Human Retinal Engineering

Howard F. Ruby Laboratory

IMG_0932 copy_edited.jpg

The Howard F. Ruby Human Retinal Engineering Laboratory combines state-of-the-art polymer, patient stem cell and microfluidic technologies to create the next generation of human retinal tissues in the dish. Engineered human retinal tissues are ideal for testing of novel gene and drug therapies as well as for autologous cell replacement.

The Laboratory was named in honor of Mr. Ruby, who was the founder of Oakwood Worldwide and an acclaimed nature photographer.  His extraordinary generosity will allow the University of Iowa Institute for Vision Research to pioneer new areas of research, and ultimately, help thousands of people who have lost or are losing their sight.

Two-Photon Lithography

Two-photon lithography is a state-of-the-art 3D printing technology that affords ultra high resolution printing of polymeric scaffolds. While scaffolds generated from biodegradable polymers are ideal for transplantation mediated autologous cell replacement, non-degradable polymers can be used for production of next-generation microphysiologics that more accuratly recapitulate the human retina. To maintain sterility our two-photon unit is housed inside a custom Biospherix unit equipped with a laminar flow hood.

IMG_0297.jpg
Trenches_Low_Mag_tilt_1,0SNH_200BlocK_diffangle_60deg_q065.tif

Left is a scanning electron micrograph depicting a 1mm photoreceptor cell delivery scaffold that was generated using our two-photon lithography system from Nanoscribe. The scaffold is designed to allow cells to enter each cup where they can extend their inner and outer segments through a porous grid at the bottom toward the underlying retinal pigmented epithelial cell layer. This scaffold was generated using polycaprolactone, a degradable material with an excellent biocompatability profile.

Characterization

AFM setup.png

Atomic force microscopy (AFM): A form of indirect microscopy that allows for ultra-high resolution (i.e., < 1 nanometer) image capture, which is ideal for evaluating surface topography and roughness. In addition this system can be used to measure mechanical properties, which include modulus and viscosity, of cells and/or materials. Below shows Nick preparing (left) and imaging a sample (right) on our asylum AMF.

AFM high res_edited.jpg

Confocal laser scanning microscopy: A form of direct optical imaging that allows for high resolution low background image capture. This system is ideal for rapid evaluation of model to print fidelity.

IMG_8594.heic
IMG_8605.heic

Sterolithography and Extrusion printing

Sterolithography and extrusion printing are valuable alternatives to ultrahigh resolution two-photon lithography. In the Ruby laboratory we use 1) the Objet30 from Stratasys (UV sterolithography) and 2) the BioX from CellInk (extrusion). These two systems have several key applications. The Objet30 is used primarily for fabrication of our microfluidic vascular perfusion platforms (image on the right) whereas the BioX is used for production of deeper RPE and vascular layers of the retina that support the overlying photoreceptor cells (image below). 

Objet 30 and print.png
Comp.png