| dc.description.abstract | Autografts remain the current “gold standard” for treating craniomaxillofacial (CMF) bone defects despite the difficulty in fitting rigid grafts into complex shaped defects. To improve CMF bone treatment, the Grunlan Lab has proposed “self-fitting” shape memory polymer (SMP) scaffolds based on a poly(ε-caprolactone)-diacrylate (PCL-DA) network. Upon heating (Ttrans~55°C), the scaffolds become malleable and can be easily press-fitted into defects for improved osseointegration. Recently, to accelerate the degradation rate of the scaffolds to more closely match bone regeneration, various poly(lactic acid) (PLA) thermoplastics were incorporated into the thermoset PCL-DA network. The resulting PCL-DA/PLA semi-interpenetrating networks (semi-IPNs) demonstrated tunable degradation rates while maintaining SMP behavior. However, the study was limited to nonporous solid films and degradation studies were limited to base-catalyzed conditions (1.0 M NaOH, pH~14, 37 °C). Herein, PCL-DA/PLA semi-IPN porous scaffolds were examined for their degradation behavior under both base-catalyzed and neutral, more physiologically relevant, conditions (1X PBS, pH~7.4, 37 °C). The base-catalyzed conditions altered the hydrolysis kinetics of several compositions and thus did not accurately predict which compositions degraded quickly under neutral conditions. Under neutral conditions, low Mn, amorphous, and hydrophilic PLA thermoplastics promoted the fastest scaffold degradation. Additionally, post-degradation thermal analyses showed that even in the fastest degrading PLC-DA/PLA semi-IPNs, both PCL and PLLA were degrading, proving that the incorporation of PLAs can promote accelerated degradation of PCL. | |
