Tyrosinase-Woven Melanin Nets for Melanoma Therapy through Targeted Mitochondrial Tethering and Enhanced Photothermal Treatment.

Manipulating intracellular biological processes and organelles has emerged as a pivotal strategy to influence cellular physiological functions. Mitochondria, recognized as the powerhouse of cells, play a crucial role in tumorigenesis and progression. Inspired by the Nature's tyrosinase-catalyzed melanin formation within melanoma cells, here an approach is developed using a polysaccharide dually-functionalized with tyrosine and triphenylphosphine (TPP) for targeted mitochondria cross-linking in melanoma cells. This technique intricately weaves melanin nets within the cells, serving as a tether for the mitochondria and effectively decelerating tumor metabolism through nanoparticle-net transformation. Tyrosinase acts as the "needle", while the functionalized polysaccharide serves as the "string" successfully constructing nets within the cell. Furthermore, the tyrosinase-catalyzed cross-linking of tyrosine not only facilitates the production of artificial melanin but also enhances the photothermal conversion efficiency of melanoma cells, leading to decrease of the tumor growth. This study unveils a non-drug method for regulating organelle physiological activity and introduces photothermal treatment. This work not only sheds light on the manipulation of cellular functions but also holds promise for advancing cancer therapeutic strategies.

Visible light-induced metal-free cascade denitrogenative borylation and iodination of nitroarenes.

An efficient method was developed for the one-pot construction of C-B and C-I via visible light-induced transformation of nitroarenes. This protocol relies on the photochemical properties of nitroarenes under visible light, followed by reduction with B2pin2 and diazotization with tBuONO. An array of arylboronates and iodobenzenes were constructed smoothly after excitation with purple LEDs at room temperature. In addition, the synthetic utility of this method was further demonstrated in the late-stage modification of a drug molecule. The advantages of this strategy include metal-free system, mild reaction conditions and acceptable substrate scope.

A Metal-Free Visible-Light Photoredox Construction and Direct C-H Functionalization of Pyridines: Green Synthesis of Polysubstituted Picolinaldehydes.

The development of a novel environmental benign and sustainable synthetic method for highly efficient construction and direct C-H functionalization of N-heterocycles remains a pivotal central research topic for organic and medicinal chemistry. Herein, a novel visible-light-enabled biomimetic aza-6π electrocyclization for efficient assembly of diverse pyridines and further tandem Minisci-type reaction were developed. A broad spectrum of polysubstituted picolinaldehydes were readily constructed with high efficacy and good functional group tolerance under metal- and oxidant-free conditions.