Optically pH-Sensing in Smart Wound Dressings Towards Real-time Monitoring of Wound States: A Review

Abstract

Background

Over the recent years, the investigations on wound dressings have been undergoing significant evolution, and now smart dressings with the function of the real-time monitoring of the wound states have been recognized as one of the most advanced treatment modalities. Among a variety of wound-related biomarkers, pH represents a promising candidate for in situ supervising the wound healing status. In this regard, a variety of optically pH sensing agents have been widely incorporated into different types of wound dressings.

Results

Herein, we first presented an overview of the advanced wound dressings, especially those commonly used in wound pH sensing. Then, a comprehensive summary of the optical pH sensing agents that could be incorporated into the wound dressings for detecting the pH alteration on the wound bed was described in detail. These materials were classified into colorimetric dyes (i.e., synthetic and plant-based dyes) and fluorescent probes (i.e., small-molecular fluorescein and fluorescent nanomaterials). Each type of pH sensing agent was fully discussed with advantages and limitations for monitoring the wound pH alteration, as well as typical examples of practical applications. To well interpret messages produced by the color-coding dressings, the approaches for defining and communicating color were also summarized, and a proof-of-concept, the smartphone-based remote supervision was particularly highlighted.

Significance

This review provides a comprehensive overview of the utilization of optically pH sensing in advanced wound dressings for the real-time monitoring of the wound states. It was expected to be an informative source for the exploitation of novel diagnostic dressings for wound management, and also a reference the for application of these materials in the biosensing of other physiological or pathological fluids.