Evaluation of cytotoxicity impacts of combined methylene blue-mediated photodynamic therapy and intracanal antibiotic medicaments on dental stem cells.

Root canal therapy is a predominant method for treatment of dental pulp and periapical diseases. Conventional methods such as mechanical instrumentations, chemical irrigation and intracanal medicaments pose a huge limitation to root canal disinfection as they kill bacteria and dental stem cells simultaneously. Therefore, much attention has been focused on finding more efficacious antibacterial methods that has no or negligible cytotoxicity for dental stem cells. Herein, we hypothesized that combining antibacterial medicaments with Antimicrobial photodynamic therapy (aPDT) and methylene blue (MB) as a photosensitizer would be effective in reducing death of dental pulp stem cells (DPSCs). To examine this, DPSCs were isolated from third molar teeth through enzymatic digestion. Isolated cells were cultured in αMEM and when reached adequate confluency, were used for further analysis. Cytotoxicity effect of different groups of MB, DAP, MB, LED and their combination on DPSCs was analyzed using MTT assay. DPSCs membrane integrity as a marker of live cells was assessed through measuring lipid peroxidation and lactate dehydrogenase (LDH) release into extracellular space. Results showed that the combination of LED, MB and TAP or aPDT, MB and DAP was more effective in reducing DPSCs death rate compared to TAP and DAP administration alone. Moreover, Malondialdehyde (MDA) and LDH levels were found to be decreased in cells exposed to combination treatment in comparison with single TAP or DAP therapy. Our study shows the promising perspectives of employing combined aPDT, MB and antibiotic medicaments for reduction of dental stem cell death.

Silymarin-Loaded Tin(IV) Nanoparticles Exhibit Enhanced Bioavailability and Antiproliferative Effects on Colorectal Cancer Cells.

Silymarin (SM) exhibits potential therapeutic effects due to having antioxidant activity. However, the low solubility and bioavailability of SM restrict its biological performance. To overcome this limitation, this study aimed to develop a nanoformulation composed of SM and dimethyltindichloride and investigate the effect of SM-loaded Sn nanoparticles on cancer cell growth and survival. An SM-Sn complex was synthesized and then characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), EDS-MAP, dynamic light scattering (DLS), and ζ-potential analysis. After that, the SW480 colorectal cancer cell line was treated with different concentrations of SM and the SM-Sn complex. Cell viability was examined through the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, analyzing apoptosis, and live-dead assay. The lipid peroxidation rate was assessed through the measurement of thiobarbituric acid (TBA). Intracellular reactive oxygen species (ROS) level and cell population in the cell cycle were measured using a flow cytometry instrument. To evaluate the colonization ability of SW480 cells, a colony formation assay was performed. Gene expression analysis was also conducted using a real-time polymerase chain reaction (PCR) technique. The findings of this study revealed the effectiveness of the SM-Sn complex in decreasing SW480 cell viability by inducing cell death-associated mechanisms. We found that the SM-Sn complex increases intracellular ROS level and malondialdehyde (MDA) content. It was also revealed that the SM-Sn complex induces cell cycle arrest and the expression of apoptotic genes. In addition, the SM-Sn complex could effectively hinder SW480 cells from constituting colonies. We conclude that the use of tin(IV) as a scaffold for enhanced delivery of SM could be considered an efficient option for inhibiting cancer cell proliferation and survival.

Combination of cisplatin treatment and photodynamic therapy attenuates cisplatin-induced cell toxicity in A2780 and A2780-CP cervical cancer cell lines.

Cervical cancer is recognized as a serious worldwide health problem. Despite various achievements for cervical cancer treatment, there are still shortcomings that lead to severe side effects. Combination therapy is fast becoming a key and promising treatment strategy, diminishing chemotherapy-mediated side effects. The objective of this study was to determine the effect of combined cisplatin treatment and photodynamic therapy (PDT) on the cervical cancer recovery. In this study, A2780 and A2780-CP cell lines were cultured in the Dulbecco's modified eagle medium (DMEM) enriched with 10% FBS and 1% antibiotic. Both cell lines were treated with cisplatin, photodynamic light (laser with methylene blue as a photosensitizer agent), and the combination of cisplatin treatment and PDT. Half maximum inhibitory concentration (IC50) was calculated for each treatment by the use of tetrazolium salt assay. Both cell lines were examined for cell membrane lipid peroxidation rate. Our findings showed that combination of cisplatin treatment and photodynamic therapy leads to two-fold decreased cisplatin IC50. Results showed that cisplatin and photodynamic light combination could effectively reduce A2780 and A2780-CP cell viability (p-value < 0.0001). Moreover, combined cisplatin and photodynamic therapy results revealed significantly increased cancer cell membrane destruction through increased lipid peroxidation, resulting in surged MDA content. Our conclusion is that combination of cisplatin and photodynamic therapy can be used as an effective and convenient treatment strategy without considerable side effects.

Evaluation of Biological Activity of Different Wavelengths of Low-Level Laser Therapy on the Cancer Prostate Cell Line Compared With Cisplatin.

Introduction: Cancer is one of the most important problems in the world. Low-level laser therapy (LLLT) has been emerged as a new approach, having both stimulation and inhibition effects on cellular function. The goal of this study was to analyze and compare the different concentrations of cisplatin and wavelengths of laser therapy on the LnCap cell lines. Methods: LnCap cells were cultured and treated with different concentrations of cisplatin (0.1, 0.4, 0.8, 1.2 and 2 µg/mL for 24 hours) and wavelengths of laser therapy (610, 630 and 810 nm) (0.45 J/cm2) separately. The viability of cells was examined by MTT assay and IC50 was also calculated. Furthermore, a combination of cisplatin IC50 (24 hours) and different wavelengths of the laser was examined. Results: The results of this study showed that 2 µg/mL of cisplatin has the most significant reduction effect on the cell viability of the LnCap cell line. Cisplatin decreased the viability of cells in a dose-dependent manner. Moreover, IC50 of cisplatin was 1.24 µg/mL. On the other hand, LLLT with wavelengths of 610, 630 and 810 nm did not show notable biological effects on cell viability. Conclusion: As known, cisplatin has the capability to reduce the viability of LnCap cell lines. However, LLLT cannot be a remarkable option for the treatment of prostate cancer. Therefore, although laser therapy showed praiseful therapeutic activity against some cancer cell lines, in this study the results indicated that defined laser wavelengths had no inhibitory effects against the prostate cancer cell line.