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
Solid and nanostructured lipid carriers for plant-derived neuroprotective agents: Advances and future perspectives
(Bentham Science Publishers, 2026) Küpeli, Esra; Mancak, Methiye; Çakırlı, Egemen; Bardakçı, Hilal; Avcı, Tuğba Buse; Özdemir, Samet
Neurodegenerative disorders, particularly Alzheimer’s disease (AD) and Parkinson’s disease (PD), continue to pose a substantial therapeutic challenge, largely due to progressive neuronal degeneration and the limited effectiveness of currently available treatments. Plant-derived bioactive compounds—including poly phenols, alkaloids, terpenoids, and flavonoids—have shown notable neuroprotective properties. However, their clinical use remains constrained by low bioavailability and limited ability to cross the blood–brain barri er (BBB). Lipid-based nanocarrier systems, especially solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), have emerged as promising alternatives for improving delivery efficiency. This review evaluates recent advances in SLN and NLC formulations developed for phytochemical delivery in neuro degenerative conditions, focusing on formulation approaches, production methods, and the physicochemical factors that govern system performance. Preclinical findings consistently indicate enhanced solubility, im proved stability, and more effective brain targeting with these systems. Even so, several challenges continue to impede their clinical translation. In particular, issues related to formulation reproducibility, scalability of production, and long-term safety remain unresolved. Alternative administration routes such as intranasal de livery offer a potential strategy to bypass the BBB, although their practical feasibility still requires further confirmation. SLN- and NLC-based systems offer a promising approach, although their clinical development is still ongoing. Future efforts should focus on establishing standardized formulation protocols, conducting rigorous in vivo studies, and ensuring alignment with regulatory requirements to facilitate successful clinical translation.
PVA kaplamanın sol-jel yöntemiyle sentezlenen demir oksit nanopartiküllerinin yapısal özelliklerine etkisi
(IKSAD (Institute of Economic Development and Social Researches), 2026) Ergenç, Tacettin; Sadullahoğlu, Gülten
In this study, the effect of polyvinyl alcohol (PVA) coating on the structural, morphological, and surface properties of iron oxide (Fe₂O₃) nanoparticles synthesized by the sol-gel method was systematically investigated. The phase composition and crystal structure were evaluated by X-ray diffraction (XRD), interplanar crystallographic spacings by transmission electron microscopy (TEM), and specific surface area and pore characteristics were evaluated using Brunauer–Emmett–Teller (BET) analyses. XRD analysis revealed that α-Fe₂O₃ and γ-Fe₂O₃ phases coexisted in the microstructure of the synthesized nanoparticles, and the PVA coating increased the relative intensity of the characteristic peaks belonging to the α-Fe₂O₃ phase. The interplanar crystallographic spacings calculated from the TEM images of the nanoparticles are in agreement with the interplanar crystallographic spacings of the phases detected in the XRD analysis. BET analysis revealed that while the surface area was 18.3433 cm²/g for Fe₂O₃-250-0 nanoparticles, this value decreased to 15.7035 cm²/g for the aged Fe₂O₃-250-2H-0 sample, and was measured as 15.9167 cm²/g in Fe₂O₃-250-1 nanoparticles due to the PVA coating effect along with an increased pore size. In the FTIR spectra, α-Fe₂O₃ and γ-Fe₂O₃ phases coexisted in the 400–700 cm⁻¹ region.
Development of a novel hplc method for the determination of axitinib in human plasma based on fluorimetric detection and precolumn derivatization with 7-chloro-4-nitrobenzofurazan: Application to a prototype pharmacokinetic study
(Editions de l'Academie Republique Populaire, 2026) Ceylan, Burhan; Önal, Cem; Önal, Armağan
Tyrosine kinase inhibitors (TKIs) are central to modern targeted cancer therapy. Axitinib, a highly selective oral TKI, primarily inhibits angiogenesis. This study aimed to develop a fast, reliable, and simple HPLC method with fluorescence detection to measure axitinib in human plasma. Sample preparation was performed using a simple and efficient liquid-liquid extraction (LLE) procedure. Axitinib was isolated from alkalinized plasma using chloroform, followed by evaporation of the organic phase. Prior to analysis, axitinib was derivatized with 7-chloro-4-nitrobenzofurazan (NBD-Cl). Separation was performed on a reversed-phase C18 column (2.6 µm, 4.6 mm × 150 mm) at 30 °C under isocratic conditions, using a mobile phase of acetonitrile and 0.1% orthophosphoric acid (75:25 v/v) at 0.9 mL min⁻¹. Fluorescence detection was set at 330 nm excitation and 405 nm emission. Axitinib eluted at 3.15 ± 0.02 minutes. The method showed excellent linearity from 0.01 to 30 ng mL⁻¹ (r = 0.9998), with LOD and LOQ of 0.003 ng mL⁻¹ and 0.01 ng mL⁻¹, respectively. Precision, expressed as RSD, did not exceed 2.65%. Validation confirmed compliance with EMA bioanalytical guidelines. The method was successfully applied in pharmacokinetic studies, enabling determination of AUC₀–t, AUC₀–∞, Cmax, Tmax, and t½. Thanks to its sensitivity and robustness, this HPLC fluorescence method is suitable for routine quantification of axitinib in human plasma and can be applied in bioavailability and bioequivalence studies.
Association of body mass index with reproductive and metabolic outcomes in women with PCOS undergoing frozen-thawed blastocyst transfer
(Galenos Publishing House, 2026) Aydın, Gerçek; Uzun, Asiye
Objective: To evaluate whether body mass index (BMI) predicts in vitro fertilization (IVF) pregnancy and perinatal outcomes in women with polycystic ovary syndrome (PCOS) undergoing frozen-thawed blastocyst transfer within a standardized protocol. Material and Methods: This retrospective cohort study included 69 frozen-thawed blastocyst transfer cycles from 53 women with PCOS at a single IVF center (June 2022-June 2025). All cycles followed a uniform progestin-primed ovarian stimulation protocol with a freeze all strategy. Pregnancy outcomes were calculated per embryo transfer cycle; perinatal outcomes were assessed using a delivery-based approach. Univariable and multivariable regression analyses were performed with robust standard errors clustered by patient, with maternal age as a potential confounder. Results: The mean maternal age was 29.5±4.1 years, and the mean BMI was 25.9±6.3 kg/m2. The live birth rate per transfer was calculated as 33.3% (23/69). BMI was not significantly associated with biochemical pregnancy, clinical pregnancy, ongoing pregnancy, or live birth rates in either univariable or multivariable analyses. In univariable analysis, increasing BMI was associated with a higher risk of gestational diabetes mellitus; however, this association lost statistical significance following multivariable adjustment, though a trend in this direction could not be excluded (p=0.087). No significant association was identified between BMI and hypertensive complications of pregnancy or neonatal outcomes. Conclusion: Based on our findings, BMI does not appear to be a strong predictor of IVF pregnancy success in women with PCOS undergoing frozen-thawed blastocyst transfer. BMI may be more relevant to perinatal metabolic risk than to reproductive outcomes.
Meniscal position after bucket-handle tear repair: A multiplanar MRI comparison of all-inside and inside-out techniques
(Elsevier, 2026) Ağır, Muzaffer; Ali, Jotyar; Sarıkaş, Murat; Toker, Berkin; Tuncay, İbrahim; Taşer, Ömer; Erden, Tunay
Hypothesis/purpose: To compare multiplanar meniscal position following all-inside and inside-out repair of bucket-handle tears using magnetic resonance imaging (MRI) and to evaluate the associa tion between meniscal shift and short-term clinical outcomes. Methods: A retrospective comparative study was performed on 83 patients who underwent arthro scopic repair of bucket-handle meniscal tears. Postoperative MRI was used to evaluate meniscal position in multiple planes by measuring coronal extrusion and sagittal anterior and posterior meniscal position relative to the tibial plateau borders. When available, postoperative measurements were additionally compared with MRI findings from contralateral asymptomatic knees as a patient-specific native refer ence. Clinical outcomes were evaluated using Lysholm, International Knee Documentation Committee (IKDC), and visual analogue scale (VAS) scores at final follow-up. Comparisons were made between all inside and inside-out repair techniques. Results: Eighty-three patients were included (45 medial, 38 lateral). In the medial meniscus, coronal position did not change significantly after repair in either technique, whereas posterior sagittal position increased by approximately 2 mm after repair regardless of repair technique (both p < 0.001). In the lateral meniscus, the meniscus shifted toward a more peripheral coronal position postoperatively in both techniques (both p < 0.001), while posterior sagittal position increased by approximately 5 mm and anterior sagittal position remained unchanged. Postoperative meniscal position was comparable between techniques and generally remained within contralateral native reference ranges. All clinical scores improved significantly without technique-dependent differences. Conclusion: All-inside and inside-out repair produced comparable coronal and sagittal meniscal posi tion at 1 year after bucket-handle repair and similar clinical improvements. Postoperative meniscal position generally remained within contralateral reference ranges regardless of repair technique. No technique-dependent differences in meniscal position or clinical outcomes were identified.
