Abeer Al Bawab

Thymoquinone in liposomes: a study of loading efficiency and biological activity towards breast cancer

Thymoquinone (2-isopropyl-5-methyl-1,4-benzoquinone) is a herbal-derived drug with potential chemopreventive and chemotherapeutic activity. However, thymoquinone suffers from high hydrophobicity causing poor solubility which limits its bioavailability and high lipophilicity causing poor formulation characteristics. Liposomes are versatile drug carriers that can be used to solve problems of drug solubility, instability, and bio-distribution. In this study, we were able to prepare thymoquinone-loaded liposomes (TQ-LP) and thymoquinone loaded in liposomes modified with Triton X-100 (XLP) with diameters of about 100 nm, and entrapment efficiency of more than 90% for TQ-LP and of 49.6% for XLP. The TQ-LP liposomes were effective in suppressing the proliferation of breast cancer cell lines MCF-7 and T47D, and at the same time exerting very low toxicity on normal periodontal ligament fibroblast. Altogether, this report describes the first successful encapsulation of thymoquinone into liposome; which maintains stability, improves bioavailability and maintains its anticancer activity.

Selection and targeting of EpCAM protein by ssDNA aptamer

Aptamers are molecules that reveal highly complex and refined molecular recognition properties. These molecules are capable of binding with high affinity and selectivity to targets, ranging from small molecules to whole living cells. Several aptamers have been selected for targeting cellular proteins and they have also used in developing therapeutics and diagnostic strategies. Epithelial cell adhesion molecule (EpCAM) is considered as a cancer stem cell (CSC) biomarker and one of the most promising targets for aptamer selection against CSCs. In this study, we have developed a ssDNA aptamer with high affinity and selectivity of targeting the EpCAM protein extracellular domain. The SELEX technique was applied and the resulted sequences were tested on EpCAM-positive human gastric cancer cell line, KATO III, and the EpCAM-negative mouse embryonic fibroblast, NIH/3T3 cells. Ep1 aptamer was successfully isolated and showed selective binding on EpCAM-positive KATO III cells when compared to EpCAM-negative NIH/3T3 cells, as observed by the flow cytometry and the confocal imaging results. Additionally, the binding of Ep1 to EpCAM protein was assessed using mobility shifting assay and aptamers-protein docking. Furthermore, the binding affinity of Ep1 was measured against EpCAM protein using EpCAM-immobilized on magnetic beads and showed apparent affinity of 118 nM. The results of this study could suggest that Ep1 aptamer can bind specifically to the cellular EpCAM protein, making it an attractive ligand for targeted drug delivery and as an imaging agent for the identification of cancer cells.

Correction: Selection and targeting of EpCAM protein by ssDNA aptamer

[This corrects the article DOI: 10.1371/journal.pone.0189558.].

Assessment of Some Heavy Metals in the Dead Sea Mud and Treatment Optimization

ABSTRACT This paper describes the experimental remediation of the Dead Sea mud and the quantitative determination of some heavy metals. Herein, two chelating agents were employed as extracting aqueous solution: ethylenediaminetetraacetic acid (EDTA) and citric acid. The study focused on the main known heavy metals that were reported previously to be in the Dead Sea mud, which are Co, Ni, Pb, Zn, and Cr. Findings had indicated that citric acid was efficient in the removal of the aforementioned heavy metals. Physicochemical parameters that were expected to affect the removal of metals in the Dead Sea mud were optimized. Those parameters were the chelating agent concentration, mixing time and speed, type of washing water, temperature, and pH. The results showed that the best removal of heavy metals from Dead Sea mud can be achieved under optimum citric acid concentration, 1.5 g/50 mL for treatment of 10 g mud. Optimum mixing speed and time were found to be 800 rpm and 1 hr, respectively. Regarding washing water, it was found that the use of the same water for repeated washing provided better removal percentages. pH values and temperature had effect on removal percentages of the heavy metals from mud. However, working at pH 7 and room temperature would provide convenient results for heavy metal removal.

Medicine in Reverse

The axiom “all life is dependent on chemicals” is true but the chemicals must be the right kind and in the right proportions for healthy growth. A second truth is that “external or internal contact with chemicals in overdose concentrations may result in either discomfort, disease or in death”. Often the very therapeutic chemicals (medicines by any other name) created to reduce or eliminate one type of malady result in complications elsewhere in the body when taken accidently in too high dosage. Furthermore, overdoses of illegitimate drugs and exposure to biotoxins damage organs and may lead to death. Examples of some molecules commonly overdosed are shown in Fig. 11.1. This chapter gives fundamental and applied information on oil-in water microemulsion and on functionalized carrier particle colloids designed to selectively bind and physiologically deactivate in vivo several commonly overdosed chemicals. EKG and NMR techniques have been employed to obtain important diagnostic information.