A Water-Soluble Photothermal Host–Guest Complex with pH-Sensitive Superlarge Redshift Absorption

Abstract

NIR absorbers for photothermal therapy are arousing great attention in tumor diagnosis and ablation. However, the inevitably wide distribution of NIR absorbers generally causes equal photothermal injuries to tumor tissues and healthy tissues. An initiative targeting strategy based on pH-sensitive redshift absorption has been proposed for NIR-induced hyperthermia only in tumor tissue. In this work, we develop a NIR absorber with superlarge redshift from middle visible light region to NIR light region once pH value drops. We also figure out a supramolecular route to improve the water solubility as well as the thermal stability of the NIR absorber in aqueous solutions. Animal experiments reveal that the tumor microenvironment can trigger selective NIR light absorbing, which is thus responsible for the tumor-selective hyperthermia and ablation. In terms of the advantages of easy preparation, low cytotoxicity, excellent tumor-selectivity, this supramolecular complex is considered to be a reliable photothermal agent for intelligent tumor-specific diagnosis and treatment.

Assembly Induced Super-Large Red-Shifted Absorption: The Burgeoning Field of Organic Near-Infrared Materials

“…There are several unique advantages of NIR materials for biological purposes: (1) they enable a higher imaging sensitivity because living cells or tissues have low absorption and emission in the NIR region; (2) they reduce the tissue damage from irradiation; and (3) they allow deeper tissue penetration than visible light. [40][41][42] These advantages will be more prominent for NIR-II materials, or short-wave infrared materials. 43 To achieve such a low-energy absorption for efficient biological applications, supramolecular assembly of organic chromophores to acquire a super-large red-shifted absorption in the NIR-II region has proved to be a more promising route than molecular design.…”

An Exceptional Broad-Spectrum Nanobiocide for Multimodal and Synergistic Inactivation of Drug-Resistant Bacteria

“…the copperLA complex on the antibacterial behavior, probably via Fenton-like reactions as inferred in previous reports. 37,38 Surprisingly, NIR irradiation of PolyCu nanoparticles gave rise to an exceptional antibacterial effect toward both bacteria, with the CFU numbers decreasing by four orders of magnitude for Amp r E. coli and six orders of magnitude for MRSA. The bacterial killing efficiencies were eventually determined to be 99.99%…”

“…30,36 It is widely reported that copper salts possess intrinsic antibacterial and antiviral capabilities, presumably due to the generation of reactive oxygen species (ROS) via Fenton-like reactions. 37,38 However, the direct use of water-soluble copper salts is infeasible due to their poor photothermal effect and high toxicity to healthy tissues. 39 As such, it is highly desired to reduce the adverse impacts of copper ions by forming a water-insoluble copper complex, and concurrently endow the resultant complex with a strong photothermal effect to achieve multimodal killing of drug-resistant bacteria.…”

Tailormade Nonradiative Rotation Tuning of the Near-Infrared Photothermal Conversion in Donor–Acceptor Cocrystals

“…Organic photothermal conversion functional materials, which can absorb light energy and generate heat, have been widely used in photothermal imaging, photothermal therapy, − photothermal-electrical devices, seawater desalination, and so on. To make full use of solar light, which has 53% near-infrared (NIR) light, many strategies are used to improve the NIR absorption and inhibit the radiation transition processes, resulting in outstanding photothermal conversion efficiency. , Based on this, polymers such as porphyrin, indocyanine green, polyaniline, and polypyrrole are most commonly used as organic photothermal conversion materials.…”