Collagen-based scaffolds for cornea tissue engineering

Vrana, Nihal Engin
In this study, collagen based scaffolds were prepared for cornea tissue engineering. Three different cell carriers (rat tail collagen foam, insoluble collagen foam and patterned collagen film) were produced using two different collagen sources. Scaffolds were designed to mimic the unique topographical features of the corneal stroma. A novel crosslinking method was developed to achieve constant foam thickness. All scaffolds were tested with the primary cells of the native corneal stroma, human keratocytes. Although both foams promoted cell growth and penetration, rat tail foams were found to be superior for keratocyte proliferation. Their degradation rates were high enough but did not compromise their structural integrity during testing. Transparency studies with the foams revealed a progressive improvement. Collagen films degraded significantly over a one month period; however, the presence of cells increased the tensile strength of the films over a 21 day period to close to that of the native cornea and compensated for the loss of strength due to degradation. The micropatterned films proved to have higher transparency than the unpatterned scaffolds. In this study, it was possible to prepare collagen based micropatterned scaffolds using a silicon wafer and then a silicone template, successively, starting from original designs. The resultant collagen films were able to control cell growth through contact guidance, restricted cells and secreted-ECM within the pattern grooves, resulting in a higher transparency in comparison to unpatterned films. Thus, the tissue engineered constructs revealed a significant potential for use as total artificial corneal substitutes.


Multiwalled Carbon Nanotube- Poly(2-Hydroxyethyl Methacrylate) Composite Conduitfor Peripheral Nerve Repair
Arslantunalı, Damla; Arslantunalı Şahin, Damla; Department of Biotechnology (2012)
There are different methods used in the surgical treatment of peripheral nerve injury. In this respect, end-to-end surgical reconnection of the damaged nerve ends or autologous nerve grafts are applied as soon as possible after the injury. When autologous tissue transplant is considered, there are some medical devices available generally for relatively short nerve defects. As a solution for this problem, different tissue engineered nerve conduits have been developed. In the current study, a pHEMA hydrogel m...
Collagen/PEO/gold nanofibrous matrices for skin tissue engineering
Akturk, Omer; Keskin, Dilek (The Scientific and Technological Research Council of Turkey, 2016-01-01)
As a novel approach in skin tissue engineering, gold nanoparticles (AuNPs) were synthesized and incorporated at different concentrations into collagen/PEO nanofibrous matrices in this study. The group containing 14.27 ppm AuNPs (CM-Au) had the best nanofibrous morphology. CM-Au was cross-linked with glutaraldehyde vapor (CM-AuX). All groups were disrupted in collagenase in 2 h, but cross-linked groups and Matriderm (R) resisted hydrolytic degradation for 7 and 14 days, respectively. Due to its small pores a...
Collagen/gold nanoparticle nanocomposites: A potential skin wound healing biomaterial
Akturk, Omer; Kismet, Kemal; Yasti, Ahmet C.; Kuru, Serdar; Duymus, Mehmet E.; Kaya, Feridun; Caydere, Muzaffer; Hucumenoglu, Sema; Keskin, Dilek (2016-08-01)
In this study, nanocomposite collagen scaffolds incorporating gold nanoparticles (AuNPs) were prepared for wound healing applications. Initially, dose (<20ppm) and size (>20nm) of AuNPs that were not cytotoxic on HaCat keratinocytes and 3T3 fibroblasts were determined. Both collagen sponges and AuNP-incorporated nanocomposites (CS-Au) were cross-linked with glutaraldehyde (CS-X and CS-AuX). Incorporation of AuNPs into cross-linked scaffolds enhanced their stability against enzymatic degradation and increase...
Collagen scaffolds with in situ-grown calcium phosphate for osteogenic differentiation of Wharton's jelly and menstrual blood stem cells
Karadas, Ozge; Yucel, Deniz; Kenar, Halime; Kose, Gamze Torun; Hasırcı, Vasıf Nejat (2014-07-01)
The aim of this research was to investigate the osteogenic differentiation potential of non-invasively obtained human stem cells on collagen nanocomposite scaffolds with in situ-grown calcium phosphate crystals. The foams had 70% porosity and pore sizes varying in the range 50-200 mu m. The elastic modulus and compressive strength of the calcium phosphate containing collagen scaffolds were determined to be 234.5 kPa and 127.1 kPa, respectively, prior to in vitro studies. Mesenchymal stem cells (MSCs) obtain...
Dielectric Analysis of Changes in Electric Properties of Doxorubicin Resistant K562 Leukemic Cells Through Electrorotation with 3 D Electrodes
Garsha, Bahrieh; Erdem, Murat; Özgür, Ebru; Gündüz, Ufuk; Külah, Haluk (2013-10-31)
In this study, dielectric characterization of multidrug resistant (MDR) K562 human leukemia cells was carried out using a MEMS-based electrorotation (ER) device with 3D electrodes. Different cell populations were utilized, which were resistant to 0.1, 0.3, and 0.5 μM doxorubicin. The ER devices with 3D quadruple electrodes (30 urn in height) were used, in order to eliminate the fringing field effect on the rotation of cells. Signals in phase quadrature were applied to the polynomial electrodes, to induce th...
Citation Formats
N. E. Vrana, “Collagen-based scaffolds for cornea tissue engineering,” M.S. - Master of Science, Middle East Technical University, 2006.