Polyurethane scaffold with in situ swelling capacity for nucleus pulposus replacement

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• 作者：Zhen Li^a ; ¹ ; Gernot Lang^a ; ^d ; ¹ ; Xu Chen^a ; Hagit Sacks^b ; Carmit Mantzur^b ; Udi Tropp^b ; Kerstin T. Mader^c ; Thomas C. Smallwood^c ; Chris Sammon^c ; R. Geoff Richards^a ; ^d ; Mauro Alini^a ; Sibylle Grad^a ; ^{sibylle.grad@aofoundation.org" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Biphasic polyurethane scaffold ; In situ swelling ; Nucleus pulposus replacement ; Organ culture ; Nucleotomy ; Intervertebral disc degeneration
• 刊名：Biomaterials
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：84
• 期：Complete
• 页码：196-209
• 全文大小：3123 K

文摘

Nucleus pulposus (NP) replacement offers a minimally invasive alternative to spinal fusion or total disc replacement for the treatment of intervertebral disc (IVD) degeneration. This study aimed to develop a cytocompatible NP replacement material, which is feasible for non-invasive delivery and tunable design, and allows immediate mechanical restoration of the IVD. A bi-phasic polyurethane scaffold was fabricated consisting of a core material with rapid swelling property and a flexible electrospun envelope. The scaffold was assessed in a bovine whole IVD organ culture model under dynamic load for 14 days. Nucleotomy was achieved by incision through the endplate without damaging the annulus fibrosus. After implantation of the scaffold and in situ swelling, the dynamic compressive stiffness and disc height were restored immediately. The scaffold also showed favorable cytocompatibility for native disc cells. Implantation of the scaffold in a partially nucleotomized IVD down-regulated catabolic gene expression, increased proteoglycan and type II collagen intensity and decreased type I collagen intensity in remaining NP tissue, indicating potential to retard degeneration and preserve the IVD cell phenotype. The scaffold can be delivered in a minimally invasive manner, and the geometry of the scaffold post-hydration is tunable by adjusting the core material, which allows individualized design.