Narrowing the Diameter of Electrospun Nanofibres

Wai Hei TseThe University of Western OntarioDepartment of Medical Biophysics

April 7, 2010

Table of ContentsIntroduction

◦Electrospinning◦Nanofibers

Materials◦Collagen◦Polycaprolactone (PCL)

ApplicationsResultsConclusions

IntroductionElectrospinning: process in which

solid fibres are produced from a polymeric solution◦Based on electrostatic charge

repulsion and fluid properties

Objective: Narrow electrospun nanofibres to a consistent diameter of 100-250 nm.

Why nanoscale?Why not larger?

Why Collagen and Polycaprolactone?BiocompatibilityCost-effective for large scale

electrospinning

Collagen PCL

•Most abundant protein

•Extracellular matrix (ECM) component

•FDA approved synthetic polymer

•Biodegradable

•Impact resistant

Applications

Collagen Scaffold (Mekhail, M. 2009)

Collagen PCL

•Spinal cord regeneration

•Tissue regeneration

•Tissue engineering •Tissue engineering

•ECM mimic •Controlled release and drug delivery

PCL Fibres (Patcharaporn, W., et al. 2005)

Factors Affecting Polymer Diameter• Flow Rate

• Electric Field Gradient • Polymer Solution

Electrospinning Apparatus

Nanotechweb.org

TheoryTaylor Cone (Doshi, J., and Reneker, D. H.)

Electrosplaying (Thompson, C.J., et al.)

ThePedia.com

Results

Inconsistent Diameter of Nanofibres (Erica Lee)

Results cont’d

Beading of PCL Nanofibre (Erica Lee)Consistent PCL Fibres (Erica Lee)

Objective!

ConclusionFlow rate and electric field gradient

are the most important factors in determining the fibre diameter

The resultant fibre diameter is relative to the contributing factors

Future Investigation

Reduce surface tension with additives Increase volumetric charge density

with saltsCo-axial Spinning

AcknowledgementsDr. Wankei Wan

◦Department of Chemical and Biochemical Engineering

Dr. Martin Zinke-Allmang◦Department of Medical Biophyiscs

Erica Lee◦M. E. Sc. Candidate; Biomedical

Engineering

Questions?

Method12% PCL solution by weightDissolved in tetrafluoroethylene

(TFE)

Nanotechweb.org