How can smart dressings change the future of wound care?

Abstract

Journal of Wound CareVol. 30, No. 7 Guest EditorialFree AccessHow can smart dressings change the future of wound care?Negar Faramarzi, Ali TamayolNegar FaramarziDepartment of Hospital Medicine, Rhode Island Hospital, Providence, USSearch for more papers by this author, Ali TamayolDepartment of Biomedical Engineering, University of Connecticut, Farmington, USSearch for more papers by this authorNegar Faramarzi; Ali TamayolPublished Online:14 Jul 2021https://doi.org/10.12968/jowc.2021.30.7.512AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail Negar FaramarziAli TamayolImpaired wound healing can be influenced by a number of factors.1 The prevalence of hard-to-heal wounds is expected to rise due to increasing levels of obesity, diabetes mellitus, peripheral artery disease, immobility and aging.2 Despite the development of various guidelines and standard procedures, hard-to-heal wounds are common and can lead to disabilities or life-threatening complications. The complex pathologies that impair wound healing are still not fully understood. To personalise the care process, detailed information about the patient's comorbidities and local wound environment are needed.Conventional dressings and wound care products are bacteriostatic and designed to seal the wound while allowing oxygen permeation, preventing tissue dehydration and absorbing exudates; in some cases dressings release therapeutics.3 Some advanced dressings function as temporary scaffolds that regulate the environment, promote cell migration and expedite tissue regeneration. Examples of these advanced systems include negative pressure wound therapy, which are designed to stimulate regeneration and regulate the environment,4 or microneedle arrays (MNAs), minimally invasive devices which distribute therapeutics spatially within the wound bed.5,6In current wound care practice, healthcare providers make a clinical assessment of the injury, select a wound dressing, and then monitor wound healing in response to that treatment. However, determining the primary driving pathology is not always straightforward and clinicians may alter the treatment strategy after lack of clinical response to the initial treatment. A system that could accurately detect wound conditions such as insufficient healing, necrotic tissue or superinfection, and effectively target an individual's unique pathologies, would revolutionise wound care, drastically decreasing the burden on healthcare systems.Most existing dressings are incapable of providing dynamic information about the wound's condition. Care providers' decisions are not currently based on detailed information about the changing wound pathologies and their response or lack thereof to attempted treatments. Patients need to be continuously monitored representing a significant financial and time burden. The COVID-19 pandemic has necessitated strict visiting regulations and created an urgent need to protect the capacity of hospitals, prompting many clinicians to utilise telemedicine. There is a pressing need for devices, dressings and bandages to provide detailed and quantitative information on a patient's wound status and enable care providers to control drug delivery remotelyResearchers have now focused on engineering materials and devices that can sense wound conditions and/or deliver therapeutics to the injury. Stimuli-responsive materials, have been widely studied for use as sensors and smart drug delivery tools. Probes that are pH-responsive have been immobilised in printed hydrogels to allow wound pH monitoring based on the colour of the dressing.7 Electrochemical sensors have also been utilised for the detection of wound moisture, pH, oxygen, glucose, etc. These sensor-enabled dressings have been reviewed elsewhere.8Delivery of therapeutics that interrupt pathophysiologic processes and induce physiologic healing has shown great promise. Due to the complexity of hard-to-heal wounds, the spatiotemporal distribution of delivered therapeutics can affect the rate and quality of healing. The paradigm of drug delivery in wound care must shift to a focus on ‘what, when, where’ to address this pathological complexity.9 Smart systems that can actively control drug delivery rate and distribution manage all of these elements at once. In one example of this a two-module system was made: a controlling unit; and a dressing.9 The controlling unit, connected to the dressing through flexible tubing, was equipped with multiple drug reservoirs connected to micropumps that could be manipulated by a microcontroller (Fig 1a, 1b), which communicated wirelessly with a smartphone. An app controlled the quantity and frequency of drug administration.Fig 1. Examples of technology-enabled and smart bandages. Schematic view of microcontroller and including its components (a). Example of integrated system operation on human body (b). Representative images of wound closure in diabetic animals receiving vascular endothelial growth factor (VEGF) on days 5 and 7 post injury showing the benefit of microneedle arrays (MNAs) in improving drug penetration and wound healing (reprinted with permission from Derakhshandeh et al.9) (c) Schematic representation of an automated bandage with integrated pH and temperature sensors and a heat-activated drug delivery system (d). An image of a typical integrated platform and its conformality to human skin; the inset shows the flexible heater covered by a layer of hydrogel carrying thermo-responsive drug carriers (e). Testing of the automated system in an in vitro model modelling infection in wounds; the automated function of the bandage was tested in response to the bacterial growth and changes in environment pH triggering of the antibiotic release at pH 6.5 (reprinted with permission from Mostafalu et al.10) (f)To control the distribution of the drug within the wound bed, MNAs were 3D printed and integrated within a flexible backing to form a conformal dressing. The platform was used to deliver vascular endothelial growth factor (VEGF) to full-thickness skin injuries cut in diabetic mice. This showed faster superior wound healing in comparison to the animals receiving VEGF topically or those only treated with phosphate-buffered saline (PBS) (Fig 1c).9 It is noteworthy that MNAs enable generation of a favourable VEGF gradient in the wound bed in comparison to other means of transdermal drug delivery, such as hypodermic needles and liquid jet injectors.5 Microneedle-mediated VEGF delivery led to less contraction, more vascularisation and less inflammation in full-thickness skin injuries in healthy pigs.Smart systems can prevent some of the complications of impaired wound healing through real-time monitoring of the wound for markers indicating infections or persistent non-healing status. These smart devices are capable of increased automation, both sensing the changing wound conditions and altering drug delivery to address them. A smart automated bandage has three essential parts: a sensor; a controller unit; and an operating unit.Sensors collect data from dynamic wound beds. Controller units process the data, communicate input and control the output which may be delivery of chemicals/medicine/factors to optimise the microenvironment for wound healing.In an important pivotal study, an automated dressing was engineered equipped with pH and temperature sensors that continuously monitor the wound pH and temperature; the platform used a flexible heater to heat an alginate layer containing thermo-responsive drug carriers (Fig 1d, 1e).10 Basic and extremely acidic pH values were defined as signs of infection and the signals from the sensors were processed by an onboard controller that could trigger antibiotic release if infection was detected. To do this, the controller would apply heat to thermo-responsive drug carriers. The engineered dressing significantly reduced the concentration of bacteria in the culture. The dressing was also successfully tested in an in vitro model mimicking wound infection, where the release of antibiotics triggered by changes in the pH of a continuously perfused contaminated chamber led to bacterial eradication (Fig 1f).Overall, while smart dressings sound futuristic, current engineering tools are sufficiently advanced for their successful fabrication. The regulatory process is a hurdle. In addition to demonstrating their benefit over existing tools, the safety of these dressings must be properly demonstrated. To design effective smart dressings, we also need to identify and target markers demonstrating hard-to-heal wounds, superinfection and other physical parameters. One potential risk factor that has not been widely explored is the cybersecurity aspect of the operation of smart dressings. This must be properly investigated before their widespread clinical use. References 1 Menke NB, Ward KR, Witten TM et al. Impaired wound healing. Clinics in Dermatology 2007; 25(1):19–25. https://doi.org/10.1016/j.clindermatol.2006.12.005 Crossref, Medline, Google Scholar2 Barnum L, Samandari M, Schmidt TA, Tamayol A. Microneedle arrays for the treatment of chronic wounds. Expert Opinion on Drug Delivery 2020; 17(12):1767–1780. https://doi.org/10.1080/17425247.2020.1819787 Crossref, Medline, Google Scholar3 Tottoli EM, Dorati R, Genta I et al. Skin wound healing process and new emerging technologies for skin wound care and regeneration. Pharmaceutics 2020; 12(8):735. https://doi.org/10.3390/pharmaceutics12080735 Crossref, Google Scholar4 Huang C, Leavitt T, Bayer LR, Orgill DP. Effect of negative pressure wound therapy on wound healing. Curr Probl Surg 2014; 51(7):301–331. https://doi.org/10.1067/j.cpsurg.2014.04.001 Crossref, Medline, Google Scholar5 Samandari M, Aghabaglou F, Nuutila K et al. Miniaturized needle array-mediated drug delivery accelerates wound healing. 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Advanced Functional Materials 2020; 30(13):1905544. https://doi.org/10.1002/adfm.201905544 Crossref, Google Scholar10 Mostafalu P, Tamayol A, Rahimi R et al. Smart bandage for monitoring and treatment of chronic wounds. Small 2018; 14(33):1703509. https://doi.org/10.1002/smll.201703509 Crossref, Google Scholar FiguresReferencesRelatedDetails 2 July 2021Volume 30Issue 7ISSN (print): 0969-0700ISSN (online): 2052-2916 Metrics Downloaded 721 times History Published online 14 July 2021 Published in print 2 July 2021 Information© MA Healthcare LimitedPDF download