Shim Ha-Eun, Yeon Yeong-Heum, Lim Dae-Hee, Nam You-Ree, Park Jin-Hyung, Lee Nam-Ho, Gwon Hui-Jeong
Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup 56212, Korea.
Materials (Basel). 2021 Nov 10;14(22):6777. doi: 10.3390/ma14226777.
In this study, biodegradable poly(L-lactide-co-ε-caprolactone) (PLCL) and poly(L-co-d,l lactide) (PLDLA) were evaluated using Geant4 (G4EmStandardPhysics_option4) for damage simulation, in order to predict the safety of these biodegradable polymers against gamma ray sterilization. In the PLCL damage model, both chain scission and crosslinking reactions appear to occur at a radiation dose in the range 0-200 kGy, but the chain cleavage reaction is expected to be relatively dominant at high irradiation doses above 500 kGy. On the other hand, the PLDLA damage model predicted that the chain cleavage reaction would prevail at the total irradiation dose (25-500 kGy). To verify the simulation results, the physicochemical changes in the irradiated PLCL and PLDLA films were characterized by GPC (gel permeation chromatography), ATR-FTIR (attenuated total reflection Fourier transform infrared), and DSC (difference scanning calorimetry) analyses. The Geant4 simulation curve for the radiation-induced damage to the molecular weight was consistent with the experimentally obtained results. These results imply that the pre-simulation study can be useful for predicting the optimal irradiation dose and ensuring material safety, particularly for implanted biodegradable materials in radiation processing.
在本研究中，使用Geant4（G4EmStandardPhysics_option4）对可生物降解的聚（L-丙交酯-共-ε-己内酯）（PLCL）和聚（L-共-d，l丙交酯）（PLDLA）进行损伤模拟，以预测这些可生物降解聚合物在伽马射线灭菌下的安全性。在PLCL损伤模型中，断链和交联反应似乎在0 - 200 kGy的辐射剂量范围内都会发生，但在高于500 kGy的高辐照剂量下，断链反应预计占主导。另一方面，PLDLA损伤模型预测断链反应将在总辐照剂量（25 - 500 kGy）下占主导。为了验证模拟结果，通过凝胶渗透色谱（GPC）、衰减全反射傅里叶变换红外光谱（ATR-FTIR）和差示扫描量热法（DSC）分析对辐照后的PLCL和PLDLA薄膜的物理化学变化进行了表征。Geant4模拟得到的辐射诱导分子量损伤曲线与实验结果一致。这些结果表明，预模拟研究对于预测最佳辐照剂量和确保材料安全性可能是有用的，特别是对于辐射加工中的植入式可生物降解材料。
