3D printed PLGA implants: How the filling density affects drug release

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• 3D Printing Technology

Background:

• Poly (D,L lactic-co-glycolic acid) (PLGA) is a widely used biodegradable polymer for drug delivery.
• 3D printing offers precise control over the architecture of drug delivery devices.
• Understanding drug release kinetics from 3D printed implants is crucial for optimizing therapeutic outcomes.

Purpose of the Study:

• To investigate the effect of filling density on ibuprofen release from 3D printed PLGA implants.
• To elucidate the mechanisms controlling drug release based on implant architecture and release environment.
• To provide insights for designing advanced 3D printed drug delivery systems.

Main Methods:

• Fabrication of mesh-shaped PLGA implants with varying theoretical filling densities (10-100%) using 3D printing (Droplet Deposition Modeling).
• Quantification of ibuprofen release in phosphate buffer (pH 7.4) and agarose gels.
• Characterization of implant properties and changes using gravimetric analysis, microscopy, DSC, GPC, and SEM.

Main Results:

• Drug release was comparable for implants with 10% and 30% filling densities.
• Implants with 100% filling density exhibited slower release kinetics and altered release profiles in agarose gels.
• Release behavior was attributed to the presence/absence of a continuous aqueous phase and system swelling, affecting drug diffusion pathways.

Conclusions:

• Filling density significantly impacts drug release from 3D printed PLGA implants.
• System swelling and the resulting diffusion path length are key factors controlling drug release.
• Agarose gel, mimicking tissue, restricts swelling and delays rapid drug release, highlighting the importance of the release environment.