Biomedical Engineering Reference
In-Depth Information
12.3.1 NanostructuredBiointerfaces
In vivo
, the interactions of a cell with its surroundings are mediated
at the molecular and macromolecular level [3]. Speciic interactions
with, for example extracellular matrix components and soluble
factors, or macromolecules in the outer membranes of adjacent
cells provide necessary signaling and communication routes. Such
interfaces have both topographic nanostructure and chemical/
biospeciic interaction sites distributed at the nanoscale [2].
The use of diverse techniques to characterize material surfaces
with great precision has led to a range of model experiments,
studying in detail the inluence of surface chemistry and surface
topography
in vitro
and
in vivo
[3]. A constant desire has been to
develop better surfaces of implant materials that are able to improve
biocompatibility, hemocompatibility, or osseointegration. With the
development and spread of nanofabrication approaches based on
lithographic, chemical synthesis and self-assembly approaches have
recently allowed material interfaces to be structured on the length
scale of the macromolecular components of the extracellular matrix
and cell membranes [126, 147].
A signiicant number of studies have focused on the effect
of surface nanotopography on cell functions such as adhesion,
motility, morphology, cytokine release, gene expression, and
differentiation [3, 38]. The ability to deine interfaces on a length
scale which match that of the mediating macromolecules in cellular
membranes and extracellular matrixes, has the potential to create
artiicial biointerfaces which are capable of communicating with/
signaling to adherent cells. Such artiicial biointerfaces would be of
immediate interest for application areas such as biomaterials, tissue
engineering, substrates for generating cells for cell therapies, and
cell-based electronics/sensors.
Additionally, the development of an implant/bone interface
may be inluenced by both nanoscale and micron-scale parameters
of topography [89]. The role of surface parameters (both bulk
chemistry and topography) requires consideration of molecular
(ionic and biomolecular) interactions with the surface, cell adhesion
phenomenon, and local biomechanical features of the established
interface. It is clear that nanoscale modiication will affect the
chemical reactivity of an endosseous implant surface and alter the
ionic and biomolecular interactions with the surface. Proposed
