Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
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Article Citation - Scopus: 3Development of Chrono-Spectral Gold Nanoparticle Growth Based Plasmonic Biosensor Platform(Elsevier, 2024) Sözmen, Alper Baran; Elveren, Beste; Erdoğan, Duygu; Mezgil, Bahadır; Baştanlar, Yalın; Yıldız, Ümit Hakan; Arslan Yıldız, AhuPlasmonic sensor platforms are designed for rapid, label-free, and real-time detection and they excel as the next generation biosensors. However, current methods such as Surface Plasmon Resonance require expertise and well-equipped laboratory facilities. Simpler methods such as Localized Surface Plasmon Resonance (LSPR) overcome those limitations, though they lack sensitivity. Hence, sensitivity enhancement plays a crucial role in the future of plasmonic sensor platforms. Herein, a refractive index (RI) sensitivity enhancement methodology is reported utilizing growth of gold nanoparticles (GNPs) on solid support and it is backed up with artificial neural network (ANN) analysis. Sensor platform fabrication was initiated with GNP immobilization onto solid support; immobilized GNPs were then used as seeds for chrono-spectral growth, which was carried out using NH2OH at varied incubation times. The response to RI change of the platform was investigated with varied concentrations of sucrose and ethanol. The detection of bacteria E.coli BL21 was carried out for validation as a model microorganism and results showed that detection was possible at 102 CFU/ml. The data acquired by spectrophotometric measurements were analyzed by ANN and bacteria classification with percentage error rates near 0% was achieved. The proposed LSPR-based, label-free sensor application proved that the developed methodology promises utile sensitivity enhancement potential for similar sensor platforms. © 2024 The Author(s)Book Part Citation - Scopus: 3Tissue Engineering Applications of Marine-Based Materials(Springer, 2022) Polat, Hürriyet; Zeybek, Nuket; Polat, MehmetTissue engineering is a promising approach in replacing or improving tissues lost or has become nonviable due to disease or trauma by the use of scaffold materials by combining engineering and biochemical/physicochemical methods. Its purpose is to create suitable matrices that support cell differentiation and proliferation toward the formation of new and functional tissue. Marine-based natural compounds are potential scaffold feedstock material in tissue engineering owing to their biocompatibility and biodegradability while providing excellent biochemical/physicochemical properties. Numerous application areas and various fabrication routes techniques described in the literature attest to the importance of these materials in tissue regeneration. This review has been carried to merge the information from a large number of studies on the marine-based scaffold materials in tissue engineering into a coherent summary. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.Conference Object Citation - WoS: 1Citation - Scopus: 1Biomimetic Peptide-Conjugated Membranes for Developing an Artificial Cornea(IEEE, 2022) Sunal, Gülşah; Pulat, Günnur; Akgün, İsmail Hakkı; Güven, Sinan; Yıldız, Ümit Hakan; Karaman, Ozan; Horzum, NesrinThe corneal endothelium is composed of a single layer of specialized endothelial cells, protecting, and nourishing the inner surface of the cornea. Corneal endothelial cells do not proliferate after birth and their number decrease with age. Trauma, inflammation, or surgical intervention can cause cell loss. When damage is extensive and the density of corneal endothelial cells decreases to a critical level, it results in corneal edema and vision loss. Besides them, when corneal endothelium has irreversible damage, the only treatment way is corneal transplantation. But there are some drawbacks such as finding donors, immune reactions, and the number of patients waiting on the transplantation lists for years. Tissue engineering approaches can provide promising alternatives for the regeneration of corneal endothelium tissue. Peptides can be used to modify and functionalize the scaffolds, allowing for the production of bioactive and biomimetic surfaces. Peptide-modified scaffold surfaces might direct and enhance the behaviors of cells. In this study, the aim was to functionalize the polycaprolactone (PCL) membranes with tissue-specific peptides and to characterize the peptide-conjugated membranes by Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS) analysis. The synthesized peptides were successfully conjugated on the PCL biomembranes.Patent Yağ Karışımlarındaki Bileşenlerin Elementel Analiz ve Genetik Algoritma Yöntemleri ile Modellenerek Belirlenmesi(Türk Patent ve Marka Kurumu, 2022)Buluş konusu analiz yöntemi ile haddeleme işlemi sonrasında alüminyum yüzey üzerinde kalan yağ artığının bileşenlerinin türü ve içeriği belirlenmektedir. Bu yöntemde, haddeleme işlemi esnasında kullanılan hadde yağı, katkı yağları ve uzun zincirli ağır yağlardan oluşan yağ bileşenlerinden farklı konsantrasyon değerine sahip numune hazırlanmaktadır. Bir sonraki adımda hazırlanan bu numuneler ile analiz edilmek istenen numuneler bir sıcaklık rampası uygulanarak sabit zaman aralığında karbon-hidrojen elementel analiz cihazı ile analiz edilmektedir. Analiz sonucu elde edilen elementel analiz kromatogramlarının en küçük ters kareler (GILS) yöntemi kullanılarak her bileşen için çok değişkenli kalibrasyon modelleri oluşturulmaktadır.Article Bitki Proteomik Çalışmalarında Kullanılan Yaklaşımlar ve Uygulama Yöntemleri(2020) Günel, Aslıhan; Hasançebi, Semra; Yalçın, Talat; Emir, Mahmut; Demirci, Yahya Emin; Dinç, Melike; Güray, Melda ZeynepProteomik yaklaşımları 2000 li yılların başlarına kadar mikroorganizmalar ve hayvansal kaynaklı örneklerde ağırlıklı olarak kullanıldı. Bu dönemde bitki proteomik çalışmaları yok denecek kadar azdır. Bitkisel dokulardaki sert hücre çeperleri, karmaşık ve çok çeşitli sekonder metabolitlerin varlığı, fazla miktardaki pigmentler, proteazlar, polifenoller, polisakkaritler, nişasta ve lipitler total protein örneklerinin hazırlanması ve proteinlerin ayrımı sırasında pek çok soruna neden olmuştur. Ancak her bir sorunun üstesinden gelmek üzere sürdürülen çabalar sayesinde bitki dünyasında da proteomik yaklaşım kullanımı yaygınlaşmıştır. Bu derlemede, örnek hazırlığından protein tanımlamaya kadar tüm basamaklar yöntemsel gelişmeleri de kapsayacak şekilde ayrıntılı olarak ele alınmış ve konuyla ilgili araştırıcıların maksimum yararlanabileceği bir kaynak oluşturulmaya çalışılmıştır.Book Part Citation - Scopus: 6Recent Advances in Chitosan-Based Systems for Delivery of Anticancer Drugs(Springer, 2020) Polat, Mehmet; Polat, HürriyetProblems in transporting drug molecules to tumor sites in required dose or constitution lead to low efficacy and significant side effects. Shielding the drug molecules in micelles, liposomes, or nanoparticles is a major line of investigation to improve chemotherapeutic treatment. Though compatibility for proper envelopment of the drug and timely release at the tumor site are required of such a carrier, protecting its own physicochemical and morphological integrity during transport is another precondition. Because of its superior polymerization capability, biocompatibility, pH dependence, and charging characteristics, chitosan has been in the forefront of potential drug carriers. Numerous synthesis routes for chitosan-based nanocarriers have been suggested to the extent that a search of the literature published since 2000 with the keywords “novel + nano + chitosan” in the title results in 527 articles, indicating the bewildering quality and quantity of the new information. This review was carried out not only to peruse this large amount of work on chitosan-based anticancer drug delivery but also to extract manageable patterns from numerous synthesis routes. The main conclusion is that the synthesis methods suggested in literature can be combined into two main routes, and the degree of hydrophobicity of the drug determines which route should be followed. © Springer Nature Singapore Pte Ltd. 2019.