Centre for Nano Science and Engineering, ‡Department of Chemical Engineering, and §Department of Materials Engineering, Indian Institute of Science , Bangalore 560012, India.
ACS Appl Mater Interfaces. 2017 Aug 30;9(34):28281-28297. doi: 10.1021/acsami.7b09299. Epub 2017 Aug 15.
The present study elucidates the facile synthesis and exceptional properties of a family of novel poly(ester amide)s (PEAs) based on bis(2-hydroxy ethylene) terephthalamide that was obtained from the poly(ethylene terephthalate) waste. Fourier transform infrared and H NMR were used to verify the presence of ester and amide in the polymer backbone. Differential scanning calorimetry data showed that the glass transition temperature decreased with as the chain length of dicarboxylic acids increased. Dynamic mechanical analysis and contact angle studies proved that the modulus values and hydrophobicity increased with as the chain lengths of dicarboxylic acids increased. In vitro hydrolytic degradation and dye release studies demonstrated that the degradation and release decreased with as the chain lengths of dicarboxylic acids increased. Modeling these data illustrated that degradation and release follow first-order degradation and zero-order release, respectively. The in vitro cytocompatibility studies confirmed the minimal toxicity characteristic of these polymers. Osteogenic studies proved that these polymers can be highly influential in diverting the cells toward osteogenic lineage. Alizarin red staining evinced the presence of twice the amount of calcium phosphate deposits by the cells on these polymers when compared to the control. The observed result was also corroborated by the increased expression of alkaline phosphatase. These findings were further validated by the markedly higher mRNA expressions for known osteogenic markers using real time polymerase chain reaction. Therefore, these polymers efficiently promoted osteogenesis. This study demonstrates that the physical properties, degradation, and release kinetics can be altered to meet the specific requirements in organ regeneration as well as facilitate simultaneous polymer resorption through control of the chain length of the monomers. The findings of this study have significant implications for designing cost-effective biodegradable polymers for tissue engineering.
本研究阐明了一种新型聚（酯酰胺）（PEAs）家族的简便合成方法及其优异性能，该聚合物基于双（2-羟乙基）对苯二甲酰胺，是由废弃的聚对苯二甲酸乙二醇酯制得。傅里叶变换红外和 H NMR 用于验证聚合物主链中酯和酰胺的存在。差示扫描量热法数据表明，玻璃化转变温度随二羧酸链长的增加而降低。动态力学分析和接触角研究表明，随着二羧酸链长的增加，模量值和疏水性增加。体外水解降解和染料释放研究表明，随着二羧酸链长的增加，降解和释放减少。对这些数据进行建模表明，降解和释放分别遵循一级降解和零级释放。体外细胞相容性研究证实了这些聚合物的最小毒性特征。成骨研究证明，这些聚合物可以高度影响细胞向成骨谱系分化。茜素红染色表明，与对照组相比，细胞在这些聚合物上形成的磷酸钙沉积物的量增加了一倍。碱性磷酸酶表达的增加进一步证实了这一结果。通过实时聚合酶链反应对已知成骨标志物的 mRNA 表达的明显增加，也验证了这一结果。因此，这些聚合物有效地促进了成骨。本研究表明，通过控制单体的链长，可以改变物理性质、降解和释放动力学，以满足器官再生的特定要求，并促进聚合物的同时吸收。这项研究的结果对设计用于组织工程的具有成本效益的可生物降解聚合物具有重要意义。
