Synthesis and properties of amino acid functionalized water-soluble perylene diimides

Photosensitive Chitosan-Based Injectable Hydrogel Chemically Cross-Linked by Perylene Bisimide Dopamine with Robust Antioxidant and Cytotoxicity Enhancer Properties for In Vitro Photodynamic Therapy of Breast Cancer

Here, we report the fabrication of an antioxidant photosensitizing hydrogel system based on chitosan (CS-Cy/PBI-DOPA) covalently cross-linked with perylene bisimide dopamine (PBI-DOPA) as a photosensitizer. The severe insolubility and low tumor selectivity limitations of perylene were overcome by conjugation with dopamine and then to the chitosan hydrogel. The mechanical and rheological study of CS-Cy/PBI-DOPA photodynamic antioxidant hydrogels illustrated interconnected microporous morphologies with high elasticity, swelling ability, and suitable shear-thinning behavior. Bio-friendly properties, such as biodegradability and biocompatibility, excellent singlet oxygen production abilities, and antioxidant properties were also delivered. The antioxidant effects of the hydrogels control the physiological levels of reactive oxygen species (ROS) generated by photochemical reactions in photodynamic therapy (PDT), which are responsible for oxidative damage to tumor cells while protecting normal cells and tissues from ROS damage, including blood and endothelial cells. In vitro, PDT tests of hydrogels were conducted on two human breast cancer cell lines, MDA-MB-231 and MCF-7. These hydrogels offered more than 90% cell viability in the dark and good photocytotoxicity performance with 53 and 43% cell death for MCF-7 and MDA-MB-231 cells, which confirmed their promising potential for cancer therapeutic applications.

Self-Assembling Peptidic Bolaamphiphiles for Biomimetic Applications

Bolaamphiphile, which is a class of amphiphilic molecules, has a unique structure of two hydrophilic head groups at the ends of the hydrophobic center. Peptidic bolaamphiphiles that employ peptides or amino acids as their hydrophilic groups exhibit unique biochemical activities when they self-organize into supramolecular structures, which are not observed in a single molecule. The self-assembled peptidic bolaamphiphiles hold considerable promise for imitating proteins with biochemical activities, such as specific affinity toward heterogeneous substances, a catalytic activity similar to a metalloenzyme, physicochemical activity from harmonized amino acid segments, and the capability to encapsulate genes like a viral vector. These diverse activities give rise to large research interest in biomaterials engineering, along with the synthesis and characterization of the assembled structures. This review aims to address the recent progress in the applications of peptidic bolaamphiphile assemblies whose densely packed peptide motifs on their surface and their stacked hydrophobic centers exhibit unique protein-like activity and designer functionality, respectively.

Enhancement of visible light driven dye degradation and photocatalytic H2 evolution over MoS2 through combination with perylene diimide aggregates

The incorporation of PPDI MBs into MoS₂ NFs changes the nature of their edge, increases the driving force to effectively separate and transfer the photogenerated charge carriers, and improves the overall photocatalytic performance of the material.

Photophysical, electrochemical, self-assembly, and molecular packing properties of a sulfur-decorated perylene derivative

A sulfur-decorated perylene derivative, 1-propanethiol-N,N′-dicyclohexyl perylene-3,4,9,10 tetracarboxylic diimide (PTPDI), was synthesized and fully characterized by 1H NMR, 13C NMR, FTIR, HRMS, UV–vis absorption, fluorescence, fluorescence lifetime, fluorescence quantum yield, cyclic voltammetry, and thermogravimetric techniques. The optical, fluorescence, and scanning electron microscopies were employed to study its self-assembly process. The photophysical properties were affected strongly by modifying the propanethiol unit linking to the perylene core. Furthermore, the chromophore showed two irreversible oxidations and two quasi-reversible reductions in dichloromethane at modest potential. The optical properties of PTPDI in various conditions and complementary density functional theory calculations were reported. Due to steric hindrance of the bulky n-propyl mercaptan substituent, PTPDI molecules are arranged in slipped face-to-face fashion to form J-aggregates. Thus, the intermolecular π–π actions of the molecule are weak, causing its high luminescence efficiency. In the meantime, the space between perylene cores is very short (3.45 Å), which is favorable for the hopping transportation of charge carrier from one molecule to an adjacent one. PTPDI could be a candidate material for acquiring a well-defined organic nanostructure with excellent charge-transporting and light-emitting capabilities.

Solid-Phase Synthesis of Peptide-Conjugated Perylene Diimide Bolaamphiphile and Its Application in Photodynamic Therapy

Here, we describe a rapid and efficient synthetic method of peptide-conjugated perylene diimide (P-PDI) using solid-phase peptide synthesis (SPPS). Due to severe insolubility of perylene dianhydride (PDA) as a starting material of perylene diimide (PDI), PDA was initially conjugated with amino acids to obtain soluble PDI derivatives. Target peptides were synthesized on a 2-chlorotrityl chloride resin using the SPPS method and then conjugated with the amino acid-appended PDI. Various conditions such as loading levels, reaction times and solvents were optimized for introducing the peptides to both sides of the amino acid-appended PDI. The final P-PDI was obtained with a maximum yield of 80% in 12 h. Its singlet oxygen-derived phototoxicity on cells was confirmed, which could be applicable to photodynamic therapy.

Self-assembly, optical and electrical properties of perylene diimide dyes bearing unsymmetrical substituents at bay position

Perylene diimides (PDIs) are one class of the most explored organic fluorescent materials due to their high luminescence efficiency, optoelectronic properties, and ready to form well-tailored supramolecular structures. However, heavy aggregation caused quenching (ACQ) effect in solid state has greatly limited their potential applications. We have easily solved this problem by chemical modification of the PDI core with only phenoxy moietie at one of the bay position. In this paper, we report two perylene bisimides with small rigid substituents, 1- phenol -N, N'-dicyclohexyl perylene-3,4,9,10-tetracarboxylic diimide (PDI 1) and 1- p-chlorophenol-N, N'-dicyclohexyl perylene-3,4,9,10-tetracarboxylic diimide (PDI 2) possess both well defined organic nanostructures and high fluorescence quantum yield in the solid state. In contrast, 1-propanol-N, N'-dicyclohexyl perylene-3,4,9,10-tetracarboxylic diimide (PDI 3) bearing a straight chain only shown weak orange fluorescence. In addition, morphological inspection demonstrated that PDI 3 molecules easily form well-organized microstructures despite the linkage of the PDI core with a straight chain. The present strategy could provide a generic route towards novel and advanced fluorescent materials and these materials may find various applications in high-tech fields.