Transpiration-Inspired Fabric Dressing for Acceleration Healing of Wound Infected with Biofilm

In chronic wound management, efficacious handling of exudate and bacterial infections stands as a paramount challenge. Here a novel biomimetic fabric, inspired by the natural transpiration mechanisms in plants, is introduced. Uniquely, the fabric combines a commercial polyethylene terephthalate (PET) fabric with asymmetrically grown 1D rutile titanium dioxide (TiO2) micro/nanostructures, emulating critical plant features: hierarchically porous networks and hydrophilic water conduction channels. This structure endows the fabric with exceptional antigravity wicking-evaporation performance, evidenced by a 780% one-way transport capability and a 0.75 g h-1 water evaporation rate, which significantly surpasses that of conventional moisture-wicking textiles. Moreover, the incorporated 1D rutile TiO2 micro/nanostructures present solar-light induced antibacterial activity, crucial for disrupting and eradicating wound biofilms. The biomimetic transpiration fabric is employed to drain exudate and eradicate biofilms in Staphylococcus aureus (S. aureus)-infected wounds, demonstrating a much faster infection eradication capability compared to clinically common ciprofloxacin irrigation. These findings illuminate the path for developing high-performance, textile-based wound dressings, offering efficient clinical platforms to combat biofilms associated with chronic wounds.

How Should Clinical Wound Care and Management Translate to Effective Engineering Standard Testing Requirements from Foam Dressings? Mapping the Existing Gaps and Needs

Significance: Wounds of all types remain one of the most important, expensive, and common medical problems, for example, up to approximately two-thirds of the work time of community nurses is spent on wound management. Many wounds are treated by means of dressings. The materials used in a dressing, their microarchitecture, and how they are composed and constructed form the basis for the laboratory and clinical performances of any advanced dressing. Recent Advances: The established structure/function principle in material science is reviewed and analyzed in this article in the context of wound dressings. This principle states that the microstructure determines the physical, mechanical, and fluid transport and handling properties, all of which are critically important for, and relevant to the, adequate performances of wound dressings. Critical Issues: According to the above principle, once the clinical requirements for wound care and management are defined for a given wound type and etiology, it should be theoretically possible to translate clinically relevant characteristics of dressings into physical test designs resulting specific metrics of materials, mechanical, and fluid transport and handling properties, all of which should be determined to meet the clinical objectives and be measurable through standardized bench testing. Future Directions: This multidisciplinary review article, written by an International Wound Dressing Technology Expert Panel, discusses the translation of clinical wound care and management into effective, basic engineering standard testing requirements from wound dressings with respect to material types, microarchitecture, and properties, to achieve the desirable performance in supporting healing and improving the quality of life of patients.

Wireless and Closed-Loop Smart Dressing for Exudate Management and On-Demand Treatment of Chronic Wounds

Chronic wounds have become a significant threat to people's physical and mental health and have increased the burden of social medical care. Intelligent wound dressing (IWD) with wound condition monitoring and closed-loop on-demand drug therapy can shorten the healing process and alleviate patient suffering. However, single-function wound dressings cannot meet the current needs of chronic wound treatment. Here, a wearable IWD consisting of wound exudate management, sensor monitoring, closed-loop therapy, and flexible circuit modules is reported, which can achieve effective synergy between wound exudate management and on-demand wound therapy. The dressing is attached to the wound site, and the wound exudate is spontaneously pumped into the microfluidic channel for storage. Meanwhile, the IWD can detect the state of the wound through the temperature and humidity sensor, and use this as feedback to control the liquid metal (LM) heater through a smartphone, thereby realizing the on-demand drug release from the hydrogel. In a mouse model of infected wounds, IWD accelerates wound healing by reducing inflammatory responses, promoting angiogenesis and collagen deposition.

A robotic venous leg ulcer system reveals the benefits of negative pressure wound therapy in effective fluid handling

We applied a market-leading, single-use negative pressure wound therapy device to a robotic venous leg ulcer system and compared its fluid handling performance with that of standard of care, superabsorbent and foam dressings and compression therapy. For each tested product, we determined a metrics of retained, residual, evaporated and (potential) leaked fluid shares, for three exudate flow regimes representing different possible clinically relevant scenarios. The single-use negative pressure wound therapy system under investigation emerged as the leading treatment option in the aspects of adequate fluid handling and consistent delivery of therapeutic-level wound-bed pressures. The superabsorbent dressing performed reasonably in fluid handling (resulting in some pooling but no leakage), however, it quickly caused excessive wound-bed pressures due to swelling, after less than a day of simulated use. The foam dressing exhibited the poorest fluid handling performance, that is, pooling in the wound-bed as well as occasional leakage, indicating potential inflammation and peri-wound skin maceration risks under real-world clinical use conditions. These laboratory findings highlight the importance of advanced robotic technology as contemporary means to simulate patient and wound behaviours and inform selection of wound care technologies and products, in ways that are impossible to achieve if relying solely on clinical trials and experience.

High porosity PEG-based hydrogel foams with self-tuning moisture balance as chronic wound dressings

A major challenge in chronic wound treatment is maintaining an appropriate wound moisture balance throughout the healing process. Wound dehydration hinders wound healing due to impeded molecule transport and cell migration with associated tissue necrosis. In contrast, wounds that produce excess fluid contain high levels of reactive oxygen species and matrix metalloproteases that impede cell recruitment, extracellular matrix reconstruction, and angiogenesis. Dressings are currently selected based on the relative amount of wound exudate with no universal dressing available that can maintain appropriate wound moisture balance to enhance healing. This work aimed to develop a high porosity poly(ethylene glycol) diacrylate hydrogel foam that can both rapidly remove exudate and provide self-tuning moisture control to prevent wound dehydration. A custom foaming device was used to vary hydrogel foam porosity from 25% to 75% by adjusting the initial air-to-solution volume ratio. Hydrogel foams demonstrated substantial improvements in water uptake volume and rate as compared to bulk hydrogels while maintaining similar hydration benefits with slow dehydration rates. The hydrogel foam with the highest porosity (~75%) demonstrated the greatest water uptake and rate, which outperformed commercial dressing products, Curafoam® and Silvercel®, in water absorption, moisture retention, and exudate management. Investigation of the water vapor transmission rates of each dressing at varied hydration levels was characterized and demonstrated the dynamic moisture-controlling capability of the hydrogel foam dressing. Overall, the self-tuning moisture control of this hydrogel foam dressing holds great promise to improve healing outcomes for both dry and exudative chronic wounds.

Engineered Sandwich-Structured Composite Wound Dressings with Unidirectional Drainage and Anti-Adhesion Supporting Accelerated Wound Healing

Proper management of exudate is of great clinical value for reducing wound infection and promoting wound healing, thus various dressings have been studied to address this widespread medical challenge. Herein, a novel sandwich-structured composite wound dressing (SCWD), integrating of a superlyophobic (SLO) polydimethylsiloxane (PDMS) layer, a superlyophilic gauze layer, and a lyophobic PDMS layer is presented, with particular unidirectional droplet drainage and stable anti-adhesion capabilities, which realizes effective management of wound exudate and provides a favorable environment for wound healing. Thanks to the stable SLO property on the PDMS surface with hierarchical micro/nanostructures, the continuously accumulated wound exudate at the interface between dressing and wound surface is gradually deformed, eventually passing through SLO PDMS layer through milli-scale channels and being absorbed by gauze layer. Experimental results show that the application of SCWD can significantly reduce the occurrence of wound infection, avoid the tearing of wound tissues when replacing dressings, and accelerate wound healing by ≈20%. The combination of SCWD and lyophilized powders of stem cells supernatant (LPSCS) is verified to better accelerate the healing process. The proposed method offers great potential in clinical applications, particularly for acute trauma wound treatments.

Evaluation of a five-layer hydrocellular polyurethane foam dressing across wound care settings in southern Europe

OBJECTIVE

The burden of chronic wounds did not disappear during the Covid-19 pandemic, so new ways to address healthcare practitioner (HCP) education had to evolve. The Teach, Try, and Talk (T3) programme was conceived in 2021 with HCPs in southern Europe (Italy, Spain and Portugal).

METHOD

Virtual education sessions with experienced HCP guest speakers were held and a five-layer hydrocellular polyurethane foam dressing (HPFD) was introduced as a way of reducing dressing change frequencies and improving clinician satisfaction. HCPs recorded their experience of the HPFD using an online form and participated in a further virtual session with experienced HCPs to discuss the results.

RESULTS

There were a total of 190 responses. A significant dressing change reduction from 3.6 changes per week to 1.8 with the HPFD (p<0.001) was observed in Italy, Spain and Portugal and within different care settings (hospital, wound clinic/health centre and the patient's home). Nearly one-third of participants stated one more day of dressing wear time was achieved by the ability of the HPFD to lock in and manage exudate, with nearly a quarter of responses stating it was due to fewer than three dressing lobes being full. The majority (97.8%) of HCPs stated they would recommend the HPFD to colleagues and patients.

CONCLUSION

The T3 programme is a highly successful method of training delivery and practice improvement across a variety of healthcare settings in southern Europe, helping support HCP engagement and ongoing development in challenging times during the Covid-19 pandemic. The programme can be adapted considering the needs of different HCPs and payor and/or healthcare systems.

Fluid handling performance of wound dressings tested in a robotic venous leg ulcer system under compression therapy

We designed, developed, built, and utilised a robotic system of a leg with two venous leg ulcers for testing the fluid handling performance of three wound dressing types. The results showed that a foam-based dressing technology is inferior in fluid handling performance when applied to an exuding venous leg ulcer, such that the dressing needs to manage the exudate in a vertical configuration with respect to the ground, that is, so that gravity pulls the exudate to concentrate in a small region at the bottom of the dressing. Moreover, wound dressings containing superabsorbent polymers do not necessarily function equally in fluid handling for venous leg ulcer scenarios, as the extreme requirements from the dressing (to manage the viscous fluid of a vertical and typically highly-exuding wound) appear to distinguish between optimal and suboptimal product performances despite that the tested products contain a superabsorbent, theoretically lumping them together to belong to a so-called 'superabsorbent dressing category'. In other words, it is a false premise to categorise products from different manufacturers into families based on material contents, and then assume that their laboratory or clinical performance is equal, so that from this point they can be judged solely on the basis of price.

Fluid Handling Dynamics and Durability of Silver-Containing Gelling Fiber Dressings Tested in a Robotic Wound System

OBJECTIVE

To develop a robotic phantom system containing multiple simulated wound replicates to determine the synergy in fluid absorbency and retention (sorptivity) performances and the post-simulated-use mechanical durability of silver-containing gelling fiber primary dressings when used with a secondary dressing, as per clinical practice.

METHODS

Using a robotic system containing six identical wound simulators, the authors tested the sorptivity performances of the Exufiber Ag + (Mölnlycke Health Care, Gothenburg, Sweden) primary dressing (ExAg-polyvinyl alcohol [PVA]) against a market-leading comparator product, when used with a secondary foam dressing. The durability of the primary dressings after simulated use was further investigated through tensile mechanical testing.

RESULTS

The ExAg-PVA primary dressing delivered greater fluid amounts for absorbency and retention by the secondary foam dressing, approximately 2- and 1.5-fold more than the comparator dressing pair after 10 and 15 hours, respectively. The ExAg-PVA dressing was also substantially less sensitive to the direction of pulling forces and, accordingly, exhibited post-use mechanical strength that was approximately four and six times greater than that of the other primary dressing (when the latter dressing was tested out-of-alignment with its visible seams) after 10 and 15 hours, respectively.

CONCLUSIONS

The dynamics of the sorptivity and fluid sharing between primary and secondary dressings and the effect of directional preference of strength of the primary dressings for adequate durability, resulting in safe post-use removals, have been described. The comparative quantification of these capabilities should help clinical and nonclinical decision-makers select dressings that best meet their patient needs.

The fluid handling performance of the curea P1 multipurpose dressing against superabsorbent and foam dressing technologies

Using a novel, automated robotic phantom system containing multiple wound simulants, we determined the fluid handling performance of the curea P1 multipurpose dressing vs market‐leading comparator superabsorbent and foam‐based dressings (FBDs). Specifically, we measured the retained, residual, evaporated, and (potentially occurring) spillover fluid shares for high‐ vs low‐viscosity exudate‐simulant test fluids, at 12, 24, and 30 hours postapplication of the dressings. These experiments were conducted for off‐loaded (‘prone’), non‐off‐loaded (‘supine’), and vertical (‘side‐lying’) simulated body positions. We found that the multipurpose dressing exhibited the best and most robust fluid handling performance across all the test configurations, for both the low‐ and high‐viscosity fluids. The FBD consistently showed the poorest performance compared to the other dressings, rendering it unlikely to be able to manage viscous exudates in ambulant patients (such as when applied to venous leg ulcers) as effectively as the other dressings. The superabsorbent dressing performed better than the foam dressing, but its fluid handling metrics were inferior to those of the multipurpose dressing. The current comparative quantification of the shares of retained, residual, evaporated, and spillover fluid, acquired through standardised laboratory tests, should help decision‐makers to select dressings that best meet their patient needs.

Nursing of A Non-Hodgkin's Lymphoma Patient with A Facial Malignant Fungating Wound

Malignant fungating wounds are severe skin lesions caused by any primary tumor, causing patient suffering and disturbing their family members. In this article, we summarize the experience of nursing a patient with non-Hodgkin's lymphoma complicated with a facial malignant wound. Initially, a chemotherapy regimen was formulated as the main treatment for the patient. Throughout the patient's treatment course, we evaluated the patient holistically, conducting debridement, anti-infection, and drainage management under the guidance of moist wound healing. Throughout the entire process, psychological nursing and health education were provided to the patient and family. Eventually, the patient's wound symptoms were well controlled, and the wound healed completely.

Not all superabsorbent wound dressings are born equal: theory and experiments

Among the advanced wound dressing types, superabsorbent (SA) dressings form an important class of dressings, particularly for the management of medium to highly exuding wounds. However, SA dressings are not all made the same. This educational article describes distinct, common SA dressing designs, which differ fundamentally in structure and composition, and, thereby, in their exudate absorption function and clinical efficacy. The diverse design families of SA dressings, including dressings with an SA polymer-sheet core, versus dressings with an air laid core, where the SA polymer grains are embedded in fluff, relate to different manufacturing processes, production techniques and associated fabrication costs. These fundamental structural and material differences across SA dressing designs from different manufacturers naturally lead to wide variations in the fluid handling characteristics of the products, which are analysed here using both theoretical and experimental bioengineering laboratory approaches. This work is primarily aimed at promoting critical thinking among health professionals who should ask manufacturers to present relevant testing data for an informed clinical decision-making with regards to the choice of the safest and best performing SA dressing for each treated wound case.

Use of a gelling fibre dressing in complex surgical or chronic wounds: a case series

OBJECTIVE

To evaluate the safety and performance of a gelling fibre dressing, with respect to wound exudate management, maceration and periwound skin conditions.

METHOD

Complex (non-healing) surgical or chronic wounds healing by secondary intention were treated with a gelling fibre dressing (Biosorb, Acelity) as part of a prospective, two-centre case series product evaluation study. Dressing performance was evaluated at each change, and weekly for up to four weeks or until the wound healed, if this was in less than four weeks. The main outcome measure was dressing performance, wound bed and periwound skin condition.

RESULTS

A total of 15 patients, aged 26-87 years, were enrolled; 10 patients (66.7%) presented with chronic wounds including venous leg ulcers (VLUs), arterial leg ulcer, one mixed leg ulcer, pressure ulcer (PU), and diabetic foot ulcers (DFUs). The remaining wounds (33.3%) were postsurgical complex wounds healing by secondary intention, located in the upper leg, foot, abdomen, and sacrum. Mean wound area was 22.6±36.6cm² (range: 1.3-144.0cm²). Treated wounds showed complete granulation in eight (53.0%) wounds, 75% granulation coverage in two (13.3%) wounds, 50% coverage in three (20.3%), and 25% coverage in two (13.3%) wounds. Patients evaluated the dressing effectiveness as 'excellent' or 'very good' in 45% of cases, 'moderate' in 45%, and 'poor' in 10% of cases. Results of Visual Analogue Scale (VAS) showed 70% of patients rated their pain as 'low' and 30% as 'moderate' at dressing removal. Clinicians' evaluation of dressing ability to absorb and retain wound exudate was rated 'excellent' or 'very good' in 80% of cases, and moderate in 20% and poor in 10% of cases. Overall, clinicians' impression of the dressing performance was reported as 'excellent' or 'very good' in 80% of cases and 'moderate' in 20% of cases. No patient had to be removed from the study due to adverse events directly related to the dressing or its performance.

CONCLUSION

These clinical findings suggest the new gelling fibre dressing to be safe and effective in wound treatment of complex (non-healing) surgical or chronic wounds, to manage exudate effectively, and to optimise the conditions of wounds healing by secondary intention.

Tissue viability nurses' experiences of managing wound exudate

Wound exudate presents several challenges for patients and nurses. The description of exudate volume, colour and viscosity varies greatly, often depending on the personal preference of the nurse. When the nature and volume of exudate has been described, management of exudate presents its own issues in terms of ensuring that the appropriate dressing or intervention is selected and used effectively. This article reports on the outcomes of a series of discussion groups held to explore the difficulties tissue viability nurse specialists experience in relation to advising non-specialist nurses about wound exudate in the practice setting.

Use of a new silver barrier dressing, ALLEVYN Ag in exuding chronic wounds

Recognising and managing wounds at risk of infection is vital in wound management. ALLEVYN Ag dressings have been designed to manage exudate in chronic wounds that are at risk of infection; are displaying signs of local infection; or where a suspected increase in bacterial colonisation is delaying healing. They combine an absorbent silver sulfadiazine containing hydrocellular foam layer, with a perforated wound contact layer and highly breathable top film. The results presented are from a multi-centre clinical evaluation of 126 patients conducted to assess the performance of ALLEVYN Ag (Adhesive, Non Adhesive and Sacrum dressings) in a range of indications. Clinicians rated the dressings as acceptable for use in various wound types in 88% of patients. The majority of clinical signs of infection reduced between the initial and the final assessment. The condition of wound tissue and surrounding skin was observed to improve, and there was significant evidence of a reduction in the level of exudate from initial to final assessment (p < 0.001). Clinicians rated ALLEVYN Ag as satisfying or exceeding expectations in over 90% of patients. The evaluation showed the dressings to offer real benefits to patients and clinicians across multiple indications when used in conjunction with local protocols.