Third Day Poster Session, 17 June 2010 - NanoTR-VI

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Poster Session, Thursday, June 17
Theme F686 - N1123
Fabrication of Aligned Silk Fibroin Nanofibers by Electrospinning
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Gamze DoanP P, UGüldemet BaalUP P*, Ali Bora BaltaP P, Ouz BayraktarP
1 Department of Textile Engineering, Uak University, Uak 64100, Turkey
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PDepartment of Textile Engineering, Ege University, zmir 35100, Turkey
PDepartment of Biotechnology and Bioengineering, zmir Istitute of Technology, zmir 35430, Turkey
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PDepartment of Chemical Engineering, zmir Istitute of Technology, zmir 35430, Turkey
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Abstract- Aligned nanofibers provide some advantages in fabrication of scaffolds for tissue engineering. In this study, silk fibroin nanofibers
were fabricated by an electrospinning unit with a rotating drum as a collector at three different drum speeds (surface velocity), and the influence
of drum speed on fiber size and alignment were investigated.
Tissue engineering is a field of regenerative medicine,
which deals with the development of tissue substitutes
(scaffolds) to repair, maintain, or improve the function of
diseased or damaged tissues. Mimicking of cell
microenviroment as close as possible when designing
scaffolds is the key issue in tissue engineering [1].
Electrospun biopolymer nanofibers have potential uses as
scaffolds, due to their resemblance to natural extra cellular
matrix (ECM), high surface area to volume ratio and high
porosities [2]. The ECM is a nano fibrous network which
holds cells and tissues together and provides a controlled
environment inside which migratory cells can move and
interact with each other [3].
Several natural or synthetic biodegrable polymers have been
turned into scaffolds for tissue engineering. Silk fibroin (SF)
is a great candidate for this purpose. It has a slow degradation
rate, good mechanical properties, high oxygen permeability
and it is non-toxic [4, 5].
One of the most widely used method for the fabrication of
nanofibrous scaffolds is electrospinning. This method involves
the ejection and stretching of a polymer solution or melt from
a capillary tube by electrostatic forces. In electrospinning
method, stationary collectors are used for the production of
random nanofiber bundles. Rotating targets such as disks and
drums are used for the fabrication of aligned nanofibers [6, 7].
Alignment of nanofibers plays an important role in repairing
tissues that have structural orientation in one direction such as
muscle and nerve tissues. According to contact guidance
theory aligned nanofiber scaffolds can exhibit more ECM
production than random nanofiber scaffolds [8]. These aligned
nanofiber scaffolds also have a more dense structure and high
strength value compared to random nanofiber scaffolds [9].
In this study, aligned nanofibers were fabricated from silk
fibroin (SF) by utilizing an electrospinning set up with a
rotating drum and the effects of the surface velocity of the
rotating drum on fiber size and alignment of fibers were
investigated.
Silk fibroin solution was prepared using 98% formic acid.
The concentration of SF in the solution was 6 wt%. Applied
voltage was 20 kV. Flow rate was set to 7 μL/min. Distance
between the collector and the needle tip was adjusted to 11.2
cm. All of these parameters were kept constant, except the
surface velocity of the rotating drum. Electrospinning was
performed at three different surface velocities: 50, 100 and
150m/min. Results revealed that the influence of drum speed
on fber alignment and fber size was significant. Figure 1
shows the SEM image of silk fibroin nanofibers collected at a
surface velocity of 150 m/min. Average fiber diameter
decreased when surface velocity of the drum increased.
Average fiber diameters were 80, 69, and 65 nm for the
surface velocities of 50, 100 and 150, respectively.
Figure 1. SEM image of silk fibroin nanofibers collected onto a drum
with a surface velocity of 150 m/min.
*Corresponding author: guldemet.basal@ege.edu.tr
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[3] http://themedicalbiochemistrypage.org/extracellularmatrix.html
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Biomaterials, 27, 3115–3124.
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[9] Kumbar, S.G., James, R., Nukavarapu, S.P., and Laurencin, C.T.,
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6th Nanoscience and Nanotechnology Conference, zmir, 2010 787