Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 30Citation - Scopus: 37Production and Characterization of a Novel Bilayer Nanocomposite Scaffold Composed of Chitosan/Si-nhap and Zein/Poss Structures for Osteochondral Tissue Regeneration(American Chemical Society, 2019) Tamburacı, Sedef; Tıhmınlıoğlu, Funda; Çeçen, Berivan; Üstün, Özcan; Ergür, Bekir Uğur; Havıtçıoğlu, Hasan; Tıhmınlıoğlu, Funda; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyOsteochondral tissue is hard to regenerate after injuries or degenerative diseases. Traditional treatments still have disadvantages, such as donor tissue availability, donor site morbidity, implant loss, and limited durability of prosthetics. Thus, recent studies have focused on tissue engineering strategies to regenerate osteochondral defects with different scaffold designs. Scaffolds have been developed from monolayer structures to bilayer scaffolds to repair the cartilage-bone interface and to support each tissue separately. In this study, Si-substituted nanohydroxyapatite particles (Si-nHap) and silica-based POSS nanocages were used as reinforcements in different polymer layers to mimic a cartilage-bone tissue interface. Chitosan and zein, which are widely used biopolymers, are used as polymer layers to mimic the structure. This study reports the development of a bilayer scaffold produced via fabrication of two different nanocomposite layers with different polymer-inorganic composites in order to satisfy the complex and diverse regenerative requirements of osteochondral tissue. The chitosan/Si-nHap microporous layer and the zein/POSS nanofiber layer were designed to mimic a bone-cartilage tissue interface. Bilayer scaffolds were characterized with SEM, compression, swelling, and biodegradation tests to determine morphological, physical, and mechanical properties. The results showed that the bilayer scaffold had a structure composed of microporous and nanofiber layers joined at a continuous interface with appropriate mechanical properties. Furthermore, in vitro cell culture studies have been performed with LDH, proliferation, fluorescence imaging, and ALP activity assays using osteosarcoma and chondrosarcoma cell lines. ALP expression levels provide a good illustration of the improved osteogenic potential of a porous chitosan/Si-nHap layer due to the Si-doped nHap incorporation. Histological data showed that both fiber and porous layers that mimic the cartilage and bone sections exhibit homogeneous cell distribution and matrix formation. Histochemical staining was used to determine the cell proliferation and ECM formation on each layer. In vitro studies indicated that zein-POSS/chitosan/Si-nHap nanocomposite bilayer scaffolds showed promising results for osteochondral regeneration. Copyright © 2019 American Chemical Society.Article Citation - WoS: 76Citation - Scopus: 85Development of Flexible Antimicrobial Packaging Materials Against Campylobacter Jejuni by Incorporation of Gallic Acid Into Zein-Based Films(American Chemical Society, 2011) Alkan, Derya; Aydemir, Levent Yurdaer; Ceylan, Çağatay; Yavuzdurmaz, Hatice; Atabay, Halil İbrahim; Atabay, Halil İbrahim; Yemencioğlu, Ahmet; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn this study, antimicrobial films were developed against Campylobacter jejuni by incorporation of gallic acid (GA) into zein-based films. The zein and zein-wax composite films containing GA between 2.5 and 10 mg/cm 2 were effective on different C. jejuni strains in a concentration-dependent manner. Zein and zein-wax composite films showed different release profiles in distilled water but quite similar release profiles at solid agar medium. Depending on incorporated GA concentration, 60-80% of GA released from the films, while the remaining GA was bound or trapped by film matrix. The GA at 2.5 and 5 mg/cm 2 caused a considerable increase in elongation (57-280%) of all zein films and eliminated their classical flexibility problems. The zein-wax composite films were less flexible than zein films, but the films showed similar tensile strengths and Young's modulus. Scanning electron microscopy indicated different morphologies of zein and zein-wax composite films. This study clearly showed the good potential of zein and GA to develop flexible antimicrobial films against C. jejuni.