Biomaterials and the Central Nervous System: Neurosurgical Applications of Materials Science - Biomaterials Science: An Integrated Clinical and Engineering Approach - page 144

inflammatory infiltrate and astrogliosis (a decreased neuronal cell density),
both of which may impair microelectrode performance [42, 48]. Efforts to
minimize this inflammatory response have focused on modifying surface
chemistry. Investigators have found that using low protein-binding coatings
on implanted microelectrodes may help in reducing the macrophage infiltrate
[42]. With further advances and modifications in the microelectrode insula-
tion materials, one can envision designing high-performance implantable
electrodes that may allow for long-term recording from a single neuron. The
leap from this technologic advance to clinical application is a short one; with
less biofouling of electrodes, the widespread use of BMI in paralyzed patients
may be achieved.
Conclusions
Identifying properties of materials that are the least likely to incite the inflam-
matory cascade has been the goal of much work in biomaterials. The desired
characteristics of an intracranial device require materials with rheologic
properties different from those of other areas of the body. These include non-
toxicity, facile integration with host tissue, and tunable mechanical proper-
ties (such as rigidity and porosity). Materials currently under investigation
share many but not all of these properties and are therefore limited in appli-
cation. Naturally occurring polymers tend to elicit less immune response
and are often degradable, but lack optimal mechanical properties, such as
rigidity. Other synthetic polymeric materials may have more tunable rigid-
ity but may lack other properties such as causing minimal tissue inflamma-
tion or structural damage. What is clear is that recent advances in the field
of materials science have informed work in neurosurgical material clinical
applications. A better understanding of which materials are less likely to
incite inflammatory reactions, or less likely to succumb to biofilm formation,
will certainly improve varied areas of neurosurgery from hydrocephalus to
drug delivery.
References
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