Architecture-Dependent Disintegration Temperature of Electrospun PNIPAM-Based Scaffolds

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials Engineering

Background:

• Electrospun poly(N-isopropylacrylamide) (PNIPAM) scaffolds exhibit temperature-dependent structural changes.
• This disintegration behavior is linked to the coil-to-globule transition but is distinct from classical transition temperatures (LCST, VPTT) due to fiber architecture.

Purpose of the Study:

• Introduce Scaffold Disintegration Temperature (SDT) as a metric for PNIPAM scaffold stability.
• Investigate the influence of macromolecular architecture and processing on scaffold disintegration.
• Correlate scaffold-level stability with polymer topology and network morphology.

Main Methods:

• Utilized statistical and graft PNIPAM copolymers with varying topologies.
• Employed electrospinning to fabricate scaffolds, varying nozzle-to-collector distance.
• Characterized scaffold disintegration using SDT and assessed network morphology and mechanical properties.

Main Results:

• Identified architecture-dependent differences in disintegration behavior, correlating with network morphology and coherence.
• Graft copolymers (with PLA or PCL side chains) showed earlier disintegration and reduced coherence compared to statistical copolymers.
• Processing conditions (nozzle-to-collector distance) modulated morphology and performance but did not alter the dominant effect of macromolecular topology.

Conclusions:

• SDT is a valuable network-level parameter for characterizing thermal behavior of electrospun PNIPAM scaffolds.
• Macromolecular architecture, particularly topology, significantly influences scaffold stability and disintegration.
• SDT complements LCST by providing a morphology-dependent measure of thermal response in fibrous materials.