3D Microstructured Scaffolds to Support Photoreceptor Polarization and Maturation

Area of Science:

• Biomaterials Science
• Retinal Biology
• Regenerative Medicine

Background:

• Blinding disorders affect the outer retina, involving photoreceptor degeneration.
• Current treatments like bolus injections lack precision for polarized photoreceptor delivery.
• Photoreceptor organization is critical for function, with apical photopigments and basal axon terminals.

Purpose of the Study:

• To develop a novel microfabricated scaffold for precise delivery and organization of photoreceptors.
• To overcome limitations of bolus injections in achieving uniform cell density and polarization.
• To create a platform for reproducible in vitro models of photoreceptor diseases.

Main Methods:

• Microfabrication of 3D, micrometer-sized scaffolds using polydimethylsiloxane and poly(glycerol-sebacate) elastomers.
• Design of cup-shaped capture wells feeding into microchannels for cell guidance.
• Testing scaffold efficiency in capturing and polarizing human pluripotent stem-cell-derived photoreceptors.

Main Results:

• The "wine glass" scaffold design successfully captured photoreceptor cell bodies and guided basal axon extensions.
• Achieved uniform organization and polarization of donor photoreceptors, surpassing bolus injection methods.
• Demonstrated the potential of the scaffold for both therapeutic delivery and in vitro disease modeling.

Conclusions:

• The developed microfabrication process yields effective polarizable photoreceptor delivery scaffolds.
• This scaffold design offers a significant advancement over bolus injections for retinal regeneration.
• The platform enables scalable and reproducible generation of in vitro models for studying photoreceptor-based diseases.