Solution combustion synthesis (SCS) of theranostic ions doped biphasic calcium phosphates; kinetic of ions release in simulated body fluid (SBF) and reactive oxygen species (ROS) generation

Theranostic ions offer suitable platforms for cancer theranostics; here, the effect of doping various amounts of theranostic ions (i.e., Sr²⁺, Fe²⁺, and Ti⁴⁺ ions) on the physicochemical properties and biological activities of calcium phosphates (CaPs) were investigated. The solution combustion synthesis (SCS) was conducted at different amounts of ions (i.e., = 0.1, 0.25, 0.5 mol). Desirable physicochemical properties were obtained in doped samples with 0.1 mol of ions. The particle size of the Sr, Fe, and Ti-doped samples was decreased from 68 to 39, 24, and 29 nm, respectively. The surface charge of the mentioned samples was changed from -20 to -24, -28, and -25 mV, respectively. Besides, the specific surface area of the mentioned samples was significantly increased from 38 to 79, 65, and 106 m²/g, respectively. It was found that bioactivity of doped CaPs improved ~95%, which relied on the high adsorption and desorption rate of Ca²⁺ ions in the simulated body fluid (SBF). The in vitro cell-based results demonstrate the potent effect of CaPs and theranostic ions doped CaPs on the reactive oxygen species (ROS) generation. In the presence of CaPs, the intracellular ROS generation is increased by about 60%. Besides, the intracellular ROS generation is improved in Sr²⁺, Fe²⁺, and Ti⁴⁺ ions doped CaPs by about 66, 64, and 68%. As a result of the high generation of ROS, the bone nodule formation of cell treated CaPs and theranostic ions doped CaPs is improved 25%-37%. Finally, it can be concluded that the use of the SCS approaches for doping of theranostic ions causes well-physicochemical properties and high biological activities.

The effect of aqueous media on the mechanical properties of fluorapatite-mullite glass-ceramics

OBJECTIVES

To verify the effects of alternating thermal changes in aqueous media and chemical composition on mechanical properties of apatite-mullite glass-ceramics and to investigate concentration of ions eluted from glass-ceramics in aqueous media.

MATERIALS AND METHODS

The glass compositions were from SiO2Al2O3P2O5CaOTiO2BaOZrO2CaF2 system. Glass-ceramics were prepared by heat-treating at 1100°C for 3h samples alternately immersed in water at 5 and 60°C. The 3-point bending strength (n=10) were determined using 3×4×25mm/bar and a universal testing machine, at a cross-head speed of 0.1mm/min. Vickers micro hardness were evaluated by applying a total of 15-20 indentations under a 100g load for 30s. Concentrations of ions eluted from glass-ceramics immersed in 60±5°C double distilled water were determined by ion chromatography. The toxicity of glass-ceramics was assessed by seeding the osteosarcoma cells (MG63) on powder for different days and their cell proliferation assessment was investigated by MTT assay. The data were analyzed using one way analysis of variance and the means were compared by Tukey's test (5% significance level).

RESULTS

The highest flexural strength and hardness values after thermal changes belonged to TiO2 and ZrO2 containing glass-ceramics which contained lower amount of released ions. BaO containing glass-ceramic and sample with extra amount of silica showed the highest amount of reduction in their mechanical strength values. These additives enhanced the concentration of eluted ions in aqueous media. MTT results showed that glass-ceramics were almost equivalent concerning their in-vitro biological behavior.

SIGNIFICANCE

Thermal changes and chemical compositions had significant effects on flexural strength and Vickers micro-hardness values.

Mogoltacin enhances vincristine cytotoxicity in human transitional cell carcinoma (TCC) cell line

Bladder cancer is the second common cancer of the genitourinary system throughout the world and intravesical chemotherapy is usually used to reduce tumour recurrence and progression. Human transitional cell carcinoma (TCC) is an epithelial-like adherent cell line originally established from primary bladder carcinoma. Here we report the effect of mogoltacin, a sesquiterpene coumarin from Ferula badrakema on TCC cells. Mogoltacin was isolated from the fruits of F. badrakema, using silica gel column chromatography and preparative thin layer chromatography. Mogoltacin did not have any significant cytotoxicity effect on neoplastic TCC cells at 16, 32, 64, 128, 200 and 600 microg ml(-1) concentrations. In order to analyse its combination effect, TCC cells were cultured in the presence of various combining concentrations of mogoltacin and vincristine. Cells were then observed for morphological changes (by light microscopy) and cytotoxicity using MTT assay. The effect of mogoltacin on vincristine toxicity was studied after 24, 48 and 72 h of drug administration. The results of MTT assay showed that mogoltacin can significantly enhance the cytotoxicity of vincristine and confirmed the morphological observations. Results revealed that combination of 40 microg ml(-1) vincristine with 16 microg ml(-1) mogoltacin increased the cytotoxicity of vincristine after 48 h by 32.8%.