Design, fabrication and evaluation of the cell micro-injector for improvement of the quality of subretinal space injection with minimum damage

Abstract

Background and Aim: An accurate cell injection in therapeutic methods is one of the most important and challenging stages in animal and human cell therapy. The aim of this study was to design and fabricate a device for injecting stem cells into the subretinal space and the vitreous body in degenerative eye diseases. Materials and Methods: In this study, the primary map of the device, metal molds and the appropriate tools for the machine were prepared. The pieces of the device were manufactured by a CNC machine and assembled together. In order to verify the device function we used immunohistochemistry (IHC) method and fluorescein was injected into the subretinal space of the rats. Tissue samples were examined by fluorescent microscope six and 24 hours after injection Results: The results of IHC showed that six and 24 hours after the injection, fluorescein dye was observed in the sub-retinal space, between retinal pigment epithelium (RPE) and neurosensory retina. Histologic samples showed minimal damage due to the insertion of needle and there was no disorganization in the retina. Conclusion: This study revealed that fluorescein can be injected by the micro-injector into the subretinal space accurately. It seems that this device has the capability to inject stem cells into the retina properly and can be used in animal models.

Keywords

• micro-injector
• stem cells
• subretinal space
• rat.