Photodynamic therapy: the imminent milieu for treating oral lesions

Developing a far-red fluorogenic beta-galactosidase probe for senescent cell imaging and photoablation

A methylene blue (MB)-based beta-galactosidase (β-gal) activatable molecule, Gal-MB, was developed for senescence imaging and light-triggered senolysis. When in contact with LacZ β-gal or senescence-associated β-gal (SA-β-gal), the photoinsensitive Gal-MB becomes fluorescent. Gal-MB also offered selective phototoxicity toward LacZ β-gal expressing cells and drug-induced senescent cells, which express SA-β-gal, after light illumination at 665 nm.

A methylene blue (MB)-based beta-galactosidase (β-gal) activatable molecule, Gal-MB, was developed for senescence imaging and light-triggered senolysis.

Effect of photodynamic therapy in the reduction of halitosis in patients with multiple sclerosis: clinical trial

Smell and odours play a vital role in social interaction. Halitosis is a social problem that affects one third of the population, causing a negative impact on the quality of life. There is little knowledge on the prevalence and management of halitosis in multiple sclerosis (MS) patients. The present study aims to evaluate the presence of halitosis in patients with MS when compared to a control group, and also evaluate treatment of the problem with antimicrobial photodynamic therapy (aPDT). This is a case-control clinical study in which 60 patients were evaluated: 30 MS patients in treatment at the Specialties Clinic School of Medicine, and 30 healthy patients, matched in age and gender for the control group. Data was collected on the duration of the disease as well as the degree of disability and medication use in the MS group. For all patients, halitosis was assessed with Oral Chroma™. Individuals with halitosis underwent treatment with tongue scraping and aPDT. The photosensitizer was methylene blue (0.005%) and a THERAPY XT-EC^® laser (660 nm, 9 J, 100 mW for 90 s per point, 320 J cm^-2, 3537 mW cm^-2) was used. Six points 1 cm apart from each other were irradiated in the tongue dorsum. There was a positive correlation between the disability and disease duration. No parameter was correlated with halitosis. Patients with MS have higher levels of SH₂ compounds when compared to the control group (p = 0.003, Mann-Whitney), but after aPDT both groups significantly reduced the levels to under the halitosis threshold. The aPDT scraping treatment was effective in the immediate reduction of halitosis in both groups.

Intratumoral Photodynamic Therapy With Newly Synthesized Pheophorbide a in Murine Oral Cancer

Photodynamic therapy (PDT) is a therapeutic alternative for malignant tumors that uses a photosensitizer. Our group recently synthesized photosensitizer pheophorbide a (Pa) from chlorophyll-a. The present study investigated the therapeutic effect of PDT using intratumoral administration of the synthetic photosensitizer Pa in an in vivo murine oral squamous cell carcinoma (OSCC) animal model. Pa accumulation was measured using the fluorescence spectrum and imaging in living C3H mice. Intratumoral treatment of Pa-PDT (IT Pa-PDT) significantly inhibited the growth of transplanted OSCC cells. Histopathological examination of tumor tissues showed that PCNA expression was significantly decreased, while TUNEL-stained cells were markedly increased in the IT Pa-PDT group compared to controls. IT Pa-PDT-induced apoptosis was confirmed by immunoblot. Reduction of Bcl-2 and cleavage of caspase 3 and PARP were observed in IT Pa-PDT. These data demonstrate that IT Pa-PDT inhibited tumor cell proliferation and induced apoptosis, which is correlated with the anticancer activity of IT Pa-PDT. These potent antitumor activities of IT Pa-PDT were observed in both the immunohistochemistry and Western blot experiments. Our findings suggest the intratumoral therapeutic potential of Pa-PDT on OSCC. Additionally, demonstrated detection of Pa using a fluorescence spectroscopy system or molecular imaging system provides a means for simultaneous diagnosis and treatment of OSCC.