Transparent Conductive Supramolecular Hydrogels with Stimuli‐Responsive Properties for On‐Demand Dissolvable Diabetic Foot Wound Dressings

Abstract

Diabetic foot ulcer (DFU) is a common complication in patients with diabetic hyperglycemia, which leaves patients at increased high risk of morbidity, infection, nontraumatic limb amputations, and even early death. [1-5] Among various efforts to address this urgent issue, wound dressings are effective strategies to provide an optimal environment for wound repair. [6,7] Traditional wound dressings for DFU treatment typically cover rubber, electrospun nanofiber, cotton wool, natural or synthetic bandages, and gauzes. [8,9] Although these dry dressings are convenient to control the initial state of wound healing, they tend to adhere to the wound area once the absorbed blood and exudate dry out. [7] Besides, the dry dressings still suffer from limitations of maintaining a moisture environment, allowing gaseous exchange, and preventing infection. [6,7] In this context, a wound dressing that can deal with the above shortcomings would be ideal to speed up diabetic foot wounds healing and improve treatment outcomes. In recent years, hydrogels have generated tremendous interest in wound healing applications. [10-16] As water-based soft materials, hydrogels can facilitate wound healing by absorbing wound exudate, preventing wound desiccation, and isolating the wound from the environment, which makes them the best choice for wound healing. [17,18] However, the currently available hydrogel dressings still require to be changed frequently, which is a laborious process and inevitably cause reinjury of the wounds, wound infection, delayed healing time, and personal suffering. [19] To this end, on-demand dissolvable hydrogels represent a new class of emerging "smart" wound dressings that can be readily operated and painlessly removed. [19-24] Generally, this type of hydrogels can form in situ and dissolve on-demand via physical crosslinking cases and chemical crosslinking cases. The dissolution of physically crosslinked hydrogels is based on physical interactions, such as molecular entanglements and/or secondary forces (e.g., ionic, H-bonding, and hydrophobic associations). [19,20,22,23] Diabetic foot ulcers (DFU) remain a very considerable health care burden, and their treatment is difficult. Hydrogel-based wound dressings are appealing to provide an optimal environment for wound repair. However, the currently available hydrogel dressings still need surgical or mechanical debridement from the wound, causing reinjury of the newly formed tissues, wound infection, delayed healing time, and personal suffering. Additionally, to meet people's increasing demand, hydrogel wound dressings with improved performance and multifunctionality are urgently required. Here, a new multifunctional supramolecular hydrogel for on-demand dissolvable diabetic foot wound dressings is designed and constructed. Based on multihydrogen bonds between hydrophilic polymers, the resultant supramolecular hydrogels present controlled and excellent properties, such as good transparency, antibacterial ability, conductive, and self-healing properties. Thus, the sup...

Conductive Biomaterials as Bioactive Wound Dressing for Wound Healing and Skin Tissue Engineering

“…Thus, the evaluation of stimuli-responsiveness and conductivity and their effects on wound healing could be studied separately. Zhao et al reported a multifunctional hydrogel dressing consisting of boronate-based dynamic network and conductive component Ag NWs [ 192 ].The boronate-based dynamic network would collapse when treated with glucose, which benefits diabetic foot wound healing by facile on-demand removal. Eventually, wounds treated with this hydrogel dressing demonstrated rapid wound contraction rate and lower glucose level.…”

Supramolecular Thermo‐Contracting Adhesive Hydrogel with Self‐Removability Simultaneously Enhancing Noninvasive Wound Closure and MRSA‐Infected Wound Healing

“…Acid can effectively damage hydrogen bonding and has been commonly used in the dissolution of hydrogel wound dressing but is excluded for the irritation to the wound. [14,56] It has been well-established that urea can break the hydrogen bonding, [57] and cyclodextrin-based host-guest interaction can be interrupted via competitive displacement by amantadine. [58] Since hydrogen bonding and host-guest interaction are two main forces that support the hydrogel matrix and the interfacial adhesion between hydrogel and skin tissue, it is reasonably expected that the on-demand painless removal of the hydrogel can be realized by the addition of urea and amantadine mixture.…”

Self‐Assembly of Naturally Small Molecules into Supramolecular Fibrillar Networks for Wound Healing

“…[ 4 ] Compared with traditional drug carriers, directed self‐assembly of bioactively natural compounds into hydrogel have many excellent properties such as self‐healing, stimuli‐responsive performances, biocompatibility, and biodegradability, which make them have great potentials in biomedical applications, including drug delivery, wound healing, tissue engineering, and so on. [ 5 ] These hydrogels are expected to have traits of high therapeutic efficacy, gentle release and no cytotoxicity. Up to now, numerous pioneering efforts have been done on the direct self‐assembly of natural small molecules, such as phenylalanine, [ 6 ] rhein, [ 7 ] amphiphilic peptides, [ 8 ] glycyrrhizic acid, [ 9 ] and curcumin.…”