Metal ion-promoted chemodynamic therapy(CDT) combined with photodynamic therapy(PDT) offers broad application prospects for enhancing anti-tumor effects. In this study, glycyrrhizic acid(GA), copper ions(Cu~(2+)), and norcantharidin(NCTD) were co-assembled to successfully prepare a natural small-molecule, carrier-free hydrogel(NCTD Gel) with excellent material properties. Under 808 nm laser irradiation, NCTD Gel responded to the tumor microenvironment(TME) and acted as an efficient Fenton reagent and photosensitizer, catalyzing the conversion of endogenous hydrogen peroxide(H_2O_2) within the tumor into oxygen(O_2), and hydroxyl radicals(·OH, type Ⅰ reactive oxygen species) and singlet oxygen(~1O_2, type Ⅱ reactive oxygen species), while depleting glutathione(GSH) to stabilize reactive oxygen species and alleviate tumor hypoxia. In vitro and in vivo experiments demonstrated that NCTD Gel exhibited significant CDT/PDT synergistic therapeutic effects. Further safety evaluation and metabolic testing confirmed its good biocompatibility and safety. This novel hydrogel is not only simple to prepare, safe, and cost-effective but also holds great potential for clinical transformation, providing insights and references for the research and development of metal ion-mediated hydrogel-based anti-tumor therapies.
Hydrogels/chemistry* ; Animals ; Photochemotherapy ; Humans ; Mice ; Antineoplastic Agents/administration & dosage* ; Photosensitizing Agents/chemistry* ; Neoplasms/metabolism* ; Female ; Copper/chemistry* ; Reactive Oxygen Species/metabolism* ; Tumor Microenvironment/drug effects* ; Cell Line, Tumor ; Male

Riboflavin-ultraviolet A (UVA) collagen cross-linking has not only achieved good clinical efficacy in the treatment of corneal diseases such as dilatation keratopathy, bullae keratopathy, infectious keratopathy, and in the combined treatment of corneal refractive surgeries, but also its efficacy and safety in scleral collagen cross-linking have been initially confirmed. To better promote the application of cross-linking in the clinical treatment of corneal and scleral diseases, exploring controllability and predictability of the surgical efficacy are both important for evaluating the surgical efficacy and personalized precision treatment. In this paper, the progress on the cross-linking depth of riboflavin-UVA collagen cross-linking, and its relationship with the cross-linking effect will be reviewed. It will provide the reference for further application of this procedure in ophthalmology clinics.
Riboflavin/pharmacology* ; Humans ; Collagen/radiation effects* ; Ultraviolet Rays ; Cross-Linking Reagents ; Corneal Diseases/drug therapy* ; Photosensitizing Agents/therapeutic use*

Research in photodynamic therapy (PDT) primarily focuses on enhancing light penetration depth, improving oxygen supply, and optimizing photosensitizer delivery. Notably, the delivery efficiency of the photosensitizer is crucial for therapeutic efficacy. Carboxyl-substituted phthalocyanines, as important photosensitizing molecules, possess unique chemical modification sites that enable direct targeted delivery or integration into diverse delivery systems. Their synthesis predominantly employs mixed- or cross-condensation, selective synthesis, and axial modification strategies to introduce carboxyl groups. However, their inherent hydrophobicity significantly hinders effective delivery. To address this limitation, modifications with peptides or quaternary ammonium salt derivatives may facilitate precise delivery to tumor cells and pathogens. With advances in nanotechnology, carboxyl-substituted phthalocyanines can serve as key photosensitizer modules, effectively integrated into nanomaterials such as biomacromolecules, inorganic metals, and polymers for both active and passive delivery. Recently, researchers have exploited the π-π stacking and other intermolecular forces among carboxyl-substituted phthalocyanine molecules to drive their self-assembly into nano-micelles, enabling carrier-free delivery or co-delivery with other therapeutic agents for synergistic effects. This review systematically outlines the synthesis strategies for carboxyl-substituted phthalo-cyanines. Taking mono-carboxyl-substituted zinc phthalocyanine as a model molecule, the performance of three delivery modalities were compared: single-molecule targeted delivery, nanocarrier-encapsulated delivery, and carrier-free self-assembled delivery, in terms of PDT efficacy, biocompatibility, and imaging-guided tracing capabilities, to provide a systematic technical framework for the rational design of novel modular photosensitizers and to advance the clinical translation of PDT in precision oncology and anti-infective therapy.
Photochemotherapy/methods* ; Indoles/administration & dosage* ; Isoindoles ; Photosensitizing Agents/administration & dosage* ; Drug Delivery Systems ; Humans

OBJECTIVE: To explore whether microneedle pretreatment can significantly improve the efficacy and safety of 5-aminolevulinic acid (ALA)-photodynamic therapy (PDT) in the treatment of oral leukoplakia. METHODS: A non-randomized controlled clinical trial was conducted. Patients with clinical and pathological diagnosis of oral leukoplakia in the Department of Oral Mucosa, Peking University School and Hospital of Stomatology were divided into experimental group and control group. The control group was treated with conventional ALA-PDT, and the experimental group was pretreated with micro- needle buckling under superficial anesthesia with lidocaine before conventional ALA-PDT. The clinical manifestations of the two groups were recorded, the lesion area was measured, the clinical efficacy was evaluated, the number of treatment sessions and treatment unit duration were analyzed, and the pain after treatment was evaluated by visual analogue scale. The above data of the two groups were statistically analyzed. RESULTS: A total of 11 patients were included in the experimental group and 19 patients were included in the control group. The complete remission rate of the experimental group and the control group was 45.5% and 36.8%, the partial remission rate was 54.5% and 57.9%, and the no remission rate was 0% and 5%, respectively. There was no significant difference in the treatment effect between the two groups. Meanwhile, the treatment unit duration of the experimental group and the control group were (9.05±5.74) min/cm² and (21.38±15.44) min/cm², respectively, and the number of treatment sessions were (2.36±0.67) times and (3.58±1.57) times, respectively. These differences between the two groups were statistically significant (t=-3.125, P < 0.05; t=-2.932, P < 0.05). Similarly, multiple linear regression analysis with 7 factors including age, dysplastic pathology, lesion classification, etc., also confirmed that pretreatment could significantly shorten the treatment unit duration (P < 0.05). In addition, there was no significant difference in pain score (visual analogue scale) between the two groups after treatment, and the microneedle puncture pretreatment did not increase the adverse reactions of ALA-PDT treatment. CONCLUSION Microneedle pretreatment followed by conventional ALA-PDT shows a good clinical effect on oral leukoplakia, which can significantly shorten the clinical treatment time, reduce the number of visits, and save medical costs.
Humans ; Photochemotherapy/instrumentation* ; Leukoplakia, Oral/drug therapy* ; Aminolevulinic Acid/therapeutic use* ; Male ; Female ; Middle Aged ; Adult ; Needles ; Photosensitizing Agents/therapeutic use* ; Aged ; Combined Modality Therapy

OBJECTIVES: The application of photodynamic therapy in solid tumors has attracted increasing attention in recent years, and the efficiency of photosensitizers is a crucial determinant of therapeutic efficacy. This study aims to evaluate the cytotoxic effects of a novel photosensitizer, PEG-MTPABZ-PyC, in photodynamic therapy against gastric cancer cells. METHODS: Gastric cancer MKN45 cells were treated with PEG-MTPABZ-PyC. A high-content live-cell imaging system was used to assess the cellular uptake kinetics and subcellular localization of the photosensitizer. The cytotoxic effects of PEG-MTPABZ-PyC-mediated photodynamic therapy were examined using the cell counting kit-8 (CCK-8) assay and flow cytometry, while the intrinsic cytotoxicity of the photosensitizer alone was verified by the CCK-8 assay. Intracellular reactive oxygen species (ROS) generation after photodynamic therapy was detected using 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA). RESULTS: PEG-MTPABZ-PyC alone exhibited no cytotoxicity toward MKN45 cells, indicating excellent cytocompatibility. The compound efficiently entered cells within 6 hours and localized predominantly in lysosomes. Upon light irradiation, PEG-MTPABZ-PyC-mediated photodynamic therapy induced significant cytotoxicity compared with the control group (P<0.05) and generated abundant intracellular ROS. CONCLUSIONS The novel photosensitizer PEG-MTPABZ-PyC demonstrates potent photodynamic cytotoxicity against gastric cancer cells, showing promising potential for further development in gastric cancer photodynamic therapy.
Humans ; Stomach Neoplasms/drug therapy* ; Photochemotherapy/methods* ; Photosensitizing Agents/pharmacology* ; Cell Line, Tumor ; Polyethylene Glycols/chemistry* ; Reactive Oxygen Species/metabolism* ; Mesoporphyrins/pharmacology*

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), as certain forms of non-melanoma skin cancer (NMSC) or keratinocyte carcinoma, are the most common forms of malignant neoplasms worldwide (Sharp et al., 2024). BCC and cSCC have been identified as two major components of NMSC, comprising one-third of all malignancies (Burton et al., 2016). Generally speaking, patients with NMSC tend to have relatively favorable survival outcomes, while different histopathological subtypes of NMSC exhibit distinct biological behaviors (Stătescu et al., 2023). Keratinocyte carcinoma, although not considered as deadly as melanoma, tends to metastasize if left untreated (Civantos et al., 2023; Nanz et al., 2024). cSCC can evolve locally, then aggressively metastasize, invade, and even lead to fatal consequences in a subset of patients (Winge et al., 2023). A solid, pigmented, smooth plaque or a hyperkeratotic papule with or without central ulceration and hemorrhage appears to be characteristic of cSCC (Thompson et al., 2016; Zhou et al., 2023). Of note, a rare type of intraepidermal cSCC in situ often appears as a velvety, demarcated, slightly raised erythematous plaque on the genitalia of men (Yamaguchi et al., 2016). Accounting for approximately 16.0% of scalp tumors and with a rising incidence, cSCC is now the second most common NMSC in humans (Verdaguer-Faja et al., 2024). According to the latest statistics, up to 2%‒5% of cSCCs in situ may gradually progress into invasive cSCCs in the final step (Rentroia-Pacheco et al., 2023). Several risk factors for the carcinogenesis and development of cSCC have been identified, including age, accumulative exposure to ultraviolet light radiation A and B, human papillomavirus infection, arsenic ingestion, chronic scarring, xeroderma pigmentosa, a relevant history of ionizing radiation, androgenetic alopecia in males, and immunosuppression therapy (Martinez and Otley, 2001; Welsch et al., 2012; Mortaja and Demehri, 2023).
Humans ; Aminolevulinic Acid/therapeutic use* ; Skin Neoplasms/pathology* ; Photochemotherapy/methods* ; Female ; Carcinoma, Squamous Cell/pathology* ; Middle Aged ; Photosensitizing Agents/therapeutic use* ; Carcinoma, Basal Cell/drug therapy*

Tongue squamous cell carcinoma (TSCC) is a prevalent malignancy that afflicts the head and neck area and presents a high incidence of metastasis and invasion. Accurate diagnosis and effective treatment are essential for enhancing the quality of life and the survival rates of TSCC patients. The current treatment modalities for TSCC frequently suffer from a lack of specificity and efficacy. Nanoparticles with diagnostic and photothermal therapeutic properties may offer a new approach for the targeted therapy of TSCC. However, inadequate accumulation of photosensitizers at the tumor site diminishes the efficacy of photothermal therapy (PTT). This study modified gold nanodots (AuNDs) with the TSCC-targeting peptide HN-1 to improve the selectivity and therapeutic effects of PTT. The Au-HN-1 nanosystem effectively targeted the TSCC cells and was rapidly delivered to the tumor tissues compared to the AuNDs. The enhanced accumulation of photosensitizing agents at tumor sites achieved significant PTT effects in a mouse model of TSCC. Moreover, owing to its stable long-term fluorescence and high X-ray attenuation coefficient, the Au-HN-1 nanosystem can be used for fluorescence and computed tomography imaging of TSCC, rendering it useful for early tumor detection and accurate delineation of surgical margins. In conclusion, Au-HN-1 represents a promising nanomedicine for imaging-based diagnosis and targeted PTT of TSCC.
Tongue Neoplasms/diagnostic imaging* ; Carcinoma, Squamous Cell/diagnostic imaging* ; Animals ; Gold/chemistry* ; Mice ; Photothermal Therapy/methods* ; Tomography, X-Ray Computed ; Photosensitizing Agents ; Metal Nanoparticles ; Humans ; Cell Line, Tumor

The probiotic strain Escherichia coli Nissle 1917 (EcN) with high biocompatibility and susceptibility to genetic modification is often applied in bacterial therapies for cancer. However, most studies have used plasmids as vectors to construct engineering strains from EcN. Plasmid-based expression systems suffer from genetic instability, and they need antibiotic selective pressure to maintain high copy number. This study aimed to employ EcN for synthesizing the photosensitizer 5-aminolevulinic acid (5-ALA). Firstly, the key genes of 5-ALA synthesis, hemA^M and hemL, were integrated into the EcN genome by the phage integration technique. Then, chemically inducible chromosomal evolution (CIChE) was adopted to increase the copy number of hemA^M and hemL and thus improved the stable synthesis of 5-ALA. The in vitro cell experiments verified that the constructed engineering strain can deliver stably synthesized 5-ALA to tumor cells and inhibit their growth. This study provided a basis for applying the engineering strains of EcN in the photodynamic therapy for tumors.
Escherichia coli/metabolism* ; Aminolevulinic Acid/metabolism* ; Photosensitizing Agents/pharmacology* ; Plasmids/genetics* ; Chromosomes, Bacterial/genetics* ; Genetic Engineering ; Humans ; Probiotics ; Photochemotherapy

Objective: To investigate the effects of low-dose photodynamic therapy on the proliferation, regulation, and secretion functions of human adipose mesenchymal stem cells (ADSCs) and the related mechanism, so as to explore a new method for the repair of chronic wounds. Methods: The experimental research methods were adopted. From February to April 2021, 10 patients (5 males and 5 females, aged 23 to 47 years) who underwent cutaneous surgery in the Department of Dermatology of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) donated postoperative waste adipose tissue. The cells were extracted from the adipose tissue and the phenotype was identified. Three batches of ADSCs were taken, with each batch of cells being divided into normal control group with conventional culture only, photosensitizer alone group with conventional culture after being treated with Hemoporfin, irradiation alone group with conventional culture after being treated with red light irradiation, and photosensitizer+irradiation group with conventional culture after being treated with Hemoporfin and red light irradiation, with sample number of 3 in each group. At culture hour of 24 after the treatment of the first and second batches of cells, the ADSC proliferation level was evaluated by 5-ethynyl-2'-deoxyuridine staining method and the migration percentage of HaCaT cells cocultured with ADSCs was detected by Transwell experiment, respectively. On culture day of 7 after the treatment of the third batch of cells, the extracellular matrix protein expression of ADSCs was detected by immunofluorescence method. The ADSCs were divided into 0 min post-photodynamic therapy group, 15 min post-photodynamic therapy group, 30 min post-photodynamic therapy group, and 60 min post-photodynamic therapy group, with 3 wells in each group. Western blotting was used to detect the protein expressions and calculate the phosphorylated mammalian target of rapamycin complex (p-mTOR)/mammalian target of rapamycin (mTOR), phosphorylated p70 ribosomal protein S6 kinase (p-p70 S6K)/p70 ribosomal protein S6 kinase (p70 S6K) ratio at the corresponding time points after photodynamic therapy. Two batches of ADSCs were taken, and each batch was divided into normal control group, photodynamic therapy alone group, and photodynamic therapy+rapamycin group, with 3 wells in each group. At culture minute of 15 after the treatment, p-mTOR/mTOR and p-p70 S6K/p70 S6K ratios of cells from the first batch were calculated and detected as before. On culture day of 7 after the treatment, extracellular matrix protein expression of cells from the second batch was detected as before. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: After 12 d of culture, the cells were verified as ADSCs. At culture hour of 24 after the treatment, the ADSC proliferation level ((4.0±1.0)% and (4.1±0.4)%, respectively) and HaCaT cell migration percentages (1.17±0.14 and 1.13±0.12, respectively) in photosensitizer alone group and irradiation alone group were similar to those of normal control group ((3.7±0.6)% and 1.00±0.16, respectively, P>0.05), and were significantly lower than those of photosensitizer+irradiation group ((34.2±7.0)% and 2.55±0.13, respectively, P<0.01). On culture day of 7 after the treatment, compared with those in normal control group, the expression of collagen Ⅲ in ADSCs of photosensitizer alone group was significantly increased (P<0.05), and the expressions of collagen Ⅰ and collagen Ⅲ in ADSCs of irradiation alone group were significantly increased (P<0.01). Compared with those in photosensitizer alone group and irradiation alone group, the expressions of collagen Ⅰ, collagen Ⅲ, and fibronectin of ADSCs in photosensitizer+irradiation group were significantly increased (P<0.01). Compared with those in 0 min post-photodynamic therapy group, the ratios of p-mTOR/mTOR and p-p70 S6K/p70 S6K of ADSCs in 15 min post-photodynamic therapy group were significantly increased (P<0.01), the ratios of p-p70 S6K/p70 S6K of ADSCs in 30 min post-photodynamic therapy group and 60 min post-photodynamic therapy group were both significantly increased (P<0.01). At culture minute of 15 after the treatment, compared with those in normal control group, the ratios of p-mTOR/mTOR and p-p70 S6K/p70 S6K of ADSCs in photodynamic therapy alone group were significantly increased (P<0.05 or P<0.01). Compared with those in photodynamic therapy alone group, the ratios of p-mTOR/mTOR and p-p70 S6K/p70 S6K of ADSCs in photodynamic therapy+rapamycin group were significantly decreased (P<0.05). On culture day of 7 after the treatment, compared with those in normal control group, the expressions of collagen Ⅰ, collagen Ⅲ, and fibronectin of ADSCs in photodynamic therapy alone group were significantly increased (P<0.01). Compared with those in photodynamic therapy alone group, the expressions of collagen Ⅰ, collagen Ⅲ, and fibronectin of ADSCs in photodynamic therapy+rapamycin group were significantly decreased (P<0.01). Conclusions: Low-dose photodynamic therapy can promote the proliferation of ADSCs, improve the ability of ADSCs to regulate the migration of HaCaT cells, and enhance the secretion of extracellular matrix protein by rapidly activating mTOR signaling pathway.
Adipose Tissue ; Female ; Fibronectins ; Humans ; Male ; Mesenchymal Stem Cells ; Photochemotherapy ; Photosensitizing Agents/pharmacology* ; Sirolimus/pharmacology* ; TOR Serine-Threonine Kinases

OBJECTIVE: To study the binding target of photosensitizer and bacteria in antimicrobial photodynamic therapy with computer-simulated target prediction and molecular docking research methods and to calculate the binding energy. METHODS: The protein names of Porphyromonas gingivalis (Pg) were obtained and summarized in Uniprot database and RCSB PDB database; the structure diagrams of methy-lene blue were screened in SciFinder database, PubChem database, ChemSpider database, and Chemical Book, and ChemBioDraw software was used to draw and confirm the three-dimensional structure for target prediction and Cytoscape software was used to build a visual network diagram; a protein interaction network was searched and built between the methylene blue target and the common target of Pg in the String database; then we selected FimA, Mfa4, RgpB, and Kgp K1 proteins, used AutoDock software to calculate the docking energy of methylene blue and the above-mentioned proteins and performed molecular docking. RESULTS: The target prediction results showed that there were 19 common targets between the 268 potential targets of methylene blue and 1 865 Pg proteins. The 19 targets were: groS, radA, rplA, dps, fabH, pyrG, thyA, panC, RHO, frdA, ileS, bioA, def, ddl, TPR, murA, lepB, cobT, and gyrB. The results of the molecular docking showed that methylene blue could bind to 9 sites of FimA protein, with a binding energy of -6.26 kcal/mol; with 4 sites of Mfa4 protein and hydrogen bond formation site GLU47, and the binding energy of -5.91 kcal/mol, the binding energy of LYS80, the hydrogen bond forming site of RgpB protein, was -5.14 kcal/mol, and the binding energy of 6 sites of Kgp K1 protein and the hydrogen bond forming site GLY1114 of -5.07 kcal/mol. CONCLUSION Computer simulation of target prediction and molecular docking technology can initially reveal the binding, degree of binding and binding sites of methylene blue and Pg proteins. This method provides a reference for future research on the screening of binding sites of photosensitizers to cells and bacteria.
Computer Simulation ; Methylene Blue ; Molecular Docking Simulation ; Photosensitizing Agents ; Porphyromonas gingivalis