Corn- and Soy-Derived Materials: Properties and Potential Clinical Applications - Medical Devices and Biomaterials for the Developing World - page 59

Stroke
Stroke is a neurological condition that, along with heart attacks, kills 17 million
around the world each year (WHO 2012). Often marked by sudden onset, strokes
result from a failure of blood, and therefore oxygen, to reach one or more parts of
the brain. Stroke can result from either blockage (ischemic) or rupture and leakage
(hemorrhagic) of a blood vessel in the brain. The condition is diagnosed using
advanced imaging techniques such as MRI and CT scans.
Stroke is closely related with cardiovascular disease, and as such many applica-
tions of biomaterials to treating heart disease and heart failure (described above) have
the potential to help stroke patients as well. While ischemic stroke is much more
common (70% of all strokes), hemorrhagic stroke is quite devastating and can result
in hematoma, or pooling of blood within the brain. The two are not to be confused,
particularly at the diagnostic stage, as treatment for the former can prove fatal when
administered to a patient who actually suffers from the latter (Bhatia 2010, 62).
Biomaterials have the potential to decrease mortality for stroke patients both by
improving the accuracy and speed of the diagnostic process (via pre-MRI labeling
of macrophages using bioactive nanoparticles) and by contributing to the re-growth
of neurons in order to restore lost tissue functionality. Biomaterials recruited to do
the latter must meet many of the criteria discussed above. In addition, they must
have the unique quality of being electrically conductive. Nanoscale materials, such
as nanotubes and nanofibers, are uniquely suited to this task because of their high
surface-to-volume ratios and ability to mimic native conditions. Soliman et al.
(2012) conducted preliminary experiments exploring the electrical properties of
carbon nanotubes and the feasibility of growing neural cells on a carbon nanotube-
hydrogel matrix.
Each of the conditions described above has potential for improved diagnosis,
treatment, or scaling through the use of biomaterials as a replacement for or com-
plement to current practices. Several techniques, such as drug delivery using nano-
particles and implantation of scaffolding for cell regeneration, have applications for
several diseases. The versatility and potential benefits of biomaterials, particularly
sustainable or reusable materials, point to new possibilities for the future of clinically
relevant engineering.
Like other medial devices, the adoption of biomaterials for clinical use in most
countries requires extensive government and industry approval. In order to be
deemed safe for clinical (or commercial) use, a biomaterial but be demonstrably
non-toxic, effective, sterilizable, and biocompatible (Ikada and Tsuji 2000). Given
the goal of improving clinical outcomes through the use of biomaterials, testing for
toxicity and biocompatibility is an appropriate first step in the evaluation of candi-
date materials.