No abstract

Organic–inorganic hybrid materials have drawn increasing attention as photothermal agents in tumor therapy due to the advantages of green synthesis, high loading efficiency of hydrophobic drugs, facile incorporation of theranostic iron, and excellent photothermal efficiency without inert components or additives. Herein, we proposed a strategy for biomimetic engineering-mediated enhancement of photothermal performance in the tumor microenvironment (TME). This strategy is based on the specific characteristics of organic–inorganic hybrid materials and endows these materials with homologous targeting ability and photothermal stability in the TME. The hybrid materials perform the functions of cancer cells to target homolytic tumors (acting as “artificial nanotargeted cells (ANTC)”). Inspired by the pH-dependent disassembly behaviors of tannic acid (TA) and ferric ion (FeIII) and subsequent attenuation of photothermal performance, cancer cell membranes were self-deposited onto the surfaces of protoporphyrin-encapsulated TA and FeIII nanoparticles to achieve ANTC with TME-stable photothermal performance and tumor-specific phototherapy. The resulting ANTC can be used as contrast agents for concurrent photoacoustic imaging, magnetic resonance imaging, and photothermal imaging to guide the treatment. Importantly, the high loading efficiency of protoporphyrin enables the initiation of photodynamic therapy to enhance photothermal therapeutic efficiency, providing antitumor function with minimal side effects.

Incorporation of CuS nanoparticles into the framework of ZIF-8 provides a chance to integrate near-infrared (NIR) light/low pH triggered release and chemo-photothermal therapy into one system. For the first time, we observed that the framework of ZIF-8 could be disintegrated at pH 7.4 under NIR laser irradiation.

Two series of substituted benzo[g]‐ or benzo[e]pyrimido[4,5‐b]indole (naphtho‐fused 7‐deazapurine) ribonucleosides were synthesized. The heterocyclic nucleobases were obtained by Negishi cross‐coupling reaction of zincated pyrimidines with naphthyl iodides, nucleophilic substitution to tetrazoles/azides and thermal cyclization or photocyclization. Nucleosides were obtained by glycosylation followed by substitution reactions and deprotection. Resulting ribonucleosides were tested for their cytotoxic activity against cancer cell lines and antiviral activities. Some derivatives showed micromolar cytotoxic activities and moderate anti‐hepatitis C virus activities. Naphtho‐fused 7‐deazapurine 2′‐deoxyribonucleoside triphosphate was successfully incorporated into DNA oligonucleotides by KOD XL DNA polymerase. Fluorescence properties of naphtho‐fused 7‐deazapurine nucleosides and oligonucleotides were also studied.