Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Free standing layer-by-layer films of polyethyleneimine and poly(l-lysine) for potential use in corneal stroma engineering
Download
index.pdf
Date
2011
Author
Altay, Gizem
Metadata
Show full item record
Item Usage Stats
314
views
99
downloads
Cite This
In this study we fabricated free standing multilayer films of polyelectrolyte complexes for potential use in tissue engineering of corneal stroma by using the layer-by-layer (LbL) approach. In the formation of these LbL films negatively charged, photocrosslinkable (methacrylated) hyaluronic acid (MA-HA) was used along with polycations polyethyleneimine (PEI) and poly(L-lysine) (PLL). Type I collagen (Col) was blended in with PLL for improving the water absorption and cell attachment properties of the films. It was shown that the LbL films could be easily peeled off from glass substrates due to the photocrosslinking of one of the LbL components, the hyaluronic acid. Film growth and composition were monitored with FTIR-ATR. Heights of peaks at 3383 cm-1, and 2958 cm-1increased along with the bilayer number confirming the polymer build-up. Film integrity and thickness were investigated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Films thicker than 5 bilayers (BLs) were found to be uniform in appearance and 10 BL (PEI/MeHA) films were calculated to be ca. 6 μm thick. Atomic force microscopy (AFM) revealed that as the number of BLs increased, surface roughness decreased. Activity of methacrylated hyaluronic acid was shown by the increased resistance of photocrosslinked multilayer films against hydrolysis by hyaluronidase. Patterns could be created on the films by photocrosslinking further proving that the crosslinking step is successful. Since the ultimate goal was to construct a corneal stroma PEI/MA-HA films were tested with corneal stroma cells, keratocytes. Cell proliferation on PEI/MA-HA films was quite poor in comparison to TCPS. In order to improve the cell adhesion the tests were repeated with PLL/MA-HA. Collagen was added to decrease the hydrophilicity and introduce cell adhesion sequences (Arg-Gly-Asp, RGD) to improve cell proliferation on the films and thus PLL+Col/MA-HA films were also tested. Introduction of collagen to the PLL/MA-HA films was found to decrease water retention of the multilayer films and improve cell viability and proliferation. Col+PLL/MA-HA LbL thus appear to be a promising platform for tissue engineering, especially of corneal stroma.
Subject Keywords
Tissue engineering.
URI
http://etd.lib.metu.edu.tr/upload/12613005/index.pdf
https://hdl.handle.net/11511/20381
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Biodegradable poly (ester-urethane) scaffolds for bone tissue engineering
Kızıltay, Aysel; Hasırcı, Nesrin; Department of Biotechnology (2011)
During last decade, polyurethanes (PUs) which are able to degrade into harmless molecules upon implantation have received a significant level of attention as a biomaterial in tissue engineering applications. Many studies are focused especially on development of PUs based on amino acid derivatives; however, there are only few applications of amino acid based PUs in tissue engineering. In this study, a biocompatible and biodegradable thermoplastic poly(ester-urethane) (PEU) based on L-lysine diisocyanate (LDI...
Silicate-doped nano-hydroxyapatite/graphene oxide composite reinforced fibrous scaffolds for bone tissue engineering
Dalgıç, Ali Deniz; Tezcaner, Ayşen; Keskin, Dilek; Evis, Zafer (SAGE Publications, 2018-3-15)
In this study, novel graphene oxide-incorporated silicate-doped nano-hydroxyapatite composites were prepared and their potential use for bone tissue engineering was investigated by developing an electrospun poly(epsilon-caprolactone) scaffold. Nanocomposite groups were synthesized to have two different ratios of graphene oxide (2 and 4 wt%) to evaluate the effect of graphene oxide incorporation and groups with different silicate-doped nano-hydroxyapatite content was prepared to investigate optimum concentra...
Influence of keratocytes and retinal pigment epithelial cells on the mechanical properties of polyester-based tissue engineering micropatterned films
Zorlutuna, Pinar; Builles, Nicolas; Damour, Odile; Elsheikh, Ahmed; Hasırcı, Vasıf Nejat (2007-08-01)
In this paper the mechanical properties of micropatterned polyester films prepared to serve as tissue engineering scaffolds of cornea were examined. Films were prepared by solvent casting of blends of poly(L-lactide-co-D,L-lactide) and poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid), on a micropatterned silicon template. They were seeded with keratocytes or retinal pigment epithelia] cells and subjected to tensile testing to assess the contribution of cells and the deposited extra-cellular matrix (ECM)...
Forced Response Prediction of Constrained and Unconstrained Structures Coupled Through Frictional Contacts
Ciğeroğlu, Ender; Menq, Chia-Hsiang (ASME International, 2009-03-01)
In this paper, a forced response prediction method for the analysis of constrained and unconstrained structures coupled through frictional contacts is presented. This type of frictional contact problem arises in vibration damping of turbine blades, in which dampers and blades constitute the unconstrained and constrained structures, respectively. The model of the unconstrained/free structure includes six rigid body modes and several elastic modes, the number of which depends on the excitation frequency. In o...
Computer simulation of grain boundary grooving by anisotropic surface drift diffusion due to capillary, electromigration and elastostatic forces
Akyıldız, Öncü; Oğurtanı, Tarık Ö.; Department of Metallurgical and Materials Engineering (2010)
The aim of this study is to develop a theoretical basis and to perform computational experiments for understanding the grain boundary (GB) grooving in polycrystalline thin film metallic conductors (interconnects) by anisotropic surface diffusion due to capillary, electromigration and elastostatic forces. To this end, irreversible thermo–kinetics of surfaces and interfaces with triple junction singularities is elaborated, and the resulting well-posed moving boundary value problem is solved using the front–tr...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
G. Altay, “Free standing layer-by-layer films of polyethyleneimine and poly(l-lysine) for potential use in corneal stroma engineering,” M.S. - Master of Science, Middle East Technical University, 2011.
