Photodynamic Therapy for Inflammatory and Cancerous Diseases of the Intestines: Molecular Mechanisms and Prospects for Application

Biochanin A mitigates colitis by inhibiting ferroptosis-mediated intestinal barrier dysfunction, oxidative stress, and inflammation via the JAK2/STAT3 signaling pathway

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory bowel disease marked by intestinal barrier dysfunction, oxidative stress, and inflammation. Biochanin A (BCA) is a natural flavonoid found in various plants, known for its anti-inflammatory, antioxidant, and anticancer properties, while its therapeutic role in UC and potential mechanism remains unexplored.

PURPOSE

To explores the therapeutic potential of BCA in alleviating UC, focusing on its effects on ferroptosis and the JAK2/STAT3 signaling pathway.

METHODS

The BCA's therapeutic effects on Dextran sulfate sodium (DSS)-induced colitis model in C57BL/6J mice was investigated. Subsequently, a comprehensive range of techniques was performed to investigate the impact of BCA on intestinal barrier integrity, oxidative stress, inflammation. Besides, the RNA sequencing was performed to explore the potential mechanism. The role of ferroptosis inhibition in BCA's effects in vitro and in vivo was explored by co-treating with the ferroptosis activator Erastin.

RESULTS

Treatment of colitis mice with BCA significantly improved DAI scores and histopathological damage scores, reduced oxidative stress, enhanced intestinal barrier function, and suppress inflammatory responses. RNA sequencing result found that BCA could lead to the inhibition of ferroptosis in mice colon tissue. Moreover, erastin co-treatment negated BCA's effects in vitro and vivo. Mechanistically, BCA exerts these effects by suppressing the JAK2/STAT3 pathway, which plays a pivotal role in ferroptosis and inflammation. Molecular docking studies further confirm the direct binding of BCA to both GPX4 and STAT3.

CONCLUSION

These results establish BCA as a promising natural compound for UC treatment, offering a novel therapeutic strategy by specifically targeting ferroptosis and its associated molecular pathways, thereby addressing key gaps in current UC management and advancing potential clinical applications.

Hypoxia-responsive oncolytic conjugate triggers type-II immunogenic cell death for enhanced photodynamic immunotherapy

Immunogenic cell death (ICD) induced by photodynamic therapy (PDT) holds great promise for enhancing anti-tumor immunotherapy; however, its clinical efficacy is often hampered by suboptimal ICD induction and the exacerbation of an immunosuppressive tumor microenvironment (TME) following PDT. Herein, we present a tumor-targeted and hypoxia-responsive peptide-photosensitizer conjugate, A6-dMP-VP, which integrates an oncolytic peptide (dMP) with a CD44-targeting motif (A6), hypoxia-responsive groups, and the photosensitizer verteporfin (VP). Following systemic administration, A6-dMP-VP preferentially accumulates in 4T1 tumors, where the hypoxic TME triggers its response. Remarkably, the combined oncolytic activity and PDT effect of A6-dMP-VP effectively induce type-II ICD via mitochondrial disruption and endoplasmic reticulum stress, leading to robust antigen release. This process significantly enhances dendritic cell maturation and cytotoxic T cell priming, ultimately achieving potent suppression of both primary and metastatic tumors. Our findings establish A6-dMP-VP as a highly effective type-II ICD inducer, offering a novel strategy to overcome the limitations of PDT and advance photodynamic-oncolytic immunotherapy.

Synthesis of porphyrin-formononetin derivatives and their anti-tumor activity studies

Photodynamic therapy (PDT) has received much attention in cancer treatment because of its low toxicity and side effects. In this study, we successfully synthesized 14 novel porphyrin-formononetin derivatives. In reactive oxygen species detection experiments, the target compounds 4a-6d caused a significant decrease in the fluorescence intensity of DPBF compared with the porphyrin parent and formononetin feedstock after illumination, and it was found that the target compound had a higher ROS quantum yield, among which the quantum yield of compound 6c was higher. In the in vitro anti-tumor activity assay, the target compounds 4a-6d exhibited a certain degree of growth inhibition against six cancer cells (A549, MDA-MB-231, HCT-116, HGC-27, DU145, and TCCSUP) under light conditions, whereas the cytotoxicity of the target compounds against the normal cells H9c2 was less. The results of the scratch assay showed that 6c could inhibit the growth of tumor cells by inhibiting the migration of DU145 cells. The experimental results indicate that the target compounds achieve the synergistic effect of PDT and chemotherapy.

Ce6-GFFY is a novel photosensitizer for colorectal cancer therapy

Photodynamic therapy is an "old" strategy for cancer therapy featuring clinical safety and rapid working, but suitable photosensitizers for colorectal cancer therapy remain lacking. This study synthesized a novel photosensitizer termed Ce6-GFFY based on a self-assembling peptide GFFY and a photo-responsive molecule chlorin e6 (Ce6). Ce6-GFFY forms macroparticles with a diameter of ∼160 nm and possesses a half-life of 10 h, as well as an ideal tumor-targeting ability in mouse models. Ce6-GFFY effectively penetrates cells and generates numerous reactive oxygen species upon 660 nm laser irradiation. The reactive oxygen species promotes the accumulation of cytotoxic T cells and decrease of myeloid-derived suppressor cells in the tumor microenvironment through immunogenic cell death, thus prohibiting the growth of both primary and metastatic tumors after once treatment. This study not only provides a strategy for photosensitizer development but also confirms a promising application of Ce6-GFFY for colorectal cancer therapy.

Cell-Penetrating Peptide Like Anti-Programmed Cell Death-Ligand 1 Peptide Conjugate-Based Self-Assembled Nanoparticles for Immunogenic Photodynamic Therapy

The tumor-specific efficacy of the most current anticancer therapeutic agents, including antibody-drug conjugates (ADCs), oligonucleotides, and photosensitizers, is constrained by limitations such as poor cell penetration and low drug delivery. In this study, we addressed these challenges by developing, a positively charged, amphiphilic Chlorin e6 (Ce6)-conjugated, cell-penetrating anti-PD-L1 peptide nanomedicine (CPPD1) with enhanced cell and tissue permeability. The CPPD1 molecule, a bioconjugate of a hydrophobic photosensitizer and strongly positively charged programmed cell death-ligand 1 (PD-L1) binding cell-penetrating peptide (CPP), is capable of self-assembling into nanoparticles with an average size of 199 nm in aqueous solution without the need for any carriers. These carrier-free nanoparticles possess the ability to penetrate the cell membrane of cancer cells and target tumors expressing PD-L1 on their surface. Notably, CPPD1 nanoparticles effectively blocked programmed cell death-1 (PD-1)/PD-L1 interactions and reduced PD-L1 expression via lysosomal degradation. They also demonstrated the responsiveness of CPPD1 nanoparticles in photodynamic therapy (PDT) to a 635 nm laser, leading to the generation of ROS, and induction of various immunogenic cell deaths (ICD). Highly penetrating CPPD1 nanoparticles could immunogenically modulate the microenvironment of CT26 cancer and were also effective in treating abscopal metastatic tumors, addressing major limitations of traditional PDT.

Hypericin-Mediated Photodynamic Therapy for Head and Neck Cancers: A Systematic Review

Background: Conventional treatments for cancers of the head and neck region are often associated with high recurrence rates and impaired quality of life. Photodynamic therapy (PDT) has emerged as a promising alternative, leveraging photosensitizers such as hypericin to selectively target tumour cells with minimal damage to surrounding healthy tissues. Objectives: We aimed to evaluate the efficacy and underlying mechanisms of hypericin-mediated PDT (HY-PDT) in treating head and neck cancers. Methods: Adhering to PRISMA 2020 guidelines, a systematic search was conducted across PubMed/Medline, Embase, Scopus, and the Cochrane Library for studies published between January 2000 and December 2024. Inclusion criteria encompassed preclinical in vitro and in vivo studies and clinical trials focusing on HY-PDT for head and neck malignancies and its subtypes. Results: A total of 13 studies met the inclusion criteria, comprising both in vitro and in vivo investigations. HY-PDT consistently demonstrated significant cytotoxicity against squamous cell carcinoma cells through apoptotic and necrotic pathways, primarily mediated by ROS generation. Hypericin exhibited selective uptake in cancer cells over normal keratinocytes. Additionally, HY-PDT modulated the tumour microenvironment by altering cytokine profiles, such as by increasing IL-20 and sIL-6R levels, which may enhance antitumor immunity and reduce metastasis. Conclusions: HY-PDT emerges as a highly promising and minimally toxic treatment modality for head and neck cancers, demonstrating efficacy in inducing selective tumour cell death and modulating the immune microenvironment. Despite the encouraging preclinical evidence, significant methodological variability and limited clinical data necessitate further large-scale, standardized and randomized controlled trials.

Aggregation-induced emission: Application in diagnosis and therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a serious health issue due to its low early diagnosis rate, resistance to chemotherapy, and poor five-year survival rate. Therefore, it is crucial to explore novel diagnostic and therapeutic approaches tailored to the characteristics of HCC. Aggregation-induced emission (AIE) is a phenomenon where the luminescence of certain molecules, typically non-luminescent or weakly luminescent in solution, is significantly enhanced upon aggregation. AIE has been extensively applied in bioimaging, biosensors, and therapy. Fluorophore materials based on AIE (AIEgens) have a wide range of application scenarios and potential for clinical translation. This review focuses on recent advances in AIE-based strategies for diagnosing and treating HCC. First, the specific functional mechanism of AIE is described. Next, we summarize recent progress in the application of AIE for multimodal imaging, biosensor detection, and phototherapy. Finally, prospects and challenges for the AIE-based application in the diagnosis and therapy of HCC are discussed.

Advancing rhodium nanoparticle-based photodynamic cancer therapy: quantitative proteomics and in vivo assessment reveal mechanisms targeting tumor metabolism, progression and drug resistance

Rhodium nanoparticles have been recently discovered as good photosensitizers with great potential in cancer photodynamic therapy by effectively inducing cytotoxicity in cancer cells under near-infrared laser. This study evaluates the molecular mechanisms underlying such antitumoral effect through quantitative proteomics. The results revealed that rhodium nanoparticle-based photodynamic therapy disrupts tumor metabolism by downregulating key proteins involved in ATP synthesis and mitochondrial function, leading to compromised energy production. The treatment also induces oxidative stress and apoptosis while targeting the invasion capacity of cancer cells. Additionally, key proteins involved in drug resistance are also affected, demonstrating the efficacy of the treatment in a multi-drug resistant cell line. In vivo evaluation using a chicken embryo model also confirmed the effectiveness of the proposed therapy in reducing tumor growth without affecting embryo viability.

PDT and antitumor immunity: the beginnings of the story

This mini-review reports a brief description of the first experiments conducted by Canti's group on the role of photodynamic therapy in generating immunity against cancer. It highlights for the first time the effective role of PDT in the induction of anti-tumor T lymphocytes and shows that this effect is tumor-specific. It has also been reported how this adoptive immunity can improve the efficacy of chemotherapy. These studies have helped to open an important new field of scientific research on the role of PDT-generated immunity and to stimulate today's important new pre-clinical approaches.

Effectiveness of photodynamic therapy on the treatment of chronic periodontitis: a systematic review during 2008-2023

Objective

This study investigated the effect of photodynamic therapy on chronic periodontitis patients and then evaluated the microbial, immunological, periodontal, and clinical outcomes. The significant effects of photodynamic therapy obtained by in vitro and in vivo studies have made it a popular treatment for periodontal diseases in recent years. Photodynamic therapy is a novel bactericidal strategy that is stronger, faster, and less expensive than scaling and root planing.

Method

This study registered on PROSPERO (CRD42021267008) and retrieved fifty-three randomized controlled trials by searching nine databases (Medline, Embase, Scopus, Open Gray, Google Scholar, ProQuest, the Cochrane Library, Web of Science, and ClinicalTrials.gov) from 2008 to 2023. Of 721 records identified through database searches following title and full-text analysis, and excluding duplicate and irrelevant publications, 53 articles were included in this systematic review. Fifty of the 53 eligible studies fulfilled all the criteria in the Joanna Briggs Institute's (JBI's) Checklist for RCTs; the remaining articles met 9-12 criteria and were considered high quality.

Results

The present study showed that photodynamic therapy in adjunct to scaling and root planing has the potential to improve periodontal parameters such as clinical attachment loss or gain, decrease in bleeding on probing, and probing pocket depth. In addition, photodynamic therapy decreases the rate of periodontal pathogens and inflammation markers, which, in turn, reduces the progression of periodontitis.

Conclusion

Photodynamic therapy is considered a promising, adjunctive, and low-cost therapeutic method that is effective in tissue repair, reducing chronic periodontitis, reducing inflammation, and well-tolerated by patients.

Investigation of the Nanoparticulation Method and Cell-Killing Effect following the Mitochondrial Delivery of Hydrophobic Porphyrin-Based Photosensitizers

Photodynamic therapy is expected to be a less invasive treatment, and strategies for targeting mitochondria, the main sources of singlet oxygen, are attracting attention to increase the efficacy of photodynamic therapy and reduce its side effects. To date, we have succeeded in encapsulating the photosensitizer rTPA into MITO-Porter (MP), a mitochondria-targeted Drug Delivery System (DDS), aimed at mitochondrial delivery of the photosensitizer while maintaining its activity. In this study, we report the results of our studies to alleviate rTPA aggregation in an effort to improve drug efficacy and assess the usefulness of modifying the rTPA side chain to improve the mitochondrial retention of MITO-Porter, which exhibits high therapeutic efficacy. Conventional rTPA with anionic side chains and two rTPA analogs with side chains that were converted to neutral or cationic side chains were encapsulated into MITO-Porter. Low-MP (MITO-Porter with Low Drug/Lipid) exhibited high drug efficacy for all three types of rTPA, and in Low-MP, charged rTPA-encapsulated MP exhibited high drug efficacy. The cellular uptake and mitochondrial translocation capacities were similar for all particles, suggesting that differences in aggregation rates during the incorporation of rTPA into MITO-Porter resulted in differences in drug efficacy.

Bibliometric analysis of photodynamic therapy and immune response from 1989-2023

Objective: Photodynamic therapy (PDT) is a minimally invasive treatment approach for precancerous and cancerous lesions, known for its ability to activate the host immune response. This study conducted a bibliometric analysis to identify the research trends and hotspots related to the immune response in PDT. Methods: We analyzed articles and reviews published from 1989 to 2023, retrieved from the Web of Science database. Using Citespace and VOSviewer, we visualized the distribution patterns of these studies in time and space. Results: The analysis revealed a substantial increase in the number of publications on PDT-related immune response since 1989. A total of 1,688 articles from 1,701 institutions were included in this analysis. Among thei nstitutions, the Chinese Academy of Sciences demonstrated exceptional productivity and a willingness to collaborate with others. Additionally, 8,567 authors contributed to the field, with Mladen Korbelik, Michael R. Hamblin, and Wei R. Chen being the most prolific contributors. The current research focus revolves around novel strategies to enhance antitumor immunity in PDT, including PDT-based dendritic cell vaccines, combination therapies with immune checkpoint inhibitors (ICIs), and the use of nanoparticles for photosensitizer delivery. Furthermore, genes such as CD8A, TNF, CD4, IFNG, CD274, IL6, IL10, CALR, HMGB1, and CTLA4 have been evaluated in the context of PDT-related immunity. Conclusion: PDT not only achieves tumor ablation but also stimulates the immune response, bolstering antitumor immunity. This study highlights the emerging hotspots in PDT-related immune response research and provides valuable insights for future investigations aimed at further enhancing antitumor immunity.

Alleviating effect of Nexrutine on mucosal inflammation in mice with ulcerative colitis: Involvement of the RELA suppression

BACKGROUND

Nexrutine is an herbal extract derived from Phellodendron amurense, known for its anti-inflammatory, antidiarrheal, and hemostatic properties. However, its effect on ulcerative colitis (UC) remains unclear.

METHODS

A mouse model of UC was induced by 3% dextran sulfate sodium, while human colonic epithelial cells NCM-460 were exposed to lipopolysaccharide. Both models were treated with Nexrutine at 300 or 600 mg/kg, with Mesalazine applied as a positive control regimen. The disease activity index (DAI) of mice was calculated, and the pathological injury scores were assessed through hematoxylin and eosin staining. The viability of NCM-460 cells was determined using the CCK-8 method. Inflammatory cytokines were detected using ELISA kits. Expression of mucin 3 (MUC3), Claudin-1, and tight junction protein (ZO-1) was detected to analyze mucosal barrier integrity. Target genes of Nexrutine were predicted using bioinformatics tools. Expression of RELA proto-oncogene (RELA) was analyzed using qPCR and western blot assays.

RESULTS

The Nexrutine treatments significantly alleviated DAI of mice, mitigated pathological changes in their colon tissues, decreased the production of pro-inflammatory cytokines, enhanced the barrier integrity-related proteins, and increased NCM-460 cell viability in vitro. RELA, identified as a target gene of Nexrutine, showed elevated levels in UC models but was substantially suppressed by Nexrutine treatment. Adenovirus-mediated RELA upregulation in mice or the overexpression plasmid of RELA in cells counteracted the effects of Nexrutine treatments, exacerbating UC-related symptoms.

CONCLUSION

This study demonstrates that Nexrutine alleviates inflammatory mucosal barrier damage in UC by suppressing RELA transcription.