Nanofiber-reinforced self-healing polysaccharide-based hydrogel dressings for pH discoloration monitoring and treatment of infected wounds.

The escalating global health concern arises from chronic wounds induced by bacterial infections, posing a significant threat to individuals. Consequently, an imperative exist for the development of hydrogel dressings to facilitate prompt wound monitoring and efficacious wound management. To this end, pH-sensitive bromothymol blue (BTB) and pH-responsive drug tetracycline hydrochloride (TH) were introduced into the polysaccharide-based hydrogel to realize the integration of wound monitoring and controlled treatment. Polysaccharide-based hydrogels were formed via a Schiff base reaction by cross-linking carboxymethyl chitosan (CMCS) on an oxidized sodium alginate (OSA) skeleton. BTB was used as a pH indicator to monitor wound infection through visual color changes visually. TH could be dynamically released through the pH response of the Schiff base bond to provide effective treatment and long-term antibacterial activity for chronically infected wounds. In addition, introducing polylactic acid nanofibers (PLA) enhanced the mechanical properties of hydrogels. The multifunctional hydrogel has excellent mechanical, self-healing, injectable, antibacterial properties and biocompatibility. Furthermore, the multifaceted hydrogel dressing under consideration exhibits noteworthy capabilities in fostering the healing process of chronically infected wounds. Consequently, the research contributes novel perspectives towards the advancement of intelligent and expeditious bacterial infection monitoring and dynamic treatment platforms.

A ZIF-8-encapsulated interpenetrated hydrogel/nanofiber composite patch for chronic wound treatment.

Designing wound dressings necessitates the crucial considerations of maintaining a moist environment and implementing effective bacterial control. Furthermore, developing a three-dimensional framework emulating the extracellular matrix (ECM) confers advantages in fostering cellular migration and proliferation. Inspired by this, hydrogel/nanofiber composites have been demonstrated as promising materials for wound dressings. The composites also overcome the disadvantages of poor mechanical properties and rapid release of traditional pure hydrogels. In this study, we constructed a calcium alginate hydrogel/polylactic acid nanofiber (CAH/PLANF) composite with an interpenetrated network. Additionally, the synthesis of zeolitic imidazolate framework-8 (ZIF-8) incorporated into the composite system endowed the system with enhanced mechanical properties and photodynamic antibacterial attributes. The obtained composite patch (ZIF-8@CAH/PLANF) exhibited excellent swelling, strong mechanical properties, low cytotoxicity, and durable photodynamic antibacterial effect with an antibacterial efficacy of higher than 99.99%. Finally, bacterial infection and wound healing properties were investigated in vivo, and the ZIF-8@CAH/PLANF patch was proven to have the ability to fight infection and accelerate wound healing.

Progress of Hydrogel Dressings with Wound Monitoring and Treatment Functions.

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.