L-glutamin stresinin grafen oksit film üzerine ekilen B35 hücre hattı üzerine etkilerinin incelenmesi
Küçük Resim Yok
Tarih
2016
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Grafen sp2 ile bağlanan karbon atomlarının tek katlı bir yapısı olarak, özgün elektriksel ve kimyasal özelliklere sahip iki boyutlu gibi görünen bir materyaldir. Biyomedikal uygulamalar açısından, sinir hücrelerinin elektriksel aktiviteye sahip olması nedeniyle grafen ve grafen oksit (GO) sinir sistemi çalışmaları için ideal bir model olarak ortaya çıkmaktadır. Glutamin (Gln) çeşitli metabolik yolaklara katılır ve merkezi sinir sisteminde (MSS) bol miktarda bulunur. Aminoasit nörotransmitterlerinin prekürsörü olarak beyinde temel bir rolü vardır. Glutamin sentetaz (GS) tarafından glutamatın ? karboksil grubuna amonyak (NH3) eklenmesiyle elde edilir ve R grubu CH2CH2CONH2'e dönüşür. Bu tez çalışmasının amacı GO'nun MSS nöronlarının kültür ortamında L-glutamin stresine karşı nöroprotektif etkisi olup olmadığını araştırmaktır. GO tozu kitosanla cam yüzeyler üzerine ince bir film olarak kaplanarak B35 nöroblastoma hücreleri bu film tabakalarına ekildi. Cam yüzeylerde kültüre edilen hücreler kontrol grubu olarak kullanıldı. 24 saat sonra her iki yüzey üzerine ekilen hücrelere L-glutamin stresi uygulandı. Hücreler L-glutamin ile eksitotoksisiteye maruz bırakıldıktan 24 saat sonra (stres sonrası) taramalı elektron mikroskobu (SEM) ile hücre morfolojileri incelendi. Hücre canlılığı MTT testi ile ölçüldü ve aktin boyama yapıldı. L-glutamin uygulamasından bir saat sonra her iki yüzey ortamında L-glutamin stresi etkisiyle hücre canlılığında azalma olduğu gözlendi. GO film üzerindeki hücrelerde cam yüzeydekilere göre hücre canlılığının daha yüksek olduğu bulundu. Yirmi dört saat sonra cam yüzeylerde hücre canlılığı %54'ten az iken, GO film üzerindekinde ise 6 saatten sonra hücrelerin iyileşmeye başladığı gözlendi. Hücre morfolojileri ve aktin boyama sonuçlarının da bu sonucu desteklediği görüldü. L-glutamin stresinin 100 mM ve üzeri konsantrasyonunda B35 hücreleri için toksik olduğu bulundu. GO'nun B35 hücrelerinin glutamat stresine karşı dayanıklılığını arttırdığı ve hücrelerin hızla iyileşmesini sağladığı gözlendi. Bu tez çalışmasının bulgularına dayanarak GO'nun ilerleyen çalışmalarla gelecekte biyomedikal uygulamalar için umut vadedici olabileceği sonucuna varılmıştır
Graphene, a monolayer of sp2-bonded carbon atoms, is a quasi–two-dimensional (2D) material with unique electrical and chemical properties. In terms of biomedical applications of graphene and graphene oxide (GO), nervous system would be an ideal breakthrough model, because neural cells are electro-active. Glutamine (Gln) is found abundantly in the central nervous system (CNS) where it participates in a variety of metabolic pathways. Its major role in the brain is being a precursor of the neurotransmitter amino acids: the excitatory amino acids, glutamate (Glu) and aspartate (Asp), and inhibitory amino acid, ?-amino butyric acid (GABA). Glutamine is synthesized from glutamate with ammonia added at the carboxyl group by glutamine synthetase, forming the CH2CH2CONH2 side chain R group. The aim of this work is to investigate whether culture of CNS neurons on GO has any neuroprotective effect against L-glutamine stress. Graphene oxide powder was coated onto glass slides as a thin film and B35 cells were cultured on graphene oxide (GO) sheets. Cultivated cells on glass slides were used as the control group. After 24 hours of cell culture, L-glutamine induced excitotoxicity was applied on B35 cells on both surfaces. After 24 hours of post-stress culture, morphologies of cells were examined by scanning electron microscopy (SEM). Cell viability was measured by MTT assay. The effects of L-glutamine stress on cell viability were visible as early as 1 hour on both surfaces. The cell viability of B35 cells on GO sheets was higher than on glass slides, and cells recovered from the stress within 6 hours on GO surfaces while viability on glass surfaces was lower than 54% after 24 hours. Cell morphology and toxicity measurements also supported this observation. We demonstrated that glutamate is toxic to B35 cells above the concentration of 100mM. The culture on GO increases the resistance to L-glutamine stress on B35 cells, and helps fast recovery. Based on the findings of this study, it is concluded that GO may have a potential for biomedical applications with further studies in the field.
Graphene, a monolayer of sp2-bonded carbon atoms, is a quasi–two-dimensional (2D) material with unique electrical and chemical properties. In terms of biomedical applications of graphene and graphene oxide (GO), nervous system would be an ideal breakthrough model, because neural cells are electro-active. Glutamine (Gln) is found abundantly in the central nervous system (CNS) where it participates in a variety of metabolic pathways. Its major role in the brain is being a precursor of the neurotransmitter amino acids: the excitatory amino acids, glutamate (Glu) and aspartate (Asp), and inhibitory amino acid, ?-amino butyric acid (GABA). Glutamine is synthesized from glutamate with ammonia added at the carboxyl group by glutamine synthetase, forming the CH2CH2CONH2 side chain R group. The aim of this work is to investigate whether culture of CNS neurons on GO has any neuroprotective effect against L-glutamine stress. Graphene oxide powder was coated onto glass slides as a thin film and B35 cells were cultured on graphene oxide (GO) sheets. Cultivated cells on glass slides were used as the control group. After 24 hours of cell culture, L-glutamine induced excitotoxicity was applied on B35 cells on both surfaces. After 24 hours of post-stress culture, morphologies of cells were examined by scanning electron microscopy (SEM). Cell viability was measured by MTT assay. The effects of L-glutamine stress on cell viability were visible as early as 1 hour on both surfaces. The cell viability of B35 cells on GO sheets was higher than on glass slides, and cells recovered from the stress within 6 hours on GO surfaces while viability on glass surfaces was lower than 54% after 24 hours. Cell morphology and toxicity measurements also supported this observation. We demonstrated that glutamate is toxic to B35 cells above the concentration of 100mM. The culture on GO increases the resistance to L-glutamine stress on B35 cells, and helps fast recovery. Based on the findings of this study, it is concluded that GO may have a potential for biomedical applications with further studies in the field.
Açıklama
Anahtar Kelimeler
Biyomühendislik, Bioengineering, Morfoloji, Morphology, Biyomedikal uygulamalar, Biomedical applications, Glutamin, Glutamine, Grafen oksit, Graphene oxide, Hücre dizisi, Cell line, Merkez sinir sistemi, Central nervous system, Toksisite, Toxicity
