Evaluation of a Novel Lateral Emitting Laser Fiber for Near-Infrared Photoimmunotherapy.

Near-infrared photoimmunotherapy (NIR-PIT) is a new cancer therapy that uses NIR light and conjugates of a tumor-targeting monoclonal antibody and phthalocyanine dye. In clinical practice, frontal and cylindrical diffusers are the only options for NIR illumination. However, illumination in a narrow space is technically difficult with such diffusers. Therefore, we evaluated a lateral illumination system using a lateral emitting laser (LEL) fiber. The LEL fiber illuminated a certain area in a lateral direction. NIR-PIT with an LEL fiber reduced luciferase activity in a light-dose-dependent manner in A431-GFP-luc cells in vitro and significantly suppressed tumor proliferation in a xenograft mouse model. To evaluate the usefulness of the LEL fiber in the illumination of a narrow space, a tumor was illuminated from the inside of a cylinder, mimicking a narrow space, and the fluorescence intensity in the tumor was monitored. In the frontal diffuser, NIR light was unevenly delivered and little light reached a distal tumor area from the illuminated side. By contrast, the LEL fiber allowed a uniform illumination of the entire tumor, and a loss of fluorescence was observed even in distal areas. These findings suggested that the LEL fiber can be used for NIR-PIT and is suitable for NIR light illumination in a narrow space.

Elimination of radiation-induced senescent cancer cells and stromal cells in vitro by near-infrared photoimmunotherapy.

INTRODUCTION: Therapy-induced senescent cancer and stromal cells secrete cytokines and growth factors to promote tumor progression. Therefore, senescent cells may be novel targets for tumor treatment. Near-infrared photoimmunotherapy (NIR-PIT) is a highly tumor-selective therapy that employs conjugates of a molecular-targeting antibody and photoabsorber. Thus, NIR-PIT has the potential to be applied as a novel senolytic therapy. This study aims to investigate the efficacy of NIR-PIT treatment on senescent cancer and stromal cells. METHODS: Two cancer cell lines (human lung adenocarcinoma A549 cells and human pancreatic cancer MIA PaCa-2 cells) and two normal cell lines (mouse fibroblast transfected with human epidermal growth factor receptor 2 [HER2] cells and human fibroblast WI38 cells) were used. The cytotoxicity of NIR-PIT was evaluated using anti-epidermal growth factor receptor (EGFR) antibody panitumumab and anti-HER2 antibody transtuzumab. RESULTS: Cellular senescence was induced in A549 and MIA PaCa-2 cells by 10 Gy γ-irradiation. The up-regulation of cellular senescence markers and characteristic morphological changes in senescent cells, including enlargement, flattening, and multinucleation, were observed in cancer cells after 5 days of γ-irradiation. Then, NIR-PIT targeting EGFR was performed on these senescent cancer cells. The NIR-PIT induced morphological changes, including bleb formation, swelling, and the inflow of extracellular fluid, and induced a significant decrease in cellular viability. These results suggested that NIR-PIT may induce cytotoxicity using the same mechanism in senescent cancer cells. In addition, similar morphological changes were also induced in radiation-induced senescent 3T3-HER2 fibroblasts by NIR-PIT targeting human epidermal growth factor receptor 2. CONCLUSION: NIR-PIT eliminates both senescent cancer and stromal cells in vitro suggesting it may be a novel strategy for tumor treatment.

Near-infrared duocarmycin photorelease from a Treg-targeted antibody-drug conjugate improves efficacy of PD-1 blockade in syngeneic murine tumor models.

Regulatory T cells (Tregs) play a crucial role in mediating immunosuppression in the tumor microenvironment. Furthermore, Tregs contribute to the lack of efficacy and hyperprogressive disease upon Programmed cell death protein 1 (PD-1) blockade immunotherapy. Thus, Tregs are considered a promising therapeutic target, especially when combined with PD-1 blockade. However, systemic depletion of Tregs causes severe autoimmune adverse events, which poses a serious challenge to Treg-directed therapy. Here, we developed a novel treatment to locally and predominantly damage Tregs by near-infrared duocarmycin photorelease (NIR-DPR). In this technology, we prepared anti-CD25 F(ab')2 conjugates, which site-specifically uncage duocarmycin in CD25-expressing cells upon exposure to NIR light. In vitro, CD25-targeted NIR-DPR significantly increased apoptosis of CD25-expressing HT2-A5E cells. When tumors were irradiated with NIR light in vivo, intratumoral CD25+ Treg populations decreased and Ki-67 and Interleukin-10 expression was suppressed, indicating impaired functioning of intratumoral CD25+ Tregs. CD25-targeted NIR-DPR suppressed tumor growth and improved survival in syngeneic murine tumor models. Of note, CD25-targeted NIR-DPR synergistically enhanced the efficacy of PD-1 blockade, especially in tumors with higher CD8+/Treg PD-1 ratios. Furthermore, the combination therapy induced significant anti-cancer immunity including maturation of dendritic cells, extensive intratumoral infiltration of cytotoxic CD8+ T cells, and increased differentiation into CD8+ memory T cells. Altogether, CD25-targeted NIR-DPR locally and predominantly targets Tregs in the tumor microenvironment and synergistically improves the efficacy of PD-1 blockade, suggesting that this combination therapy can be a rational anti-cancer combination immunotherapy.

Attenuated polyethylene glycol immunogenicity and overcoming accelerated blood clearance of a fully PEGylated dendrimer.

Polyethylene glycol (PEG) is a popular biocompatible polymer and PEGylated nanoparticles passively accumulate in tumor tissues because of their enhanced permeability and retention effects. Recently, the anti-PEG immunity of PEGylated nanoparticles has become an issue that needs to be solved for their clinical applications. Dendrimers are highly branched and well-defined polymers with many terminal groups, which act as potent drug carriers. In this study, we examined the pharmacokinetics, biodistribution, anti-PEG immunity, and tumor accumulation of a fully PEGylated polyamidoamine (PAMAM) dendrimer after the first and second injections and compared them to those of a PEGylated liposome with the same lipid component as Doxil®. The PEGylated dendrimer showed greater blood circulation than that of the PEGylated liposome after the first and second injections in rats. In mice injected with the PEGylated dendrimer, much less anti-PEG immunoglobulin M (IgM) was generated than that in mice injected with the PEGylated liposome. The PEGylated dendrimer accumulated in the tumor after both the first and second injections. Our results indicated that the PEGylated dendrimer with a small size and high PEG density showed attenuated anti-PEG immunity and overcame the accelerated blood clearance phenomenon, which is useful for drug delivery systems for cancer treatment.

Synthesis and biological evaluation of EGFR binding peptides for near-infrared photoimmunotherapy.

Near-infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that involves photoimmunotherapy drug injection and NIR light exposure. In NIR-PIT, antibodies are commonly used as target-directed molecules carrying IRDye700DX (IR700). However, antibodies have disadvantages, such as high cost, complex development strategies, and poor tumor penetration. In contrast, peptides have lower production costs, can be easy to chemically synthesize and modify, and can also be used for tumor-targeting like antibodies. In this study, we developed a novel PIT drug using a peptide as the target-directed molecule. Epidermal growth factor receptor (EGFR) was selected as the target, and monovalent and bivalent EGFR-binding peptides were synthesized. The bivalent peptide showed sufficient binding to EGFR-positive cells, and a bivalent peptide-IR700 conjugate with a long linker induced morphological changes in EGFR-positive cells. Additionally, the drug significantly reduced cell viability in vitro in an NIR light-dose- and drug-concentration-dependent manner. These results indicate the feasibility of NIR-PIT in treating cancer using peptide-based drugs.

Pelvic floor muscle contraction automatic evaluation algorithm for pelvic floor muscle training biofeedback using self-performed ultrasound.

INTRODUCTION: Non-invasive biofeedback of pelvic floor muscle training (PFMT) is required for continuous training in home care. Therefore, we considered self-performed ultrasound (US) in adult women with a handheld US device applied to the bladder. However, US images are difficult to read and require assistance when using US at home. In this study, we aimed to develop an algorithm for the automatic evaluation of pelvic floor muscle (PFM) contraction using self-performed bladder US videos to verify whether it is possible to automatically determine PFM contraction from US videos. METHODS: Women aged ≥ 20 years were recruited from the outpatient Urology and Gynecology departments of a general hospital or through snowball sampling. The researcher supported the participants in their self-performed bladder US and videos were obtained several times during PFMT. The US videos obtained were used to develop an automatic evaluation algorithm. Supervised machine learning was then performed using expert PFM contraction classifications as ground truth data. Time-series features were generated from the x- and y-coordinate values of the bladder area including the bladder base. The final model was evaluated for accuracy, area under the curve (AUC), recall, precision, and F1. The contribution of each feature variable to the classification ability of the model was estimated. RESULTS: The 1144 videos obtained from 56 participants were analyzed. We split the data into training and test sets with 7894 time series features. A light gradient boosting machine model (Light GBM) was selected, and the final model resulted in an accuracy of 0.73, AUC = 0.91, recall = 0.66, precision = 0.73, and F1 = 0.73. Movement of the y-coordinate of the bladder base was shown as the most important. CONCLUSION: This study showed that automated classification of PFM contraction from self-performed US videos is possible with high accuracy.

Clinical features and treatment outcomes of Fournier's gangrene in a single tertiary emergency hospital: Simplified Fournier's Gangrene Severity Index score is a predictor for death.

To assess the predictive reliability of the Simplified Fournier's Gangrene Severity Index Score (SFGSI) for mortality in Japanese patients with Fournier's gangrene (FG), we compared the clinical features and outcomes of a patient sample with the SFGSI. The medical records of 36 patients diagnosed with FG at our hospital between October 2007 and September 2022 were reviewed retrospectively. Clinical and laboratory variables, including SFGSI, were evaluated and predictive factors for fatality were investigated using multivariate logistic regression analysis. The median age and body mass index were 65 and 24.2, respectively. Eight patients had cooccurring chronic kidney disease and 23 had diabetes. None were taking sodium-glucose co-transporter-2 (SGLT-2) inhibitors. The causative organisms were diverse, and no specific trends in causative organisms were observed. 26 patients underwent debridement of necrotic tissue including eight colostomies, two orchiectomies, and one cystectomy. Multivariate logistic regression analysis revealed that SFGSI alone was an independent predictor of case fatality, with an odds ratio of 20.167 (95% CI: 1.66-245.53). In conclusion, the fatality rate was 19.4%, which was comparable to that reported in other studies. The SFGSI was an independent predictor of mortality in this study.