Sintered electrospun polycaprolactone for controlled model drug delivery.

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Materials Engineering

Background:

• Electrospinning is a versatile technique for creating fibers for drug delivery.
• Drug loading and release are often limited by surface area.
• Sintering electrospun fibers offers a novel approach for sustained drug release.

Purpose of the Study:

• To investigate the potential of sintered electrospun polycaprolactone (PCL) fibers as capsules for long-term drug delivery.
• To evaluate the effect of sintering temperature on PCL fiber morphology, porosity, and drug release kinetics.
• To correlate PCL capsule properties with the release profiles of model compounds with varying molecular weights.

Main Methods:

• Electrospinning of polycaprolactone (PCL) fibers.
• Sintering of PCL fibers at different temperatures (56-59°C).
• In vitro exposure of PCL fibers and capsules for up to 1042 days.
• Characterization of fiber morphology and pore size.
• Drug release studies using Rhodamine B, Rose Bengal, and BSA-FITC as model compounds.
• COMSOL simulations to model release rates based on capsule properties.

Main Results:

• Electrospun PCL fibers maintained morphology for over 1000 days.
• Sintering significantly decreased pore size, with higher temperatures leading to greater reduction.
• PCL capsules sintered at 58-59°C showed reduced surface porosity but retained entrapped pores.
• Drug release rates were dependent on molecular weight and available porosity (RhB > RB >> BSA-FITC).
• Sintered capsules at 58-59°C exhibited sustained release profiles, continuing after 12 days, unlike those sintered at lower temperatures.

Conclusions:

• Sintering electrospun PCL fibers is a viable method for creating drug-eluting capsules with tunable, long-term release characteristics.
• Controlled reduction of porosity through sintering modulates drug release kinetics, enabling sustained delivery.
• The PCL capsules demonstrate potential for extended performance in drug delivery applications, with release profiles influenced by sintering temperature and molecular properties of the released compound.