Effect of Molecular Weight and Functionality on Acrylated Poly(caprolactone) for Stereolithography and Biomedical Applications
Effect of Molecular Weight and Functionality on Acrylated Poly(caprolactone) for Stereolithography and Biomedical Applications
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DOI：
10.1021/acs.biomac.8b00784
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发表时间：
2018-09-01
影响因子：
6.2
通讯作者：
Guymon, C. Allan
中科院分区：
文献类型：
--
作者：
Green, Brian J.;Worthington, Kristan S.;Guymon, C. Allan
可降解聚合物是许多生物医学聚合物应用中不可或缺的组成部分。这些材料原位分解的能力已经成为组织工程的关键组成部分，允许支架引导细胞和组织生长，同时促进天然组织的逐渐再生。这项工作的目的是了解预聚物的分子量和功能的光固化聚（己内酯）（PCL）在确定反应动力学，机械性能，聚合物降解，生物相容性和立体光刻的适用性的作用。PCL是一种用于许多生物医学应用的可降解聚合物，用丙烯酸酯基团官能化，以通过立体光刻实现光聚合和三维打印。研究了具有不同分子量和官能度的PCL预聚物，以了解分子结构在反应动力学、机械性能和降解速率中的作用。光固化聚己内酯的机械性能取决于交联密度，并与预聚物的分子量和官能度直接相关。高分子量、低官能度的PCLDA预聚物表现出较低的模量和较高的断裂应变，而低分子量、高官能度的PCLTA预聚物表现出较低的断裂应变和较高的模量。此外，交联PCL的降解曲线遵循类似的趋势，低交联密度导致降解时间比更高交联聚合物的降解时间短2.5倍。此外，光聚合的PCL在体外和体内都表现出生物相容性，对接种的小鼠诱导的多能干细胞或植入猪视网膜时没有观察到有害影响。最后，通过使用数字光投影立体光刻制造简单结构来显示创建三维PCL结构的能力。低分子量、高功能性PCLTA预聚物打印物体，其特征尺寸接近50 μ m的硬件分辨率极限。这项工作奠定了基础，为未来的工作，在制造微尺度PCL结构的广泛的组织再生应用。
Degradable polymers are integral components in many biomedical polymer applications. The ability of these materials to decompose in situ has become a critical component for tissue engineering, allowing scaffolds to guide cell and tissue growth while facilitating gradual regeneration of native tissue. The objective of this work is to understand the role of prepolymer molecular weight and functionality of photocurable poly(caprolactone) (PCL) in determining reaction kinetics, mechanical properties, polymer degradation, biocompatibility, and suitability for stereolithography. PCL, a degradable polymer used in a number of biomedical applications, was functionalized with acrylate groups to enable photopolymerization and three-dimensional printing via stereolithography. PCL prepolymers with different molecular weights and functionalities were studied to understand the role of molecular structure in reaction kinetics, mechanical properties, and degradation rates. The mechanical properties of photocured PCL were dependent on cross-link density and directly related to the molecular weight and functionality of the prepolymers. High-molecular weight, low-functionality PCLDA prepolymers exhibited a lower modulus and a higher strain at break, while low-molecular weight, high-functionality PCLTA prepolymers exhibited a lower strain at break and a higher modulus. Additionally, degradation profiles of cross-linked PCL followed a similar trend, with low cross-link density leading to degradation times up to 2.5 times shorter than those of more highly cross-linked polymers. Furthermore, photopolymerized PCL showed biocompatibility both in vitro and in vivo, causing no observed detrimental effects on seeded murine-induced pluripotent stem cells or when implanted into pig retinas. Finally, the ability to create three-dimensional PCL structures is shown by fabrication of simple structures using digital light projection stereolithography. Low-molecular weight, high-functionality PCLTA prepolymers printed objects with feature sizes near the hardware resolution limit of 50 mu m. This work lays the foundation for future work in fabricating microscale PCL structures for a wide range of tissue regeneration applications.