Natural polymer gels with sensitivity to near-infrared (NIR) light have attracted the attention of scientists working on intelligent drug delivery systems. Compared to ultraviolet or visible light, NIR light has the advantages of strong trigger levels, deep penetration through affected tissues, and fewer side effects. Herein, we present a topical photothermal hydrogel for NIR-controlled drug delivery. The proposed DexIEM-GM-Laponite hydrogel was prepared through free radical polymerization of vinyl-functionalized dextran (DexIEM), vinyl-modified graphene oxide (GM), and Laponite; thereafter, the hydrogel was loaded with ciprofloxacin (CIP, an antibacterial drug) as a model drug. With the Laponite content increased, the density of crosslinking in the hydrogel increased, and its mechanical properties improved noticeably. Under NIR irradiation, the DexIEM-GM-Laponite hydrogel exhibited a photothermal property, where the surface temperature increased from 26.8 to 55.5 °C. The simulation of subcutaneous drug delivery experiments ex vivo showed that under the specified pork tissue thickness (2, 4, and 6 mm), the CIP release remained NIR-controllable. Additionally, the results of the antibacterial performance tests indicated the excellent antibacterial effect of the hydrogel, and the blood hemolysis ratio of the hydrogel was less than 5%, signifying good blood compatibility. This work will provide an avenue for the application of NIR light-responsive materials in antimicrobial therapy.
Keywords: antibacterial; drug delivery; drug-loaded hydrogel; near-infrared radiation; photothermal.