Bazan-Panana Geraldine Denise, Torres-Calla Manuel J, Carranza-Oropeza María Verónica
Department of Chemical Engineering, Major National University of San Marcos, Lima 15081, Peru.
Faculty of Physical Sciences, Major National University of San Marcos, Lima 15081, Peru.
Polymers (Basel). 2025 Jun 19;17(12):1708. doi: 10.3390/polym17121708.
In this study, poly-DL-lactic acid (PDLLA) was synthesized via ring-opening polymerization (ROP) to develop a biomedical scaffold for tissue engineering. A rotary evaporator with a two-stage vacuum pump under an inert atmosphere and constant stirring was used. A factorial design with three factors (oligomerization time, ROP time, and catalyst concentration) at two levels was applied. Polymers were characterized by FTIR, capillary viscometry, H-NMR, DSC, and TGA. The kinetic study revealed a first-order model, indicating that the polymerization rate depends linearly on monomer concentration. The activation energy (70.5 kJ/mol) suggests a moderate energy requirement, consistent with ring-opening polymerization, while the high pre-exponential factor (6.93 × 10 min) reflects a significant frequency of molecular collisions. The scaffold was fabricated via extrusion and 3D printing, and its morphology, porosity, mechanical properties, and contact angle were studied. The highest molecular weight PDLLA was obtained with 6 h of oligomerization, 4 h of ROP, and 1% catalyst concentration. The samples exhibited thermal stability below 40 °C, while the scaffold reached 71.6% porosity, an 85.97° contact angle, and a compressive strength of 4.24 MPa with an elastic modulus of 51.7 MPa. These findings demonstrate the scaffold's potential for biomedical applications.
在本研究中，通过开环聚合（ROP）合成了聚-DL-乳酸（PDLLA），以开发用于组织工程的生物医学支架。使用了在惰性气氛和持续搅拌下配备两级真空泵的旋转蒸发仪。应用了一个包含三个因素（齐聚时间、ROP时间和催化剂浓度）、两个水平的析因设计。通过傅里叶变换红外光谱（FTIR）、毛细管粘度测定法、氢核磁共振（H-NMR）、差示扫描量热法（DSC）和热重分析法（TGA）对聚合物进行了表征。动力学研究揭示了一个一级模型，表明聚合速率与单体浓度呈线性关系。活化能（70.5 kJ/mol）表明能量需求适中，这与开环聚合一致，而高指前因子（6.93×10 min）反映了分子碰撞的显著频率。通过挤出和3D打印制备了支架，并对其形态、孔隙率、力学性能和接触角进行了研究。在齐聚6小时、ROP 4小时和催化剂浓度为1%的条件下获得了分子量最高的PDLLA。样品在40°C以下表现出热稳定性，而支架的孔隙率达到71.6%，接触角为85.97°，抗压强度为4.24 MPa，弹性模量为51.7 MPa。这些发现证明了该支架在生物医学应用中的潜力。
