Kim Jinku, Yaszemski Michael J, Lu Lichun
Tissue Engineering and Biomaterials Laboratory, Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
J Biomed Mater Res A. 2009 Sep 15;90(4):1010-20. doi: 10.1002/jbm.a.32166.
Novel biodegradable injectable poly(ethylene glycol)-(PEG) based macromers were synthesized by reacting low-molecular weight PEG (MW: 200) and dicarboxylic acids such as sebacic acid or terephthalic acid. Chemical structures of the resulting polymers were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy characterizations. Differential scanning calorimetry (DSC) showed that these polymers were completely amorphous above room temperature. After photopolymerization, dynamic elastic shear modulus of the crosslinked polymers was up to 1.5 MPa and compressive modulus was up to 2.2 MPa depending on the polymer composition. The in vitro degradation study showed that mass losses of these polymers were gradually decreased over 23 weeks of period in simulated body fluid. By incorporating up to 30 wt % of 2-hydroxyethyl methylmethacrylate (HEMA) into the crosslinking network, the dynamic elastic modulus and compressive modulus was significantly increased up to 7.2 and 3.2 MPa, respectively. HEMA incorporation also accelerated the degradation as indicated by substantially higher mass loss of up to 27% after 20 weeks of incubation. Cytocompatability studies using osteoblasts and neural cells revealed that cell metabolic activity on these polymers with or without HEMA was close to the control tissue culture polystyrene. The PEG-based macromers developed in this study may be useful as scaffolds or cell carriers for tissue engineering applications.
通过使低分子量聚乙二醇（MW：200）与癸二酸或对苯二甲酸等二元羧酸反应，合成了新型可生物降解的可注射聚乙二醇（PEG）基大分子单体。通过傅里叶变换红外（FTIR）和核磁共振（NMR）光谱表征确定了所得聚合物的化学结构。差示扫描量热法（DSC）表明，这些聚合物在室温以上完全无定形。光聚合后，根据聚合物组成，交联聚合物的动态弹性剪切模量高达1.5 MPa，压缩模量高达2.2 MPa。体外降解研究表明，在模拟体液中，这些聚合物在23周内的质量损失逐渐减少。通过在交联网络中加入高达30 wt%的甲基丙烯酸2-羟乙酯（HEMA），动态弹性模量和压缩模量分别显著提高到7.2和3.2 MPa。HEMA的加入也加速了降解，孵育20周后质量损失高达27%，表明降解程度更高。使用成骨细胞和神经细胞进行的细胞相容性研究表明，在含或不含HEMA的这些聚合物上的细胞代谢活性接近对照组织培养聚苯乙烯。本研究中开发的PEG基大分子单体可能作为组织工程应用的支架或细胞载体。
