The golden method of peripheral nerve system injury is the nerve autograft, but it is associated with
drawbacks such as donor site morbidity, needs of second incisions and the shortage of nerve grafts.
Comparatively, connecting the nerve defect directly is an alternative. Unfortunately, if the defects
are long, the induced tension will deteriorate the nerve regeneration. These limitations led to the
development of artificial nerve guidance conduit (NGC). The market available NGC have problems
of unsatisfactory functional recovery and may collapse after the implantation. These are attributed
to material and structural deficiencies. Therefore, there is essential to study a biomaterial, which has
excellent biological and physical properties to fit the NGC application. In addition, some studies
suggested that the poor functional recovery resulted from the NGC implantation were due to the
lack of micro-guidance inside the conduit. Thus, it is necessary to investigate the structural
influence on the functional recovery of peripheral nerve injury.
Crosslinked urethane-doped polyester elastomer (CUPE) is newly invented for a blood vessel graft
because it possesses similar mechanical properties of blood vessel which is similar to nerve as well.
Therefore, CUPE was also considered to be the NGC. Its biocompatibility has been proved to be
excellent in the previous study done by Dr. Andrew SL, Ip. Targeting on the long peripheral nerve
regeneration, the aims of this study are (1) to investigate the biocompatibility of CUPE in in-vitro
condition and (2) to study the influence of nerve-like structure on the peripheral nerve system injury
in an animal model. The ultimate goal is to enhance the functional recovery of peripheral nerve
system injury by implanting a flexible biomaterial, CUPE, which has a nerve-like microarchitecture.
It is hypothesized that the nerve-like structure can promote the axonal regeneration.
The surface energy and roughness of CUPE were investigated. It showed a relatively low surface
energy compared to other conventional biopolymers such that the cell adhesion and also the
proliferation were inhibited. Therefore, the CUPE was modified by the immersion into a high
glucose DMEM. The change in the hydrophilicity, roughness and cell viability of medium treated
CUPE were studied. The hydrophilicity of treated CUPE was increased but the roughness was
remaining unchanged whereas the pH of the immersion solution did not cause any effect on the cell
activity on the CUPE. In the pilot animal study, five channels along the CUPE-NGC had a similar
myelinated fiber density and population compared to the nerve autograft. Also, the channels in the
CUPE-NGC were fragmented.
In summary, the medium treatment could enhance the hydrophilicity of CUPE and the cell activity
on CUPE. Such modifications did not governed by the pH of the medium. The NGC-CUPE with
five channels, which imitated a basic nerve structure was shown to have a similar tissue
regeneration and the functional recovery as the nerve autograft did. The results proved the
hypothesis that the nerve-like structure can promote the functional recovery of peripheral nerve
system injury with the use of a new biomaterial, CUPE as the NGC substrate. / published_or_final_version / Orthopaedics and Traumatology / Master / Master of Philosophy
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/174387 |
| Date | January 2012 |
| Creators | Choy, Wai-man., 蔡維敏. |
| Contributors | Ip, WY, Yeung, KWK |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B47326621 |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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