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

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 is to design and fabricate a device for injecting stem cells into the subretinal space and the vitreous body in degenerative eye diseases.

In this study, the primary map of the device and the metal molds were prepared and the appropriate tool for the machine was made. The pieces of the device were produced by the CNC machine respectively and assembled to each other. To verifying the device function, immunohistochemistry (IHC) was used and the injection of fluorescein into the subretinal space was done in rats. Tissue samples were examined six hours and 24 hours after injection by fluorescent microscope.

The results of IHC showed that six hours and 24 hours after the injection, fluorescein dye was observed in the sub-retinal space, between retinal pigment epithelium (RPE) and neurosensory retina. Eye histologic layers showed minimal damage due to the insertion of needle and there was no disorganization in the retina.

This study revealed that the micro-injector had been able to inject fluorescein into the subretinal space accurately. It seems that this device has the ability to inject stem cells into the retina properly and can be used in animal models.
keywords: Micro-injector, Stem cells, Subretinal space, Rat.