Photodynamic Therapy Associated with a Blue Dye Papain-Based Gel and Evaluation of Its Degradation of Type I Collagen Fibers

Antimicrobial photodynamic chemotherapy mediated by PapaMBlue on chronic periodontal disease: Study protocol for a randomized, blind, controlled trial

BACKGROUND

The elimination of the pathogenic microorganisms of the periodontal pocket is one of the main points for success in periodontal treatment. The objective of this study is to investigate the clinical and antimicrobial effect of papain-mediated photodynamic therapy in the clinical treatment of periodontal disease.

METHODS

Twenty patients with chronic periodontitis will be selected. Patients will be randomly divided into 2 groups (n = 10). Group 1 will receive conventional periodontal treatment and group 2 will receive conventional treatment and antimicrobial photodynamic therapy (PACT). Conventional treatment will consist of oral hygiene guidance, with brushing technique instructions and recommendation of daily flossing. The calculus deposits on the teeth will be removed with ultrasound equipment and curettes for scraping and root planning. The PACT will be performed at the end of each periodontal treatment session, at sites with bags ≥4 mm. PapaMblue photosensitizer will be deposited in the periodontal pockets with a syringe and a pre-irradiation time of 1 minute will be adopted. Then, the laser emitting wavelength of 660 nm, with power of 100 mW, for 2 minutes, radiant exposure of 30 J/cm and power density of 250 mW/cm will be applied. Patients will undergo clinical evaluations before treatment (day 1) at 30, 60, and 90 days after the end of treatment; and microbiological evaluations before and immediately after treatment. The distribution of the data within each group and the homogeneity of the variances will be verified. With this information, the most appropriate statistical test in each evaluation will be used. The sample calculation is based on the literature and the significance level of 5% will be adopted.

DISCUSSION

The combination of PACT with methylene blue in a papain gel and the conventional treatment may increase the reduction of bacteria in periodontal pockets.

Tetraphenylporphine-Modified Polymeric Nanoparticles Containing NIR Photosensitizer for Mitochondria-Targeting and Imaging-Guided Photodynamic Therapy

Near-infrared (NIR) photodynamic therapy (PDT) is a promising antitumor strategy under NIR light irradiation to kill cancer cells. Mitochondria has a critical function in sustaining cellular viability and death, which is the ideal organelle for PDT. Here, we reported a tetraphenylporphine (TPP)-conjugated amphiphilic copolymer and an iodinated boron dipyrromethene photosensitizer (BDPI) with high singlet oxygen yield to form nanoparticles (PBDPI-TPP), which could realize mitochondria-targeting and improve the NIR imaging-guided PDT. The as-prepared mitochondria-targeting nanoplatform could show effective subcellular localization and bring about significant irreversible mitochondrial injury for enhanced PDT. Both in vitro and in vivo experiments revealed that the mitochondria-targeting PDT system could achieve a remarkable therapeutic effect, indicating that it is a promising nanoplatform for NIR imaging-guided PDT in cancer therapeutics.