Pfleiderer B, Moore A, Tokareva E, Ackerman J L, Garrido L
NMR Center, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown 02129, USA.
Biomaterials. 1999 Mar;20(6):561-71. doi: 10.1016/s0142-9612(98)00208-7.
Linear and cyclic polysiloxanes and extracts (free polymer) from a silicone gel-filled implant are used to investigate the reactivity of silicones in vivo. Aqueous emulsions of polysiloxanes and controls (without polysiloxanes) are injected once (day 0, approximately 10% w/v) or six times (starting at day 0, every 14 days, approximately 3% w/v) in the right thigh of rats and the popliteal and lumbar lymph nodes are harvested (3 rats per time point and compound investigated) at 2, 16, 30, 44, 58 and 72 days after the injection. 29Si NMR spectroscopy is used to detect and evaluate the presence of polysiloxanes and their metabolites in the lymph nodes. In addition to the resonance associated with the polysiloxane injected (approximately -20 ppm), the NMR spectra of lymph nodes show new resonances that are attributed to partially hydrolyzed polysiloxanes (-5 to -15 ppm) and silica (-90 to - 120 ppm). These resonances are not present in polysiloxanes emulsions before injection or in the lymph nodes of controls. Our results demonstrate that all polysiloxanes and extracts from silicone gel-filled implants are biotransformed in the lymph nodes, but high molecular weight polymer degrades at a slower rate than oligomers.
线性和环状聚硅氧烷以及来自硅胶填充植入物的提取物（游离聚合物）被用于研究硅氧烷在体内的反应性。将聚硅氧烷的水乳液和对照物（不含聚硅氧烷）一次性（第0天，约10% w/v）或分六次（从第0天开始，每14天一次，约3% w/v）注射到大鼠的右大腿中，并在注射后第2、16、30、44、58和72天收获腘窝和腰淋巴结（每个时间点和所研究的化合物取3只大鼠）。采用29Si核磁共振波谱法检测和评估淋巴结中聚硅氧烷及其代谢产物的存在情况。除了与注射的聚硅氧烷相关的共振峰（约-20 ppm）外，淋巴结的核磁共振波谱还显示出归因于部分水解的聚硅氧烷（-5至-15 ppm）和二氧化硅（-90至-120 ppm）的新共振峰。这些共振峰在注射前的聚硅氧烷乳液或对照物的淋巴结中不存在。我们的结果表明，所有来自硅胶填充植入物的聚硅氧烷和提取物在淋巴结中都会发生生物转化，但高分子量聚合物的降解速度比低聚物慢。
