Rapid and Superior Bacteria Killing of Carbon Quantum Dots/ZnO Decorated Injectable Folic Acid‐Conjugated PDA Hydrogel through Dual‐Light Triggered ROS and Membrane Permeability

Abstract

One of the most difficult challenges in the biomedical field is bacterial infection, which causes tremendous harm to human health. In this work, an injectable hydrogel is synthesized through rapid assembly of dopamine (DA) and folic acid (FA) cross‐linked by transition metal ions (TMIs, i.e., Zn2+), which was named as DFT‐hydrogel. Both the two carboxyl groups in the FA molecule and catechol in polydopamine (PDA) easily chelates Zn2+ to form metal–ligand coordination, thereby allowing this injectable hydrogel to match the shapes of wounds. In addition, PDA in the hydrogel coated around carbon quantum dot‐decorated ZnO (C/ZnO) nanoparticles (NPs) to rapidly generate reactive oxygen species (ROS) and heat under illumination with 660 and 808 nm light, endows this hybrid hydrogel with great antibacterial efficacy against Staphylococcus aureus (S. aureus, typical Gram‐positive bacteria) and Escherichia coli (E. coli, typical Gram‐negative bacteria). The antibacterial efficacy of the prepared DFT‐C/ZnO‐hydrogel against S. aureus and E. coli under dual‐light irradiation is 99.9%. Importantly, the hydrogels release zinc ions over 12 days, resulting in a sustained antimicrobial effect and promoted fibroblast growth. Thus, this hybrid hydrogel exhibits great potential for the reconstruction of bacteria‐infected tissues, especially exposed wounds.

Carbon Dots as Potent Antimicrobial Agents

“…58 highlighted above, Xiang, et al . decorated an injectable folic acid-conjugated polydopamine hydrogel with carbon-ZnO hybrid nanoparticles, and used the resulting material for wound dressing to accelerate wound healing and control antibacterial activity 83. There were ROS generation and heat production in the hydrogel with 660 nm and 808 nm light illumination, showing activities against S. aureus and E. coli .…”

“…There were ROS generation and heat production in the hydrogel with 660 nm and 808 nm light illumination, showing activities against S. aureus and E. coli . Potential use of the material in the reconstruction of bacteria-infected tissues, especially exposed wounds, was proposed 83.…”

Composite Hydrogels in Three-Dimensional in vitro Models

“…hydrogel through rapid assembly of dopamine and folic acid crosslinked by transition metal ions and introduced ZnO NPs into the hydrogel. They found that reactive oxygen species generated within the hydrogel matrix made it a great antibacterial composite against Staphylococcus aureus (Xiang et al, 2019). Schwartz et al incorporated ZnO NPs into PNIPAAm hydrogels, which exhibited excellent bactericidal behavior toward Escherichia coli with a concentration of ZnO as low as 0.74 mmol/ml (Schwartz et al, 2012).…”

<p>High UV-Vis-NIR Light-Induced Antibacterial Activity by Heterostructured TiO₂-FeS₂ Nanocomposites</p>

“…The results indicated that in the system of TiO 2 -FeS 2 NCs, under light irradiation, the increases of ROS generation enhanced for the destruction of bacterial membrane. [45][46][47]…”