind Turbine Applications