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Resection of retroperitoneal tumors is usually perfomed using the anterior retroperitoneal approach. Our report presents an innovative method utilizing a robotic surgical system. A 50-yr-old male patient visited our hospital due to a known paravertebral mass. Magnetic resonance imaging showed a well-encapsulated mass slightly abutting the abdominal aorta and left psoas muscle at the L4-L5 level. The tumor seemed to be originated from the prevertebral sympathetic plexus or lumbosacral trunk and contained traversing vessels around the tumor capsule. A full-time robotic transperitoneal tumor resection was performed. Three trocars were used for the robotic camera and working arms. The da Vinci Surgical System® provided delicate dissection in the small space and the tumor was completely removed without damage to the surrounding organs and great vessels. This case demonstrates the feasibility of robotic resection in retroperitoneal space. Robotic surgery offered less invasiveness in contrast to conventional open surgery.

The low survival rate of graft stem cells after transplantation into recipient tissue is a major obstacle for successful stem cell therapy. After transplantation into the site of spinal cord injury, the stem cells face not only hypoxia due to low oxygen conditions, but also a lack of nutrients caused by damaged tissues and poor vascular supply. To improve the survival of therapeutic stem cells after grafting into the injured spinal cord, we examined the effects of cotransplanting mouse neural stem cells (mNSCs) and adipose tissue-derived mesenchymal stem cells (AT-MSCs) on mNSC viability. The viability of mNSCs in coculture with AT-MSCs was significantly increased compared to mNSCs alone in an in vitro injury model using serum deprivation (SD), hydrogen peroxide (H(2)O(2)), and combined (SD + H(2)O(2)) injury mimicking the ischemic environment of the injured spinal cord. We demonstrated that AT-MSCs inhibited the apoptosis of mNSCs in SD, H(2)O(2), and combined injury models. Consistent with these in vitro results, mNSCs transplanted into rat spinal cords with AT-MSCs showed better survival rates than mNSCs transplanted alone. These findings suggest that cotransplantation of mNSCs with AT-MSCs may be a more effective transplantation protocol to improve the survival of cells transplanted into the injured spinal cord.

These results suggest a proliferative, protective, and neural inductive potential of FGF-2 for transplanted hBMSCs, as well as a possible role for sustained FGF-2 delivery along with hBMSCs transplantation in the injured spinal cord. Future studies will be required to ascertain the safety FGF-2-containing HCPNs before clinical application.

These results strongly suggest the potential utility of mNSCs modified by a hypoxia-inducible VEGF gene expression system in the development of effective stem cell transplantation protocols in SCI.

Gene delivery offers therapeutic promise for the treatment of neurological diseases and spinal cord injury. Several studies have offered viral vectors as vehicles to deliver therapeutic agents, yet their toxicity and immunogenicity, along with the cost of their large-scale formulation, limits their clinical use. As such, non-viral vectors are attractive in that they offer improved safety profiles compared to viruses. Poly(ethylene imine) (PEI) is one of the most extensively studied non-viral vectors, but its clinical value is limited y its cytotoxicity. Recently, chitosan/DNA complex nanoparticles have een considered as a vector for gene delivery. Here, we demonstrate that DNA nanoparticles made of hyaluronic acid (HA) and chitosan have low cytotoxicity and induce high transgene expression in neural stem cells and organotypic spinal cord slice tissue. Chitosan-TPP/HA nanoparticles were significantly less cytotoxic than PEI at various concentrations. Additionally, chitosan-TPP/HA nanoparticles with pDNA induced higher transgene expression in vitro for a longer duration than PEI in neural stem cells. These results suggest chitosan-TPP/HA nanoparticles may have the potential to serve as an option for gene delivery to the spinal cord.

Objective: The objective of this study is to evaluate the safety and efficacy of a tumor-specific apoptosis-inducing gene, apoptin, as delivered by the non-viral carrier, PAM-RG4, in an animal model of spinal cord tumor. Methods: Male Sprague-Dawley rats were given a 2.5-ml intramedullary injection of C6 glioma (100 000) cells and randomized into three groups (day 0). On day 5, animals received a 7.5-ml intramedullary injection of Dulbecco's modified Eagle's medium (Group 1; n ¼ 7), PAM-RG4/control gene polyplex (Group 2; n ¼ 7), or PAM-RG4/apoptin gene polyplex (Group 3; n ¼ 8). Hindlimb functional strength was assessed every other day for the duration of the study. The spinal cords of killed animals were collected and hematoxylineosin stained. Results: Following treatment, animals that received apoptin had significantly higher mean functional hindlimb scores than those of sham control animals, showing a level of preserved hindlimb function throughout the study. In addition, Group 1 (sham control) and Group 2 (control gene) animals had median survival scores lower than those of animals receiving apoptin. Histopathological analysis showed marked retardation of tumor progression in apoptin-treated animals compared with sham controls. Conclusion: Our study suggests that apoptin is safe for use in the mammalian spinal cord as well as effective in slowing the progression of tumor growth in the spinal cord. The significant slowing of tumor progression, as manifested by the preserved hindlimb function, coupled with the reduction in tumor volume, shows local non-viral delivery of apoptin could serve as an emerging therapy for the treatment of intramedullary spinal cord tumors.

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