Başkent University

About: Başkent University is a education organization based out in Ankara, Turkey. It is known for research contribution in the topics: Transplantation & Population. The organization has 4652 authors who have published 10380 publications receiving 143117 citations. The organization is also known as: Başkent Üniversitesi.

Aptamer-Gated Nanoparticles for Smart Drug Delivery

Abstract: Aptamers are functional nucleic acid sequences which can bind specific targets. An artificial combinatorial methodology can identify aptamer sequences for any target molecule, from ions to whole cells. Drug delivery systems seek to increase efficacy and reduce side-effects by concentrating the therapeutic agents at specific disease sites in the body. This is generally achieved by specific targeting of inactivated drug molecules. Aptamers which can bind to various cancer cell types selectively and with high affinity have been exploited in a variety of drug delivery systems for therapeutic purposes. Recent progress in selection of cell-specific aptamers has provided new opportunities in targeted drug delivery. Especially functionalization of nanoparticles with such aptamers has drawn major attention in the biosensor and biomedical areas. Moreover, nucleic acids are recognized as an attractive building materials in nanomachines because of their unique molecular recognition properties and structural features. A active controlled delivery of drugs once targeted to a disease site is a major research challenge. Stimuli-responsive gating is one way of achieving controlled release of nanoparticle cargoes. Recent reports incorporate the structural properties of aptamers in controlled release systems of drug delivering nanoparticles. In this review, the strategies for using functional nucleic acids in creating smart drug delivery devices will be explained. The main focus will be on aptamer-incorporated nanoparticle systems for drug delivery purposes in order to assess the future potential of aptamers in the therapeutic area. Special emphasis will be given to the very recent progress in controlled drug release based on molecular gating achieved with aptamers.

Early onset of subclinical atherosclerosis in women with gestational diabetes mellitus

Abstract: Objective Common carotid artery intima-media thickness (CIMT) is a non-invasively assessed marker of subclinical atherosclerosis. Our aim in this study was to investigate CIMT in women with gestational diabetes mellitus (GDM). Methods Thirty women with GDM and 40 unaffected women (as a control group) were included in the study. Blood samples were drawn from each woman in the morning after they had fasted for at least 8 h, and levels of fasting glucose, insulin, homocysteine, total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol and very low-density lipoprotein (VLDL) cholesterol were measured, along with the CIMT in the two groups. Results The mean triglyceride (P = 0.016) and VLDL cholesterol (P = 0.011) levels in the GDM group were significantly higher than those in the unaffected women. There were no significant differences between the groups with respect to plasma levels of total cholesterol, HDL cholesterol, LDL cholesterol and insulin. The mean homocysteine (P = 0.027) and fasting glucose (P = 0.019) levels in women with GDM were significantly higher than those in the control group. Patients with GDM had significantly higher CIMT than did the unaffected women (0.582 ± 0.066 mm vs. 0.543 ± 0.049 mm, P = 0.006). CIMT correlated positively with maternal age (r = 0.316, P = 0.008), body mass index (BMI) at the time of a 50-g oral glucose load test (r = 0.414, P = 0.001) and homocysteine levels (r = 0.332, P = 0.008), and fasting glucose (r = 0.265, P = 0.031) and 1-h glucose value (r = 0.410, P = 0.001) at the time of the oral glucose tolerance test. There was a positive correlation between the presence of GDM and CIMT (r = 0.372, P = 0.001). However, stepwise multiple regression analysis showed that GDM/no GDM (95% CI +0.012 to +0.076, P = 0.008) and BMI at the time of the 50-g test (95% CI +0.001 to +0.009, P = 0.011) were independent parameters related to CIMT. Conclusion Women with GDM have increased CIMT compared with unaffected women. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.

Assessment of bone mineral density in the jaws and its relationship to radiomorphometric indices.

Abstract: Objectives: The aim of this study was to evaluate maxillary, mandibular and femoral neck bone mineral density using dual energy X-ray absorptiometry (DXA) and to determine any correlation between the bone mineral density of the jaws and panoramic radiomorphometric indices. Methods: 49 edentulous patients (18 males and 31 females) aged between 41 and 78 years (mean age 60.2 ± 11.04) were examined by panoramic radiography. Bone mineral density (BMD) of the jaws and femoral neck was measured with a DXA; bone mineral density was calculated at the anterior, premolar and molar regions of the maxilla and mandible. Results: The mean maxillary molar BMD (0.45 g cm−2) was significantly greater than the maxillary anterior and premolar BMD (0.31 g cm−2, P < 0.05). Furthermore, the mean mandibular anterior and premolar BMD (1.39 g cm−2 and 1.28 g cm−2, respectively) was significantly greater than the mean mandibular molar BMD (1.09 g cm−2, P < 0.01). Although BMD in the maxillary anterior and premolar regions were cor...

Cellular Behavior on Epidermal Growth Factor (EGF)-Immobilized PCL/Gelatin Nanofibrous Scaffolds

Abstract: Nano-scaled poly(e-caprolactone) (PCL) and PCL/gelatin fibrous scaffolds with immobilized epidermal growth factor (EGF) were prepared for the purpose of wound-healing treatments. The tissue scaffolds were fabricated by electrospinning and the parameters that affect the electrospinning process were optimized. While the fiber diameters were 488 ± 114 nm and 663 ± 107 nm for PCL and PCL/gelatin scaffolds, respectively, the porosities were calculated as 79% for PCL and 68% for PCL/gelatin scaffolds. Electrospun PCL and PCL/gelatin scaffolds were first modified with 1,6-diaminohexane to introduce amino groups on their surfaces, then EGF was chemically conjugated to the surface of nanofibers. The results obtained from Attenuated Total Reflectance Fourier Transform Infrared (ATR–FT-IR) spectroscopy and quantitative measurements showed that EGF was successfully immobilized on nanofibrous scaffolds. L929 mouse fibroblastic cells were cultivated on both neat and EGF-immobilized PCL and PCL/gelatin scaffolds in orde...