Singlet oxygen photo-production by perylene bisimide derivative Langmuir-Schaefer films for photodynamic therapy applications

Diesters of monoimide of perylene-3,4,9,10-tetracarboxylic acid - Synthesis, characterization, and application for dyeing polyester fibre, polystyrene, and poly (methyl methacrylate) films

Three dyes-diesters of monoimides of perylene-3,4,9,10-tetracarboxylic acid were synthesized in three-stage process: esterification, hydrolysis, and monoimidation as potential fluorescent light-stable colorants for high visibility safety wear. The structure of these compounds was confirmed by 1H nuclear magnetic resonance spectroscopy and mass spectrometry, and their spectroscopic and physicochemical properties were determined. Colorants were applied to dyeing polyester fibre and polystyrene and poly (methyl methacrylate) films. The light, wash, and rubbing fastness of the dyeings were determined, and chromaticity coordinates were measured and discussed.

New Highly Fluorescent Water Soluble Imidazolium-Perylenediimides: Synthesis and Cellular Response

The synthesis and characterization of two new water soluble 2,6-bis(imidazolylmethyl)-4-methylphenoxy-containing perylenediimides, PDI-1 and PDI-2, are described. These compounds demonstrate a high fluorescence quantum yield in water and were investigated as potential photosensitizers for generating reactive oxygen species with applications in anticancer activities. The HeLa cell line (VPH18) was used to evaluate their efficacy. Fluorescence microscopy was employed to confirm the successful internalization of PDI-1 and PDI-2, while confocal microscopy revealed the specific locations of both PDIs within the lysosomes and mitochondria. In vitro studies were conducted to evaluate the anticancer activity of PDI-1 and PDI-2. Remarkably, these photosensitizers demonstrated a significant ability to selectively eliminate cancer cells when exposed to a specific light wavelength. The water solubility, high fluorescence quantum yield, and selective cytotoxicity of these PDIs toward cancer cells highlight their potential as effective agents for targeted photodynamic therapy. In conclusion, the findings presented here provide a strong foundation for the future exploration and optimization of PDI-1 and PDI-2 as effective photosensitizers in photodynamic therapy, potentially leading to improved treatment strategies for cancer patients.

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.

Hierarchical self-assemblies of carnosine asymmetrically functioned perylene diimide with high optoelectronic response

HYPOTHESIS

Taking advantage of photoinduced electron transfer, one dimensional organic nanomaterials with tunable donor-acceptor (D-A) interface provide a promising avenue to get high optoelectric properties. However, strong charge transfer interaction between D and A segments impedes the formation of long-range ordered structure, which limits the charge transport through efficient π electronic delocalization. Incorporation of chiral peptide offering various hydrogen bonding (H-bonding) along with asymmetric molecular structure enables substantially controllable D-A interface and tunable organization of the π-conjugates.

EXPERIMENTS

A new amphiphilic perylene diimide (CUPDI) with PDI as an acceptor is designed and synthesized. A polar chiral dipeptide composed of β-alanine and l-histidine with the imidazole ring as the donor i.e., l-carnosine, is incorporated at one of imides. Transition of various supramolecular assemblies of CUPDI is realized by changing CUPDI concentration and solvents. The photoelectronic properties of the assemblies are investigated as well as their association with the microstructure of the nanomaterials.

FINDINGS

Delicately tuned hydrogen bonds between the peptides and π-π interaction between PDI cores in different solvents enable the formation of assemblies with multifarious microstructures such as small spherical aggregates, nanowires with uniform diameter, nanobelts, and irregular aggregates. The maximum amount of photocurrent enhancement is up to 1.08 µA observed for the nanobelt, four times higher than that of irregular aggregates. However, the nanowires show the best performance of 7.1-fold in response to ammonia. Thus, the photoelectric performances are strongly dependent on the the molecular arrangement within the nanomaterials.

Langmuir-Schaefer Perylene Derivative Films: Influence of the Molecular Chemical Structure on the Supramolecular Arrangement

Since the optical and electrical properties of organic thin films devices depend on their supramolecular arrangement and the molecular chemical structure, the understanding of such characteristics is essential for the optimization of these devices. In this study, we determine the supramolecular arrangement of thin films produced using the Langmuir-Schaefer (LS) technique and explain how its supramolecular arrangement is affected by the molecular chemical structure using two perylene derivatives: bis-butylimide (BuPTCD) and bis-phenethylimide (PhPTCD). The optical absorption measurements reveal that both films grow homogeneously and indicate that the presence of H aggregates (forbidden emission) is higher for BuPTCD LS film than for PhPTCD LS film. Atomic force microscopic analysis shows that the PhPTCD LS film is rougher than the BuPTCD film. In addition, FTIR analyses indicate that both films have head-on molecular organization. XRD patterns reveal that both the BuPTCD LS film and the PhPTCD LS film are crystalline, but that crystallinity is more prevalent in the BuPTCD LS film. Thus, the results show that the difference presented in the chemical structures leads the films to have different supramolecular arrangements, with consequences for their optical properties.

Nanocellulose/Fullerene Hybrid Films Assembled at the Air/Water Interface as Promising Functional Materials for Photo-electrocatalysis

Cellulose nanomaterials have been widely investigated in the last decade, unveiling attractive properties for emerging applications. The ability of sulfated cellulose nanocrystals (CNCs) to guide the supramolecular organization of amphiphilic fullerene derivatives at the air/water interface has been recently highlighted. Here, we further investigated the assembly of Langmuir hybrid films that are based on the electrostatic interaction between cationic fulleropyrrolidines deposited at the air/water interface and anionic CNCs dispersed in the subphase, assessing the influence of additional negatively charged species that are dissolved in the water phase. By means of isotherm acquisition and spectroscopic measurements, we demonstrated that a tetra-sulfonated porphyrin, which was introduced in the subphase as anionic competitor, strongly inhibited the binding of CNCs to the floating fullerene layer. Nevertheless, despite the strong inhibition by anionic molecules, the mutual interaction between fulleropyrrolidines at the interface and the CNCs led to the assembly of robust hybrid films, which could be efficiently transferred onto solid substrates. Interestingly, ITO-electrodes that were modified with five-layer hybrid films exhibited enhanced electrical capacitance and produced anodic photocurrents at 0.4 V vs Ag/AgCl, whose intensity (230 nA/cm2) proved to be four times higher than the one that was observed with the sole fullerene derivative (60 nA/cm2).

Applications of Photoinduced Phenomena in Supramolecularly Arranged Phthalocyanine Derivatives: A Perspective

This review focuses on the description of several examples of supramolecular assemblies of phthalocyanine derivatives differently functionalized and interfaced with diverse kinds of chemical species for photo-induced phenomena applications. In fact, the role of different substituents was investigated in order to tune peculiar aggregates formation as well as, with the same aim, the possibility to interface these derivatives with other molecular species, as electron donor and acceptor, carbon allotropes, cyclodextrins, protein cages, drugs. Phthalocyanine photo-physical features are indeed really interesting and appealing but need to be preserved and optimized. Here, we highlight that the supramolecular approach is a versatile method to build up very complex and functional architectures. Further, the possibility to minimize the organization energy and to facilitate the spontaneous assembly of the molecules, in numerous examples, has been demonstrated to be more useful and performing than the covalent approach.

Supramolecular Chiral Discrimination of D-Phenylalanine Amino Acid Based on a Perylene Bisimide Derivative

The interaction between homochiral substituted perylene bisimide (PBI) molecule and the D enantiomer of phenylalanine amino acid was monitored. Spectroscopic transitions of PBI derivative in aqueous solution in the visible range were used to evaluate the presence of D-phenylalanine. UV-visible, fluorescence, FT-IR, and AFM characterizations showed that D-phenylalanine induces significant variations in the chiral perylene derivative aggregation state and the mechanism is enantioselective as a consequence of the 3D analyte structure. The interaction mechanism was further investigated in presence of interfering amino acid (D-serine and D-histidine) confirming that both chemical structure and its 3D structure play a crucial role for the amino acid discrimination. A D-phenylalanine fluorescence sensor based on perylene was proposed. A limit of detection (LOD) of 64.2 ± 0.38 nM was calculated in the range 10-7-10-5 M and of 1.53 ± 0.89 μM was obtained in the range 10-5 and 10-3 M.