Gökhan Dikmen

Characterization of Solid Lipid Nanoparticles Containing Caffeic Acid and Determination of its Effects on MCF-7 Cells

Many anticancer drugs that are currently used in cancer treatment are natural products or their analogues by structural modification. Caffeic acid (3, 4-dihydroxycinnamic acid; CA) is classified as hydroxycinnamic acid and has a variety of potential pharmacological effects, including antioxidant, immunomodulatory and anti-inflammatory activities. As a drug carrier, solid lipid nanoparticles (SLNs) introduced to improve stability, provide controlled drug release, avoid organic solvents and are obtained in small sizes. In this study, we developed solid lipid nanoparticles incorporating with caffeic acid using hot homogenization method. Caffeic acid loaded solid lipid nanoparticles were characterized regarding particle size, zeta potential, drug entrapment efficiency, drug release, scanning electron microscopy (SEM) and FT-IR. The effects of caffeic acid loaded solid lipid nanoparticles on MCF-7 cells were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dimethyl tetrazolium bromide (MTT) test and Annexin V-PI analysis. As a result, solid lipid nanoparticles could potentially be used for the delivery of caffeic acid and solid lipid nanoparticles formulation enhanced the effects of caffeic acid on MCF-7 cells. Some relevant patents are also referred in this article.

Solid lipid nanoparticles: Reversal of tamoxifen resistance in breast cancer

&NA; The objective of the present study was to investigate the effect of tamoxifen (Tam) loaded solid lipid nanoparticles (SLNs) on MCF7 Tam‐resistant breast cancer cells (MCF7‐TamR). Tam‐SLNs were produced by the hot homogenization method. The characterization studies of Tam‐SLNs demonstrated good physical stability with small particle size. The in vitro cytotoxicity results showed that Tam‐SLNs enhanced the efficacy of Tam and reversed the acquired Tam resistance by inducing apoptosis, altering the expression levels of specific miRNA and the related apoptosis‐associated target‐genes in both MCF7 and MCF7‐TamR cells without damaging the MCF10A control cells (p < 0.05). In conclusion, we demonstrated a molecular mechanism of the induction of apoptosis by Tam‐SLNs in MCF7 and MCF7‐TamR cells, and thus, we demonstrated that Tam‐SLNs were more effective than Tam. The present study suggests that the use SLNs may be a potential therapeutic strategy to overcome Tam‐resistance in breast cancer for clinical use. Graphical abstract Tam‐SLNs could potentially overcome Tam‐resistance by inducing apoptosis in breast cancer. Figure. No Caption available.

A novel [Mn2(μ-(C6H5)2CHCOO)2(bipy)4](bipy)(ClO4)2 complex loaded solid lipid nanoparticles: synthesis, characterization and in vitro cytotoxicity on MCF-7 breast cancer cells

Abstract Manganese (Mn)-based complexes have been drawing attention due to the fact that they are more effective than other metal complexes. However, the use of Mn(II)-based complexes in medicine remains limited because of certain side effects. The aim of this study was to investigate the cytotoxic and apoptotic effects of a novel Mn(II) complex [Mn2(μ-(C6H5)2CHCOO)2(bipy)4](bipy)(ClO4)2 and Mn(II) complex loaded solid lipid nanoparticles (SLNs) on MCF-7 and HUVEC control cells. The average diameter of Mn(II) complex was about 1120 ± 2.43 nm, while the average particle size of Mn(II) complex-SLNs was ∼340 ± 2.27 nm. The cytotoxic effects of Mn(II) complex and Mn(II)-SLNs were 86.8 and 66.4%, respectively (p < .05). Additionally, both Mn(II) complex (39.25%) and Mn(II)-SLNs (38.05%) induced apoptosis and increased the arrest of G0/G1 phase. However, Mn(II) complex exerted toxic effects on the HUVEC control cell (63.4%), whereas no toxic effects was observed when treated with Mn(II)-SLNs at 150 μM. As a consequence, SLNs might be potentially used for metal-based complexes in the treatment of cancer due to reducing size and toxic effects of metal-based complexes.

The Anticancer Activity of Complex [Cu2(μ-(C6H5)2CHCOO)3(bipy)2)] (ClO4) -Solid Lipid Nanoparticles on MCF-7 Cells

Recent studies have focused on the potential use of metal-based complexes for the treatment of cancer. However, there are some limitations of metal-based ligands for the treatment of cancer due to their toxic effects. In the present study, a novel bimetallic Cu(II) complex, [Cu2(μ-(C6H5)2CHCOO)3 (bipy)2)](ClO4), has firstly been synthesized and characterized by FT-IR, and X-ray crystallography. Furthermore, Cu(II) complex-loaded solid lipid nanoparticles (SLNs) were initially prepared by hot homogenization method to overcome their toxic effects. After characterization, comparative cytotoxic and apoptotic activities of the complex and Cu(II) complex-SLNs on human breast cancer cells (MCF-7) and human umbilical vein endothelial cells (HUVEC) were determined. Cu(II) complex demonstrated considerable in vitro cytotoxic effects on MCF-7 (p<0.05) and induced apoptotic cell death (88.02 ± 3.95%) of MCF-7 cells. But, the complex has also toxic effects (69.5%) on HUVEC control cells. For this purpose, Cu(II) complex-loaded solid lipid nanoparticles (SLN) were firstly produced, with a distrubution range of 190±1.45 nm to 350±1.72 nm and zeta potentials of -27.4±1.98 mV and -18.2±1.07 mV, respectively. The scanning electron microscopy (SEM) images of SLNs were also obtained. In vitro studies have shown that Cu(II) complex-SLNs help in reducing the side effect of Cu(II) complex (29.9%) on HUVEC control cells. Therefore, metal based complex might potentially be used for cancer treatment through nanoparticle based drug delivery systems.

THE INVESTIGATION OF THE EFFECT OF GRAIN SIZE ON RAMAN AND 29Si MAS NMR SPECTRA OF BENTONITES FROM TURKEY

Bilim ve endustri alaninda killere oldukca yogun bir ilgi vardir. Literaturde; titresim spektroskopisi ve ozellikle FT-IR ve NMR spektroskopik yontemlerinin, killer uzerine olan bilimsel calismalarda siklikla kullanildigi gorulmektedir. Buna karsin yorumlanabilir bir spektrum eldesinin guc olusundan dolayi ozellikle Raman spektrumlarina ayni siklikta rastlanilmamaktadir. Cogu zaman, bircok calismada parcacik boyutu Raman ve NMR spektrumlarinin kalitesine tesir eden bir unsur olarak ele alinmaz. Bu calismada Unye yoresinden elde edilen killer icin farkli parcacik boyutlarina sahip numuneler hazirlanmis, Raman ve 29Si NMR spektrumlari alinmis ve parcacik boyutunun spektrumlar uzerine tesiri incelenmistir