New experimental model to evaluate the effect of negative pressure wound therapy and viscosity exudates in foam dressings using confocal microscopy

Abstract

Negative pressure wound therapy is currently one of the most popular treatment approaches that provide a series of benefits to facilitate healing, including increased local blood perfusion with reduced localized oedema and control of wound exudate. The porous foam dressing is a critical element in the application of this therapy and its choice is based on its ability to manage exudate. Industry standards often employ aqueous solutions devoid of proteins to assess dressing performance. However, such standardized tests fail to capture the intricate dynamics of real wounds, oversimplifying the evaluation process. This study aims to evaluate the technical characteristics of two different commercial polyurethane foam dressings during negative pressure wound therapy. We introduce an innovative experimental model designed to evaluate the effects of this therapy on foam dressings in the presence of viscous exudates. Our findings reveal a proportional increase in dressing fibre occupancy as pressure intensifies, leading to a reduction in dressing pore size. The tests underscore the pressure system's diminished efficacy in fluid extraction with increasing fluid viscosity. Our discussion points to the need of establishing standardized guidelines for foam dressing selection based on pore size and the necessity of incorporating real biological exudates into industrial standards.

1. INTRODUCTION

In the technical field of surgery and traumatology, negative pressure wound therapy (hereinafter referred to as NPWT) consists of the application of subatmospheric pressure to a wound bed, as a form of topical and non‐invasive treatment, facilitating the healing through a multimodal action. ¹ NPWT is currently one of the most popular treatment approaches that provide a number of benefits to facilitate healing, including increased local blood perfusion with reduced localized oedema and control of wound exudate. In addition, NPWT represents a trophic stimulus for cell proliferation, promoting the formation of granulation tissue and providing a closed and moist environment for the wound, which is optimal for the healing and isolation of bacteria from the environment. ² , ³ Other benefits can be associated with NPWT, such as the reduction of dressing changes, the reduction in the costs of associated treatments, as well as a better treatment tolerance for the patient. ³

NPWT comprises a suction pump with tubing connected to a porous foam dressing covered by an adherent dressing. This way, the porous foam dressing is placed over the wound bed, and controlled continuous negative pressure is applied in a range of values between 50 and 125 mmHg. ⁴ , ⁵

The porous foam dressing is a critical element in the application of NPWT. It is well documented in the literature ⁶ , ⁷ that foams can often match to the properties of the ideal wound dressing by maintaining high humidity at the wound/dressing interface, removing excess exudate and toxic components, permitting gaseous exchange, providing thermal insulation, protecting from secondary infection, protecting from particulate or toxic contamination and also allowing removal without trauma at dressing changes.

In general, reticulated foams are used in NPWT because they allow the application of negative pressure to the wound and facilitate the drainage of exudate. ⁷ Most commercially available NPWT dressings are made of polyurethane foam (black sponges) with pore sizes between 400 and 600 μm or polyvinyl alcohol (white sponges) with smaller pore diameters of 60–270 μm, resulting in less tissue ingrowth compared to polyurethane foams. ⁵ , ⁸ The size of the foam pore is one of the critical factors for the management of exudate in NPWT. Smaller pore sizes allow for greater fluid retention properties. Conversely, larger pore sizes typically facilitate increased fluid absorption from the wound into the dressing, better handling of viscous fluids and greater evaporation from the dressing to the environment. ⁹ , ¹⁰

In NPWT, the choice of the dressing is based on its ability to manage exudate. The ideal dressing should have a high capacity for absorbing exudates thereby preventing maceration of the peri‐wound skin and reducing the frequency of replacement. ¹¹

The exudate from an actual wound comprises water, fibrin, glucose, immune cells, platelets, proteins, growth factors, proteases, metabolic waste products, microorganisms and dead cells. ¹² Wound exudates can be categorized as serous, serosanguineous, sanguineous, seropurulent, fibrinous, purulent, haemopurulent and haemorrhagic, each with varying consistencies. ¹²

In the clinical context, it is clear that a foam dressing must manage a wide range of exudate viscosities from different wound types or even from the same wound at different stages of healing. ¹⁰ Current industry test standards follow the EN 13726, which often include the use of aqueous solutions, without proteins to test dressing performance. These solutions are unrealistic and oversimplify the complexity of the real wounds. ¹⁰

Accordingly, the purpose of this study was to evaluate and compare the technical characteristics of two different commercial polyurethane foam dressings during NPWT through two in vitro tests. The first assay was dedicated to quantify the diminution of the pore size under NPWT. The second assay aimed to analyse the drainage capacity of the dressings with fluids of different viscosities during the NPWT.

2. MATERIALS AND METHODS

2.1. Materials

The dressings tested in this study were as follows:

• Vivano® Med Foam Kit (Hartmann). It is a black cross‐linked, open porous, sterile hydrophobic polyester foam dressing for NPWT. It is a single‐use, non‐reprocessable disposable product.

• 3M™ V.A.C.® Granufoam™ Dressing. It is a black cross‐linked, open porous (400–600 μm), hydrophobic, sterile polyurethane ether foam dressing for NPWT. It is a single‐use, non‐reprocessable disposable product.

The NPWT was applied with the following systems:

• 3M™ V.A.C® Ulta Therapy Unit, used as V.A.C® Therapy. It is an integrated wound management system that provides NPWT.

• Vivano® Tec Port is a flexible port system for the suction of wound exudates and for applying pressure to the wound during treatment with negative pressure therapy.

The materials used for the simulated bench tests were as follows:

• Transparent methacrylate support sheet as a medium of support of the commercial polyurethane foam dressings.

• Adhesive polyurethane drapes.

• Jackson‐Pratt drains to infuse the fluids.

• Polyurethane bubble layers.

• Measuring cup to measure the volume of simulated fluid extracted.

Simulate fluid of different viscosities made of food‐standard Xanthan gum powder at a concentration of 0.1%, 0.15% or 0.2% mixed with distilled water. ¹³

The pore size measurements were made with a confocal microscope (Confocal Nikon A1R; Software Nis elements AR; Lens 10×; Excitation 640 nm; Emission 662–737 nm).

2.2. Methods

First, we investigated the quantification of the pore size diminution under NPWT of two commercial polyurethane foam dressings. We developed a test set‐up consisting of a layer of methacrylate where the commercial dressings (Vivano® Med Foam Kit (Hartmann); 3M™ V.A.C.® Granufoam™ Dressing) were placed. The commercial dressings were covered with an adhesive polyurethane drape. The NPWT system (Vivano® Tec Port; 3MTM V.A.C® Ulta Therapy Unit) was placed in the middle of the commercial foam dressings to carry on the simulated negative pressure therapy. For each commercial foam dressing, a pressure of −125 mmHg was exerted for 48 h using each corresponding negative wound therapy system (Figures 1 and 2).

FIGURE 1.

Depiction of the first set up with the Vivano® Med Foam Kit and the Vivano® Tec Port (Hartmann).

FIGURE 2.

Depiction of the first set up with the 3M™ V.A.C.® Granufoam™ Dressing and the 3M™ V.A.C® Ulta Therapy Unit.

Then, a sample of each commercial dressing was placed into a sample holder and connected to the NPWT system. The sample was wrapped with an adhesive polyurethane drape to create the vacuum once the negative pressure system was activated (Figures 3 and 4). The behaviour of the sample was visualized through a confocal microscope during the application of different negative pressures (−25, −50, −75, −100, −125 and −150 mmHg; Figures 4, 5, 6). Figure 7 shows the first set‐up and Roadmap.

FIGURE 3.

Depiction of the Vivano® Med Foam Kit sample connected to the Vivano® Tec Port (Hartmann).

FIGURE 4.

Depiction of the 3M™ V.A.C.® Granufoam™ Dressing sample connected to the 3MTM V.A.C® Ulta Therapy Unit.

FIGURE 5.

Depiction of the Vivano® Med Foam Kit sample connected to the Vivano® Tec Port (Hartmann) at the confocal microscope.

FIGURE 6.

Depiction of the 3M™ V.A.C.® Granufoam™ Dressing sample connected to the 3MTM V.A.C® Ulta Therapy Unit at the microscope confocal.

FIGURE 7.

First testing set‐up and Roadmap.

Confocal microscope data: Confocal Nikon A1R; Software Nis elements AR; Lens 10×; Excitation 640 nm; Emission 662–737 nm. Taking advantage of the self‐fluorescence of the polyurethane dressings by exciting them with a 640 nm laser, the dressings emission was recorded at 662–737 nm. Using confocal microscopy, optical sectioning was made at 1 mm thickness in the Z‐axis. A surface of 70.654 mm² was scanned in the XY‐axis. Then, the signal level in this volume was quantified and three‐dimensional reconstructions and maximum projections were made (Figures 5 and 6).

The fluorescence signal intensity is measured with the confocal microscope at each of the pressures exerted on the foam dressing. This fluorescence signal intensity is expressed in arbitrary units ¹⁴ and represented through a ratio between all the measurements performed. It can be correlated with the percentage of volume occupied by the foam dressing in the specified surface scanned.

The second test was dedicated to analysing the drainage capacity of both commercial dressings with fluids of different viscosities during the NPWT. To simulate the physical characteristics of native exudate fluids, different viscosities made of food‐standard Xanthan gum powder at a concentration of 0.1%, 0.15% or 0.2% were mixed with distilled water according to the model developed by Lustig et al. ¹³

The set‐up developed consisted of a layer of methacrylate where the commercial dressings under testing were placed. Under the commercial dressing, a polyurethane bubble layer was positioned to assure the fluid distribution as even as possible (Figure 8). A Jackson‐Pratt drain was used to infuse the simulated fluid into the dressing through a syringe. The dressing with the bubble layer and the Jackson‐Pratt drain was wrapped with an adhesive polyurethane drape to create the vacuum once connected to the negative pressure system (Figure 9). The negative pressure system used was 3M™ V.A.C® Ulta Therapy Unit, used as V.A.C® Therapy. A measuring cup to measure the volume of the simulated fluid extracted from the dressing was located between the suction tubing and the negative pressure system (Figure 10).

FIGURE 8.

Depiction of the lower face of the dressing under testing with the bubble layer and the Jackson‐Pratt drain wrapped with the adhesive polyurethane drape.

FIGURE 9.

Depiction of the upper face of the dressing under testing with the bubble layer and the Jackson‐Pratt drain wrapped with the adhesive polyurethane drape.

FIGURE 10.

Depiction of the set‐up of the second test.

Figure 10 is a depiction of the set‐up of the second test. The syringe, through which the different fluids are introduced in the foam dressing, is connected to the dressing sample through the Jackson‐Pratt drain. The negative pressure system is connected to the dressing sample and the measuring cup, where the extracted fluid is housed. Figure 11 shows the second testing set‐up and Roadmap.

FIGURE 11.

Second testing set‐up and Roadmap.

Upon initiation of the test, the simulated fluid was heated to 36°C in order to reproduce the body temperature. The NPTW was started with a pressure of −125 mmHg. After 1 h, the extracted volume data were visualized in the measuring cup, obtaining the first test results (total volume extracted from the dressing).

Finally, a sample of the dressing under testing was placed into a sample holder and connected to the negative wound therapy system. The sample was wrapped with an adhesive polyurethane drape to achieve the vacuum once connected to the negative pressure system. The behaviour of the sample was visualized through a confocal microscope during the application of −125 mmHg. Taking advantage of the self‐fluorescence of the polyurethane dressings by exciting them with a 640 nm laser, the dressing emission was recorded at 662–737 nm. Using confocal microscopy, optical sectioning was made at 1 mm thickness in the Z‐axis. A surface of 93 700 mm² was scanned in the XY‐axis. Then, the signal level in this volume was quantified and three‐dimensional reconstructions and maximum projections were made.

The test was performed for both commercial dressings (Vivano® Med Foam Kit (Hartmann); 3M™ V.A.C.® Granufoam™ Dressing) with the following simulated fluids:

• 100 mL of 0.9% sodium chloride (acting as a control).

• 100 mL of xanthan gum powder at a concentration of 0.1%w/w, mixed with distilled water.

• 100 mL of xanthan gum powder at a concentration of 0.15%w/w, mixed with distilled water.

• 100 mL of xanthan gum powder at a concentration of 0.2%w/w, mixed with distilled water.

3. RESULTS

The results of the first test demonstrated the diminution of the dressing pore size as the negative pressure increased. Through the images and data obtained from the confocal microscope, it can be observed how the space occupied by the fibres of the dressing increases as the pressure exerted rises and, therefore, the size of the dressing pore is reduced.

A picture of the confocal microscope demonstrating the reduction of the Vivano® Med Foam Kit (Hartmann) dressing pore is presented in Figures 12 and 13.

FIGURE 12.

Confocal three‐dimensional reconstruction images of the Vivano® Med Foam Kit (Hartmann) dressing under different pressures.

FIGURE 13.

Confocal maximum projection images of the Vivano® Med Foam Kit (Hartmann) dressing under different pressures.

A picture of the confocal microscope demonstrating the reduction of the 3M™ V.A.C.® Granufoam™ Dressing pore is presented in Figures 14 and 15.

FIGURE 14.

Confocal three‐dimensional reconstruction images of the 3M™ V.A.C.® Granufoam™ dressing under different pressures.

FIGURE 15.

Confocal maximum projection images of the 3M™ V.A.C.® Granufoam™ dressing under different pressures.

Figures 16 and 17 show the graphical representation of the fluorescence signal intensity ratio in both dressings as the negative pressure applied increases. It can be correlated with the percentage of volume occupied by the fibres of the foam dressing in the surfaced scanned. The higher the signal intensity ratio, the greater the percentage of volume occupied by the fibres of the foam dressing and therefore, the smaller the pore size of the foam dressing.

FIGURE 16.

Graphical representation of the fluorescence signal intensity ratio of the Vivano® Med Foam Kit (Hartmann) as the negative pressure applied increases.

FIGURE 17.

Graphical representation of the fluorescence signal intensity ratio of the 3M™ V.A.C.® Granufoam™ dressing as the negative pressure applied increases.

There is a positive correlation with a Pearson correlation coefficient of 0.99, which demonstrates the linear relationship between the pressure exerted and the fluorescence signal intensity ratio.

The results of the second test demonstrated that the pressure system was able to extract less fluid as the viscosity fluid increased without significant differences for the increased viscosities tested (see Tables 1 and 2).

TABLE 1.

Volume extracted by the negative pressure system using 3M™ V.A.C.® Granufoam™ dressing with fluids of different viscosities.

3M™ V.A.C.® Granufoam™	100 mL of 0.9% sodium chloride	100 mL Goma xantana a 0.01% w/w	100 mL Goma xantana a 0.015% w/w	100 mL Goma xantana a 0.02% w/w
Extracted fluid (after 1 h)	65 mL	50 mL	50 mL	50 mL

TABLE 2.

Volume extracted by the negative pressure system using Vivano® Med Foam Kit (Hartmann) dressing with fluids of different viscosities.

Vivano® Med Foam Kit (Hartmann)	100 mL of 0.9% sodium chloride	Goma xantana a 0.01% w/w	Goma xantana a 0.015% w/w	Goma xantana a 0.02% w/w
Extracted fluid (after 1 h)	52 mL	40 mL	40 mL	40 mL

The results of the second test demonstrated that the space occupied in both dressings (Vivano® Med Foam Kit (Hartmann); 3M™ V.A.C.® Granufoam™ Dressing) was bigger as the viscosity of the simulated fluid increased, being the pressure exerted constant at −125 mmHg.

Pictures of the confocal microscope demonstrating the increase of the occupied volume in the Vivano® Med Foam Kit (Hartmann) dressing as the viscosity of the fluid increases are presented in Figures 18 and 19.

FIGURE 18.

Confocal three‐dimensional reconstruction images of the Vivano® Med Foam Kit (Hartmann) dressing with different viscosity fluids with a negative pressure exerted of −125 mmHg.

FIGURE 19.

Confocal maximum projection images of the Vivano® Med Foam Kit (Hartmann) dressing with different viscosity fluids with a negative pressure exerted of −125 mmHg.

Pictures of the confocal microscope demonstrating the increase of the occupied volume in the 3M™ V.A.C.® Granufoam™ dressing as the fluid viscosity increases are presented in Figures 20 and 21.

FIGURE 20.

Confocal three‐dimensional reconstruction images of the 3M™ V.A.C.® Granufoam™ dressing with different viscosity fluids with a negative pressure exerted of −125 mmHg.

FIGURE 21.

Confocal maximum projection images of the 3M™ V.A.C.® Granufoam™ dressing with different viscosity fluids with a negative pressure exerted of −125 mmHg.

4. DISCUSSION

These findings offer a comprehensive understanding of how negative pressure influences dressing pore size, fibre foam dressing occupancy and fluid extraction efficiency in wound care.

A recent study ¹⁵ using a robotic venous leg ulcer system indicates significant differences in the fluid handling capabilities of different wound care technologies, particularly sNPWT versus standard of care dressings. Our results align with this previous research. Using confocal microscopy data, we further investigate the physical basis for these differences, particularly examining the role of dressing pore size.

Building upon our findings regarding the performance of foam dressings under NPWT, it is imperative to consider the specific role of dressing pore size. This factor is crucial in determining the clinical efficacy of dressings in wound management. ¹⁰ , ¹⁶ The pore size of NPWT dressings significantly influences granulation tissue formation. Foams employed in wound dressings for commercial purposes show diverse pore sizes, spanning from 25 to 1000 μm. ¹⁷ In particular, the commercial foams used in NPWT have variable pore diameters, ranging between 60 and over 600 μm. ⁸ Reduced pore diameters result in diminished tissue ingrowth but may compromise the effective management of viscous fluids. Efficient management of wound exudate is critical in preventing complications such as maceration and infection. ¹⁷ Dressings with an optimized pore size can effectively balance the absorption and removal of fluids, thereby maintaining an ideal healing environment. ¹⁰ , ¹⁶

The initial test results underscore a consistent trend: dressing pore size diminishes with increasing negative pressure. Through the use of confocal microscope images and data analysis, the study observed a proportional increase in the space occupied by dressing fibres as pressure intensified. Consequently, this increase in fibre occupancy led to a reduction in dressing pore size. Figures 12, 13, 14, 15 vividly illustrated these structural changes within the Vivano® Med Foam Kit (Hartmann) and the 3M™ V.A.C.® Granufoam™ Dressing, demonstrating the decrease in pore size as pressure rose.

Figures 16 and 17 further elucidated this correlation through the fluorescence signal intensity ratio in relation to the volume occupied by dressing fibres. Despite differing measurement configurations between the dressings, a higher signal intensity ratio correlated with a greater percentage of volume occupied by dressing fibres, indicating smaller pore sizes in the foam dressing.

In the second test, the study investigated the impact of fluid viscosity on dressing space occupancy. Results indicated that as fluid viscosity increased, the space occupied within both dressings expanded, while the pressure remained constant at −125 mmHg. This finding was supported by confocal microscope images in Figures 18 and 19 (Vivano® Med Foam Kit) and Figures 20 and 21 (3M™ V.A.C.® Granufoam™ Dressing), illustrating the increase in occupied volume as fluid viscosity rose.

Moreover, the second test also highlighted that the ability of the pressure system to extract fluid decreased as fluid viscosity increased. Notably, this reduction in fluid extraction efficiency was consistent across various viscosity levels tested, indicating a challenge in extracting fluids with higher viscosities.

The observations align closely with our clinical team's experiences using NPWT: commercial foam dressings swiftly saturate when exposed to various wound exudates. This trend become more pronounced as the negative pressure intensifies, indicating a potential risk of foam dressings easily becoming obstructed by typical wound exudate. This concern amplifies in cases involving complex exudates, wherein only the least viscous fluids manage to permeate the cellular structure of the dressing.

Biological exudates exhibit a wide range of viscosities and may contain clots, debris and fibrin, contributing to their complexity. Consequently, the foam dressing essentially functions as a filter, rapidly reaching saturation levels during NPWT. This saturation leads to heightened frequency of dressing changes throughout the NPWT process, elongating the duration of the therapy and diminishing its efficacy. The increase in dressing changes highlights the need for a cost‐effectiveness analysis.

These comprehensive findings emphasize the multifaceted nature of wound dressing behaviour under varying negative pressures and fluid viscosities. Understanding the interplay between pressure, dressing structure and fluid dynamics is crucial in optimizing wound care strategies. Insights gleaned from these results could potentially lead to the development of more adaptable dressing materials and enhanced pressure systems, catering to diverse wound characteristics and improving overall treatment efficacy.

These findings are substantiated by our newly developed experimental approach, which involves utilizing confocal microscopy. This method enables the analysis of dressing behaviour under varied viscosities both with and without fluids, while implementing NPWT.

In their research, Lustig et al. ¹³ conducted an analysis of wound dressing efficacy concerning viscous exudates within a simulated sacral pressure ulcer system. The study involved the assessment of two dressing products through comprehensive experiments, exposing the dressings to exudate‐like fluids under varying mechanical, thermodynamic and usage conditions.

In this study, we introduce a novel experimental model aimed at assessing the impact of NPWT on foam dressings in the presence of viscous exudates using confocal microscopy. Both investigations emphasize the necessity of incorporating real biological exudates into industrial standards. Presently, standards such as EN 13726 utilize aqueous solutions devoid of proteins to evaluate dressing performance. However, these solutions are deemed unrealistic, simplifying the complexity inherent in real wound conditions. ¹⁰ The research findings underscore the importance of accounting for the realistic nature of biological exudates in setting industrial standards for accurate assessment of dressing efficacy.

This study provides valuable insights into the relationship between negative pressure, dressing pore size, fibre occupancy and fluid extraction efficiency in wound care. However, several limitations should be considered when interpreting these findings.

Limited generalizability: The study focuses on specific types of dressings (Vivano® Med Foam Kit and 3M™ V.A.C.® Granufoam) and their response to negative pressure and varying fluid viscosities. Generalizing these findings to other dressings or wound types may not be appropriate due to variations in material composition, structure and wound characteristics.

Limited fluid variability: The study examines simulated fluids with different viscosities. However, it might not encompass the full spectrum of wound exudate complexity, which can vary significantly in viscosity, composition and other properties. This limitation could restrict the applicability of findings to real wound fluid dynamics.

Lack of clinical context: The study operates within a laboratory setting using simulated fluids. The absence of in vivo or clinical validation limits the direct translation of these findings to real world wound care scenarios where factor like patient‐specific conditions and wound environment complexities come into play.

Based on the findings of this paperwork, the potential direction for future research could be as follows.

Exploring different dressing types and configurations: expand the study to include a broader range of wound dressings with distinct compositions, structures and pore architectures; investigate how different dressing configurations (e.g., foam, gauze, hydrogel) respond to varied negative pressure levels in terms of pore size alterations.

Comprehensive fluid viscosity analysis: conduct a more extensive analysis of fluid viscosities to discern the thresholds at which the efficacy of fluid extraction diminishes significantly across various dressing types; examine the effect of diverse fluid types (e.g., serous, purulent) on dressing performance under negative pressure.

Clinical relevance and translation: bridge findings from laboratory studies to clinical settings by evaluating the practical implications of dressing pore alterations and fluid extraction efficiency in wound healing outcomes; investigate the potential impact of these findings on optimizing NPWT protocols and wound care strategies.

In conclusion, while our study provides essential insights into the performance of foam dressings in NPWT, it also highlights several areas for further research. Future studies should explore a wider range of dressing materials, in vivo settings, diverse pressure settings and patient‐centred outcomes. Additionally, the economic implications of dressing choices and the potential benefits of technological innovations in foam dressings warrant further exploration. Our discussion points aim at a clear need for further research, particularly in establishing standardized guidelines for foam dressing selection based on pore size. Furthermore, exploring patient‐centred outcomes in relation to dressing pore size could provide valuable insights for personalized wound care.

FUNDING INFORMATION

This work has been made possible by a research grant (DTEC21/01) from Instituto de Investigación Sanitaria Valdecilla (IDIVAL).

CONFLICT OF INTEREST STATEMENT

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Biographies

Patricia Zorrilla de la Fuente, MSc, MEng Telecommunication Engineer. Researcher at Instituto de Investigación Sanitaria Valdecilla (IDIVAL), PhD student in Industrial Engineering at Universidad de Cantabria.

Federico Castillo Suescún, PhD in Medicine, Surgeon at Hospital Universitario Marqués de Valdecilla, Researcher at Instituto de Investigación Sanitaria Valdecilla (IDIVAL).

José Luis Lázaro Martínez, PhD, Tenured Professor at Universidad Complutense de Madrid. Director of the Diabetic Foot Research Group at Instituto de Investigación Sanitaria Hospital Clínico San Carlos de Madrid (IdISSC).

Ramón Sancibrian Herrera, PhD in Industrial Engineering, Professor at Universidad de Cantabria.

Galo Peralta Fernández, PhD in Medicine, Managing Director at Instituto de Investigación Sanitaria Valdecilla (IDIVAL).

de la Fuente PZ, Suescún FC, Lázaro‐Martínez JL, Sancibrian Herrera R, Peralta Fernández G. New experimental model to evaluate the effect of negative pressure wound therapy and viscosity exudates in foam dressings using confocal microscopy. Int Wound J. 2024;21(7):e14964. doi: 10.1111/iwj.14964

DATA AVAILABILITY STATEMENT

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.