In vitro assessment of bioactive coatings for neural implant applications

✍ Scribed by Massia, Stephen P. ;Holecko, Matthew M. ;Ehteshami, Gholam R.

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 214 KB
• Volume: 68A
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.a.20009

✦ Synopsis

Abstract

Recent efforts in our laboratory have focused on developing methods for immobilizing bioactive peptides to low cell‐adhesive dextran monolayer coatings and promoting biospecific cell adhesion for biomaterial implant applications. In the current study, this dextran‐based bioactive coating technology was developed for silicon, polyimide, and gold, the base materials utilized to fabricate our prototype neural implants. Chemical composition of all modified surfaces was verified by X‐ray photoelectron spectroscopy (XPS). We observed that surface‐immobilized dextran supported very little cell adhesion in vitro (24‐h incubation with serum‐supplemented medium) on all base materials. Inactive nonadhesion‐promoting Gly‐Arg‐Ala‐Asp‐Ser‐Pro peptides immobilized on dextran‐coated materials promoted adhesion and spreading at low levels not significantly different from dextran‐coated substrates. Arg‐Gly‐Asp (RGD) peptide‐grafted surfaces were observed to promote substantial fibroblast and glial cell adhesion with minimal PC12 (neuronal cell) adhesion. In contrast, dextran‐coated materials with surface‐grafted laminin‐based, neurite‐promoting Ile‐Lys‐Val‐Ala‐Val (IKVAV) peptide promoted substantial neuron cell adhesion and minimal fibroblast and glial cell adhesion. It was concluded that neuron‐selective substrates are feasible using dextran‐based surface chemistry strategies. The chemical surface modifications could be utilized to establish a stable neural tissue–implant interface for long‐term performance of neural prosthetic devices. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 177–186, 2004