Department of Biomedical Engineering, University of Minnesota, 312 Church St. SE, 7-105 Nils Hasselmo Hall, Minneapolis, Minnesota 55455, United States.
Department of Pharmaceutics, University of Minnesota, 308 SE Harvard St, Room 9-177 Weaver Densford Hall, Minneapolis, Minnesota 55455, United States.
Biomacromolecules. 2022 Jan 10;23(1):163-173. doi: 10.1021/acs.biomac.1c01197. Epub 2021 Dec 13.
Biodegradable and biocompatible elastomers are highly desirable for many biomedical applications. Here, we report synthesis and characterization of poly(ε-caprolactone)--poly(β-methyl-δ-valerolactone)--poly(ε-caprolactone) (PCL-PβMδVL-PCL) elastomers. These materials have strain to failure values greater than 1000%. Tensile set measurements according to an ASTM standard revealed a 98.24% strain recovery 10 min after the force was removed and complete strain recovery 40 min after the force was removed. The PβMδVL midblock is amorphous with a glass-transition temperature of -51 °C, and PCL end blocks are semicrystalline and have a melting temperature in the range of 52-55 °C. Due to their thermoplastic nature and the low melting temperature, these elastomers can be readily processed by printing, extrusion, or hot-pressing at 60 °C. Lysozyme, a model bioactive agent, was incorporated into a PCL-PβMδVL-PCL elastomer through melt blending in an extruder, and the blend was further hot-pressed into films; both processing steps were performed at 60 °C. No loss of lysozyme bioactivity was observed. PCL-PβMδVL-PCL elastomers are as cytocompatible as tissue culture polystyrene in supporting cell viability and cell growth, and they are degradable in aqueous environments through hydrolysis. The degradable, cytocompatible, elastomeric, and thermoplastic properties of PCL-PβMδVL-PCL polymers collectively render them potentially valuable for many applications in the biomedical field, such as medical devices and tissue engineering scaffolds.
可生物降解和生物相容的弹性体在许多生物医学应用中是非常理想的。在这里，我们报告了聚（ε-己内酯）-聚（β-甲基-δ-戊内酯）-聚（ε-己内酯）（PCL-PβMδVL-PCL）弹性体的合成与表征。这些材料的断裂伸长率大于 1000%。根据 ASTM 标准进行的拉伸定标测量显示，在力移除 10 分钟后，应变恢复了 98.24%，在力移除 40 分钟后完全恢复了应变。PβMδVL 中嵌段为无定形，玻璃化转变温度为-51°C，PCL 端嵌段为半结晶，熔融温度在 52-55°C 范围内。由于其热塑性和低熔融温度，这些弹性体可以通过在 60°C 下打印、挤出或热压轻松加工。溶菌酶，一种模型生物活性物质，通过在挤出机中熔融共混被掺入到 PCL-PβMδVL-PCL 弹性体中，然后将共混物进一步在 60°C 下热压成膜；这两个加工步骤都是在 60°C 下进行的。没有观察到溶菌酶生物活性的损失。PCL-PβMδVL-PCL 弹性体在支持细胞活力和细胞生长方面与组织培养聚苯乙烯一样具有细胞相容性，并且在水介质中通过水解可降解。PCL-PβMδVL-PCL 聚合物的可降解、细胞相容、弹性和热塑性特性共同赋予它们在生物医学领域的许多应用中潜在的价值，例如医疗设备和组织工程支架。
