摘要
Epidural scarring occurs inevitably in the defect after spinal laminectomy, and thus how to prevent or reduce it becomes a challenging topic. In the present study, an injectable hydrogel and its dexamethasone （DEX）-loaded hydrogel systems were adopted to prevent epidural scarring in a postlaminectomy rat model. The hydrogel system composed of poly（D,L-lactic acid-co-glycolic acid）-poly（ethylene glycol）-poly（D,L-lactic acid-co-glycolic acid） （PLGA-PEG-PLGA） triblock copolymers was a free-flowing sol at room temperature, and spontaneously turned into a semi-solid gel at body temperature. A lumbar 3 total laminectomy was performed on Sprague Dawley （SD） rats, and the efficacy of the injectable hydrogel with or without drugs in preventing epidural scar formation was evaluated via the gross anatomical observation and histological examination at one month post-surgery. The results demonstrate that the use of hydrogel alone reduced epidural scarring significantly, whereas the efficacy of the DEX-loaded hydrogels presented an irregular dose-dependency of drug and even the inappropriate drug doses resulted in the negative results. Therefore, the present study confirms that the PLGA-PEG- PLGA hydrogel holds potential as a barrier device to decrease peridural scarring, and reveals that the sustained delivery of the steroid hormone DEX to prevent surgery-related adhesions in the laminectomy defect is complex. Moreover, our in vivo studies also remind the researchers to pay attention to the irregular dose-dependency of the hormone drugs.
Epidural scarring occurs inevitably in the defect after spinal laminectomy, and thus how to prevent or reduce it becomes a challenging topic. In the present study, an injectable hydrogel and its dexamethasone （DEX）-loaded hydrogel systems were adopted to prevent epidural scarring in a postlaminectomy rat model. The hydrogel system composed of poly（D,L-lactic acid-co-glycolic acid）-poly（ethylene glycol）-poly（D,L-lactic acid-co-glycolic acid） （PLGA-PEG-PLGA） triblock copolymers was a free-flowing sol at room temperature, and spontaneously turned into a semi-solid gel at body temperature. A lumbar 3 total laminectomy was performed on Sprague Dawley （SD） rats, and the efficacy of the injectable hydrogel with or without drugs in preventing epidural scar formation was evaluated via the gross anatomical observation and histological examination at one month post-surgery. The results demonstrate that the use of hydrogel alone reduced epidural scarring significantly, whereas the efficacy of the DEX-loaded hydrogels presented an irregular dose-dependency of drug and even the inappropriate drug doses resulted in the negative results. Therefore, the present study confirms that the PLGA-PEG- PLGA hydrogel holds potential as a barrier device to decrease peridural scarring, and reveals that the sustained delivery of the steroid hormone DEX to prevent surgery-related adhesions in the laminectomy defect is complex. Moreover, our in vivo studies also remind the researchers to pay attention to the irregular dose-dependency of the hormone drugs.
基金
financially supported by the Science and Technology Developing Foundation of Shanghai(No.12JC1402600)
the National Natural Science Foundation of China(Nos.51273217
21474019
81372002 and 31170925)
National 863 Hi-tech Project(No.2015AA033703)
