Intelligent Hybrid Hydrogels for Rapid In Situ Detection and Photothermal Therapy of Bacterial Infection

Abstract

Diseases induced by bacterial infections increasingly threaten the health of people all over the world; thus, it is urgent and significant to early diagnose and effectively eliminate infections to save people’s lives. To this end, we synthesized an intelligent hydrogel that integrated in situ visualized diagnosis and photothermal therapy of bacterial infections. By simply and subtly incorporating pH-sensitive bromothymol blue (BTB) and near-infrared (NIR)-absorbing conjugated polymer (termed as PTDBD) into thermosensitive chitosan (CS)-based hydrogel, the synthesized BTB/PTDBD/CS hydrogel can diagnose the acidic microenvironment of Staphylococcus aureus (S. aureus) biofilm and infected wounds by showing visualized color change. After rapid diagnosis, the hydrogel can immediately treat the infection site by local hyperthermia under irradiation of NIR laser (808 nm) and even the stubborn biofilm that is difficult to eradicate. Since the dominating antibacterial mechanism is hyperthermia, the hybrid hydrogel shows broad-spectrum antibacterial activity against Gram-positive, Gram-negative, and drug-resistant bacteria. In addition, it has low cytotoxicity to normal cells and no effect on the main organs of mice. It paves a brand new avenue to develop smart and facile diagnosis and a treatment platform for bacterial infections.

A Review on Hydrogels with Photothermal Effect in Wound Healing and Bone Tissue Engineering

“…They employed PTDBD as a photo-initiator, β-glycerophosphate as a sol-gel conversion agent, and chitosan as scaffold material to obtain a visual antibacterial hydrogel. After 8 min of NIR irradiation, the temperature of the hydrogel up to 55 °C and showed a strong destructive effect on S. aureus [ 145 , 146 ].…”

Functional hydrogels for diabetic wound management

“…Then photothermal therapy after in situ visual diagnosis. 166 Reproduced with permission from Wang et al , ACS Appl. Mater.…”

“…10(b) ]. 166 By incorporating a pH-sensitive bromothymol blue (BTB), the hydrogel showed visible color changes corresponding to various pH levels in the infected wound microenvironment. Based on a naked-eye diagnosis, photothermal therapy triggered by NIR light can be applied if needed.…”

Intelligent Silk Fibroin Based Microneedle Dressing (i‐SMD)

“…Several indexes of wound secretion, such as pH and inflammatory factors, are closely related to the wound recovery condition. [6][7][8][9][10] Therefore, monitoring these indexes could reflect the healing process. Currently, considerable effort has been devoted to devices to monitor wound detection and promote healing, such as hydrogel patches and microchips.…”