Photodynamic Therapy Activity Research Articles

A Metal‐Free Mesoporous Carbon Dots/Silica Hybrid Type I Photosensitizer with Enzyme‐Activity for Synergistic Treatment of Hypoxic Tumor

AbstractAs a less O2‐dependent photodynamic therapy (PDT), type I PDT is an effective approach to overcome the hypoxia‐induced low efficiency against solid tumors. However, the commonly used metal‐involved agents suffer from the long‐term biosafety concern. Herein, a metal‐free type I photosensitizer, N‐doped carbon dots/mesoporous silica nanoparticles (NCDs/MSN, ≈40 nm) nanohybrid with peroxidase (POD)‐like activity for synergistic PDT and enzyme‐activity treatment, is developed on gram scale via a facile one‐pot strategy through mixing carbon source and silica precursor with the assistance of template. Benefiting from the narrow bandgap (1.92 eV) and good charge separation capacity of NCDs/MSN, upon 640 nm light irradiation, the excited electrons in the conduction band can effectively generate O2•− by reduction of dissolved O2 via a one‐electron transfer process even under hypoxic conditions, inducing apoptosis of tumor cells. Moreover, the photoinduced O2•− can partially transform into more toxic •OH through a two‐electron reduction. Moreover, the POD‐like activity of NCDs/MSN can catalyze the endogenous H2O2 to •OH in the tumor microenvironment, further synergistically ablating 4T1 tumor cells. Therefore, a mass production way to synthesize a novel metal‐free type I photosensitizer with enzyme‐mimic activity for synergistic treatment of hypoxic tumors is provided, which exhibits promising clinical translation prospects.

Solvent Induced Conversion of a Self-Assembled Gyrobifastigium to a Barrel and Encapsulation of Zinc-Phthalocyanine within the Barrel for Enhanced Photodynamic Therapy.

A rare gyrobifastigium architecture (GB) was constructed by self-assembly of a tetradentate donor (L) with PdII acceptor in DMSO. The GB was converted to its isomeric tetragonal barrel (MB) upon treatment with water. The hydrophobic cavity of MB has been explored for the encapsulation of zinc-phthalocyanine (ZnPc), which is an excellent photosensitizer for photodynamic therapy (PDT). However, the poor water-solubility and aggregation tendency are the main reasons for the suboptimal PDT performance of free ZnPc in the aqueous medium. Effective solubilization of ZnPc in an aqueous medium was achieved by encapsulating it in the cavity of MB. The inclusion complex (ZnPc⊂MB) showed enhanced singlet oxygen generation in water. Higher cellular uptake and anticancer activity of the ZnPc⊂MB compared to free ZnPc on HeLa cells indicate that encapsulation of ZnPc in an aqueous host is a potential strategy for enhancement of its PDT activity in water.

Solvent Induced Conversion of a Self‐Assembled Gyrobifastigium to a Barrel and Encapsulation of Zinc‐Phthalocyanine within the Barrel for Enhanced Photodynamic Therapy

AbstractA rare gyrobifastigium architecture (GB) was constructed by self‐assembly of a tetradentate donor (L) with PdII acceptor in DMSO. The GB was converted to its isomeric tetragonal barrel (MB) upon treatment with water. The hydrophobic cavity of MB has been explored for the encapsulation of zinc‐phthalocyanine (ZnPc), which is an excellent photosensitizer for photodynamic therapy (PDT). However, the poor water‐solubility and aggregation tendency are the main reasons for the suboptimal PDT performance of free ZnPc in the aqueous medium. Effective solubilization of ZnPc in an aqueous medium was achieved by encapsulating it in the cavity of MB. The inclusion complex (ZnPc⊂MB) showed enhanced singlet oxygen generation in water. Higher cellular uptake and anticancer activity of the ZnPc⊂MB compared to free ZnPc on HeLa cells indicate that encapsulation of ZnPc in an aqueous host is a potential strategy for enhancement of its PDT activity in water.

Comparison of the anti-cancer activity of 5-aminolevulinic acid-mediated photodynamic therapy after continuous wave and pulse irradiation in different histological types of canine mammary sarcoma tumors.

Canine mammary sarcoma tumors (CMST) are the most aggressive tumors with poor prognosis in dogs. Due to inadequate treatment options for CMST, recent studies have focused on alternative treatment strategies. We previously determined the optimized protocol of 5-ALA-based photodynamic therapy (PDT) in canine liposarcoma. However, its molecular mechanisms in the treatment of different histological types of CMST remain unclear.In this context, we, for the first time, assessed 5-aminolevulinic acid (5-ALA)-PDT-mediated anti-cancer activity and its molecular mechanism after continuous wave (CW) and pulse radiation (PR) on three different histological types (liposarcoma, chondrosarcoma, and osteosarcoma) of CMST cells by WST-1, Annexin V, ROS, acridine orange/propidium iodide staining, RT-PCR, and western blot analysis.Our findings showed that 5-ALA/PDT significantly suppressed the proliferation of CMST cells (p < 0.01) and induced apoptosis via increased ROS level and overexpression of Caspase-9 and Caspase-3 mRNA and cleaved protein levels in especially liposarcoma and chondrosarcoma cells following CW and PR irradiation at 9J/cm2. However, the response of CMST cells to 5-ALA was different upon CW and PR irradiation due to differences in their origin.Collectively, our findings provided the first evidence that 5-ALA-based PDT could be used as an alternative treatment strategy, especially liposarcoma and chondrosarcoma. However, further in vitro and in vivo studies are required to elucidate the underlying molecular mechanism of the efficacy of 5-ALA in CMST cells at the molecular level.

Comparison of sonodynamic, photodynamic and sonophotodynamic therapy activity of fluorinated pyridine substituted silicon phthalocyanines on PC3 prostate cancer cell line

BackgroundSonophotodynamic therapy (SPDT), a combination of photodynamic therapy (PDT) and sonodynamic therapy (SDT), may offer theraputic advantage. The therapeutic effects of sonodynamic, photodynamic, and sonophotodynamic of 5-(trifluoromethyl)-2-thiopyridine substituted silicon phthalocyanine (gy3) and its quaternized derivative (gy3q) were examined in vitro on prostate cancer using PC3 cells. MethodsThe SDT, PDT and SPDT efficiency was determined by using MTT test.Apoptosis mechanism was evaluated by HOPI staining. Results and DiscussionsAccording to MTT results, the phthalocyanines decreased cell viability when compared with a control group. Also, apoptosis measurement data represents that the phthalocyanines would produce much better therapeutic outcomes compare to PDT and SDT by utilizing SPDT. Further studies should be performed to understand the effectiveness of SPDT.

Action of Photodynamic Therapy at Low Fluence in 9 L/lacZ Cells after Interaction with Chlorins

Gliosarcoma (GS) is a primary malignant neoplasm of the central nervous system, treated with an unfavorable prognosis with surgery, radiotherapy, and chemotherapy. The treatment for GS consists of surgical resection, almost always accompanied by radiotherapy and/or chemotherapy, given the invasive behavior of the tumor. Photodynamic Therapy (PDT) is studied as an alternative method that combines light, a photosensitizer (PS), and molecular oxygen. This study aimed to compare the effects of PDT using the photosensitizers Fotoenticine (FTC) and Photodithazine (PDZ) at low concentrations and fluences. For this study, 9 L/lacZ cells, concentrations of 1.55 µg mL−1, 12.5 µg mL−1, and 50 µg mL−1 of chlorins and fluences of 1, 5, and 10 J/cm2 were used. A test was also carried out with Trypan Blue in L929 cells at the mentioned concentrations at 5 J/cm2. Both chlorins were internalized in the cytoplasm, with a significant reduction in viability (&gt;95%) in almost all groups and altered cell adhesion and morphology after PDT. HSP70 expression decreased in both PS, while HSP27 increased only in PDT with FTC, and although there was a change in cell adhesion in the 9 L/LacZ lineage it was not observed in the L929 fibroblast lineage. Both chlorins were effective, highlighting the concentration of 50 µg mL−1 at the fluence of 5 J/cm2; according to the present study, the PDZ showed better results.

A versatile NiS2/FeS2 hybrid nanocrystal for synergistic cancer therapy by inducing ferroptosis and pyroptosis

Due to the heterogeneous and complex tumor microenvironment (TME), it remains challenging to effectively treat solid tumors with monotherapy. The development of a versatile nanomaterial strategy for synergistic chemodynamic/photodynamic/photothermal therapies has the potential to overcome this challenge. Herein, we designed and synthesized NiS2/FeS2 hybrid nanoparticles (NiS2/FeS2 NPs), which are further modified with polyvinyl pyrrolidone (PVP) to improve their biocompatibility. PVP-NiS2/FeS2 NPs exhibit synergistic activities of chemodynamic therapy (CDT), photodynamic therapy (PDT), and photothermal therapy (PTT) with multimodal imaging capabilities. With the presence of Fe2+/Fe3+ and Ni2+/Ni3+ redox couples, the PVP-NiS2/FeS2 NPs exhibit GSH peroxidase-like reactivity and trigger Fenton reaction, leading to robust ·OH generation and pyroptosis/ferroptosis after near infared irradiation (NIR). In response to the PVP-NiS2/FeS2 NPs and PVP-NiS2/FeS2 NPs + NIR treatment, the breast tumors formed in the syngeneic BABL/c mice were eliminated and their metastases suppressed by inhibiting the EMT pathway. Consistent with the apparent involvement of these programmed cell death pathways in activating tumor immunity, we demonstrate that PVP-NiS2/FeS2 NPs + NIR can eliminate metastatic tumors in an immune system dependent manner. Therefore, PVP-NiS2/FeS2 NPs represent a promising strategy to treat metastatic breast cancer.

Comparative evaluation of the antimicrobial efficacy of nanoparticle-mediated photodynamic therapy versus photodynamic therapy and conventional disinfection in endodontics: A systematic review and meta-analysis.

The aim of this systematic review was to assess the antimicrobial activity of nanoparticle-mediated photodynamic therapy (N-PDT) on Enterococcus faecalis biofilms in the presence of dentin substrate when compared to photodynamic therapy (PDT) and conventional disinfection protocols. This systematic review was registered in Open Science Framework (10.17605/OSF.IO/GBR3F). Six databases, namely PubMed, Embase, Web of Science, Scopus, Medline, and Google Scholar, were searched for English language articles until June 2022. Laboratory studies assessing the antimicrobial activity of N-PDT against E. faecalis biofilm in human or bovine teeth were included. The risk of bias (RoB) was evaluated using the Joanna Briggs Institute tool for quasi-experimental studies. Meta-analysis was performed using the random-effects maximum likelihood model. The search revealed 2804 articles, out of which 9 studies were included in the final review. Seven articles had low RoB and two had moderate RoB. Chitosan and diode laser at 810 nm were the most commonly used nanoparticle and light source, respectively. The meta-analysis of bacterial reduction log and percentage reduction revealed that N-PDT had better antimicrobial efficacy than the control group. When the bacterial reduction log of N-PDT was compared with PDT, PDT performed better N-PDT, and for percentage reduction, there was no difference. The currently available evidence is low and inconclusive with regard to the superior efficacy of N-PDT. The type of nanoparticle, incubation time, light source, and exposure time were found to be covariates that influence the antimicrobial efficacy of N-PDT.

An Overview of Potential Natural Photosensitizers in Cancer Photodynamic Therapy.

Cancer is one of the main causes of death worldwide. There are several different types of cancer recognized thus far, which can be treated by different approaches including surgery, radiotherapy, chemotherapy or a combination thereof. However, these approaches have certain drawbacks and limitations. Photodynamic therapy (PDT) is regarded as an alternative noninvasive approach for cancer treatment based on the generation of toxic oxygen (known as reactive oxygen species (ROS)) at the treatment site. PDT requires photoactivation by a photosensitizer (PS) at a specific wavelength (λ) of light in the vicinity of molecular oxygen (singlet oxygen). The cell death mechanisms adopted in PDT upon PS photoactivation are necrosis, apoptosis and stimulation of the immune system. Over the past few decades, the use of natural compounds as a photoactive agent for the selective eradication of neoplastic lesions has attracted researchers' attention. Many reviews have focused on the PS cell death mode of action and photonanomedicine approaches for PDT, while limited attention has been paid to the photoactivation of phytocompounds. Photoactivation is ever-present in nature and also found in natural plant compounds. The availability of various laser light setups can play a vital role in the discovery of photoactive phytocompounds that can be used as a natural PS. Exploring phytocompounds for their photoactive properties could reveal novel natural compounds that can be used as a PS in future pharmaceutical research. In this review, we highlight the current research regarding several photoactive phytocompound classes (furanocoumarins, alkaloids, poly-acetylenes and thiophenes, curcumins, flavonoids, anthraquinones, and natural extracts) and their photoactive potential to encourage researchers to focus on studies of natural agents and their use as a potent PS to enhance the efficiency of PDT.

In VitroPhotodynamic Activities of Amphiphilic Phthalocyanine‐Amino Appendedβ‐Cyclodextrin Conjugates as Efficient Schiff Base Photosensitizer

AbstractWater‐soluble phthalocyanine has been considered as a potential photosensitizer for photodynamic therapy (PDT) applications. To achieve the best efficiency of phthalocyanine in PDT, amphiphilic zinc phthalocyanine was purposely designed and synthesized by conjugation withβ‐cyclodextrin. Herein, we synthesized two novel zinc phthalocyanine derivatives connected toβ‐cyclodextrin moieties through covalent Schiff base linkage (TFP‐ZnPc/AβCD). In this procedure, aldehyde substituted phthalocyanine and amino‐appendedβ‐cyclodextrins with different length amino side chains were used. The compounds were characterized using FT‐IR,1H NMR, MALDI‐TOF, and UV‐vis. The newly designed photosensitizers did not self‐assemble in water and generated significant singlet oxygenvia1,3‐DPBF (1,3‐diphenylisobenzofuran) bleaching. Simultaneously, longer amino side chains increase1O2production efficiency. The PDT activity of the new TFP‐ZnPc/AβCD complexes was then examined on human breast cancer (MDA‐MB‐231) and fibroblast cells.In vitroresults show that PDT is more effective against cancer cells than normal cells. The new TFP‐ZnPc/AβCD could be an effective PDT drug.

Polymer theranostics with multiple stimuli-based activation of photodynamic therapy and tumor imaging.

Background: Efficient theranostic strategies concurrently bring and use both the therapeutic and diagnostic features, serving as a cutting-edge tool to combat advanced cancers. Goals of the Investigation: Here, we develop stimuli-sensitive theranostics consisting of tailored copolymers forming micellar conjugates carrying pyropheophorbide-a (PyF) attached by pH-sensitive hydrazone bonds, thus enabling the tumor microenvironment-sensitive activation of the photodynamic therapy (PDT) effect, fluorescence or phosphorescence. Results: The nanomedicines show superior anti-tumor PDT efficacy and huge tumor-imaging potential, while reducing their accumulation, and potentially side effects, in the liver and spleen. The developed theranostics exhibit clear selective tumor accumulation at high levels in the mouse sarcoma S180 tumor model with almost no PyF found in the healthy tissues after 48 h. Once in the tumor, illumination at λexc = 420 nm reaches the therapeutic effect due to the 1O2 generation. Indeed, an almost complete inhibition of tumor growth is observed up to 18 days after the treatment. Conclusion: The clear benefit of the specific PyF release and activation in the acidic tumor environment for the targeted delivery and tissue distribution dynamics was proved. Conjugates carrying pyropheophorbide-a (PyF) attached by pH-sensitive hydrazone bonds showed their excellent antitumor PDT effect and its applicability as advanced theranostics at very low dose of PyF.

Glycerol group substituted bis(2-pyridylimino)isoindoline (BPI) complexes: synthesis, characterization and investigation of their biological properties.

In this study, a glycerol group substituted bis(2-pyridylamino)isoindoline (BPI-OH) ligand and its metal complexes (M = Pt, Cu and Co) were synthesized. Characterization of all new compounds was carried out using FT-IR, NMR, UV-Vis, and mass spectroscopy. Various biological activities of BPI derivatives were also tested. The antioxidant activities of BPI-OH, Pt-BPI-OH, Cu-BPI-OH, and Co-BPI-OH were 87.52 ± 4.62%, 98.05 ± 5.61%, 92.20 ± 5.12%, and 89.27 ± 4.74%, at 200 mg L-1 concentration respectively. BPI derivatives displayed perfect DNA cleavage activity and plasmid DNA was completely broken at all tested concentrations. The antimicrobial and antimicrobial photodynamic therapy (APDT) activities of the compounds were investigated and BPI derivatives showed good APDT. E. coli cell viability was inhibited at 125 and 250 mg L-1. BPI-OH, Pt-BPI-OH, Cu-BPI-OH, and Co-BPI-OH also successfully inhibited the biofilm formation of S. aureus and P. aeruginosa. Furthermore, the antidiabetic activity of BPI derivatives was studied. This study also evaluates the binding affinities of four compounds (BPI-OH, Pt-BPI-OH, Cu-BPI-OH, and Co-BPI-OH) to various residues of DNA using hydrogen bond distance measurements and binding energies. The results show that the BPI-OH compound forms hydrogen bonds with residues in the major groove of DNA, while BPI-Pt-OH, BPI-Cu-OH, and BPI-Co-OH compounds form hydrogen bonds with residues in the minor groove. The hydrogen bond distances for each compound range from 1.75 to 2.2 Angstroms.

Construction of mPt/ICG-αA nanoparticles with enhanced phototherapeutic activities for multidrug-resistant bacterial eradication and wound healing.

The emergence of multidrug-resistant (MDR) bacterial infections calls for novel strategies for effective bacterial inhibition and wound healing. Phototherapeutic approaches are promising in treating bacterial infection because of their high efficiency, noninvasiveness, and few side effects; however, their antibacterial effect is limited by the formation of biofilms in wounds. Herein, we report novel composite nanoparticles (mPt/ICG-αA NPs) combining mesoporous platinum (mPt) nanoparticles, indocyanine green (ICG) and α-amylase (αA) for combating MDR bacteria and treating wound infection, which integrates a triple bacterial inhibition mechanism arising from the combination of photodynamic therapy (PDT), photothermal therapy (PTT) and α-amylase enzymatic activities. The combination of mPt and ICG significantly enhances the effect of PTT and the temperature can be increased up to 80.8 °C to induce efficacious bacterial degeneration. Meanwhile, mPt/ICG-αA (mPIA) NPs with a low concentration of 25 μg mL-1 exhibited a remarkable catalase activity (CAT) and could continuously decompose endogenous H2O2 into O2 in a hypoxic microenvironment, thereby enhancing the PDT effect to achieve broad-spectrum bactericidal activity. mPIA NPs showed excellent MDR antibacterial efficiency against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli), and the bactericidal rate reached up to 99.0% and 97.2% with single 808 nm near-infrared light irradiation, respectively. mPIA NPs also exhibited an excellent ability to destroy biofilms and biocompatibility. Animal experiments further suggested that mPIA NPs could achieve the successful repairment of wounds infected with S. aureus in living systems, while this platform demonstrated negligible toxicity towards mice. Considering the superior performances of mPIA NPs, the synergistic αA-CAT-PDT-PTT boosted therapeutic activity presented in the current work provides a promising method to effectively fight against biofilm-related infectious diseases and wound healing.

Biotin and boron-dipyrromethene-tagged platinum(IV) prodrug for cellular imaging and mito-targeted photocytotoxicity in red light.

A platinum(IV) prodrug, cis,cis,trans-[Pt(NH3)2Cl2(biotin)(L)] (1), derived from cisplatin, where HL is the PEGylated red-light active boron-dipyrromethene (BODIPY) ligand, was synthesized, characterized and its photocytotoxicity evaluated. The complex showed a near-IR absorption band at 653 nm (ε ∼9.19 × 104 M-1 cm-1) in dimethyl sulfoxide and Dulbecco's phosphate-buffered saline (1 : 1 v/v) at pH 7.2. When excited at 630 nm, it showed an emission band at 677 nm in DMSO with a fluorescence quantum yield of 0.13. The 1,3-diphenylisobenzofuran titration experiment gave a singlet oxygen quantum yield (ΦΔ) of ∼0.32. A mechanistic DNA photocleavage study revealed singlet oxygen as the reactive oxygen species (ROS). The complex with biotin and PEGylated-distyryl-BODIPY showed significantly higher cellular uptake in A549 cancer cells as compared to non-cancerous Beas-2B cells from flow cytometry, indicating selectivity towards cancer cells. A dichlorodihydrofluorescein diacetate assay showed cellular ROS generation. Confocal images revealed predominant internalization in the mitochondria. The prodrug showed remarkable photodynamic therapy (PDT) activity in cancerous A549 and multidrug-resistant MDA-MB-231 cells with a high photocytotoxicity index value (half-maximal inhibitory concentration (IC50): 0.61-1.54 μM in red light), while being non-toxic in the dark. The chemo-PDT activity was significantly less in non-tumorigenic lung epithelial cells (Beas-2B). The prodrug effectively triggered cellular apoptosis, which was confirmed by the Annexin V-FITC/propidium iodide assay, and the alteration of the mitochondrial membrane potential was substantiated by the JC-1 dye assay. The β-tubulin immunofluorescence assay confirmed that incubating the cells with a light-treated complex resulted in the rapture of the cytoskeletal structure and the formation of apoptotic bodies. The results demonstrate that the prodrug triggered apoptosis via DNA damage, a reduction in mitochondrial function and disruption of the cytoskeletal framework.

Sn(IV)-porphyrinoids for photodynamic anticancer and antimicrobial chemotherapy.

Photodynamic therapy (PDT) is a mode of treatment for different types of cancers, which involves a nontoxic photosensitizer (PS), a light source to activate the PS, and ground-state molecular oxygen (3O2). Light activation of the PS leads to the generation of reactive oxygen species (ROS), which initiates a toxic effect on the surrounding cellular substrates, thereby destroying the cancerous cells. The commercially used PDT drug Photofrin® which is a tetrapyrrolic porphyrin-based photosensitizer has drawbacks such as aggregation in water, prolonged skin photosensitivity, variability in chemical compositions, and minimal absorbance in the red-light region. Metallation of the porphyrin core with diamagnetic metal ions aids the photogeneration of singlet oxygen (ROS). Metalating with Sn(IV) provides a six-coordination octahedral geometry with trans-diaxial ligands. This approach suppresses aggregation in aqueous media and increases ROS generation upon light exposure due to the heavy atom effect. Bulky trans-diaxial ligation hinders the approach of the Sn(IV) porphyrins, thereby suppressing aggregation effects. In this review, we document the recently reported Sn(IV) porphyrinoids and their photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties. In a similar manner to PDT, the photosensitizer is used to kill the bacteria upon irradiation with light during PACT. Often, bacteria develop resistance against conventional chemotherapeutic drugs over time, decreasing their antibacterial properties. However, in the case of PACT, it is difficult to generate resistance against singlet oxygen produced by the photosensitizer.

Bromo- and glycosyl-substituted BODIPYs for application in photodynamic therapy and imaging.

The introduction of heavy atoms into the BODIPY-core structure has proven to be a straightforward strategy for optimizing the design of such dyes towards enhanced generation of singlet oxygen rendering them suitable as photosensitizers for photodynamic therapy (PDT). In this work, BODIPYs are presented by combining the concept of bromination with nucleophilic aromatic substitution (SNAr) of a pentafluorophenyl or a 4-fluoro-3-nitrophenyl moiety to introduce functional groups, thus improving the phototoxic effect of the BODIPYs as well as their solubility in the biological environment. The nucleophilic substitution enabled functionalization with various amines and alcohols as well as unprotected thiocarbohydrates. The phototoxic activity of these more than 50 BODIPYs has been assessed in cellular assays against four cancer cell lines in order to more broadly evaluate their PDT potential, thus accounting for the known variability between cell lines with respect to PDT activity. In these investigations, dibrominated polar-substituted BODIPYs, particularly dibrominated glyco-substituted compounds, showed promising potential as photomedicine candidates. Furthermore, the cellular uptake of the glycosylated BODIPYs has been confirmed via fluorescence microscopy.

Green synthesis of iron oxide nanoparticles derived from water and methanol extract of Centaurea solstitialis leaves and tested for antimicrobial activity and dye decolorization capability

In this research, nanoparticles derived from water extract of Centaurea solstitialis leaves were used as green adsorbent in Fenton reaction for Reactive Red 180 (RR180) and Basic Red 18 (BR18) dyes removal. At optimum operating conditions, nanoparticles proved high performance in the tested dyes removal with more than 98% of removal elimination. The free-radical scavenging, DNA nuclease, biofilm inhibition capability, antimicrobial activity, microbial cell viability, and antimicrobial photodynamic therapy activities of the iron oxide nanoparticles (FeO-NPs) derived from water and methanol extract of plant were investigated. Each of the following analysis: SEM-EDX, XRD, and Zeta potential was implemented for the prepared NPs characterization and to describe their morphology, composition and its behavior in an aqueous solution, respectively. It was found that, the DPPH scavenging activities increased when the amount of nanoparticles increased. The highest radical scavenging activity achieved with FeO-NPs derived from water extract of plant as 97.41% at 200 mg/L. The new green synthesized FeO-NPs demonstrated good DNA cleavage activity. FeO-NPs showed good in vitro antimicrobial activities against human pathogens. The results showed that both synthesized FeO-NPs displayed 100% antimicrobial photodynamic therapy activity after LED irradiation. The water extract of FeO-NPs and methanol extract of FeO-NPs also showed a significant biofilm inhibition.

Photodynamic Inactivation of Bacteria and Biofilms with Benzoselenadiazole-Doped Metal-Organic Frameworks.

Bacterial biofilms are difficult to treat due to their resistance to traditional antibiotics. Although photodynamic therapy (PDT) has made significant progress in biomedical applications, most photosensitizers have poor water solubility and can thus aggregate in hydrophilic environments, leading to the quenching of photosensitizing activity in PDT. Herein, a benzoselenadiazole-containing ligand was designed and synthesized to construct the zirconium (IV)-based benzoselenadiazole-doped metal-organic framework (Se-MOF). Characterizations revealed that Se-MOF is a type of UiO-68 topological framework with regular crystallinity and high porosity. Compared to the MOF without benzoselenadiazole, Se-MOF exhibited a higher 1O2 generation efficacy and could effectively kill Staphylococcus aureus bacteria under visible-light irradiation. Importantly, in vitro biofilm experiments confirmed that Se-MOF could efficiently inhibit the formation of bacteria biofilms upon visible-light exposure. This study provides a promising strategy for developing MOF-based PDT agents, facilitating their transformation into clinical photodynamic antibacterial applications.

Carbon Dots Derived from Tea Polyphenols as Photosensitizers for Photodynamic Therapy

Photodynamic therapy (PDT) has become an emerging cancer treatment method. Choosing the photosensitizer (PS) compounds is one of the essential factors that can influence the PDT effect and action. Carbon dots (CDs) have shown great potential as photosensitizers in PDT of cancers due to their excellent biocompatibility and high generation of reactive oxygen species (ROS). Here, we used tea polyphenol as raw material for synthesized tea polyphenol carbon dots (T-CDs) that show dual emission bands of red and blue fluorescence and can efficiently generate hydroxyl radicals (OH) under mildly visible irradiation with a LED light (400-500 nm, 15 mW cm-2). The extremely low cytotoxicity and excellent biocompatibility of T-CDs without light irradiation were tested using MTT and hemolytic assay. Further, T-CDs have been shown by in vivo experiments, using a mouse breast cancer cell line (4T1) subcutaneously injected in the back of the mouse buttock as a model, to effectively inhibit the tumor cell proliferation in solid tumors and show an excellent PDT effect. In addition, pathological sections of the mice tissues after further treatment showed that the T-CDs had no apparent impact on the major organs of the mice and did not produce any side effect lesions. This work demonstrates that the as-synthesized T-CDs has the potential to be used as a PS in cancer treatment.

Nanotherapeutic Intervention in Photodynamic Therapy for Cancer.

The clinical need for photodynamic therapy (PDT) has been growing for several decades. Notably, PDT is often used in oncology to treat a variety of tumors since it is a low-risk therapy with excellent selectivity, does not conflict with other therapies, and may be repeated as necessary. The mechanism of action of PDT is the photoactivation of a particular photosensitizer (PS) in a tumor microenvironment in the presence of oxygen. During PDT, cancer cells produce singlet oxygen (1O2) and reactive oxygen species (ROS) upon activation of PSs by irradiation, which efficiently kills the tumor. However, PDT's effectiveness in curing a deep-seated malignancy is constrained by three key reasons: a tumor's inadequate PS accumulation in tumor tissues, a hypoxic core with low oxygen content in solid tumors, and limited depth of light penetration. PDTs are therefore restricted to the management of thin and superficial cancers. With the development of nanotechnology, PDT's ability to penetrate deep tumor tissues and exert desired therapeutic effects has become a reality. However, further advancement in this field of research is necessary to address the challenges with PDT and ameliorate the therapeutic outcome. This review presents an overview of PSs, the mechanism of loading of PSs, nanomedicine-based solutions for enhancing PDT, and their biological applications including chemodynamic therapy, chemo-photodynamic therapy, PDT-electroporation, photodynamic-photothermal (PDT-PTT) therapy, and PDT-immunotherapy. Furthermore, the review discusses the mechanism of ROS generation in PDT advantages and challenges of PSs in PDT.