Structure-function relationships and source-to-ground distance in electrospun polycaprolactone.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Materials Science

Background:

• The mechanical properties of electrospun scaffolds are critical for their performance in tissue engineering applications.
• Poly(epsilon-caprolactone) (PCL) is a widely used biodegradable polymer for scaffold fabrication.

Purpose of the Study:

• To investigate the impact of source-to-ground distance on the mechanical properties and microstructure of electrospun PCL scaffolds.
• To understand how varying fabrication parameters influence scaffold strength and failure behavior.

Main Methods:

• Electrospinning of PCL scaffolds using varied source-to-ground distances (10, 15, 20 cm), solids concentrations (12, 18 wt.%), and mandrel rotation speeds (0-12 m/s).
• Mechanical testing including tensile tests to evaluate elastic modulus, tensile strength, and elongation at failure.
• Scanning electron microscopy (SEM) for morphological analysis and quantification of fiber alignment.

Main Results:

• Increased source-to-ground distance led to a microstructure with greater fiber rearrangement under load, tripling tensile strength.
• Higher rotational speeds generally enhanced fiber alignment and strength, but only at high speeds.
• Shorter distances (10 cm) resulted in heavily point-bonded fibers, exhibiting lower tensile strength and significantly increased elongation at failure due to localized necking.

Conclusions:

• Source-to-ground distance is a critical parameter influencing electrospun scaffold microstructure, mechanical properties, and failure modes.
• Optimizing this distance can significantly enhance scaffold strength and tailor failure characteristics for specific tissue engineering requirements.
• Understanding fiber-fiber interactions during electrospinning, influenced by distance, is key to controlling scaffold biocompatibility and performance.