Abstract
Purpose :
Transplantation of stem-cell derived retinal tissue is a promising potential therapy for inherited retinal degenerations, which are currently incurable. The recent development of three-dimensional cultured retina in vivo has provided a new donor substrate for evaluation. However, experimental transplantation protocols would require dissection of the stem-cell derived retinal micro-organs into micro-sheets. We investigated the use of 27-gauge vitreoretinal surgery micro-instruments to prepare micro-sheets of photoreceptor cells for transplantation to the subretinal space of mice.
Methods :
Primary donor mouse neuroretinal sheets were used to model the stem cell derived three-dimensional retinal micro-organs for transplantation. The donor retinas were dissected into micro-sheets using commercially-available 27-gauge sharp-tipped vertical and horizontal scissors (Vitreq USA Inc., NH), loaded into a micro needle, and injected into the subretinal space of a mouse eye. Post-surgery retinas were imaged in vivo, before the mice were sacrificed, and the eyes extracted, fixed, sectioned and stained for immunofluorescent microscopy.
Results :
Using the 27-gauge micro-scissors, the donor retinal tissue was successfully dissected into micro-sheets measuring approximately 2 by 3 mm. The tested instruments achieved clean cutting of the tissue, perpendicular to the retina, and avoided tearing the edges of the micro-sheets. The micro-sheets could be aspirated up into the 21-gauge transplantation needle and successfully injected into the subretinal space of murine eyes. In vivo Spectralis imaging and fluorescent microscopy of stained sections of extracted eyes confirmed that the micro-sheets had survived following injection into the subretinal space.
Conclusions :
The use of 27-gauge micro-scissors in human vitreoretinal surgery, based on their ability to safely and efficiently dissect retina and resect membranes in vivo, is already commonplace. Here we have demonstrated that these surgical tools are also useful for preparation of micro-sheets of dissected retinal tissue for delivery into the eye of a mouse model organism, achieving clean perpendicular cutting and avoiding tearing of tissue edges. Commercially-available fine-gauge scissors could be useful in the preparation of biosynthetic retinal tissue for human clinical trials of photoreceptor transplantation.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.