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
Synergistic cytotoxicity of bentonite–zeolite 4A nanocomposite in human melanoma cells
(Taylor & Francis, 2026) Duman, Nilay; Evcin, Atilla; Çelik, Sefa; Oraloğlu, Göktürk; Caner, Ayşe
The cytotoxic effects of bentonite and zeolite 4A nanoparticles (NPs), as well as their nanocomposite (NC), were investigated in human melanoma (G361) cells. Although both materials have demonstrated anticancer potential, their effects on melanoma remain insufficiently explored. This study aimed to evaluate the cellular responses induced by bentonite and zeolite 4A NPs, individually and in combination, in G361 cells. Methods: Physicochemical characterization was performed using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). IC₅₀ values were determined for bentonite NPs, zeolite 4A NPs, and the NC. Cell viability was assessed using the MTT assay, while apoptosis was evaluated through caspase-3 activity measured by ELISA. Results: All treatments exhibited dose-dependent cytotoxicity in melanoma cells. Notably, the NC demonstrated a strong synergistic interaction, enhancing cytotoxic effects and enabling reduced effective concentrations. Despite the pronounced cytotoxicity observed in the NC group, no significant increase in caspase-3 activity was detected compared to control. These findings suggest the involvement of caspase-independent cell death mechanisms, particularly necrotic or non-classical apoptotic processes. Conclusion: The bentonite/zeolite 4A nanocomposite exerts synergistic cytotoxic effects in melanoma cells. While the results highlight its therapeutic potential, further mechanistic studies are required to clarify the underlying pathways prior to clinical translation.
Aesthetic preformed paediatric crowns in primary incisors: A bibliometric study and critical analysis
(Springer Nature Link, 2026) Taşdemir, Tülin; Erbaş Ünverdi, Gizem; Çehreli, Zafer Cavit
Purpose The aim of this bibliometric study was to assess clinical research regarding preformed crowns used for the treat ment of primary anterior teeth. Methods A search was conducted in the Web of Science Core Collection (WoSCC) for publications on preformed crowns for primary anterior teeth, and was completed in a single day (August 8, 2025), identifying 379 articles. After filtering for original research and case report/series published in English, 40 relevant articles were selected for review. These publications were evaluated based on annual publication trends, study designs, journals, citation counts, authors, and keywords, using the ‘biblioshiny’ program in RStudio. Additionally, the review included critical analysis of articles with full texts to collect detailed information on study design, sample size, and clinical outcomes. Results The review of 40 articles over three decades showed a 4.57% annual increase in publication number on preformed crowns for primary anterior teeth, especially since 2012, with USA authors leading. The data reveal temporal trends in preveneered preformed metal crowns for anterior primary teeth, strip crown success, zirconia crowns (gingival health, qual ity of life and parental satisfaction comparisons), and preformed crowns for primary anterior teeth after pulpal treatment. Amongst them, the journal “Pediatric Dentistry” had published the most papers. Recent studies highlighted zirconia crowns’ high retention and gingival health benefits, whilst strip crowns showed lower durability. Conclusion For anterior primary teeth, that zirconia crowns offered high durability, aesthetics, and parental satisfaction. The heterogeneity of study designs underscores the necessity for more comprehensive research to inform paediatric dentistry practices.
Novel peripheral and nonperipheral tetrasubstituted zinc(II) phthalocyanines with ester-containing coumarin substituents: Synthesis, characterization, aggregation, thermal and antioxidant studies
(Springer Nature Link, 2026) Özgül Artuç, Gamze
In this study, nonperipheral and peripheral zinc metallophthalocyanine compounds substituted with coumarin contain ing ester groups were synthesized, their chemical structures were characterized, and their aggregation behaviours were investigated. Their antioxidant properties were investigated using 1,1-diphenyl-2-picrylhydrazine (DPPH). The antioxidant activity studies revealed that the peripheral substituted phthalocyanine compound had higher antioxidant activity than the nonperipheral phthalocyanine compound. Their thermal analysis were investigated using thermal gravimetric analy sis. Thermal analysis studies concluded that the synthesized zinc metal phthalocyanine compounds are thermally stable compounds.
Nicotinic acid–modified chitosan nanoparticles for enhanced resveratrol delivery and anticancer activity
(Wiley, 2026) Şentürk, Sema; Kaplan, Özlem; Bal, Kevser; Küçükertuğrul Çelik, Sibel; Gökşen Tosun, Nazan; Gök, Mehmet Koray
This study focused on functionalizing chitosan with nicotinic acid, the active form of vitamin B3, to obtain a new derivative (ChiNico) with enhanced solubility at physiological pH, improved proton buffering capacity, and in vitro anticancer activity, and to develop resveratrol-loaded nanoparticles (nChiNico-RES) for enhanced anticancer performance. Chitosan was modified through EDC-mediated amidation, and successful conjugation was confirmed by FTIR, 1H NMR, and GPC/SEC analyses. Nicotinic acid grafting increased molecular weight, introduced characteristic amide signals, improved solubility at physiological pH, and enhanced proton buffering capacity. Nanoparticles were prepared by ionotropic gelation and showed sizes of 100–140nm, PDI values below 0.4, and a positive surface charge of +18 to +20mV. Blank nanoparticles exhibited minimal cytotoxicity, while resveratrol-loaded formulations demonstrated significant anticancer activity in HeLa cervical cancer cells and HT-29 human colon adenocarcinoma cell line. Notably, nChiNico-RES reduced HeLa and HT-29 cell viability more effectively than free resver atrol and nanoparticles based on unmodified chitosan, indicating an additive contribution from nicotinic acid. In contrast, the cytotoxic effect on healthy BJ fibroblasts remained considerably lower, supporting the biocompatibility and selective potential of the system. Overall, nicotinic acid modification improves chitosan's carrier performance and offers a novel strategy by combin ing two natural bioactive molecules within a single nanoparticle platform.
The letrozole use in reproductive medicine: Beyond aromatase inhibition - a comprehensive review
(Galenos Publishing House, 2026) Aydın, Gerçek; Hatırnaz, Şafak; Hatırnaz, Ebru Saynur; Çetinkaya, Mehmet Bilge; Akdeniz, Muhterem; Dokuzeylül Güngör, Nur; Güler, Oğuz; Merdanoğlu, Merdan Ali; Uzun, Asiye; Eroğlu, Semra; Dahan, Michael
Letrozole and other aromatase inhibitors are increasingly recognized as first-line ovulation induction (OI) medications, offering an efficient and physiologic approach to ovarian stimulation that enhances outcomes in reproductive medicine. By selectively inhibiting aromatase and maintaining lower peripheral estrogen levels, letrozole supports mono- or bi-follicular development while reducing the risk of supraphysiologic estradiol exposure seen with traditional gonadotropin regimens. These pharmacological characteristics have contributed to its expanding use not only in OI but also in various assisted reproductive technologies. To evaluate the clinical benefits, effectiveness, and safety of using letrozole in in vitro fertilization (IVF), in vitro maturation (IVM), and OI, with particular attention to reproductive outcomes, ovarian response, endometrial effects, cycle characteristics, and treatment-related adverse events. A comprehensive systematic search covering the period from December 2000 to November 2025 was conducted across major electronic databases including PubMed, Embase, the Cochrane Library, and Google Scholar. The search strategy incorporated predefined keywords related to letrozole, aromatase inhibition, OI, IVF, and IVM. Studies involving randomized controlled trials, observational cohorts, and meta analyses were included, while non-clinical and non-reproductive data were excluded. Relevant outcomes were extracted and synthesized qualitatively. Letrozole demonstrates broad clinical utility in reproductive medicine, spanning assisted reproductive techniques, ovarian stimulation strategies, and the management of ovarian hyperstimulation syndrome risk, ectopic pregnancy, and endometriosis-related infertility. Its targeted estrogen suppression, cost-effectiveness, and favorable safety profile make it a valuable component of individualized treatment protocols. Nonetheless, further high-quality research is required to refine optimal dosing strategies, identify ideal patient populations, and clarify long-term reproductive and obstetric safety.
