Stimuli-Responsive Nanoplatform-Assisted Photodynamic Therapy Against Bacterial Infections

Abstract

Bacterial infections are common diseases causing tremendous deaths in clinical settings. It has been a big challenge to human beings because of the antibiotics abuse and the newly emerging microbes. Photodynamic therapy (PDT) is a reactive oxygen species-based therapeutic technique through light-activated photosensitizer (PS). Recent studies have highlighted the potential of PDT as an alternative method of antibacterial treatment for its broad applicability and high efficiency. However, there are some shortcomings due to the low selectivity and specificity of PS. Growing evidence has shown that drug delivery nanoplatforms have unique advantages in enhancing therapeutic efficacy of drugs. Particularly, stimuli-responsive nanoplatforms, as a promising delivery system, provide great opportunities for the effective delivery of PS. In the present mini-review, we briefly introduced the unique microenvironment in bacterial infection tissues and the application of PDT on bacterial infections. Then we review the stimuli-responsive nanoplatforms (including pH-, enzymes-, redox-, magnetic-, and electric-) used in PDT against bacterial infections. Lastly, some perspectives have also been proposed to further promote the future developments of antibacterial PDT.

Antibiotics and Bacterial Resistance—A Short Story of an Endless Arms Race

“…Another promising idea, which is based on the synergistic effect of nanomaterial-based strategies with antibiotics, is provided by antibacterial photodynamic therapy (aPDT). In general, PDT induces reactive oxygen species (ROS) by using a light-activated photosensitizer [ 287 ]. Recently, it was reported that the photosensitizer, that is, 5, 10, 15, 20-Tetrakis(3-hydroxyphenyl)chlorin (temoporfin), suppressed the expression of the antibiotic resistance gene mecA (encoding PBP2a) and considerably reduced MRSA drug resistance.…”

Smart dental materials for antimicrobial applications

“…In another work, emodin-chitosan NPs were designed as PS in aPDT therapy against S. mutans biofilm on the enamel surface ex-vivo [ 223 ]. To improve the antimicrobial specificity and selectivity, stimuli-responsive nanoplatforms have been proposed to enhance the delivery of PS [ 261 ]. Different signals from pH levels, enzymes, redox, magnetic, and electric have been used and reviewed here [ 261 ].…”

“…To improve the antimicrobial specificity and selectivity, stimuli-responsive nanoplatforms have been proposed to enhance the delivery of PS [ 261 ]. Different signals from pH levels, enzymes, redox, magnetic, and electric have been used and reviewed here [ 261 ]. For example, in dentistry, magnetic fields have been used in the targeted delivery of magnetic materials.…”

Targeted antibacterial photodynamic therapy with aggregation‐induced emission photosensitizers

“…Even undergoing mutations, it is hard for bacteria to evade ROS-mediated ablation because ROS oxidation can act on multitargets, leading to resistance loss. 8 Benefiting from the role of ROS in the immune defense mechanism against bacteria, bacterial infections can be potentially treated by improving ROS generation or interfering with ROS defense mechanisms. 9 Photosensitizers (PSs) can produce ROS under appropriate light stimulation for broad-spectrum treatment of bacteria and reduce bacterial resistance concerns, making antibacterial photodynamic therapy (APDT) a potential alternative antibacterial modality.…”