1Wisconsin National Primate Research Center, University of Wisconsin-Madison, Wisconsin.
Departments of2Medical Physics.
J Neurosurg. 2024 Jul 26;141(6):1554-1566. doi: 10.3171/2024.4.JNS24367. Print 2024 Dec 1.
The objective of this study was to develop and evaluate the feasibility and safety of a novel transaxial surgical approach for the delivery of human induced pluripotent stem cell-derived dopaminergic neuroprogenitor cells (DANPCs) into the putamen nucleus using nonhuman primates and surgical techniques and tools relevant to human clinical translation.
Nine immunosuppressed, unlesioned adult cynomolgus macaques (4 females, 5 males) received intraputaminal injections of vehicle or DANPCs (0.9 × 105 to 1.1 × 105 cells/µL) under real-time intraoperative MRI guidance. The infusates were combined with 1-mM gadoteridol (for intraoperative MRI visualization) and delivered via two tracks per hemisphere (ventral and dorsal) using a transaxial approach. The total volumes of infusion were 25 µL and 50 µL for the right and left putamen, respectively (infusion rate 2.5 µL/min). Animals were evaluated with a battery of clinical and behavioral outcome measures and euthanized 7 or 30 days postsurgery; full necropsies were performed by a board-certified veterinary pathologist. Brain tissues were collected and processed for immunohistochemistry, including against the human-specific marker STEM121.
The optimized surgical technique and tools produced successful targeting of the putamen via the transaxial approach. Intraoperative MR images confirmed on-target intraputaminal injections in all animals. All animals survived to scheduled termination without clinical evidence of neurological deficits. The first 4 animals to undergo surgery had mild brain swelling noted at the end of surgery, of which 3 had transient reduced vision; administration of mannitol therapy and reduced intravenous fluid during the surgical procedure addressed these complications. Immunostaining against STEM121 confirmed the presence of grafted cells along the injection track within the targeted putamen area of DANPC-treated animals. All adverse histological findings were limited in scope and consistent with surgical manipulation, injection procedure, and postsurgical inflammatory response to the mechanical disruption caused by the cannula insertion.
The delivery system, injection procedure, and DANPCs were well tolerated in all animals. Prevention of mild brain swelling by mannitol dosing and reduction of intravenous fluids during surgery allowed visual effects to be avoided. The results of the study established that this novel transaxial approach can be used to correctly and safely target cell injections to the postcommissural putamen and support clinical investigation.
本研究旨在开发并评估一种新的经颅手术方法的可行性和安全性，以便使用非人灵长类动物和与人类临床转化相关的手术技术和工具，将人诱导多能干细胞衍生的多巴胺能神经祖细胞（DANPC）递送至壳核。
9 只免疫抑制、未受损的成年食蟹猴（4 只雌性，5 只雄性）在实时术中 MRI 引导下接受壳核内注射载体或 DANPC（0.9×105 至 1.1×105 个细胞/µL）。输注物与 1mM 钆特醇（用于术中 MRI 可视化）混合，并使用经颅手术方法通过每个半球的两条轨道（腹侧和背侧）进行递送。右和左壳核的总输注体积分别为 25µL 和 50µL（输注速率为 2.5µL/min）。动物通过一系列临床和行为结果测量进行评估，并在手术后 7 或 30 天安乐死；由具有董事会认证的兽医病理学家进行全面尸检。收集并处理脑组织进行免疫组织化学染色，包括针对人类特异性标记物 STEM121。
优化的手术技术和工具通过经颅手术方法成功地将壳核作为目标。术中 MRI 图像证实所有动物均在目标壳核内进行了靶向注射。所有动物均存活至预定终止，无神经功能缺损的临床证据。前 4 只接受手术的动物在手术结束时出现轻度脑肿胀，其中 3 只出现短暂的视力下降；在手术过程中给予甘露醇治疗和减少静脉输液解决了这些并发症。针对 STEM121 的免疫染色证实，在 DANPC 治疗动物的靶向壳核区域内，沿着注射轨迹存在移植细胞。所有不良组织学发现均在范围上有限，与手术操作、注射程序以及套管插入引起的机械破坏后的术后炎症反应一致。
在所有动物中，递药系统、注射程序和 DANPC 均耐受良好。通过甘露醇给药预防轻度脑肿胀，并在手术过程中减少静脉输液，避免了视觉效果的出现。该研究结果表明，这种新的经颅方法可用于正确和安全地将细胞注射到后连合壳核，并支持临床研究。
