Monitoring wound progression to healing in diabetic foot ulcers using three-dimensional wound imaging

Employing of Curcumin-Silver Nanoparticle-Incorporated Sodium Alginate-Co-Acacia Gum Film Hydrogels for Wound Dressing

Skin wound healing is time-consuming and frequently accompanied by bacterial infections and the development of scars. The rise of antibiotic-resistant bacterial strains has sparked a growing interest in naturally occurring bioactive substances, like curcumin, that possess wound-healing capabilities. Silver is a natural antimicrobial agent, and finds extensive use in specialized wound dressings. Silver nanoparticles (AgNPs) were synthesized using an eco-friendly approach, employing curcumin. The prepared nanoparticles have been characterized using TEM, DLS, and zeta potential. The prepared AgNPs were loaded on sodium alginate-co-gum arabic hydrogel. Two hydrogel samples (with and without AgNPs) have been applied for wound healing. The developed silver nanoparticles that were created exhibited effective action against both types of bacteria, namely Gram-negative and Gram-positive. Alg-co-AG-AgNPs demonstrated faster wound healing rates compared to using the control hydrogel sample. The novel dressings of curcumin-silver nanoparticle-incorporated sodium alginate-co-gum arabic hydrogels (Alg-co-AG-AgNPs) exhibited exceptional biocompatibility and have the potential to serve as a wound dressing that possesses antibacterial properties and reduces scarring.

Clinical validation of a smartphone application for automated wound measurement in patients with venous leg ulcers

Chronic wounds are associated with significant clinical, economic and quality-of-life burden. Despite the variety of wound imaging systems available in the market for wound assessment and surveillance, few are clinically validated among patients of Asian ethnicity. We aimed to clinically validate the accuracy of a smartphone wound application (Tissue Analytics [TA], Net Health Systems Inc, Florida, USA), versus conventional wound measurements (visual approximation and paper rulers), in patients of Asian ethnicity with venous leg ulcers (VLU). A prospective cohort study of patients presenting with VLU to a specialist wound nurse clinic over a 5-week duration was conducted. Each patient received seven wound measurements: one by a trained wound nurse clinician, and three separate wound measurements using TA on each of the iOS and Android operating systems. Inter-rater and intra-rater reliability between clinical and TA-based measurements were analysed using intra-class correlation statistics, with values of <0.5, 0.5 to 0.75, 0.75 to 0.9, and >0.9 indicating poor, moderate, good and excellent reliability, respectively. 82 patients (51% males), with a mean age at 65.8 years, completed the 5-week study duration. 25 (30%) had underlying diabetes mellitus. Chinese, Malay and Indian ethnicity comprised 68%, 12% and 11%, respectively. The VLU healed in 26 (32%) of patients within the study period. In total, 358 wound episodes with 2334 wound images were analysed. Inter-rater reliability for length, width and area between wound nurse measurements and TA application measurements was good (range 0.799-0.919, P < 0.001). Separate measurements of intra-rater reliability for length, width and area within the iOS or Android systems were excellent (range 0.967-0.985 and range 0.977-0.984 respectively, P < 0.001). Inter-rater reliability between TA used on the iOS and Android systems was also excellent (0.987-0.989, P < 0.001). Tissue Analytics, a smartphone wound application, is a useful adjunct for wound assessment and surveillance in VLU patients of Asian ethnicity.

The role of artificial intelligence technology in the care of diabetic foot ulcers: the past, the present, and the future

Foot ulcers are common complications of diabetes mellitus and substantially increase the morbidity and mortality due to this disease. Wound care by regular monitoring of the progress of healing with clinical review of the ulcers, dressing changes, appropriate antibiotic therapy for infection and proper offloading of the ulcer are the cornerstones of the management of foot ulcers. Assessing the progress of foot ulcers can be a challenge for the clinician and patient due to logistic issues such as regular attendance in the clinic. Foot clinics are often busy and because of manpower issues, ulcer reviews can be delayed with detrimental effects on the healing as a result of a lack of appropriate and timely changes in management. Wound photographs have been historically useful to assess the progress of diabetic foot ulcers over the past few decades. Mobile phones with digital cameras have recently revolutionized the capture of foot ulcer images. Patients can send ulcer photographs to diabetes care professionals electronically for remote monitoring, largely avoiding the logistics of patient transport to clinics with a reduction on clinic pressures. Artificial intelligence-based technologies have been developed in recent years to improve this remote monitoring of diabetic foot ulcers with the use of mobile apps. This is expected to make a huge impact on diabetic foot ulcer care with further research and development of more accurate and scientific technologies in future. This clinical update review aims to compile evidence on this hot topic to empower clinicians with the latest developments in the field.

Reliability of a Three-Dimensional Wound Camera and Correlation With Routine Ruler Measurement in Diabetes-Related Foot Ulceration

BACKGROUND

In an era of increasing technology and telehealth utilization, three-dimensional (3D) wound cameras promise reliable, rapid, and touch-free ulceration measurements. However, reliability data for commercially available devices in the diabetes foot service setting is lacking. We aimed to evaluate the reliability of diabetes-related foot ulceration measurement using a 3D wound camera in comparison to the routinely used ruler and probe.

METHOD

Participants were prospectively recruited from a tertiary interdisciplinary diabetes foot service. Ulcerations were measured at each visit by two blinded observers, first by ruler and probe, and then using a 3D wound camera twice. Reliability was evaluated using intraclass correlation coefficients (ICC). Measurement methods were compared by Pearson correlation.

RESULTS

Sixty-three ulcerations affecting 38 participants were measured over 122 visits. Interobserver reliability of ruler measurement was excellent for estimated area (ICC 0.98, 95% CI 0.97-0.98) and depth (ICC 0.93, 95% CI 0.90-0.95). Intraobserver and interobserver reliability of the 3D wound camera area was excellent (ICC 0.96, 95%CI 0.95-0.97 and 0.97 95% CI 0.96-0.98, respectively). Depth was unrecordable in over half of 3D wound camera measurements, and reliability was inferior to probe measurement. Area correlation between methods was good (R = 0.88 and 0.94 per observer); however, depth correlation was poor (R = 0.49 and 0.65).

CONCLUSIONS

3D wound cameras offer practical advantages over ruler-based measurement. In diabetes-related foot ulceration, the reliability and comparability of area measurement was excellent across both methods, although depth was more reliably obtained by the probe. These limitations, together with cost, are important considerations if implementing this technology in diabetes foot care.

Point-of-Care Ultrasound as a Tool to Assess Wound Size and Tissue Regeneration after Skin Grafting

Chronic wounds can be difficult to heal and are often accompanied by pain and discomfort. Multiple skin substitutes or cellularized/tissue-based skin products have been used in an attempt to facilitate closure of complex wounds. Allografts from cadaveric sources have been a viable option in achieving such closure. However, early assessment of graft incorporation has been difficult clinically, often with delayed evidence of failure. Visual cues to assess graft integrity have been limited and remain largely superficial at the skin surface. Furthermore, currently used optical imaging techniques can penetrate only a few millimeters deep into tissue. Ultrasound (US) imaging offers a potential solution to address this limitation. This work evaluates the use of US to monitor wound healing and allograft integration. We used a commercially available dual-mode (US and photoacoustic) scanner operating only in US mode. We compared the reported wound size from the clinic with the size measured using US in 45 patients. Two patients from this cohort received an allogenic skin graft and underwent multiple US scans over a 110-d period. All data were processed by two independent analysts; one of them was blinded to the study. We measured change in US intensity and wound contraction as a function of time. Our results revealed a strong correlation (R² = 0.81, p < 0.0001) between clinically and US-measured wound sizes. Wound contraction >91% was seen in both patients after skin grafting. An inverse relationship between wound size and US intensity (R² = 0.77, p < 0 .0001) indicated that the echogenicity of the wound bed increases as healthy cells infiltrate the allograft matrix, regenerating and leading to healthy tissue and re-epithelization. This work indicates that US can be used to measure wound size and visualize tissue regeneration during the healing process.

Usefulness of high-frequency ultrasound to assess the healing progress of shin ulcers

INTRODUCTION

As the average lifespan becomes longer, the number of cases of chronic shin ulcers is rising, which is slowly becoming a societal problem. Currently, there no methods for objective evaluation of ulcer healing process.

AIM OF THE STUDY

The aim of the study was to assess the use of high-frequency ultrasound to monitor the healing of shin ulcers subjected to laser biostimulation.

MATERIAL AND METHODS

The study included 8 patients (4 men and 4 women) aged from 46 to 81 years with 9 shin ulcers in whom the healing process did not progress within 8 weeks despite effective causal treatment. The ulcers were subjected to laser biostimulation. The induced changes were monitored using high-frequency ultrasound and photographic records. Ultrasound examination was used to assess the depth of ulceration and the thickness of granulation tissue, migrating epidermis, subepidermal low-echogenic band (SLEB) and epidermis in the immediate vicinity. The wound severity index and ulcer vascularity were also assessed.

RESULTS

As a result of laser therapy, in 7 out of 9 cases the ulcers healed completely and in the remaining 2 cases ulcer size was reduced. During the ulcer healing process induced by laser therapy, ultrasound examination revealed decreasing ulcer depth, wound severity index and SLEB thickness. Granulation tissue increased in thickness and there was an epidermal formation effect (newly formed epidermis was much thicker than the one surrounding the wound and became thicker as a result of laser therapy sessions). During the healing of ulcers induced by laser therapy no significant changes were observed in ulcer vascularity and thickness of the surrounding epidermis.

CONCLUSIONS

High-frequency ultrasound is a useful technique for the imaging of leg ulcers. It allows one to monitor their healing process induced by laser biostimulation. Further research on the subject needs to be pursued.

Development of a computer-based quantification method for immunohistochemically-stained tissues and its application to study mast cells in equine wound healing (proof of concept)

Background

There is a growing interest in the scientific community to use computer-based software programs for the quantification of cells during physiological and pathophysiological processes. Drawbacks of computer-based methods currently used to quantify immunohistochemical staining are the complexity of use, expense of software and overly-simplified descriptions of protocol thereby limiting reproducibility. The precise role of mast cells in equine cutaneous wound healing is unknown. Given the contribution of mast cells to the chronic inflammation observed in human keloid, a pathology similar to exuberant granulation tissue (EGT) in horses, mast cells might be present in high numbers in equine limb wounds predisposed to EGT. The main goal of this study was to develop a reliable and reproducible quantification method for immunostained tissues using a computer software that is widely available, at no cost, to the scientific community. A secondary goal was to conduct a proof of concept using the newly-established method to quantify mast cells during wound healing at different anatomical sites (body and limb) in horses to see if a different pattern is observed in limb wounds, which are predisposed to EGT.

Results

A good intraclass correlation coefficient (ICC, 0.67 p < 0.05) was found between the computer-based ImageJ method and manual counting. An excellent intra-operator ICC of 0.90 (p < 0.01) was found for the ImageJ quantification method while a good interoperator ICC of 0.69 (p < 0.01) was measured. No significant difference was observed between the variation of the ImageJ and that of the manual counting method. Mast cells were localized below the epidermis, around cutaneous appendages and blood vessels. Mast cell numbers did not differ significantly in relation to anatomical location or time of healing.

Conclusions

The computer-based quantification method developed is reliable, reproducible, available, cost-free and could be used to study different physiological and pathological processes using immunohistochemistry.

Synthesis of Silver Nanoparticles Using Curcumin-Cyclodextrins Loaded into Bacterial Cellulose-Based Hydrogels for Wound Dressing Applications

Chronic wounds are often recalcitrant to treatment because of high microbial bioburden and the problem of microbial resistance. Silver is a broad-spectrum natural antimicrobial agent with wide applications extending to proprietary wound dressings. Recently, silver nanoparticles have attracted attention in wound management. In the current study, the green synthesis of nanoparticles was accomplished using a natural reducing agent, curcumin, which is a natural polyphenolic compound that is well-known as a wound-healing agent. The hydrophobicity of curcumin was overcome by its microencapsulation in cyclodextrins. This study demonstrates the production, characterization of silver nanoparticles using aqueous curcumin:hydroxypropyl-β-cyclodextrin complex and loading them into bacterial cellulose hydrogel with moist wound-healing properties. These silver nanoparticle-loaded bacterial cellulose hydrogels were characterized for wound-management applications. In addition to high cytocompatibility, these novel dressings exhibited antimicrobial activity against three common wound-infecting pathogenic microbes Staphylococcus aureus, Pseudomonas aeruginosa, and Candida auris.