BioAdhere: tailor-made bioadhesives for epiretinal visual prostheses.

Area of Science:

• Biomaterials Science
• Ophthalmology
• Regenerative Medicine

Background:

• Visual prostheses using epiretinal stimulating arrays are a promising therapy for retinal dystrophies and degenerations.
• Current fixation methods for these arrays can be traumatic, necessitating innovative solutions.
• Development of novel bioadhesive peptides (peptesives) is explored for secure and gentle array fixation.

Purpose of the Study:

• To develop tailor-made bioadhesive peptides (peptesives) for fixating epiretinal stimulating arrays.
• To evaluate the binding capabilities and biocompatibility of these peptesives.
• To demonstrate the efficacy of peptesives in a proof-of-principle fixation experiment.

Main Methods:

• Identification of binding motifs on stimulating array material (Parylene C) and retinal extracellular matrix (ECM) proteins.
• Genetic fusion of anchor peptides (Cecropin A, KH1, KH2, Osteopontin) to reporter proteins for binding assays.
• Cytotoxicity testing (ISO 10993) using L-929 and R28 retinal progenitor cells.
• Proof-of-concept experiments for fixation capabilities in ex vivo eyes.

Main Results:

• The YmPh-CecA construct showed enhanced binding to Parylene C.
• eGFP-Osteopontin bound to multiple ECM proteins; eGFP-KH1 and eGFP-KH2 showed specific strong binding to collagen I and fibronectin, respectively.
• The peptide cecropin-A-DZ-OPN demonstrated good biocompatibility in cytotoxicity tests.
• Peptesive-coated arrays showed increased adhesion in proof-of-concept experiments.

Conclusions:

• Bioadhesive peptides (peptesives) can be tailored for specific binding to implant materials and retinal ECM.
• The developed peptesives exhibit good biocompatibility, crucial for medical applications.
• This study demonstrates the first successful application of peptesives for fixating macroscopic objects, offering a non-traumatic alternative for visual prosthesis fixation.