Inhibition of cathepsin-K and matrix metalloproteinase by photodynamic therapy

Toxicity evaluation of indocyanine green mediated photodynamic therapy

BACKGROUND

The aim of the study is to determine the cytotoxic, genotoxic and inflammatory effects of indocyanine green (ICG) mediated photodynamic therapy (PDT) in direct contact with L-929 mouse fibroblast cells and over a dentin barrier.

METHODS

Eight groups were evaluated; control (C), group with a dentin barrier (D), ICG applied directly on the cells (ICG), ICG applied over a dentin barrier (D-ICG), only laser applied (L), laser applied over a dentin barrier (D-L), ICG and laser applied directly on the cells (ICG-L), ICG and laser applied over a dentin barrier (D-ICG-L). Cell viability was evaluated via ATP Assay, DNA damage was evaluated via Comet Assay, and inflammatory markers IL-1β and TNF-α were assessed via ELISA test.

RESULTS

Cell viability decreased in group ICG (p<0.001). Cell viability decrease was higher in Group ICG-L (p<0.001). Cell viability decrease was lower in group D-ICG-L (p>0.05). Group L caused an increase in cell number (p<0.001). DNA damage was observed in ICG, D-ICG, and ICG-L groups (p<0.05). None of the groups displayed an increase of inflammatory markers IL-1β and TNF-α (p>0.05).

CONCLUSIONS

The presence of dentin between ICG and cells acted as a barrier and protected the cells. ICG-mediated PDT did not cause any cytotoxic, genotoxic or inflammatory effect. The use of ICG-mediated PDT for cavity disinfection is acceptable, but at this concentration its use in periodontal pocket disinfection is not recommended due to its cytotoxic and genotoxic properties.

Osseointegration of photodynamic active biomaterials for bone regeneration in an animal bone model over a period of 12 months

OBJECTIVES

Previous efforts led to the development of two different polymeric biomaterials for periodontal regeneration with antibacterial photodynamic surface activity. The present study aimed to investigate osseointegration and bone formation of both materials in an ovine model.

METHODS

Both biomaterials: 1) urethane dimethacrylate-based Biomaterial 1 (BioM1) and 2) tri-armed oligoester-urethane methacrylate-based Biomaterial 2 (BioM2) are enriched with beta-tri-calcium phosphate and the photosensitizer meso-tetra(hydroxyphenyl)chlorin (mTHPC). These materials were implanted in non-critical size bone defects in the sheep femur (n = 16) and tibia (n = 8). Empty defects served as controls (n = 16). Polyfluorochrome sequential bone labeling was carried out at baseline and after 3, 6, and 12 months. Animals were sacrificed after 12 months. Bone specimens (n = 40) were fixed and subjected to microtomographic analysis (µCT) for the evaluation of the bone-volume-fraction (BV/TV), trabecular number and trabecular thickness. Subsequently, histological sections were arranged and polyfluorochrome sequential bone labeling was analyzed by confocal laser scanning microscopy (cLSM).

RESULTS

cLSM analysis revealed that highest remodeling and bone formation activity occurred during the second half of the study period (6-12 months). Bone formation in the tibia was significantly lower for the control (2.71 ± 1.26%) as compared to BioM1 (6.01 ± 2.99%) and BioM2 (6.45 ± 2.12%); (p = 0.006, p = 0004). Micro-computed tomography revealed a BV/TV volume fraction of 44.72 ± 9.01% in femur defects filled with BioM1 which was significantly higher compared to the control (32.27 ± 7.02%; p = 0.01). Bone architecture (trabecular number, trabecular thickness) did not significantly differ from the self-healed defects.

SIGNIFICANCE

Both biomaterials, especially BioM1 showed good osseointegration and bone formation characteristics and can be recommended for further examination in periodontal regeneration studies.

Clinical Evaluation of Bilateral Multiple Gingival Recession Treatment with Autogenous Connective Tissue Graft Associated with Low-Level Laser Therapy

BACKGROUND

Gingival recession (GR) is described as an apical displacement of the gingival margin in relation to the cementoenamel junction, exposing the root surface to the oral cavity environment. This study aimed to evaluate the clinical results of a bilateral root coverage (RC) of GR associated with an autogenous connective tissue graft (aCTG) alone or combined with low-level laser therapy (aCTG + LLLT).

METHODS

This cross-sectional, split-mouth, double-blind, clinical pilot study featured three individuals who attended a periodontics post-graduate program with the main complaint of GR and dental hypersensitivity (DHS). Of these, only one patient met the inclusion criteria and the parameters evaluated were: DHS, the keratinized tissue's thickness and width clinical attachment level (CAL), probing on depth (PD), and bilateral GR based on Cairo RT I. The patient was evaluated by a first clinical evaluator and the treatment was randomly divided into two groups, G1: aCTG only (control group, n = 3 teeth per side) and G2: aCTG + LLLT (test group, n = 3 teeth per side). LLLT used a diode laser (660 nm) with a dose of 3 J/cm² per point and 4 s per point was applied in four different periods, preoperatively; transoperatively and immediately postoperatively, the application was performed in three points (eight applications) on alternate days for 7 days and a 90-day follow-up was performed for clinical evaluations of the periodontal parameters and the collected data were analyzed by Kruskal-Wallis and Dunn tests.

RESULTS

the RC mean percentage was <95% in both groups after 90 days. Comparing treatment sides, G1 (n = 3/3, 100%) had a higher prevalence of RC than G2 had (n = 3/3, 95%). DHS significantly decreased after 90 days in both groups. Both groups showed an improvement in the other periodontal parameters evaluated during the short-term follow-up; mainly, PD had a statistically significant (p ˂ 0.05) increase after 90 days and a CAL decrease during this period; KTW and KTT also had a significant increase in both groups (p ˂ 0.05).

CONCLUSIONS

the results indicated that aCTG + LLLT might have an additional benefit to GR root coverage within the evaluated time and this section also includes the within-study limitations.

The anti-ovarian cancer effect of RPV modified paclitaxel plus schisandra B liposomes in SK-OV-3 cells and tumor-bearing mice

AIMS

Due to poor targeting ability of anti-tumor drugs and self-adaptation of tumors, the chemotherapy of ovarian cancer is still poorly effective. In recent years, the treatment of tumor with nano-targeted agents has become a potential research focus. In this study, a new type of short cell-penetrating peptide RPV-modified paclitaxel plus schisandrin B liposomes were constructed to disrupt VM channels, angiogenesis, proliferation and migration for the treatment of ovarian cancer.

MATERIALS AND METHODS

In this study, clone assay, TUNEL, Transwell, wound-healing, CAM and mimics assay were used to detect the effects of RPV-modified liposomes on ovarian cancer SK-OV-3 cells before and after treatment. HE-staining, immunofluorescence and ELISA were used to further detect the expression of tumor-related proteins.

KEY FINDINGS

RPV-modified paclitaxel plus schisandrin B liposomes can inhibit angiogenesis, VM channel formation, invasion and proliferation of ovarian SK-OV-3 cells. In vitro and in vivo studies showed that tumor-related protein expression was down-regulated. Modification of RPV can prolong the retention time of liposome in vivo and accumulate in the tumor site, increasing the anti-tumor efficacy.

SIGNIFICANCE

The RPV-modified paclitaxel plus schisandrin B liposomes have good anti-tumor effect, thus may provide a new avenue for the treatment of ovarian cancer.