Tailoring properties of microsphere-based poly(lactic-co-glycolic acid) scaffolds

Biodegradable polymer scaffolds are being extensively investigated for uses in tissue engineering because of their versatility in fabrication methods and range of achievable chemical and mechanical properties. In this study, poly(lactic-co-glycolic acid) (PLGA) was used to make various types of microspheres that were processed into porous scaffolds that possessed a wide range of properties. A heat sintering step was used to fuse microspheres together around porogen particles that were subsequently leached out, allowing for a 10-fold increase in mechanical properties over other PLGA scaffolds. The sintering temperature was based on the glass transition temperature that ranged from 43 to 49°C, which was low enough to enable drug loading. Degradation times were observed to be between 30 and 120 days, with an initial compressive modulus ranging from 10 to 100 MPa, and after 5 days of degradation up to 10 MPa was retained. These scaffolds were designed to allow for cell ingrowth, enable drug loading, and have an adjustable compressive modulus to be applicable for soft or hard tissue implants. This study combined well-established methods, such as double emulsion microspheres, polymer sintering, and salt leaching, to fabricate polymer scaffolds useful for different tissue engineering applications.