Houk Christopher J, Beltran Felipe O, Grunlan Melissa A
Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, United States.
Department of Materials Science & Engineering, Texas A&M University, College Station, Texas 77843, United States.
Polym Degrad Stab. 2021 Dec;194. doi: 10.1016/j.polymdegradstab.2021.109763. Epub 2021 Oct 27.
Irregularly shaped craniomaxillofacial (CMF) defects may be advantageously treated by "self-fitting" shape memory polymer (SMP) scaffolds, namely those prepared from poly(ε-caprolactone)diacrylate (PCL-DA) networks and PCL-DA/poly(L-lactic acid) (PLLA) (75:25 wt%) semi-interpenetrating polymer networks (semi-IPNs). In addition to achieving good scaffold-tissue contact, a polydopamine (PD) coating can be leveraged to enhance bioactivity for improved osseointegration. Sterilization with ethylene oxide (EtO) represents a logical choice due to its low operating temperature and humidity. Herein, for the first time, the impact of EtO sterilization on the material properties of PD-coated SMP scaffolds was systematically assessed. Morphological features (i.e., pore size and pore interconnectivity), and bioactivity were preserved as were PCL crystallinity, PLLA crystallinity, and crosslinking. These latter features led to sustained shape memory properties, and compressive modulus. EtO-sterilized, PD-coated scaffolds displayed similar degradation behaviors versus analogous non-sterilized scaffolds. This included maintenance of compression modulus following 28 days of exposure to non-accelerated degradation conditions.
形状不规则的颅颌面（CMF）缺损可以通过“自适配”形状记忆聚合物（SMP）支架进行有效治疗，即由聚（ε-己内酯）二丙烯酸酯（PCL-DA）网络以及PCL-DA/聚（L-乳酸）（PLLA）（75:25重量比）半互穿聚合物网络（半IPN）制备的支架。除了实现良好的支架与组织接触外，聚多巴胺（PD）涂层可用于增强生物活性，以改善骨整合。由于环氧乙烷（EtO）的操作温度和湿度较低，因此采用EtO灭菌是一个合理的选择。在此，首次系统评估了EtO灭菌对PD涂层SMP支架材料性能的影响。形态特征（即孔径和孔隙连通性）以及生物活性得以保留，PCL结晶度、PLLA结晶度和交联也得以保留。这些特征导致了持续的形状记忆性能和压缩模量。经EtO灭菌的PD涂层支架与类似的未灭菌支架表现出相似的降解行为。这包括在暴露于非加速降解条件28天后压缩模量的维持。
