Junior ResearchBy: Shannon Daily & Tyler Crawford

Fabrication of an electrospun nanofibrous scaffold for use in the field of tissue engineering

Purpose:

To create a nanofibrous mesh consisting of polycaprolactone and another biological polymer which enables cell activity and seeks to eventually provide an application in the field of tissue engineering toward a biomimetic skin graft.

Main Qualities to Replicate in the Creation of an Artificial Skin Graft

Protection from infection Prevent fluid/heat loss Ability to support and maintain tissue

growth Skin properties

› Friction & elasticity For easy movement and manipulation

The Extracellular Matrix (ECM)

ECM - main structural tissue of skin› Helps skin renew and generate› Provides signals to intercellular pathways

Main components› Glycoproteins (such as collagen)› Proteoglycans› Hyaluronic Acid

Engineered ECMs are known as scaffolds

Electrospinning

Ability to create scaffolds › mimic the ECM in size and porosity› Have high surface to volume ratio

More space for cells to attach and grow Increases biocompatibility

Easy to vary mechanical and biological properties through changing materials

Flexible- allows cells to manipulate their environment

Polycaprolactone (PCL)

Biocompatible polymer Biodegradable at a slow enough rate to allow

increased cell growth and stability Easy to manipulate Relatively low melting point- easy to use Clinically safe (FDA approval) Proven to have potential for scaffolds in

relation to tissue regeneration› Has created scaffolds w/ ideal conditions

High porosities Large amounts of surface areas

Additional Biochemical Material

Much research has shown that adding another biochemical can:

Increase stress resistance Provide better adhesion of cells to the final

scaffold Increase the potential for cell proliferation

Biochemical should› Be a component of skin naturally› Must be able to be combined in a solution

to be electrospun

Potential Biochemical Polymers

Collagen› Advantages

biodegradable and biocompatible plays important role in tissue formation

› Disadvantages Very expensive complex handling properties

Gelatin› Advantages

naturally derived from collagen, similar properties Cost efficient and easy to manipulate

› Disadvantages can provoke inflammatory response Poor electrospinnability unless combined with specific solvents

Potential Polymers continued…

Hyaluronic Acid› Advantages:

Excellent biocompatibility and biodegradability Main component of ECM

› Disadvantages  High viscosity, surface tension, and water retention make it difficult to form uniform

sized fibers

Elastin› Advantages

 Provides elasticity to skin- essential for this skin quality

› Disadvantages  highly insoluble Potential health risk

Fibrinogen› Advantages

Essential for wound healing Promotes cell migration and cellular interaction

› Disadvantages  difficult to control matrix properties

Potential Polymers Continued:

Alginate› Advantages

Good for health reasons (low toxicity, immunogenic) Low cost

› Disadvantages Poor spinnability (possibly be fixed with addition of a synthetic polymer)

Chitosan› Advantages

natural polymer, biocompatible and biodegradable Cellular binding capabilities Accelerates wound healing Anti-bacterial properties

› Disadvantages high viscosity limits spinnability Fibers can swell in aqueous solution- need to be cross linked to maintain

structural qualities

Experimental Design Progress: Procedure

Create solutions of PCL and other polymer varying the concentrations

Spin these solutions creating nanofilament meshes

Analyze meshes for fiber and pore qualities using scanning electron microscope

Culture fibroblast cells and seed into meshes created

Experimental Design Progress:Data and Analysis Data obtained will

include:› Fiber diameter and

pore diameter of the mesh

› Concentration of the chemical

› Amount of cell activity throughout mesh

Analysis will include:› For what

concentration of chemical did the most cell activity occur

References

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