Photochemically modified diamond-like carbon surfaces for neural interfaces

A.P Hopper,J.M Dugan,A.A Gill,E.M Regan,J.W Haycock,S Kelly,P.W May,F Claeyssens

doi:10.1016/j.msec.2015.09.013

Abstract

Diamond-like carbon (DLC) was modified using a UV functionalization method to introduce surface-bound amine and aldehyde groups. The functionalization process rendered the DLC more hydrophilic and significantly increased the viability of neurons seeded to the surface. The amine functionalized DLC promoted adhesion of neurons and fostered neurite outgrowth to a degree indistinguishable from positive control substrates (glass coated with poly-L-lysine). The aldehyde-functionalized surfaces performed comparably to the amine functionalized surfaces and both additionally supported the adhesion and growth of primary rat Schwann cells. DLC has many properties that are desirable in biomaterials. With the UV functionalization method demonstrated here it may be possible to harness these properties for the development of implantable devices to interface with the nervous system.

Highlights

Diamond possesses a range of valuable mechanical and tribological properties, which offer interesting opportunities for the development of future applications
The diamond-like character of the diamond-like carbon (DLC) produced is dependent upon the ratio of sp2 and sp3 carbon, with a higher sp3 content resulting in more diamond-like properties
DLC was applied to the surface of glass cover-slips via pulsed laser deposition

Summary

Introduction

Diamond possesses a range of valuable mechanical and tribological properties, which offer interesting opportunities for the development of future applications. One such property, which is useful within biological research, is the ease with which it can be doped or functionalized whilst retaining its stability and biocompatibility [1]. The diamond-like character of the DLC produced is dependent upon the ratio of sp and sp carbon, with a higher sp content resulting in more diamond-like properties Both DLC and diamond may be readily photo-functionalized with the aid of ultraviolet (UV) radiation allowing the attachment of a wide range of organic functional groups at the surface of the material [3]. Such an approach is ideal for modifying DLC for biomedical applications where the surface termination strongly affects protein and cell adhesion

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Conclusion