A Bacteria‐Responsive Porphyrin for Adaptable Photodynamic/Photothermal Therapy

Abstract

We report a cationic porphyrin 5,10,15,20‐tetrakis‐(4‐N‐methylpyridyl)‐porphyrin (TMPyP) that can respond to specific bacteria, followed by adaptable photodynamic/photothermal therapy processes. TMPyP could be reduced to phlorin by facultative anaerobes with a strong reducing ability such as E. coli and S. typhimurium in hypoxic environments, possessing strong NIR absorption and remarkable photothermal conversion capacity, thus demonstrating excellent antimicrobial activity (>99 %) by photothermal therapy. While in an aerobic environment with aerobic bacteria, TMPyP functioned as a typical photosensitizer that killed bacteria effectively (>99.9 %) by photodynamic therapy. By forming a host–guest complex with cucurbit[7]uril, the biocompatibility of TMPyP significantly improved. This kind of bacteria‐responsive porphyrin shows specificity and adaptivity in antimicrobial treatment and holds potential in non‐invasive treatments of bacterial infections.

Synergistic photothermal antibacterial therapy enabled by multifunctional nanomaterials: progress and perspectives

“…Hu et al designed and synthesized a water-soluble cationic porphyrin, 5,10,15,20-tetrakis-(4- N -methylpyridyl)-porphyrin (TMPyP), with an iodine anion as an anion. 57 TMPyP carried four positive charges on the peripheral N -methylpyridine group, which enhanced the water solubility of hydrophobic porphyrin rings and helped adsorb by negatively charged bacteria. However, as a small molecule with a positive charge, TMPyP could destroy cell membranes and cause cell death, so it was highly cytotoxic to intestinal cells.…”

Mechanosensitive non-equilibrium supramolecular polymerization in closed chemical systems

“…Supramolecular polymers 1-5 refer to molecular self-assembly into larger, more complex structures driven by reversible non-covalent interactions. This eld has attracted continuous attention as these supramolecular structures could endow materials with unique properties, such as self-healing 6, 7 and responsivity [8][9][10] . Most synthetic supramolecular polymers are formed under equilibrium or as metastable (kinetically trapped) states, whereas living organisms use biofuel-driven dissipative supramolecular structures far from equilibrium to perform complex biological functions.…”

A pH-Responsive Drug Delivery System Based on Conjugated Polymer for Effective Synergistic Chemo-/Photodynamic Therapy

“…It is thus of immense significance to explore up-to-date cancer diagnostic and treatment strategies, which are ongoing challenges for researchers in related fields [ 2 , 3 ]. Recently, photodynamic therapy (PDT) has provided a promising perspective for anticancer treatments [ 4 , 5 , 6 ]. Compared with conventional therapy methods, PDT possesses unique advantages, such as high spatial selectivity, negligible system toxicity and the prevention of multidrug resistance [ 7 , 8 , 9 , 10 ].…”