Curcumin-silica nanocomplex preparation, hemoglobin and DNA interaction and photocytotoxicity against melanoma cancer cells.

Melanoma is a malignant cancer of the skin associated with a high mortality. Early medical diagnosis and surgical intervention are essential for the treatment of melanoma. The use of plant-based compounds is an important strategy for the prevention and treatment of different types of cancers. Curcumin is a promising natural anticancer compound used towards treatment for various kinds of cancers. Studies have shown that curcumin could be applied as a photosensitizer in cancer photodynamic therapy (PDT). PDT uses light and a photosensitizing agent which produce reactive oxygen species leading to cancer cell death. The main obstacle for using curcumin as photosensitizer is its low solubilization ability in an aqueous environment. To improve its application in cancer treatment, we synthetized curcumin-silica nanoparticles as photosensitizer for photodynamic treatment of human melanoma cancer cells. Scanning electron microscopy, Transmission electron microscopy, Powder X-ray diffraction and Thermo geometric analysis indicated that curcumin was loaded on silica. The solubility of curcumin in water increased by using silica nanoparticles which wasconfirmed by spectroscopy results. The spectroscopy study confirmed the interaction of curcumin-silica nanocomplex with double strand DNA and no interaction with hemoglobin. The curcumin-silica nanocomplex and curcumin photodynamic effect was investigated on human melanoma cancer cells (A375) and also human fibroblast cells. The cell toxicity experiments showed that the curcumin-silica nanocomplex had greater photodynamic effects on cancer cell death as compared to free curcumin. The apoptotic assay by acridine orange/ethidium bromide (AO/EB) dual staining and colony forming ability confirmed the MTT results. Therefore, these results suggest that the curcumin-silica nanocomplex has great potential to be employed in photodynamic treatment of melanoma cancer.

Antimicrobial photodynamic and wound healing activity of curcumin encapsulated in silica nanoparticles.

The multidrug resistance of pathogenic bacteria has become a serious problem to public health. Therefore finding novel approaches to combat multidrug resistant bacteria have therefore become increasingly important. One promising approach is antimicrobial photodynamic therapy (aPDT) which involves the use of photosensitizer (nontoxic dyes) that are excited by visible light and produce oxygen free radicals in the presence of oxygen. In this study, we investigated the antimicrobial photodynamic effect of free curcumin and curcumin silica nanoparticle as photosensitizer on planktonic and biofilm forms of Pseudomonas aeruginosa, Staphylococcus aureus. After performing MTT assay (to evaluate curcumin nano complex toxicity on human fibroblast cells), the effect of aPDT at 465 nm on bacteria in the planktonic and biofilm forms were investigated. The results showed that by using curcumin in the form of curcumin-silica nanoparticle as photosensitizer, there is a reduction in the number of bacteria in planktonic condition and bacterial biofilm production. Curcumin-silica nanoparticle not only did not show any significant cytotoxic effect against human normal fibroblast but also showed wound healing properties as confirmed with in vitro scratch assay. Therefore, aPDT based curcumin-silica nanoparticle could be suggested as novel approach in the treatment of multi drug resistant bacteria in chronic wound infection condition.

Simple chemiluminescence determination of ketotifen using tris(1,10 phenanthroline)ruthenium(II)- Ce(IV) system.

A new method using chemiluminescence (CL) detection has been developed for the simple determination of ketotifen fumarate (KF). The method is based on the catalytic effect of KF in the CL reaction of tris(1,10 phenanthroline)ruthenium(II), Ru(phen)3 (2+), with Ce(IV) in sulfuric acid medium. The CL response was detected using a lab-made chemiluminometer. Effects of chemical variables were investigated and under optimum conditions, the CL intensity was proportional to the concentration of the drug over the range 0.34-34.00 µg mL(-1) KF. The limit of detection (S/N=3) was 0.09 µg mL(-1). Effects of common ingredients were investigated and the method was applied successfully for determining KF in pharmaceutical formulations and human plasma. The percent of relative standard deviation (n=11) at level of 3.4 µg mL(-1) of KF was 4.6% and the minimum sampling rate was 70 samples per hour. The possible CL mechanism is proposed based on the kinetic characteristic of the CL reaction, CL spectrum, UV-Vis and phosphorescence spectra.