Person:
ŞAHİN, ALİ

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

OrgUnit Logo
Organizational Unit

Job Title

Last Name

ŞAHİN

First Name

ALİ

Name

Filters

2020 - 20212
Reset filters

Settings

Author: YILMAZ, BETÜL × Has files: true ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    PublicationOpen Access
    Propolis-Based Nanofiber Patches to Repair Corneal Microbial Keratitis
    (MDPI, 2021-04-28) ŞAHİN, ALİ; Ulag, Songul; Ilhan, Elif; Demirhan, Ramazan; Sahin, Ali; Yilmaz, Betul Karademir; Aksu, Burak; Sengor, Mustafa; Ficai, Denisa; Titu, Aurel Mihail; Ficai, Anton; Gunduz, Oguzhan
    In this research, polyvinyl-alcohol (PVA)/gelatin (GEL)/propolis (Ps) biocompatible nanofiber patches were fabricated via electrospinning technique. The controlled release of Propolis, surface wettability behaviors, antimicrobial activities against the S. aureus and P. aeruginosa, and biocompatibility properties with the mesenchymal stem cells (MSCs) were investigated in detail. By adding 0.5, 1, and 3 wt.% GEL into the 13 wt.% PVA, the morphological and mechanical results suggested that 13 wt.% PVA/0.5 wt.% GEL patch can be an ideal matrix for 3 and 5 wt.% propolis addition. Morphological results revealed that the diameters of the electrospun nanofiber patches were increased with GEL (from 290 nm to 400 nm) and Ps addition and crosslinking process cause the formation of thicker nanofibers. The tensile strength and elongation at break enhancement were also determined for 13 wt.% PVA/0.5 wt.% GEL/3 wt.% Ps patch. Propolis was released quickly in the first hour and arrived at a plateau. Cell culture and contact angle results confirmed that the 3 wt.% addition of propolis reinforced mesenchymal stem cell proliferation and wettability properties of the patches. The antimicrobial activity demonstrated that propolis loaded patches had antibacterial activity against the S. aureus, but for P. aeruginosa, more studies should be performed.
  • Thumbnail Image
    PublicationOpen Access
    3D printed artificial cornea for corneal stromal transplantation
    (PERGAMON-ELSEVIER SCIENCE LTD, 2020-06) ŞAHİN, ALİ; Ulag, Songul; Ilhan, Elif; Sahin, Ali; Yilmaz, Betul Karademir; Kalaskar, Deepak M.; Ekren, Nazmi; Kilic, Osman; Oktar, Faik Nuzhet; Gunduz, Oguzhan
    The aim of this study is to understand the optical, biocompatible, and mechanical properties of chitosan (CS) and polyvinyl-alcohol (PVA) based corneal stroma constructs using 3D printing process. Corneal stroma is tested for biocompatibility with human adipose tissue-derived mesenchymal stem cells (hASCs). Physico-chemical and chemical characterization of the construct was performed using scanning electron microscopy (SEM), fourier transforms infrared spectroscopy (FTIR). Optical transmittance was analyzed using UV-Spectrophotometer. Results showed fabricated constructs have required shape and size. SEM images showed construct has thickness of 400 mu m. The FTIR spectra demonstrated the presence of various predicted peaks. The swelling and degradation studies of 13%(wt)PVA and 13%(wt)PVA/(1, 3, 5)%(wt)CS showed to have high swelling ratios of 7 days and degradation times of 30 days, respectively. The light transmittance values of the fabricated cornea constructs decreased with CS addition slightly. Tensile strength values decreased with increasing CS ratio, but we found to support intraocular pressure (IOP) which ranges from 12 to 22 mm-Hg. Preliminary biostability studies showed that composite constructs were compatible with hASCs even after 30 days' of degradation, showing potential for these cells to be differentiated to stroma layer in future. This study has implications for the rapid and custom fabrication of various cornea constructs for clinical applications.