The Optimized Formulation of Tamoxifen-Loaded Niosomes Efficiently Induced Apoptosis and Cell Cycle Arrest in Breast Cancer Cells.

The aim, as proof of concept, was to optimize niosomal formulations of tamoxifen in terms of size, morphology, encapsulation efficiency, and release kinetics for further treatment of the breast cancer (BC). Different assays were carried out to evaluate the pro-apoptotic and cytotoxicity impact of tamoxifen-loaded niosomes in two BC cells, MDA-MB-231 and SKBR3. In this study, tamoxifen was loaded in niosomes after optimization in the formulation. The formulation of niosomes supported maximized drug entrapment and minimized their size. The novel formulation showed improvement in storage stability, and after 60 days only, small changes in size, polydispersity index, and drug entrapment were observed. Besides, a pH-dependent release pattern of formulated niosomes displayed slow release at physiological pH (7.4) and a considerable increase of release at acidic pH (5.4), making them a promising candidate for drug delivery in the BC treatment. The cytotoxicity study exhibited high biocompatibility with MCF10A healthy cells, while remarkable inhibitory effects were observed after treatment of cancerous lines, MDA-MB-231, and SKBR3 cells. The IC50 values for the tamoxifen-loaded niosomes were significantly less than other groups. Moreover, treatment with drug-loaded niosomes significantly changed the gene expression pattern of BC cells. Statistically significant down-regulation of cyclin D, cyclin E, VEGFR-1, MMP-2, and MMP-9 genes and up-regulation of caspase-3 and caspase-9 were observed. These results were in correlation with cell cycle arrest, lessoned migration capacity, and increased caspase activity and apoptosis induction in cancerous cells. Optimization in the formulation of tamoxifen-loaded niosomes can make them a novel candidate for drug delivery in BC treatment.

Enhanced Antibacterial Activity of Echinacea angustifolia Extract against Multidrug-Resistant Klebsiella pneumoniae through Niosome Encapsulation.

With the increased occurrence of antibiotic-resistant bacteria, alternatives to classical antibiotics are urgently needed for treatment of various infectious diseases. Medicinal plant extracts are among the promising candidates due to their bioactive components. The aim of this study was to prepare niosome-encapsulated Echinacea angustifolia extract and study its efficacy against multidrug-resistant Klebsiella pneumoniae strains. Encapsulation was first optimized by Design of Experiments, followed by the empirical study. The obtained niosomes were further characterized for the size and morphology using dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Spherical niosomes had a diameter of 142.3 ± 5.1 nm, as measured by DLS. The entrapment efficiency (EE%) of E. angustifolia extract reached up to 77.1% ± 0.3%. The prepared niosomes showed a controlled drug release within the tested 72 h and a storage stability of at least 2 months at both 4 and 25 °C. The encapsulated E. angustifolia displayed up to 16-fold higher antibacterial activity against multidrug-resistant K.pneumoniae strains, compared to the free extract. Additionally, the niosome exhibited negligible cytotoxicity against human foreskin fibroblasts. We anticipate that the results presented herein could contribute to the preparation of other plant extracts with improved stability and antibacterial activity, and will help reduce the overuse of antibiotics by controlled release of natural-derived drugs.