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.

Keratin: a material that provides strength in biomaterials such as nails, bird beaks, horns, etc. Biodegradable Has same beta-sheet composition as spider silk Elastin: A material that provides elasticity to artery walls, lung tissue, skin, ligaments, etc. Biodegradable More elastic than 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

Independent Variables: Dependent Variables: The parameters of the method including electrospinning method variables: distance to collector plate size of collector plate flow rate of jet voltage needle gauge and chemical variables of the mat: concentration of the spun solution ratio of Elastin to Keratin tensile strength extensibility of the fibrous mat produced from the Electrospinning.

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 Syringe Pump Timer Alligator Clip Wires Atomic Force Microscope Balance Scoopula 2 Glass Stir Rods Tensile Tester (external) Distilled Water Refrigerator

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

 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

 Optimize the conditions for electrospinning keratin and elastin individually 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.

June Holidays –Semi Finals Optimizing ratio of Keratin to Elastin through Flow rate Further Work; Combining results with AOS Term 2 To optimise electrospinning condition of individual polymers (buffer weeks: 2 weeks) Term 1 Be familiarised with equipmentTest for possibility of combining

Aluiji, A., Ferrero, F., Mazzuchetti, G., Tonin, C., Varesano, A., Vineis, C.(2008) Structure and properties of keratin/PEO blend nanofibers. European Polymer Journal 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 (MIR- FEL). International Journal of Mass Spectrometry 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 MSDS Sheets: Keratin Powder: Elastin from bovine neck ligament: F=SPEC#test, click MSDS on left side bar 1 M hydrochloric acid: Polyethylene oxide(PEO): eneoxide&N1=S_ID&ST=RS&N25=0&F=PR#test, click MSDS on left side bar

Thank you!