Biomedical Engineering Reference
In-Depth Information
cells transplanted into spinal cord injured animals differentiated into various neural
cells, improving axonal regeneration and motor function [
46
]. Significantly, in a
recently reported clinical application of CB stem cells to treat a patient with a
spinal cord injury, it was stated that transplantation of CB cells improved her
sensory perception and mobility in the hip and thigh regions [
47
]. Both CT and
MRI studies revealed regeneration of the spinal cord at the injury site. Neither
additional patients nor additional studies in this area have yet been reported.
Evaluating the safety and potential efficacy of CB stem cells for spinal cord injury
in a clinical trial setting is a logical extension of the pre-clinical work and early
case-study report.
14.4 Orthopedic Applications
The potential of CB stem cells to generate bone and cartilage has been recently
examined. It is estimated that more than 1 million individuals in the USA annually
suffer from articular joint injuries involving cartilage, ligaments, and/or tendons,
as well as difficult to heal bone fractures [
48
]. CB contains both ES-like and MSC
capable of differentiating into both bone and cartilage [
49
]. In fact, when CB stem
cells were placed into animals with fractured femurs there was significant bone
healing. Work from the laboratories of Szivek [
50
] and Harris (unpublished data)
have also examined the ability of cord blood stem cells to become cartilage in
comparison to tissues derived from bone marrow MSC and adipose stem cells,
with early encouraging results. As discussed below, CT may be a better source of
stem cells for these applications than CB.
14.5 Hearing Loss
A recent animal study demonstrated the CB stem cells may have clinical utility to
repair inner ear damage and restore hearing [
51
]. Human CB stem cells, when
intravenously injected into immunodeficient mice made deaf by exposure to
kanamycin, high intensity noise, or a combination of these insults, migrated and
engrafted into the cochlea of the deaf mice and the levels of engraftment correlated
with both the severity of damage and the treatment dose. Analysis at 60 days post-
treatment showed that the mice in the CB treatment group had well-repaired
cochlea with dramatic hair cell regrowth, while control mice showed no sign of
repair or hair cell regeneration. This study has led to a clinical trial to investigate
autologous CB infusions for childhood hearing damage that is now being con-
ducted at Memorial Hermann Hospital, Houston TX [
52
].
