Low Rui Hao
Lim Yao Chong
Tracey Atkinson
Patrick Steiner
It is the material that makes up the main “axels” of orb-weaver
spider webs.
It has a High tensile strength and High extensibility.
It has a composite structure of:
• 20% crystalline regions
• 80% highly elastic substances
Extendible regions of the spider dragline silk connect crystalline
regions to produce the amazing properties of the spider silk.
Ranges from biomedical uses, such as ligaments and sutures,
to bullet proof vests and parachutes.
Spider silk is not widely used in the industry, because it is not
readily available and there is no method to mass produce it.
However, the properties of the spider silk prove it is possible to
replace materials such as Kevlar.
Elastin:
• A material that provides
elasticity to artery walls,
lung tissue, skin,
ligaments, etc.
• Biodegradable
• More elastic than spider
silk
Keratin:
• a material that provides
strength in biomaterials such
as nails, bird beaks, horns,
etc.
• Biodegradable
• Has same beta-sheet
composition as spider silk
• A polymer is dissolved in a volatile solvent and placed in a
syringe.
• The solution is charged with a high voltage.
• The high voltage creates an electric field that causes
the polymer to be spun out in thin threads (nanofibers) to a
collector plate.
• A fibrous mat is formed.
To create fibrous electrospun mats with blended fibers, part
keratin part elastin, to mimic the high tensile strength and
extensibility of spider dragline silk.
• Blended fibers: parallel syringes method (physical mixture)
By combining Elastin and Keratin spun under optimal
conditions into blended fibres in electrospun mats, a mat with
tensile strength and extensibility similar to that of spider silk will
be produced.
1. Polymers used
2. Syringe pumps used
3. Solvents used
4. Solution size spun
5. Power source
6. Syringes used
7. Cover for collector plate(aluminum foil coated in
polyethyleneoxide [PEO] base mat)
8. Spin time
The parameters of the method
including electrospinning method
variables:
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distance to collector plate
size of collector plate
flow rate of jet
voltage
needle gauge
• tensile strength
• extensibility
of the fibrous mat produced from
the Electrospinning.
and chemical variables of the mat:
• concentration of the spun solution
• ratio of Elastin to Keratin
Independent Variables:
Dependent Variables:
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Safety Goggles
Lab Coats
Power Source, up to 30 kV
5 mL syringes
22 gauge needles
Pasteur pipettes
5 mL graduate cylinders(2)
50 mL beakers(2)
Hot plates(2) for stirring
2 Small magnetic stir bars
Aluminum Foil
3cm by 3cm collector plate
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Syringe Pump
Timer
Alligator Clip Wires
Atomic Force Microscope
Balance
Scoopula
2 Glass Stir Rods
Tensile Tester (external)
Distilled Water
Refrigerator
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20 g of Polyethyleneoxide(PEO)
1 M hydrochloric acid, 1 L
Elastin Powder, 20 g, Elastin Products Company Inc.
Keratin 20 g, Advanced Scientific and Chemical Inc.
Urea Powder, 120 g, Sigma Aldrich
Phase 1
• Preparation
Phase 2
• Optimizing Spinning parameters of
each Polymer
Phase 3
• Prove Hypothesis by varying ratio of
Elastin to Keratin through Flow rate
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To dissolve Keratin and Elastin in suitable
solvents to be used in Electrospinning
To determine spin time of the respective
solutions of Keratin and Elastin (estimation)
To prepare a PEO coating on the collecting
plate (ease of removing of mat)
Phase 1
• Preparation
Phase 2
• Optimizing Spinning parameters of
each Polymer
Phase 3
• Prove Hypothesis by varying ratio of
Elastin to Keratin through Flow rate
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Optimize the conditions for electrospinning
keratin and elastin individually
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distance to collector plate
size of collector plate
flow rate of jet
voltage
needle gauge
The optimal conditions found will be kept
constant in Phase 3 of the experiment
Phase 1
• Preparation
Phase 2
• Optimizing Spinning parameters of
each Polymer
Phase 3
• Prove Hypothesis by varying ratio of
Elastin to Keratin through Flow rate
• Spin the optimal parameters of Keratin and Elastin.
• Measure Tensile strength of “optimal hybrid mat”
• Repeat the experiment with different flow rate of Keratin and Elastin
respectively.
• Plot a graph of amount of Beading against Independent
Variable Tested
• The lesser number of beading, the better the fibers
• Plot a graph of diameter of the nanofibers against
Independent Variable Tested.
• A consistent diameter of the fiber is considered the best
• Plot a graph of tensile strength against flow rate of
different ratios. (one of which is the optimal spinning
condition)
1. We will be measuring the tensile strength and extensibility of each of the
fibrous mats. Multiple small sections of each mat spun will be tested for both
extensibility and tensile strength. This allows for multiple data points for each set
of variables without using as much of the materials.
2. We will be comparing the extensibility and tensile strength of each set of mats
to that of spider silk, trying to find the parameters that best mimic the properties of
this material.
4. Analysis of variance (ANOVA) tests will be run on each variable. There will be
three trials run for each variable at very spread out points. Each of those mats will
be tested for extensibility and tensile strength, using 5 small sections of each mat
if possible to achieve more data points. These data points will be graphed on the
same graph as “variable x” vs. elasticity and “variable x” vs. tensile strength,
variable x being the variable currently being tested. The area on this graph where
the tensile strength and extensibility are determined to be optimal in ratio will be
tested in smaller increments to determine a more exact value for optimal condition
of “variable x”. This will be repeated for all the variables.
5. The data points from each mat will be averaged together for each of the data
points. There will be about five segments taken from each mat. There will be three
spread out conditions tried for each variable, and five tested once a more specific
region is tested.
6. ANOVA tests will be run initially on each variable. Data points will then be
combined into scatter plots with two dependent variables(elasticity and tensile
strength) and one independent variable, like distance to the collector plate.
Term 1
Be familiarised with equipment
Test for possibility of combining
Term 2
To optimise electrospinning condition of
individual polymers
(buffer weeks: 2 weeks)
June Holidays –Semi Finals
Optimizing ratio of Keratin to Elastin through Flow
rate
Further Work; Combining results with AOS
Aluiji, A., Ferrero, F., Mazzuchetti, G., Tonin, C., Varesano, A., Vineis, C.(2008) Structure and properties of keratin/PEO blend
nanofibers. European Polymer Journal. 44. 2465-2475.
Awazu, K., Ishii, K., Kanai, T., Natio, Y., Yashihashi-Suzuki(2004). Matrix-assisted laser
desorption/ionization of protein samples containing a denaturant at high concnetratin using a mid-infrared free electron laster (MIRFEL). International Journal of Mass Spectrometry. 15. 49-46.
Buttafoco, L., Dijkstra, P.J., Engbers-Buijtenhuijs, P., Feijen, J., Kolkman, N.G., Poot, A.A.,
Vermes, I.(2006). Electrospinning of collage and elastin for tissue engineering applications. Biomaterials. 27. 224-234
MSDS Sheets:
Keratin Powder: http://www.sciencelab.com/msds.php?msdsId=9924435
Elastin from bovine neck ligament:
http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en&N4=E1625|SIGMA&N5=SEARCH_CONCAT_PNO|BRAND_KEY&
F=SPEC#test, click MSDS on left side bar
1 M hydrochloric acid: http://www.jtbaker.com/msds/englishhtml/H3880.htm
Polyethylene oxide(PEO):
http://www.sigmaaldrich.com/catalog/Lookup.do?N5=All&N3=mode+matchpartialmax&N4=polyethyleneoxide&D7=0&D10=polyethyl
eneoxide&N1=S_ID&ST=RS&N25=0&F=PR#test, click MSDS on left side bar
Thank you!