Photodynamic Efficiency Research Articles

Daylight-driven antimicrobial fabrics: Design strategy for enhancing efficiency based on electrostatic repulsion-FRET synergistic effects of dual photosensitizers

Designing antimicrobial textile materials with non-specific, broad-spectral absorption and multicolor is of great importance in personal health protection. In this study, a highly efficient, broad-spectrum responsive, and dual-color photodynamic antimicrobial nylon/cotton blended fabric (N/C-RB/ZP) was prepared through a one-bath dyeing process based on photosensitive Rose Bengal (RB) and tetra[β-(4-sodium sulfonylphenoxy)]-phthalocyanine zinc(II) (ZP). The prepared N/C-RB/ZP shows a visible absorption range of 450–700 nm and a mixed color. Additionally, N/C-RB/ZP-0.5 % exhibits superior singlet oxygen (1O2) production capacity, manifesting a “1 + 1 > 2” synergistic effect. The mechanism of synergistic enhancement of photodynamic efficiency by electrostatic repulsion-fluorescence resonance energy transfer (FRET) process between two kinds of liked-charge dyes on heterogeneous fibers was confirmed. N/C-RB/ZP-0.5 % exhibits excellent antimicrobial activity against Staphylococcus aureus (99.99 %) and Escherichia coli (99.67 %) after 90 min of irradiation under daylight flashlight (14 ± 1 mW/cm2), along with good biological safety. Furthermore, after three cycles or 20 times of standard washing, the antibacterial rate remained above 80 % and 75 %, respectively. This dual-photosensitizers modification method for heterogeneous fibers provides a novel strategy for developing efficient, non-resistant, and color-tunable daylight-driven antimicrobial textiles in the fields of healthcare and personal protection.

Dual-Activatable Nano-Immunomodulator for NIR-II Fluorescence Imaging-Guided Precision Cancer Photodynamic Immunotherapy.

Photodynamic immunotherapy which combines photodynamic therapy with immunotherapy has become an important and effective method for the treatment of cancer. However, most cancer photodynamic immunotherapeutic systems are not able to achieve precise release of immunomodulators, resulting in systemic side effects and poor patient outcomes. Herein, a dual-activatable nano-immunomodulator (DIR NP), which both its photodynamic effect and agonist release can be activated under specific stimuli, is reported for precision cancer photodynamic immunotherapy. The DIR NP is self-assembled from an R848-conjugated amphiphilic polymer (mPEG-TK-R848) and a hydrophobic oxidized bovine serum albumin (BSA-SOH)-conjugatable photosensitizer (DIR). DIR NPs may generate a small amount of 1O2 under 808nm laser irradiation, leading to the cleavage of thioketal (TK) moiety and release of R848 and DIR. The released DIR may conjugate with tumor-overexpressed BSA-SOH, improving its photodynamic efficiency and NIR-II fluorescence signal. Such photodynamic efficiency improvement may further enhance the release of cargoes upon irradiation. The activated photodynamic effect induces immunogenic cell death (ICD) to release immune factors and R848 can enhance the maturation of dendritic cells for inhibiting the growth of both primary and distant tumors and eliminating lung metastasis. Therefore, this study provides a dual-activatable intelligent nano-immunomodulator for precise regulation of tumor photodynamic immunotherapy.

Photo-Triggered Fluorescence Polyelectrolyte Nanoassemblies: Manipulate and Boost Singlet Oxygen in Photodynamic Therapy.

Photodynamic therapy (PDT) is a clinically approved therapeutic modality that has shown great potential for cancer treatment. However, there exist two major problems hindering PDT applications: the nonspecific phototoxicity requiring patients to stay in dark post-PDT, and the limited photodynamic efficiency. Herein, we report a photo-triggered porphyrin polyelectrolyte nanoassembling (photo-triggered PPN) strategy, in which porphyrin photosensitizer and photoswitchable energy accepter are assembled into polyelectrolyte micelles by a combined force of charge interaction and metal-ligand coordination. The polyelectrolyte-based PPN exhibits good biocompatibility, and bestows a unique "confining isolated" inner microenvironment for fully overcoming the π-π stacking of porphyrins with significant photodynamic efficiency (123-fold enhancement). Due to the high Förster resonance energy transfer (FRET) (91.5 %) between porphyrin and photoswitch in closed-form, we could use light as a specific trigger to modulate photoswitch between closed- and open-form, and manipulate the 1O2 generation in three stages: pre-PDT (quenching 1O2 generation), during PDT (activating 1O2 generation), and post-PDT (silencing 1O2 generation). This de novo strategy has for the first time realized remotely manipulating and boosting 1O2 generation in PDT, well resolving the critical and general challenges of limited photodynamic efficiency and side effects from nonspecific phototoxicity.

Intracellularly manipulable aggregation of the aggregation-induced emission luminogens

Biophotonics has seen significant advancements with the development of optical imaging techniques facilitating the noninvasive detection of biologically relevant species. Aggregation-induced emission (AIE) materials have emerged as a novel class of luminogens exhibiting enhanced luminescence or photodynamic efficiency in the aggregated state, making them ideal for biomedical applications. The intracellularly controlled aggregation of aggregate-induced emission luminogens (AIEgens) enables high-resolution imaging of intracellular targets and diagnosis of related diseases, and enables disease therapy by exploiting the novel properties of aggregates. This review provides an in-depth analysis of the strategies employed to modulate the aggregation of AIEgens, focusing on the importance of molecular modifications to improve hydrophilicity and achieve precise control over the intercellular aggregation of AIEgens. Furthermore, the representative applications of AIEgens in bioimaging, such as enzyme activity monitoring, protein tracking, organelle function monitoring, and in vivo tumor-specific therapeutics, are reviewed. Additionally, we outline the challenges and future opportunities for AIE research, emphasizing the importance of the strategies for realizing the precisely controllable aggregation of AIEgens inside cells and the need for extending AIEgens’ absorption and emission wavelengths. This review aims to elucidate the rational development of responsive AIEgens for advanced biomedical applications.

Fabrication of albumin-Ti3C2 MXene quantum dots-based nanohybrids for breast cancer imaging and synergistic photo/chemotherapeutics

Advancement in the development of new materials with theranostic and phototherapeutic potential along with receptiveness to external stimuli has been persistently inspiring oncology research. Herein, titanium carbide-based MXene quantum dots (FHMQDs) have been synthesized and modified to take advantage of stimuli-responsive behavior and target specificity for breast cancer cells. With a size of around 3 nm, the developed FHMQDs demonstrate high fluorescent emission at around 460 nm. With ∼90 % encapsulation efficiency of doxorubicin (DOX), the developed system also offers rapid DOX release behavior when encountering an acidic pH (5.4). Further, the in vitro assessment of the developed FHMQDs on MDA-MB 231 breast cancer cells presents excellent target specificity to cancer cells which was reflected by its high cytotoxicity against cancer cells. Additionally, the outstanding photodynamic efficiency of FHMQDs due to excessive Reactive Oxygen Species (ROS) generating ability along with apoptosis promoting capability of FHMQDs in cancer cells demonstrates a synergistic approach in cancer theranostics. Encouragingly, the fabricated FHMQDs also exhibited fluorescent labelling and bioimaging capacity which makes it an incredible platform that ensures theranostic excellence in breast cancer research.

Multimodal integrated and broadband light-driven antibacterial cellulose fabric based on π-π coupling enhanced intermolecular FRET

Fabrication of antimicrobial photodynamic therapy (aPDT) materials based on organic photosensitizers has garnered considerable attention within functional textiles. However, the UV- or narrow-band absorption range of the photosensitizers results in poor photon utilization of the fabrics, limiting the photodynamic efficiency and wasting solar energy. In this study, a broadband light-driven antibacterial cellulose fabric (CF-ZnPc/NAD) was developed by loading carboxyl-modified zinc(II) phthalocyanine photosensitizer (CAZnPc) and cationic 1,8-naphthalimide fluorescent molecule (NAD) on the fabric via covalent binding and electrostatic adsorption assembly, facilitating the intermolecular π-π coupling and fluorescence resonance energy transfer (FRET) process. There is a 2.54-fold increase in photo-induced ROS generation capacity of CF-ZnPc/NAD via the FRET process compared to that of CF-ZnPc, and it also exhibited a strong photothermal effect (PTT), wherein the temperature of the fabric increased from 24.5 to 53.5 °C within 80 s of illumination (λ > 400 nm, 75 mW/cm2). CF-ZnPc/NAD exhibited strong light-harvesting capacity and a combination of aPDT and PTT, achieving excellent antibacterial performance against Staphylococcus aureus (Gram-positive, S. aureus) and Escherichia coli (Gram-negative, E.coli) with 99.99 % bacterial reduction under 90 min of illumination (λ > 400 nm, 10 ± 1 mW/cm2). This study demonstrates a novel and facile strategy for successfully fabricating high-performance antibacterial cellulose fabrics with potential biomedical prospects.

Cationic thiazolothiazole derivatives – A new class of photosensitizing agents against Staphylococcus aureus

The assessment of thiazolothiazoles (TzTz) as photosensitizers in photodynamic inactivation (PDI) experiments is reported for the first time. Mono and dicationic TzTz derivatives were synthesized, and their photosensitizing ability was assessed on Staphylococcus aureus cells, both in suspension or attached to a surface, and using white light. The biological results showed that the photodynamic efficiency of these derivatives is dependent on the TzTz structure and irradiation time. The best results were obtained with the monocationic derivative TPATzTzPyMe+ that allowed to reach a value over 7 log (99.9999 %) cell inactivation after white light irradiation for 30 min. Furthermore, TPATzTzPyMe+ also revealed to be effective on the inactivation of S. aureus adhered to surfaces, a good indication of its potential to prevent biofilm formation. TPATzTzPyMe+ was also effective against Escherichia coli, with a reduction in cell viability of 5.7 log after irradiation for 30 min.

Amphiphilic AIE Fluorescent Probe: A Dual-Functionality Strategy for Efficient Antibacterial Therapy Fluorescence Bioimaging against Staphylococcus aureus.

Drug-resistant bacteria present a grave threat to human health. Fluorescence imaging-guided photodynamic antibacterial therapy holds enormous potential as an innovative treatment in antibacterial therapy. However, the development of a fluorescent material with good water solubility, large Stokes shift, bacterial identification, and high photodynamic antibacterial efficiency remains challenging. In this study, we successfully synthesized an amphiphilic aggregation-induced emission (AIE) fluorescent probe referred to as NPTPA-QM. This probe possesses the ability to perform live-bacteria fluorescence imaging while also exhibiting antibacterial activity, specifically against Staphylococcus aureus (S. aureus). We demonstrate that NPTPA-QM can eliminate S. aureus at a very low concentration (2 μmol L-1). Moreover, it can effectively promote skin wound healing. Meanwhile, this NPTPA-QM exhibits an excellent imaging ability by simple mixing with S. aureus. In summary, this research presents a straightforward and highly effective method for creating "amphiphilic" AIE fluorescent probes with antibacterial properties. Additionally, it offers a rapid approach for imaging bacteria utilizing red emission.

Nanoencapsulation of a Far-Red Absorbing Phthalocyanine into Poly(benzylmalate) Biopolymers and Modulation of Their Photodynamic Efficiency.

Two different poly(benzylmalate) biopolymers, a hydrophobic non-PEGylated (PMLABe73) and an amphiphilic PEGylated derivative (PEG42-b-PMLABe73), have been used to encapsulate a phthalocyanine chosen for its substitution pattern that is highly suitable for photodynamic therapy. Different phthalocyanine/(co)polymers ratios have been used for the nanoprecipitation. A set of six nanoparticles has been obtained. If the amphiphilic PEGylated copolymer proved to be slightly more efficient for the encapsulation and to lower the aggregation of the phthalocyanine inside the nanoparticles, it is, however, the hydrophobic PMLABe73-based nanoparticles that exhibited the best photodynamic efficiency.

Beta cyclodextrin conjugated Au[sbnd]Fe3O4 Janus nanoparticles with enhanced chemo-photothermal therapy performance

The strategic integration of multi-functionalities within a singular nanoplatform has received growing attention for enhancing treatment efficacy, particularly in chemo-photothermal therapy. This study introduces a comprehensive concept of Janus nanoparticles (JNPs) composed of Au and Fe3O4 nanostructures intricately bonded with β-cyclodextrins (β-CD) to encapsulate 5-Fluorouracil (5-FU) and Ibuprofen (IBU). This strategic structure is engineered to exploit the synergistic effects of chemo-photothermal therapy, underscored by their exceptional biocompatibility and photothermal conversion efficiency (∼32.88 %). Furthermore, these β-CD-conjugated JNPs enhance photodynamic therapy by generating singlet oxygen (1O2) species, offering a multi-modality approach to cancer eradication. Computer simulation results were in good agreement with in vitro and in vivo assays. Through these studies, we were able to prove the improved tumor ablation ability of the drug-loaded β-CD-conjugated JNPs, without inducing adverse effects in tumor-bearing nude mice. The findings underscore a formidable tumor ablation potency of β-CD-conjugated Au-Fe3O4 JNPs, heralding a new era in achieving nuanced, highly effective, and side-effect-free cancer treatment modalities. Statement of significanceThe emergence of multifunctional nanoparticles marks a pivotal stride in cancer therapy research. This investigation unveils Janus nanoparticles (JNPs) amalgamating gold (Au), iron oxide (Fe3O4), and β-cyclodextrins (β-CD), encapsulating 5-Fluorouracil (5-FU) and Ibuprofen (IBU) for synergistic chemo-photothermal therapy. Demonstrating both biocompatibility and potent photothermal properties (∼32.88 %), these JNPs present a promising avenue for cancer treatment. Noteworthy is their heightened photodynamic efficiency and remarkable tumor ablation capabilities observed in vitro and in vivo, devoid of adverse effects. Furthermore, computational simulations validate their interactions with cancer cells, bolstering their utility as an emerging therapeutic modality. This endeavor pioneers a secure and efficacious strategy for cancer therapy, underscoring the significance of β-CD-conjugated Au-Fe3O4 JNPs as innovative nanoplatforms with profound implications for the advancement of cancer therapy.

Photosensitive AIEgens sensitize bacteria to oxidative damage and modulate the inflammatory responses of macrophages to salvage the photodynamic therapy against MRSA

The urgent need for antimicrobial agents to combat infections caused by multidrug-resistant bacteria facilitates the exploration of alternative strategies such as photosensitizer (PS)-mediated photoinactivation. However, increasing studies have discovered uncorrelated bactericidal activities among PSs possessing similar photodynamic and pathogen-targeted properties. To optimize the photodynamic therapy (PDT) against infections, we investigated three type-I PSs of D-π-A AIEgens TI, TBI, and TTI. The capacities of reactive oxygen species (ROS) generation of TI, TBI, and TTI did not align with their bactericidal activities. Despite exhibiting the lowest photodynamic efficiency, TI exhibited the highest activities against methicillin-resistant Staphylococcus aureus (MRSA) by impairing the anti-oxidative responses of bacteria. By comparison, TTI, characterized by the strongest ROS production, inactivated intracellular MRSA by potentiating the inflammatory response of macrophages. Unlike TI and TTI, TBI, despite possessing moderate photodynamic activities and inducing ROS accumulation in both MRSA and macrophages, did not exhibit any antibacterial activity. Therefore, relying on the disturbed anti-oxidative metabolism of pathogens or potentiated host immune responses, transient ROS bursts can effectively control bacterial infections. Our study reevaluates the contribution of photodynamic activities of PSs to bacterial elimination and provides new insights into discovering novel antibacterial targets and agents.

Highly Efficient Photodynamic Hydrogel with AIE-Active Photosensitizers toward Methicillin-Resistant Staphylococcus aureus Ultrafast Imaging and Killing.

Methicillin-resistant Staphylococcus aureus (MRSA) causes great health hazards to society because most antibiotics are ineffective. Photodynamic treatment (PDT) has been proposed to combat MRSA due to the advantage of imaging-guided no-drug resistance therapy. However, the traditional photosensitizers for PDT are limited by aggregation-caused quenching for imaging and low photodynamic antibacterial efficiency. In this work, we synthesize a new aggregation-induced emission (AIE) photosensitizer (APNO), which can ultrafast distinguish between Gram-positive and Gram-negative bacteria within 3 s by AIE-active photosensitizer imaging. Meanwhile, APNO can generate antibacterial reactive oxygen species under light irradiation, which holds potential for antibacterial PDT. Then, APNO is loaded by PHEAA hydrogel to obtain a highly efficient photodynamic hydrogel (APNO@gel). In vitro results show complete inhibition of MRSA by APNO@gel under lower-power light irradiation. Transcriptome analysis is performed to investigate antibacterial mechanism of APNO@gel. Most importantly, APNO@gel also exhibits significant inhibition and killing ability of MRSA in the MRSA wound infection model, which will further promote rapid wound healing. Therefore, the photodynamic hydrogel provides a promising strategy toward MRSA ultrafast imaging and killing.

Synthesis of a new Zn-phthalocyanine, photophysical, photochemical, and sono-photochemical properties and DFT studies

In recent years cancer has become a global problem and burden to the health system. Photodynamic therapy (PDT) and sonodynamic therapy (SDT) are promising alternatives for cancer treatment. It is very important to use phthalocyanines as sensitizers in such treatments. In this study, a new type of Zn-phthalocyanine compound (2) peripherally substituted with 4-Hydroxy-7-methoxyquinoline was synthesized and characterized, and its photodynamic and sono-photodynamic efficiencies were examined. Additionally, the electronic and spectroscopic properties of the compounds were calculated theoretically using Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) methods. The effect of the solvent on the reactivity of the compounds was examined by the Conductive-Like Polarizable Continuum Model (CPCM). The results have indicated that singlet oxygen quantum yield has increased in the sono-photochemical study (ΦΔ=0.98) compare to the photodynamic study (ΦΔ=0.70). Experimental and theoretical study results show that the reactivity of the new ligand increases with Zn metal.

Quantitative characterization of vascular targeted photodynamic therapy efficiency for port-wine stains using image processing techniques

SignificanceVascular targeted photodynamic therapy (V-PDT) is a clinically approved therapeutic approach for treating vascular-related diseases, such as port-wine stains (PWS). For accurate treatment, various light doses are required for different lesions due to the irregularity of vascular size, shape, degree of disease, which commonly alters during different stages of V-PDT, making quantitative analysis of treatment efficiency is highly needed. ApproachLesion images before and after V-PDT treatment of patients with PWS were used to construct a quantitative method to characterize the differences among lesions. Image analysis techniques were applied to calculate Euclidean distances and two-dimensional correlation coefficients for V-PDT efficiency evaluation. ResultsAccording to the image analysis, V-PDT with good treatment efficiency resulted in a larger Euclidean distance and a smaller correlation coefficient, in comparison with the case having lower V-PDT efficiency. ConclusionsThe new method to quantify the Euclidean distances and correlation coefficients is developed, which is promising for the quantitative analysis of V-PDT efficiency for PWS.

In vitro Proof of Concept of Photodynamic Therapy Efficiency in the Treatment of Glioblastoma

Significance5-ALA photodynamic therapy (5-ALA-PDT) could be a novel approach to treat glioblastoma. However, we observed an in vitro resistance of human glioblastoma cells to 5-ALA-PDT. ABCG2, a transporter responsible of the efflux of the photosensitizer protoporphyrine IX (PpIX) could be implied in this resistance. We aimed here to correlate PpIX accumulation and ABCG2 transporter expression with the efficacy of in vitro PDT on glioblastoma. ApproachFor each of 6 cell lines (4 glioblastomas, 2 controls), assessment of: cell death after PDT (Cell viability); PpIX metabolization and efflux (fluorometry); ABCG2 transporter transcriptomic expression (RTqPCR) and proteinic expression (Western-blot; flow cytometry); PpIX and ABCG2 transporter localization (Confocal microscopy). ResultsWe have observed different time and dose dependent PDT efficacy and PpIX metabolization regarding the different cell lines studied. ConclusionsThere is a correlation between intracellular PpIX, its efflux, and PDT efficacy. Our preliminary results need to be correlated with ABCG2 expression.

Rationally Designed Benzobisthiadiazole-Based Covalent Organic Framework for High-Performance NIR-II Fluorescence Imaging-Guided Photodynamic Therapy.

Although being applied as photosensitizers for photodynamic therapy, covalent organic frameworks (COFs) fail the precise fluorescence imaging in vivo and phototherapy in deep-tissue, due to short excitation/emission wavelengths. Herein, this work proposes the first example of NIR-II emissive and benzobisthiadiazole-based COF-980. Comparing to its ligands, the structure of COF-980 can more efficiently reducing the energy gap (ΔES1-T1) between the excited state and the triplet state to enhance photodynamic therapy efficiency. Importantly, COF-980 demonstrates high photostability, good anti-diffusion property, superior reactive oxygen species (ROS) generation efficiency, promising imaging ability, and ROS production in deep tissue (≈8mm). Surprisingly, COF-980 combined with laser irradiation could trigger larger amount of intracellular ROS to high efficiently induce cancer cell death. Notably, COF-980 NPs precisely enable PDT guided by NIR-II fluorescence imaging that effectively inhibit the 4T1 tumor growth with negligible adverse effects. This study provides a universal approach to developing long-wavelength emissive COFs and exploits its applications for biomedicine.

Thiophene Stability in Photodynamic Therapy: A Mathematical Model Approach.

Thiophene-containing photosensitizers are gaining recognition for their role in photodynamic therapy (PDT). However, the inherent reactivity of the thiophene moiety toward singlet oxygen threatens the stability and efficiency of these photosensitizers. This study presents a novel mathematical model capable of predicting the reactivity of thiophene toward singlet oxygen in PDT, using Conceptual Density Functional Theory (CDFT) and genetic programming. The research combines advanced computational methods, including various DFT techniques and symbolic regression, and is validated with experimental data. The findings underscore the capacity of the model to classify photosensitizers based on their photodynamic efficiency and safety, particularly noting that photosensitizers with a constant rate 1000 times lower than that of unmodified thiophene retain their photodynamic performance without substantial singlet oxygen quenching. Additionally, the research offers insights into the impact of electronic effects on thiophene reactivity. Finally, this study significantly advances thiophene-based photosensitizer design, paving the way for therapeutic agents that achieve a desirable balance between efficiency and safety in PDT.

Photodynamic inactivation of Listeria monocytogenes using a natural aggregation-induced emission photosensitizer and its application in salmon preservation

Photodynamic sterilization has been regarded as a promising alternative to conventional antibacterial approaches. However, the photodynamic efficiency of conventional photosensitizer is often compromised by aggregation-induced quenching effects. Photosensitizers, especially natural products, with aggregation-induced emission (AIE) properties open a new avenue for photodynamic sterilization. Herein, we investigated the photodynamic antibacterial performance and mechanism of the AIE-type natural product of berberine (BBR) against Listeria monocytogenes (L. monocytogenes). The bactericidal effect was assessed through the determination of minimum bactericidal concentration and implementation of anti-biofilm experiments. The results showed that BBR can significantly suppress the proliferation of L. monocytogenes and can efficiently remove the L. monocytogenes-derived biofilm in a concentration-dependent trend. The mechanism of killing L. monocytogenes has been speculated based on bacterial morphology characterization, viability staining results, enzyme activity assays, DNA electrophoresis analysis, and molecular docking. The excellent anti-bacterial activity of BBR mediated photodynamic process may account for its abilities to the irreversibly disruption of bacterial membrane, inhibition of intracellular enzyme activity and decomposition of intracellular DNA molecules. We also demonstrated that BBR embedded sodium alginate/chitosan packaging film is feasible to maintain the freshness of salmon under light illumination by inhibiting the bacterial proliferation.

Recyclable and Environmentally Friendly Magnetic Nanoparticles with Aggregation-Induced Emission Photosensitizer for Sustainable Bacterial Inactivation in Water.

Bacterial photodynamic inactivation based on the combined actions of photosensitizers, light, and oxygen presents a promising alternative for eliminating bacteria compared to conventional water disinfection methods. However, a significant challenge in this approach is the inability to retrieve photosensitizers after phototreatment, posing potential adverse environmental impacts. Additionally, conventional photosensitizers often exhibit limited photostability and photodynamic efficiency. This study addresses these challenges by employing an aggregation-induced emission (AIE) photosensitizer, iron oxide magnetic nanoparticles (Fe3O4 MNPs), and Pluronic F127 to fabricate AIE magnetic nanoparticles (AIE MNPs). AIE MNPs not only exhibit fluorescence imaging capabilities and superior photosensitizing ability but also demonstrate broad-spectrum bactericidal activities against both Gram-positive and Gram-negative bacteria. The controlled release of TPA-Py-PhMe and magnetic characteristics of the AIE MNPs facilitate reuse and recycling for multiple cycles of bacterial inactivation in water. Our findings contribute valuable insights into developing environmentally friendly disinfectants, emphasizing the full potential of AIE photosensitizers in photodynamic inactivation beyond biomedical applications.

Synthesis and photodynamic activity of novel thieno[3,2–b]thiophene fused BODIPYs with good bio-solubility and anti-aggregation effect

To discover new photosensitizers with long wavelength UV–visible absorption, high efficiency, and low side effects for photodynamic therapy, here, a series of novel thieno[3,2–b]thiophene-fused BODIPY derivatives were designed, synthesized and characterized. These compounds had a distinct absorption band at 640–680 nm, fluorescence emission at 650–760 nm, and good solubility with anti-aggregation effects. These new compounds possessed obvious singlet oxygen generation ability and photodynamic anti-Eca-109 cancer cells activities in vitro. Among them, compound II4 could be well uptaked by Eca-109 cells, and result in the apoptosis after laser irradiation, and have outstanding photodynamic efficiency both in vitro and in vivo. Therefore, II4 could be considered as a potential photosensitizer drug candidate for PDT and photo-imaging.