Enhanced neurite alignment on micro‐patterned poly‐L‐lactic acid films

Abstract

The ability of the damaged central nervous system and peripheral nervous system to properly recover hinges on the regenerative mechanisms and functional reconnection to appropriate targets. Successful pathfinding of axons is controlled by a complex interplay of diffusible or substrate-bound biochemical and electrical cues. Physical guidance has also been shown to occur in vivo and in vitro, either via cell-cell or cell-extracellular matrix mediated contact. In the current study, we probe the role of contact guidance in facilitating neural regeneration and pathfinding. Using soft lithographic techniques, we have created thin films of poly-L-lactic acid polymer (PLLA) possessing periodic features approaching the nanometer regime. Rat PC-12 cells and chick sympathetic neurons were subsequently cultured onto these substrates and parameters, such as neurite emergence and orientation angle, neurite length, and neuronal architecture are characterized. Our results reveal that both PC-12 and chick sympathetic neurites can be effectively guided by unidirectional grooves as small as 100 nm in height and 1 microm in width. Moreover, sympathetic cells produced neurites that were longer on patterned substrata than on controls. The development of novel degradable micro/nanopatterned substrates for cell study will permit more in-depth analysis of contact mediated guidance mechanisms in addition to having applications in neural and tissue engineering.

Directing neuronal cell growth on implant material surfaces by microstructuring

“…36 In contrast, indirect surface patterning like casting or imprinting did not influence the chemical composition of the surface, as also demonstrated by Li et al (2007). 38 This result is more than favorable, considering the fact that the manufacturing technique of indirect patterning such as molding is more economic, reproducible, and feasible for incorporation in the commercial electrode manufacturing process. 39 A previous study identified microstructured platinum as a fibroblast repellent implant surface.…”

“…21 By contrast, Li et al described a reversed behavior of embryonic sympathetic neurons: aligned neurites were significantly elongated, whereas neurites of PC-12 cells showed only a tendency toward elongation. 38 Interestingly, Hansen described significantly elongated neurites of SGC explants on platinum when compared to silicone. 42 However, in our study we could not corroborate these results.…”

Biomaterial and Cell Interactions - The Foreign Body Response as an Obstacle in Nanomedicine

“…Results demonstrated cellular alignment and increased axonal extension on these nanostructured surfaces [6,7]. These outcomes led us to believe such designs may also provide similar effects in vivo.…”

Polymer Thin Films for Biomedical Applications

“…For the nonphotolithographic approach, grooves with a sinusoidal cross -section were created by casting a solution of PLA onto the template, followed by peeling off the dried fi lm from the template [234,235] . The neurites of cells from chick sympathetic ganglia were found to align parallel to the grooves, and to be longer on patterned fi lms than on unpatterned controls.…”