WARF TECHNOLOGIES

Photoreceptors are specialized cells that capture and convert light into signals that can be processed by the retina and visual centers of the brain. Supportive cells called the retinal pigment epithelium (RPE) grow adjacent to the photoreceptors and are critical to their health and function. All blinding disorders of the outer retina involve dysfunction and eventual degeneration of the photoreceptors, either alone (e.g., retinitis pigmentosa) or involving the RPE (e.g., age-related macular degeneration or AMD).

Currently, these patients have limited treatment options. One broadly applicable strategy would be to replace photoreceptors (alone or in combination with RPE). To date the only approved pluripotent stem cell-based clinical trials underway in humans involve transplantation of RPE cells alone (via bolus injection or on planar scaffolds). While representing an important advance, transplanting RPE alone will not rescue vision in advanced disease when photoreceptors have been lost. Furthermore, existing technologies cannot recapitulate the precise spatial orientation and polarization of photoreceptors required for proper function.

Using state-of-the-art microfabrication techniques, UW–Madison researchers have developed microstructured scaffold systems that can guide the growth of photoreceptor cells and mimic polarized outer retinal tissue. The scaffolds also may be used for transplantation of organized photoreceptor tissue with or without RPE.

Transplantation of photoreceptor-seeded scaffolds may improve grafted cell retention, survival, integration and functional visual rescue as compared to simple bolus injections. By recapitulating in vivo outer retinal architecture, these uniquely fabricated scaffolds also can be used for in vitro developmental and disease studies as well as drug screening.

The microfabrication process for scaffold production is fully compatible with numerous biomaterials, including biodegradable and non-biodegradable materials, thus allowing the scaffolds to be tailored to both in vitro and in vivo applications. The scaffolds feature biocompatible support layers (e.g., PDMS film) patterned with an array of unique through-holes having a curvilinear cell receiver and cell guide channels. The structure enables photoreceptors to be grown in a polarized orientation that mimics their development in vivo.

• Photoreceptor scaffold systems for cell culturing, transplantation, developmental modeling, disease modeling and drug screening

• Enables formation of organized, multicellular constructs
• Mimics in vivo cellular structure and development
• Potential new treatment for patients with limited options
• Offers an alternative to simple bolus injection

The researchers continue to optimize a design combining the photoreceptor and RPE scaffold structures.

For More Information About the Inventors

• Zhenqiang Ma
• David Gamm
• Shaoqin Gong

Publications

• Read an article about this technology.

Tech Fields

• Drug Discovery & Development : Disease models
• Engineering : Micro & nanotechnologies