The frictional energy absorber effectiveness and its impact on the pressure ulcer prevention performance of multilayer dressings.

Pressure ulcers including heel ulcers remain a global healthcare concern. This study comprehensively evaluates the biomechanical effectiveness of the market-popular ALLEVYN® LIFE multilayer dressing in preventing heel ulcers. It focuses on the contribution of the frictional sliding occurring between the non-bonded, fully independent layers of this dressing type when the dressing is protecting the body from friction and shear. The layer-on-layer sliding phenomenon, which this dressing design enables, named here the frictional energy absorber effectiveness (FEAE), absorbs approximately 30%-45% of the mechanical energy resulting from the foot weight, friction and shear acting to distort soft tissues in a supine position, thereby reducing the risk of heel ulcers. Introducing the novel theoretical FEAE formulation, new laboratory methods to quantify the FEAE and a review of relevant clinical studies, this research underlines the importance of the FEAE in protecting the heels of at-risk patients. The work builds on a decade of research published by our group in analysing and evaluating dressing designs for pressure ulcer prevention and will be useful for clinicians, manufacturers, regulators and reimbursing bodies in assessing the effectiveness of dressings indicated or considered for prophylactic use.

The hemostatic and comforting effects of oral adhesive bandages in tooth extraction: a randomized controlled clinical study.

OBJECTIVES: To compare oral adhesive bandages with the classic compression method and evaluate the clinical efficacy of this wound dressing material in improving postoperative comfort, wound healing, and hemostasis in tooth extraction. MATERIALS AND METHODS: The study was designed as a randomized controlled clinical trial. A total of 120 patients were recruited and randomly assigned to the study group and the control group. In the study group, oral adhesive bandages were used as wound dressing. In the control group, patients bit on cotton balls and gauze, as usual. Hemorrhage, comfort, and healing levels were evaluated at postoperative 1 h, 24 h, and 7 days. The adhesion time of the oral adhesive bandages was also recorded. RESULTS: The average adhesion time of the oral adhesive bandages was 26.6 h. At postoperative 1 and 24 h, the hemostatic levels of the oral adhesive bandage group were significantly higher than those of the control group. The oral adhesive bandage group also reported significantly higher comfort scores than the control group. Both groups had similar healing levels and side effects. But the mean score for wound healing was slightly higher in the oral adhesive bandage group. CONCLUSIONS: Oral adhesive bandages were more effective than cotton balls and gauze in providing hemostatic and comfort effects on extraction wounds. CLINICAL RELEVANCE: Oral adhesive bandages possess clinical value in the management of extraction wounds.

Accuracy, Repeatability, and Reproducibility of a Hand-Held Structured-Light 3D Scanner across Multi-Site Settings in Lower Limb Prosthetics.

The aim of this work was to assess the accuracy, repeatability, and reproducibility of a hand-held, structured-light 3D scanner (EINScan Pro 2X Plus with High Definition Prime Pack, SHINING 3D Tech. Co., Ltd., Hangzhou, China), to support its potential use in multi-site settings on lower limb prosthetics. Four limb models with different shapes were fabricated and scanned with a metrological 3D scanner (EINScan Laser FreeScan 5X, SHINING 3D Tech. Co., Ltd., Hangzhou, China) by a professional operator (OP0). Limb models were then mailed to three sites where two operators (OP1, OP2) scanned them using their own structured-light 3D scanner (same model). OP1 scanned limb models twice (OP1-A, OP1-B). OP0, OP1-A, and OP2 scans were compared for accuracy, OP1-A and OP1-B for repeatability, and OP1-A and OP2 for reproducibility. Among all comparisons, the mean radial error was <0.25 mm, mean angular error was <4°, and root mean square error of the radial distance was <1 mm. Moreover, limits of agreement were <3.5% for perimeters and volumes. By comparing these results with respect to clinically-relevant thresholds and to the literature available on other 3D scanners, we conclude that the EINScan Pro 2X Plus 3D Scanner with High Definition Prime Pack has good accuracy, repeatability, and reproducibility, supporting its use in multi-site settings.

Recent Advances in the Synthesis of the Marine-Derived Alkaloid Fascaplysin and Its Metabolites Homofascaplysins A-C.

The fascaplysin and homofascaplysin class of marine natural products has a characteristic 12H-pyrido[1,2-a:3,4-b']diindole pentacyclic structure. Fascaplysin was isolated in 1988 from the marine sponge Fascaplysinopsis bergquist sp. The analogs of fascaplysin, such as homofascaplysins A, B, and C, were discovered late in the Fijian sponge F. reticulate, and also have potent antimicrobial activity and strong cytotoxicity against L-1210 mouse leukemia. In this review, the total synthesis of fascaplysin and its analogs, such as homofascaplysins A, B, and C, will be reviewed, which will offer useful information for medicinal chemistry researchers who are interested in the exploration of marine alkaloids.

Intramolecular Hydrogen Bonds Assisted Construction of Planar Tricyclic Structures for Insensitive and Highly Thermostable Energetic Materials.

Safety is fundamental for the practical development and application of energetic materials. Three tricyclic energetic compounds, namely, 1,3-di(1H-tetrazol-5-yl)-1H-1,2,4-triazol-5-amine (ATDT), 5'-nitro-3-(1H-tetrazol-5-yl)-2'H-[1,3'-bi(1,2,4-triazol)]-5-amine (ATNT), and 1-(3,4-dinitro-1H-pyrazol-5-yl)-3-(1H-tetrazol-5-yl)-1H-1,2,4-triazol-5-amine (ATDNP), were effectively synthesized through a simple two-step synthetic route. The introduction of intramolecular hydrogen bonds resulted in excellent molecular planarity for the three new compounds. Additionally, they exhibit regular crystal packing, leading to numerous intermolecular hydrogen bonds and π-π interactions. Benefiting from planar tricyclic structural features, ATDT, ATNT, and ATDNP are insensitive (IS > 60 J, FS = 360 N) when exposed to external stimuli. Furthermore, ATNT (Td = 361.1 °C) and ATDNP (Td = 317.0 °C) exhibit high decomposition temperatures and satisfying detonation performance. The intermolecular hydrogen bonding that produced this planar tricyclic molecular structure serves as a model for the creation of innovative multiple heterocycle energetic materials with excellent stability.

Film dressings from Thai mango seed kernel extracts versus nanocrystalline silver dressings in antibacterial properties.

Introduction: The extract from the Mango Seed Kernel (MSK) has been documented to exhibit antibacterial activity against Gram-positive and Gram-negative bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa. This suggests that biomaterials containing MSK extract could be a viable alternative to conventional wound treatments, such as nanocrystalline silver dressings. Despite this potential, there is a notable gap in the literature regarding comparing the antibacterial effectiveness of MSK film dressings with nanocrystalline silver dressings. This study aimed to develop film dressings containing MSK extract and evaluate their antibacterial properties compared to nanocrystalline silver dressings. Additionally, the study aimed to assess other vital physical properties of these dressings critical for effective wound care. Materials and methods: We prepared MSK film dressings from two cultivars of mango from Thailand, 'Chokanan' and 'Namdokmai'. The inhibition-zone method was employed to determine the antibacterial property. The morphology and chemical characterization of the prepared MSK film dressings were examined with scanning electron microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR), respectively. The absorption of pseudo-wound exudate and water vapor transmission rate (WVTR) of film dressings were evaluated. Results: The results showed that 40% of MSKC film dressing had the highest inhibition zone (20.00 ± 0.00 mm against S. aureus and 17.00 ± 1.00 mm against P. aeruginosa) and 20%, 30%, and 40% of MSKC and MSKN film dressings had inhibition zones similar to nanocrystalline silver dressing for both S. aureus and P. aeruginosa (p > 0.05). In addition, all concentrations of the MSK film dressings had low absorption capacity, and Chokanan MSK (MSKC) film dressings had a higher WVTR than Namdokmai MSK (MSKN) film dressings. Conclusion: 20%, 30%, and 40% of MSK film dressing is nearly as effective as nanocrystalline silver dressing. Therefore, it has the potential to be an alternative antibacterial dressing and is suitable for wounds with low exudate levels.

A new dressing system for accelerating wound recovery after primary total knee arthroplasty: a feasibility study.

PURPOSE: Currently, postoperative wound infection and poor healing of total knee arthroplasty have been perplexing both doctors and patients. We hereby innovatively invented a new dressing system to reduce the incidence of postoperative wound complications. METHODS: We enrolled 100 patients who received primary unilateral total knee arthroplasty and then applied the new dressing system. The data collected included the number of dressing changes, postoperative hospital stay, Visual Analogue Scale score (VAS), the Knee Society Score (KSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), ASEPSIS scores, The Stony Brook Scar Evaluation Scale (SBSES), wound complications, dressing cost, the frequency of shower and satisfaction. Subsequently, a statistical analysis of the data was performed. RESULTS: Our findings demonstrated the average number of postoperative dressing changes was 1.09 ± 0.38, and the average postoperative hospital stay was 3.72 ± 0.98 days. The average cost throughout a treatment cycle was 68.97 ± 12.54 US dollars. Collectively, the results of VAS, KSS, and KOOS revealed that the pain and function of patients were continuously improved. The results of the four indexes of the ASEPSIS score were 0, whereas the SBSES score was 3.58 ± 0.52 and 4.69 ± 0.46 at two weeks and one month after the operation, respectively. We observed no wound complications until one month after the operation. Remarkably, the satisfaction rate of the patients was 91.85 ± 4.99% one month after the operation. CONCLUSION: In this study, we invented a new dressing system for surgical wounds after total knee arthroplasty and further confirmed its clinical feasibility and safety. CHINESE CLINICAL TRIAL REGISTRY: ChiCTR2000033814, Registered 13/ June/2020.

Use of person-centred music to manage wound dressing-related pain: a mixed method case study.

OBJECTIVE: To determine whether person-centred music (PCMusic) contributes to reducing pain during painful leg ulcer dressing change procedures indicated by: decreased levels of indicators related to stress; decreased pain scores; and a more favourable treatment climate during the dressing change procedure. METHOD: A case study of a 51-year-old female patient with chronic inherited disease weakening her connective tissues. Quantitative data entailed temporal measurements of stress indicators including: heart pulse rate; oxygen saturation (SpO2); saliva cortisol; and a visual analogue scale (VAS). Qualitative data comprised phenomenological treatment descriptions and patient/licensed practical nurse (LPN) questionnaires. RESULTS: The patient's body temperature remained steady throughout all treatments. Blood pressure was excluded due to missing data. No significant pulse rate differences in relation to music/no music could be observed during treatment. Comparing PCMusic to the patient's own other music (POOM), the pulse rate was greater in both magnitude and variation when the patient listened to POOM. Oxygen saturation showed no significant difference between PCMusic and music/no music. No significant difference was observed pre-/post-debridement with music. Similarly, no significant difference was observed pre-/post-debridement with no music. Treatment with no music showed the highest VAS score; PCMusic treatments had the lowest scores. Qualitative data showed that both patient and LPNs found that PCMusic decreased pain during dressing change. CONCLUSION: The results of this case study indicate that PCMusic is a suitable complementary treatment to decrease patient pain. Patients' general health status is important when using quantitative stress/pain marker measurements. For cohort selection in future studies, we suggest healthy patients undergoing slightly painful or unpleasant treatments, patients in postoperative care and obstetric care.

Effect of platelet-rich plasma combined with negative pressure wound therapy in treating patients with chronic wounds: A meta-analysis.

A meta-analysis was conducted to comprehensively explore the effects of platelet-rich plasma (PRP) combined with negative pressure wound therapy (NPWT) in treating patients with chronic wounds. Computer searches were conducted, from database infection to November 2023, in EMBASE, Google Scholar, Cochrane Library, PubMed, Wanfang and China National Knowledge Infrastructure databases for randomized controlled trials (RCTs) on the use of PRP combined with NPWT technology for treating chronic wounds. Two researchers independently screened the literature, extracted data and conducted quality assessments according to the inclusion and exclusion criteria. Stata 17.0 software was employed for data analysis. Overall, 18 RCTs involving 1294 patients with chronic wounds were included. The analysis revealed that, compared with NPWT alone, the use of PRP combined with NPWT technology significantly improved the healing rate (odds ratios [OR] = 1.92, 95% confidence intervals [CIs]: 1.43-2.58, p < 0.001) and total effective rate (OR = 1.31, 95% CI: 1.23-1.39, p < 0.001), and also significantly shortened the healing time of the wound (standardized mean difference = -2.01, 95% CI: -2.58 to -1.45, p < 0.001). This study indicates that the treatment of chronic wounds with PRP combined with NPWT technology can significantly enhance clinical repair effectiveness and accelerate wound healing, with a high healing rate, and is worth further promotion and practice.

Silver nanoparticle dressing: The knowledge of advantages and limits improves the indications in clinical practice.

Silver nanoparticle dressings have gained popularity recently as a way to treat challenging wounds. Notwithstanding the properties of Ag-NPS (silver nanoparticles) described by several articles, there is a lack of clinical studies that guide healthcare professionals to specific and conscious use. In this case series, Ag-NPS dressing was tested on a randomized group of 10 patients with complex wounds requiring conservative treatment. Each case was analysed, recording the patient's history, the peculiar characteristics and the progressive changes in the wound. The wound bed and the quality of the peri-wound skin improved and a decrease in signs of infection was observed. The application of the dressing was simple and comfortable for the patient and it was appreciated for its sealing ability. A few capacity restrictions showed up: those should be read as elements to improve the indications for this peculiar dressing. The thin tissue matrix of the Ag-NPS dressing does not allow for massive absorption and also performs poorly in reducing little exudate. The reduction in wound width is also limited: reconstructive surgery was required in half of the enrolled patients to achieve wound healing.

Changes in wound symptoms and quality of life of patients with newly diagnosed malignant fungating wounds.

OBJECTIVE: This study examined changes in wound symptoms and the health-related quality of life (HRQoL) of patients with newly diagnosed malignant fungating wounds, and explored the factors that impacted the changes in HRQoL. METHOD: This prospective longitudinal study included patients from three hospitals in China who had been diagnosed with malignant fungating wounds. Questionnaires were used to assess patients' HRQoL and their wound symptoms at the time of diagnosis (T0), as well as at one, three and six (T1, T2 and T3, respectively) months following the treatment period. Factors related to changes in HRQoL were analysed using generalised estimating equation models. RESULTS: A total of 162 patients were included in the study. The patients reported low overall HRQoL. In three health-related dimensions (functional status, social relations and mental health), patients reported lower functional status at the time of wound diagnosis (T0), which then increased slowly with treatment over time. A lower QoL was associated with odour, exudate, bleeding, pruritus, a low performance status and the need for the dressing of wounds. CONCLUSION: The HRQoL of patients with malignant fungating wounds exhibited significant changes across different periods. It is thus of great importance to formulate pragmatic, patient and family-centred palliative wound care management strategies.

Electrospun organic/inorganic hybrid nanofibers for accelerating wound healing: a review.

Electrospun nanofiber membranes hold great promise as scaffolds for tissue reconstruction, mirroring the natural extracellular matrix (ECM) in their structure. However, their limited bioactive functions have hindered their effectiveness in fostering wound healing. Inorganic nanoparticles possess commendable biocompatibility, which can expedite wound healing; nevertheless, deploying them in the particle form presents challenges associated with removal or collection. To capitalize on the strengths of both components, electrospun organic/inorganic hybrid nanofibers (HNFs) have emerged as a groundbreaking solution for accelerating wound healing and maintaining stability throughout the healing process. In this review, we provide an overview of recent advancements in the utilization of HNFs for wound treatment. The review begins by elucidating various fabrication methods for hybrid nanofibers, encompassing direct electrospinning, coaxial electrospinning, and electrospinning with subsequent loading. These techniques facilitate the construction of micro-nano structures and the controlled release of inorganic ions. Subsequently, we delve into the manifold applications of HNFs in promoting the wound regeneration process. These applications encompass hemostasis, antibacterial properties, anti-inflammatory effects, stimulation of cell proliferation, and facilitation of angiogenesis. Finally, we offer insights into the prospective trends in the utilization of hybrid nanofiber-based wound dressings, charting the path forward in this dynamic field of research.

Effect of dressing with different antiseptic agents on reproductive parameters in rats undergoing abdominal incision.

Antiseptic agents used in the postoperative period affect the functions of many tissues in the body, including the testicles. In this study, the effect of dressings administered with different antiseptic agents on testicular functions in rats that underwent abdominal incisions was investigated. A total of 48 Sprague-Dawley rats were used in the study. Each of the rats in the study group underwent a 4 cm-long skin and muscle operation. The incision was then stitched immediately. Antiseptics, hemp seed oil, hemp leaf oil, and cannabidiol oil were then administered to the rats for 10 days to provide antisepsis. The rats were sacrificed 24 hours after the last administration, and testicular tissues were removed. Testicular tissues were used for histopathological examination and biochemical analysis, while epididymal tissue was used for sperm analysis. According to the results, the MDA level in the antiseptic-administered group was higher than in the other experimental groups (p<0.05). Levels of SOD, CAT activities, and GSH content were found to be lower in the antiseptic group than in the hemp seed oil, hemp leaf oil, and cannabidiol oil groups (p<0.05). In testicular histology, the SEED group had the highest Johnsen score, and the antiseptic group had the lowest score (p<0.05). While JAK, P-JAK2, STAT3, PSTAT3, and NF-κB were generally higher in the antiseptic group compared to the other groups, they were lower in the SEED group. Additionally, sperm total motility rate and epididymal sperm density were highest in the SEED group (p<0.05). As a result, it was determined that cannabidiol seed oil had a good effect on testicular histology and sperm quality in male rats during the wound healing process.

Marine Bromotyrosine Derivatives in Spotlight: Bringing Discoveries and Biological Significance.

The Verongida order comprises several sponge families, such as Aplysinellidae, Aplysinidae, Ianthellidae, and Pseudoceratinidae, reported for producing bromotyrosine-derived compounds. First identified in 1913, bromotyrosine derivatives have since captivated interest notably for their antitumor and antimicrobial properties. To date, over 360 bromotyrosine derivatives have been reported. Our review focuses specifically on bromotyrosine derivatives newly reported from 2004 to 2023, by summarizing current knowledge about their chemical diversity and their biological activities.

Characterizations of Centrifugal Electrospun Polyvinyl Alcohol/Sodium Alginate/Tamanu Oil/Silver Nanoparticles Wound Dressing.

Known for its water solubility, flexibility, strong adhesion, and eco-friendly nature, polyvinyl alcohol (PVA) is widely used in various industries. In the medical field, it is used for applications such as creating bandages and orthopaedic devices. Incorporating sodium alginate (SA) into PVA membranes enhances their structural integrity, breathability, and permeability, thereby minimising the risk of cellular damage in the wound zone. Moreover, the addition of tamanu oil (C alophyllum inophyllum L.) and silver nanoparticles, both of which are known for their antibacterial properties and benefits in traditional wound healing, further enhances the membranes' wound-healing effectiveness. Following production, the membranes undergo a series of tests designed to evaluate their physical properties as well as their antioxidant and antibacterial capabilities. Subsequently, in vitro testing is conducted using human skin cells; experiments on Wistar rats are then performed. Numerous experiments have consistently demonstrated that the performance of polyvinyl alcohol/sodium alginate/tamanu oil (PVA/SA/Oil) membrane is superior to that of polyvinyl alcohol/sodium alginate/tamanu oil/silver nanoparticles (PVA/SA/Oil/Ag NP) membrane. Specifically, the polyvinyl alcohol/sodium alginate (PVA/SA) combination exhibits an impressive wound-healing rate of 98.82% after 15 days, with cells maintaining a high viability of 92% in a nourishing environment. Moreover, these membranes exhibit exceptional resistance to the oxidation of free radicals, surpassing the 70% threshold, and they possess antibacterial activity against Staphylococcus aureus subsp. aureus in vitro. Based on the obtained results, the nanofiber membranes composed of polyvinyl alcohol/ alginate/ tamanu oil, with or without silver nanoparticles, have shown potential as wound dressings in the wound care discipline.

Acute Burn Care.

LEARNING OBJECTIVES: After studying this article and viewing the videos, the participant should be able to: 1. Describe the current epidemiology of burn injuries. 2. Understand burn pathophysiology and perform a wound assessment. 3. Summarize the initial emergency management of a burn patient. 4. Calculate the anticipated fluid resuscitation requirements for a burn injury, and diagnose the complications of overresuscitation. 5. Describe the diagnosis and management of inhalation injury. 6. List the goals of wound care for superficial and deep burns, and describe the closed dressing technique. 7. Perform excision of a burn wound. 8. Compare various wound closure techniques using autografts and skin substitutes. SUMMARY: Plastic surgeons are essential members of the multidisciplinary burn team. Burn injuries remain common, and plastic surgeons have an opportunity to develop and innovate the field of acute burn care in light of workforce shortages. Burn pathophysiology is complex and dynamic, which informs the challenges encountered during the perioperative phase. Accurate burn wound assessment remains difficult, with implications for diagnosis and management. A systematic approach is required when stabilizing a major burn and/or inhalation injury with newly updated fluid resuscitation and triage guidelines. Wound care continues to evolve, with an emphasis on a closed dressing technique. For deeper burns, new surgical techniques are emerging for surgical débridement, along with improvements to traditional methods of tangential excision. Following excision, a number of established and novel techniques are available to close the wound with either autografts or skin substitutes.

Effect of EGCG-based paste as intracanal dressing, in MMPs 2 and 9 expression in dog's periapical lesions.

High expression of MMP-2 and MMP-9 in periapical lesions plays an important role in the degradation of the extracellular matrix. This study aimed to investigate the effect of epigallocatechin-3-gallate (EGCG)-based endodontic paste as an intracanal dressing on the expression of MMP-2 and MMP-9 in periapical lesions. Periapical lesions were experimentally induced in 35 mature beagle dog premolars randomly divided into healthy teeth, untreated periapical lesions, periapical lesions treated in a single session (control groups), and periapical lesions treated in two sessions with EGCG or calcium hydroxide-based pastes (experimental groups). After 120 days, specimens were obtained for histopathologic and immunofluorescence analyses to assess the expression of MMP-2 and MMP-9. The statistical analysis was performed using a p-value of 0.05. Endodontic treatment in two sessions using medication with EGCG and calcium hydroxide-based pastes provided similar repair of the apical and periapical tissues and neoformation of periodontal ligament fibers, cementum, and alveolar bone (p>0.05). The experimental groups treated in two sessions with both medications presented expression of MMP-2 and MMP-9 similar to that in healthy teeth (p>0.05), and significantly lower than teeth treated in a single session or untreated periapical lesions (p <0.001). Expression of MMP-2 and MMP-9 was observed in the cytoplasm of fibroblasts, osteoblasts, cementoblasts, cementocytes, and vascular endothelium. The use of EGCG-based endodontic paste reduced the expression of MMP-2 and MMP-9 and allowed repair of periapical lesions, similar to calcium hydroxide-based paste, and superior to treatment performed in a single session.

The efficacy of bandage contact lens in relieving the aggravation of dry eye disease after complicated cataract or/and IOL surgery.

PURPOSE: In the present study, we aimed to evaluate the efficacy of the bandage contact lens (BCLs) in the treatment of dry eye disease (DED) after complicated cataract or/and intraocular lens (IOL) surgery. METHODS: In this retrospective, single-centered, observational study, we collected data from 69 patients who underwent complicated cataract or/and IOL surgery. Of these, 35 cases wore their own BCLs immediately after the operation, while the other 34 cases did not have their own BCLs and were instead covered with gauze. The Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp microscope examination, keratograph analysis, and Schirmer I test were measured at baseline, 1 week and 1 month postoperatively. RESULTS: In the BCL group, the score of the OSDI questionnaire was significantly decreased at 1 week and 1 month postoperatively compared with baseline levels (P = 0.000, collectively). Moreover, the fluorescein staining score of the BCL group was remarkably decreased 1-week and 1-month postoperatively compared with the non-BCL group (P = 0.000 and P = 0.000, respectively). Furthermore, the redness score of the BCL group was also better compared with the non-BCL group at 1 week and 1 month postoperatively (P = 0.014 and P = 0.004, respectively). CONCLUSIONS: Complicated cataract or/and IOL surgery would intensify the DED. Early application of BCLs postoperatively improved patients' comfort and alleviated dry eye-related symptoms and signs. Furthermore, this mechanism might involve the acceleration of corneal epithelial healing, the alleviation of ocular stress response and the stabilization of the tear film. TRIAL REGISTRATION: Trial registration ClinicalTrials, NCT04120389. Registered 10 October 2019-retrospectively registered.

Chitin nanofibrils assisted 3D printing all-chitin hydrogels for wound dressing.

The direct ink writing technique used in 3D printing technology is generally applied to designing biomedical hydrogels. Herein, we proposed a strategy for preparing all-chitin-based inks for wound dressing via direct ink writing technique. The ß-chitin nanofibers (MACNF) with a high aspect ratio were applied as a nanofiller to modulate the rheological properties of the alkaline dissolved chitin solution. The printing fidelity significantly depends on the MACNF introduction amount to the composite ink. 5-10 wt% MACNF ratio showed superior printing performance. The printed scaffold showed a uniform micron-sized pore structure and a woven network of nanofibers. Due to the good biocompatibility of chitin and the stereoscopic spatial skeleton, this scaffold showed excellent performance as a wound dressing, which can promote cell proliferation, collagen deposition and the angiogenesis of wounds, demonstrating its potential in biomedical applications. This approach successfully balanced the chitinous printability and biofunctions.