Progress of Hydrogel Dressings with Wound Monitoring and Treatment Functions

Abstract

Hydrogels are widely used in wound dressings due to their moisturizing properties and biocompatibility. However, traditional hydrogel dressings cannot monitor wounds and provide accurate treatment. Recent advancements focus on hydrogel dressings with integrated monitoring and treatment functions, using sensors or intelligent materials to detect changes in the wound microenvironment. These dressings enable responsive treatment to promote wound healing. They can carry out responsive dynamic treatment in time to effectively promote wound healing. However, there is still a lack of comprehensive reviews of hydrogel wound dressings that incorporate both wound micro-environment monitoring and treatment functions. Therefore, this review categorizes hydrogel dressings according to wound types and examines their current status, progress, challenges, and future trends. It discusses various wound types, including infected wounds, burns, and diabetic and pressure ulcers, and explores the wound healing process. The review presents hydrogel dressings that monitor wound conditions and provide tailored treatment, such as pH-sensitive, temperature-sensitive, glucose-sensitive, pressure-sensitive, and nano-composite hydrogel dressings. Challenges include developing dressings that meet the standards of excellent biocompatibility, improving monitoring accuracy and sensitivity, and overcoming obstacles to production and commercialization. Furthermore, it provides the current status, progress, challenges, and future trends in this field, aiming to give a clear view of its past, present, and future.

Keywords: hydrogel; treatment; wound dressing; wound monitoring.

Figure 1

Temporal trend in published research articles on “hydrogels”, spanning the years from 1950 to 2022.

Figure 2

The evolutionary progression of hydrogels and dressings, along with contemporary hydrogel innovations for wound monitoring and treatment.

Figure 3

Wound healing is a complex process that can be broadly divided into four sequential stages: (A) hemostatic stage, (B) inflammatory stage, (C) proliferative stage, and (D) remodeling stage [64].

Figure 4

The pH value in the wound microenvironment changes with time [72].

Figure 5

An advanced multi-purpose dressing for wound monitoring and management. (A) Schematic representation of dressing treatment of epidermal wounds, with pH-sensitive and drug-eluting components. (B-i) Porous sensors were fabricated using a 3D bioprinter equipped with a co-axial flow microfluidic nozzle. (B-ii) Schematic of fiber deposition using the co-axial flow system. (B-iii) 3D printer can be programmed to produce arrays of porous sensors for fabrication of large-scale dressings. (C) Dressings can be lyophilized and sterilized for storage and transportation. (D) Synthetic Brilliant Yellow and naturally derived cabbage juice were used as model pH indicators for the fabrication of the sensors. Sensor arrays enable detecting spatial variations of pH on the wound site. Drug-eluting scaffolds release high doses of antibiotics at the wound site to eradicate the bacteria that may remain on the wound site each time the dressing is replaced. (E) The multi-purpose dressing can maintain a conformal contact with irregular surfaces [36].

Figure 6

Schematic representation of multifunctional hydrogels for wound management. (a) Illustration demonstrating the preparatory steps involved in the synthesis of multifunctional hydrogels. (b) Schematic diagram showcasing multifunctional hydrogels’ intelligent wound monitoring capabilities when employed as wound dressings. This includes the processes of wound recognition, real-time condition monitoring, and personalized wound management [73].

Figure 7

Diagram depicting the hydrogel microenvironment: BTB/PTDBD/CS—Enabling responsive naked-eye diagnosis and photothermal treatment for wound infection [38].

Figure 8

The body temperature rises when a wound becomes infected or inflamed [77].

Figure 9

Drug release from PVA/SA-g-NIPAM hydrogel dressings at different temperatures [80].

Figure 10

Schematic diagram of the structure and working principle of intelligent, flexible, electronic integrated wound dressing. (a) The integrated system consists of a polydimethylsiloxane-encapsulated flexible electronic layer and an UV-responsive antibacterial hydrogel. The flexible electronic device is integrated with a sensor for monitoring temperature and four UV-LEDs for emitting UV light (365 nm) to trigger the release of antibiotic from the UV-responsive antibacterial hydrogel when needed; a Bluetooth chip is also integrated for wireless data transmission in real time. (b) Conceptual view of the integrated system for infected-wound monitoring and on-demand treatment: (i) real-time monitoring of wound temperature and providing an alert of hyperthermia caused by infection; (ii) turning on UV-LEDs to trigger the release of antibiotics; (iii) infection inhibition by the released antibiotics, resulting in decreased wound temperature [81].

Figure 11

Schematic illustration of an automated smart bandage [82].

Figure 12

The hydrogel wound dressing is made with a Schiff base and phenyl borate ester bond [84].

Figure 13

Visualization of a zwitterionic PCB hydrogel dressing, coated with a pH indicator (phenol red) and glucose-sensitive enzymes (GOX and HRP), for pH and glucose concentration detection in wound exudate. (a) Scheme of PCB hydrogel dressing for the detection of pH value and glucose concentration in wound exudate. (b) Functionalized wound dressing for simultaneous detection of pH values (under visible light) and glucose concentrations (under UV light) [37].

Figure 14

Observation of the AIL−C8 hydrogel pressure sensor for manual monitoring. Tracked movements included: (a) shoulder movement, (b) elbow movement, (c) wrist movement, (d) waist movement, (e) leg movement, (f) elbow bends at 90° and 120° angles, and (g) writing [39].

Figure 15

Formulation approaches for a thermo-responsive hydrogel dressing, embedded with a wireless Bluetooth module to facilitate the continuous real-time monitoring of wound temperature [92].

Figure 16

Schematic depiction of the fabrication and utilization of a responsive MXene-based hydrogel system. (a) The formation and drug release process of the MXene−based hydrogel system. (b) Deep chronic infected wound treated with NIR responsive AgNPs−loaded MXene−based hydrogel system [100].