İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Seryum oksit nanopartküller: Sentez, karakterizasyon ve analitik kimya uygulamaları
(BİDGE Yayınları, 2025) Özdemir Olgun, Fatoş Ayça
Nanoteknoloji, nano boyutta mühendisliği ve teknolojiyi kapsayan endüstri, elektronik ve sağlık alanında birçok uygulaması olan bir bilim dalıdır. Nanopartiküller 1-100 nm boyutlarına sahip nano boyutlu malzemeleri kapsamaktadır (Khan Ibrahim et al., 2017). Nanopartiküllerin nano ölçekli olmasıyla yığın malzemelerden farklı fiziksel ve kimyasal özelliklere sahiptir. Yığın malzemelerden daha iyi özellik göstermesiyle pek çok alanda nanopartiküller yenilikler sunarak malzemelerin özellikleri iyileştirmek ve daha verimli hale getirmek için sıklıkla kullanılırlar. Bu alandaki araştırmalar nanopartiküllerin fiziksel ve kimyasal özelliklerini inceleyerek çeşitli uygulama alanlarındaki rollerini anlamayı hedeflemektedir. Seryum oksit nanopartikülleri bu bakımdan önemli bir tür olup çeşitli endüstriyel ve çevre uygulamalarında kullanım alanları geliştirilen bir malzemedir (Altammar, 2023).
Application of liquid-liquid microextraction techniques for trace level determination of organic/inorganic analytes in biological, medical, environmental and forensic samples
(Elsevier, 2025) Chormey, Dotse Selali; Bodur, Sezin Erarpat; Öztürk Er, Elif; Zaman, Buse Tuğba; Bodur, Süleyman; Şaylan, Meltem; Dalgıç Bozyiğit, Gamze; Serbest, Hakan; Bakırdere, Sezgin
The drawbacks of the conventional liquid-liquid extraction method have been greatly alleviated with the advent of liquid-liquid microextraction methods, which are being actively utilized as effective sample preparation tools for biological, medical, environmental and forensic samples. The complex nature of these sample matrices tend to hinder the accuracy and precision of analytical measurements, and have the potential to cause false positive and false negative results. With sample preparation remaining an integral part of accurate determination of organic and inorganic analytes in complex samples, liquid-liquid microextraction as an efficient sample preparation approach facilitates the acquisition of analytes in final forms that are suitable for modern and classical analytical instruments. The use of very low solvent volumes in liquid-liquid microextraction methods leads to very high enrichment factors, and the availability of different extractants paves way for selective analyte extractions. Recent calls for greener approaches of analysis have been met with the introduction of several green solvents that boost the greenness of liquid-liquid microextraction methods and equally maintain the superiority of the methods. © 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Formulation and characterization of an oleuropein-enriched oral spray gel: Microbiological performance and in ovo histopathological safety
(MDPI Publishing, 2026) Alparslan, Levent; Özdemir, Samet; Karacan, Burak; Tutar, Ömer Faruk; Doğan, Tunay; Akar, Remzi Okan; Yıldırım, Elifnur Gizem; Erdoğan, Nusret
Background/Objectives: Oleuropein is a bioactive phenolic compound from olive leaves with antimicrobial and antioxidant activity. This study aimed to develop a sprayable oral gel containing an oleuropein-rich aqueous extract and to evaluate its pharmaceutical performance antimicrobial efficacy and in ovo biological response. Methods: Oleuropein content was quantified using a validated chromatographic method. Polymeric systems were screened to select an optimized sprayable formulation. Physicochemical stability, dose uni formity, and antimicrobial activity against major cariogenic bacteria were evaluated. In ovo biological evaluation was conducted using the chick chorioallantoic membrane angiogene sis model together with histopathological examination of embryonic heart and liver tissues. Results: Oleuropein content was determined as 288.6 µg/mL in the olive leaf extract and 255.1 µg/mL in the final formulation. The optimized oral spray showed stable physico chemical properties, with pH maintained at 6.90 ± 0.02 and no relevant changes in viscosity during storage. The mean delivered dose per actuation was 0.128 ± 0.015 g, corresponding to 32.6 µg oleuropein per spray. The formulation exhibited inhibitory activity against all tested cariogenic microorganisms, with MIC values ranging from 13.3 to 170.7 µg/mL and MBC values generally two-fold higher. In the CAM assay, significant concentration- and time-dependent antiangiogenic effects were observed after 24–48 h at moderate and higher concentrations. Histopathological evaluation revealed dose-dependent acute degenerative and congestive changes in heart and liver tissues without evidence of fibrosis or steatosis. Conclusions: The oleuropein-based sprayable oral gel is a promising localized delivery system with adequate stability dose uniformity and antimicrobial efficacy. In ovo findings provide a conservative assessment of systemic exposure and support further development for oral biofilm and caries-related applications.
Development of brimonidine-loaded ethosomes for glaucoma: Investigation of intraocular pressure-lowering potential in vivo
(MDPI Publishing, 2026) Özdemir, Samet; Sağıroğlu, Ali Asram; Şen, Eslim; Gelmez Yıldız, Büşra; Karimli, Laman; Ezgi Durgun, Meltem; Çelebi, Ali Riza Cenk; Özsoy, Yıldız
Background/Objectives: Brimonidine tartrate (BRT), a selective α2-adrenergic receptor agonist, is commonly used in the treatment of glaucoma. However, conventional eye drop formulations suffer from poor ocular bioavailability and rapid elimination. This study aimed to develop and evaluate BRT-loaded ethosomes as a nanocarrier-based alternative to enhance intraocular delivery and therapeutic efficacy. Methods: Ethosomes were prepared using the thin-film hydration method and optimized via central composite design. The optimized formulation was subjected to physicochemical characterization, in vitro release testing, and ocular irritation assessment using the Hen egg test—chorioallantoic membrane (HET-CAM) model. Additionally, the intraocular pressure (IOP)-lowering efficacy of the formulation was evaluated in a rat glaucoma model. Results: The optimized ethosomal formulation exhibited favorable physicochemical properties, including a mean particle size of 122.6 ± 0.7 nm, zeta potential of −1.8 ± 0.9 mV, and encapsulation efficiency of 87.33 ± 0.04%. In vitro release data followed Higuchi kinetics. HET-CAM analysis indicated non-irritancy. In vivo, the ethosomal BRT formulation achieved comparable IOP-lowering effects to the marketed eye drops at one-third of the dose. Conclusions: The developed BRT loaded ethosomal system demonstrated promising physicochemical stability, sustained release, and therapeutic potential. These findings suggest that ethosomes may offer a safe and effective strategy for enhancing the ocular delivery of BRT in glaucoma therapy.
Anatomical study of the superficial and deep circumflex iliac arteries: Morphology, variability, and surgical relevance
(Springer Nature Link, 2026) Ok, Fatma; Nteli Chatzioglou, Gkionoul; Karip, Burak; Önal, Vildan; Yıldız, Nilay; Tatar, Burak Ergün; Gayretli, Özcan
Purpose The vascular anatomy of the groin region plays an important role in reconstructive surgery and regional anesthesia, yet data on the precise morphology and topography of the superficial and deep circumflex iliac arteries remain limited. Methods 28 lower extremities of fourteen formalin-fixed male cadavers were dissected to examine the superficial and deep circumflex iliac arteries. Their origins, branching patterns, diameters, and spatial relationships to the inguinal ligament and femoral triangle were recorded. Morphometric distances were measured with a digital caliper, and correlations between parameters were analyzed statistically. Results The superficial circumflex iliac artery arose exclusively from the femoral artery in all cases and was consistently located within the femoral triangle. Its mean origin diameter was 1.83±0.46 mm. The deep circumflex iliac artery showed greater variability, originating from the external iliac artery in half of the cases and from the femoral artery in the other half. Its mean origin diameter was 2.25±0.40 mm, and it was located outside the femoral triangle in 71.4% of cases. Multiple significant correlations were identified between vessel diameters, bifurcation points, and their spatial relationships with the inguinal ligament. Conclusion The superficial circumflex iliac artery displays consistent anatomy, whereas the deep circumflex iliac artery demonstrates notable variability in origin and topography, though with stable vessel caliber. These findings provide detailed morphometric insights that may support safer flap design and improve surgical and anesthetic planning in the groin region.
