根據目前用於椎間盤退化脊柱融合術的植入物臨床缺點，本研究針對植入物籠架進行改良。目前的臨床手術是利用籠架穩定植入物，在融合過程中存在籠架位移沉降及填充藥物分散等問題，此前的大鼠尾椎實驗模型已顯示這些限制。因此，本研究透過的3D列印改良籠架及含藥物列印樹脂來提升植入物的穩定性與融合效率。
首先，主要目標是基於術前CT成像進行客製化的3D列印植入物設計。這些植入物將根據CT成像中的椎間盤結構量身訂製，以確保完美貼合，避免尺寸不匹配所可能導致的位移問題。植入物設計具有微網格形成的粗糙表面結構，以增加與周圍骨組織的摩擦力，從而促進早期融合穩定性。其次，植入物的網狀多孔結構引導骨細胞生長並促進椎間模型與相鄰椎骨之間的骨融合。這種設計提供理想的微環境，有助於細胞附著、增殖和組織整合，進而促進新骨形成。
為了進一步增強脊柱椎間融合，本研究將小分子藥物辛伐他汀整合到3D列印材料中。辛伐他汀原為降血脂藥物，在近年來的研究中顯示具有促進骨生成的效果。透過光固化3D列印技術的非加熱製程特性，印製含有藥物的植入物籠架。使籠架本身直接含有刺激骨生成的小分子藥物，搭配網格結構填充藥物粉末，解決先前藥物分散問題，確保藥物從列印籠架中持續釋放。此外，網狀結構增加接觸面積有助於持續釋放，解決手術期間單次藥物給藥的限制。這種持續釋放效果將在三個月及更長期間內促進新骨形成完成椎間骨融合。
本研究利用具有粗糙表面和多孔結構的客製化3D列印植入物，製造持續的藥物遞送機制，克服了籠架沉降、填充藥物分散及一次性給藥相關的挑戰。這種綜合改良方法不僅提升了植入物的穩定性，還促進了有效的脊柱椎間融合，改善並加速預後。

This study addresses the challenge of intervertebral disc degeneration through orthopedic surgery involving spinal fusion with implants. The current approach utilizes cages to stabilize implants during fusion, but previous rat tail model experiments revealed issues such as cage subsidence and scattered drugs. This study aims to enhance implant stability and fusion efficiency using a comprehensive approach. The primary objective involves personalized implant through a custom-made 3D printing based on preoperative CT imaging. Implants will feature barb surface structures for increased friction, promoting early-stage fusion stability. Subsequently, a mesh-like porous structure will be incorporated to guide cell growth and facilitate fusion between the intervertebral model and adjacent vertebrae. To further enhance spinal intervertebral fusion, simvastatin will be integrated into the implant printing material. The non-thermal characteristic of SLA printing will allow drugs to be dispersed to the resin without degradation. Printed implants will directly contain small-molecule drugs that stimulate bone generation. This approach will prevent drug scattered issues during surgery and ensure sustained drug release from the 3D printing cage. The mesh will also contribute to continuous drug delivery, addressing the limitations of single-dose administration during surgery. In essence, this study aims to overcome challenges associated with implant subsidence, drug dispersion, and one-time drug administration by utilizing personalized 3D-printed implants with rough and porous structures, combined with sustained drug delivery mechanisms. The goal is to enhance implant stability and promote effective spinal intervertebral fusion for improved patient outcomes.

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