In Vivo Testing and Conduit Development for Spinal Cord Injury

This report explores the development of a conduit for acute spinal cord injury, focusing on in vivo testing methods. It details biocompatibility testing using PEEK polymer, crucial for mechanical properties and cellular compatibility. The report emphasizes the importance of animal models, particularly rabbits, dogs, and cats, for evaluating material performance and tissue reaction. Cell types, including Schwann cells, olfactory ensheathing cells (OECs), and fibroblasts, are discussed in the context of their use in the conduit. Immunological testing, such as arterial blood gas (ABG) and lactate levels, are described, alongside cell staining techniques using Golgi stain. Histological and electrophysiological investigations, including the analysis of myelinated fibers, axon diameter, and CMAP/SNAP measurements, are presented as vital components of conduit evaluation. The report highlights the significance of these tests in assessing the effectiveness of spinal cord injury conduits, providing a comprehensive overview of the research process.

Running head: CONDUIT
CONDUIT OF ACUTE SPINAL CORD INJURY
Name of the Student
Name of the University
Author note

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The spinal cord is made up of nerve fibres. It runs down from the brain in a canal in the
centre of the spine bones. These bones shield the spinal cord. The spinal cord is protected by the
meninges in addition to well cushioned by cerebrospinal fluid (Banga et al. 2016). A spinal cord
injury (SCI) is impairment of the spinal cord causing momentary or permanent changes in the
activity. This paper is structured to discuss about making a conduit of acute spinal cord injury.
In vivo test system includes the following-
Biocompatibility testing:
The conduit or the channel would be made with metal only, also spine fusion is
obligatory. The use of PEEK polymer is recommended as it is reliant on upon its mechanical
belongings in addition to biocompatibility. The polymer supplies used in the spinal devices need
to be test prior installation. The biocompatibility of PEEK polymer is providing a suitable
biological responses regarding the cellular and tissue compatibility
Animal models are vital for appraising biocompatibility, tissue reaction also mechanical
function of nerve conduit preceding to the clinical application (Novikova et al. 2018). In vivo
studies in different animal species provide authorisation in evaluating the material for longer
time along with clinically applicable biological situations.
Cell type utilised
Along with progenitor cells, research has shown that the use of critically segregated
cells, such as olfactory ensheathing cells (OECs), Schwann cells as well as fibroblasts, required
after SCI. The cells obtained are cultured, making them suitable for translational. Schwann cells
are theoretically harvested autologously from peripheral nerves in method analogous to the
nerves, which are harvested to heal large gaps created due injury in central nervous system that

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includes spinal cord (Kumar et al. 2015). OECs can be obtained due to autologous
transplantation along with nasal biopsies in addition grown in cell culture till required.
Fibroblasts might be quarantined from skin as well as cultured for allowing genetic manipulation
prior to conduit structuring.
Immunological testing
The immunological test that is required for the estimation of injury in the spinal cord is
Arterial blood gas (ABG) extents that can determine appropriateness of oxygenation in addition
to ventilation. Lactate levels are also noted for in vivo experimentation as it helps in monitoring
the perfusion status as it is required during presence of shock.
Cell staining
Spinal cord consists of glial cells and myelinated axons. Glial cells are only visible
through Golgi stain. Therefore, conduit making for spinal cord injury required staining of cells
through golgi stain in order to identify the proper cells that are to be cultured in-vivo. The Golgi
stain uses silver nitrate to stain densely (Liu et al. 2018). The neurons of the cells get stained and
gets distinguished from the others. It reveals the morphological diversity of neurons.
Animal models
Animal models are used prior application into humans. Rabbit is considered to be the
most frequently used model in this case. The gaps ranges between 2 to 50 mm. Hence, has a
tendency for suiting the spinal conduit. Nevertheless, Rabbit is considered to be an expensive
model of study. In some cases, dogs and cats are also used. Dogs have better motor and sensory
nerves which is an essential part in spinal cord functioning. Mutual species are exclusive to

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buying plus uphold in addition to there are effectively no molecular probes obtainable for
mechanistic studies (Lee et al. 2017).
Even though animal models are meticulously imitator of the automatic as well as
physiological human clinical conditions. It should be noted that these models signify exclusively
an estimation of the human reaction to different pathologic aspects. Each animal model has
distinctive benefits plus weaknesses when used for trial study of spinal injury.
There is also some ethical debate towards use of non-human primates for research. The
supposed resemblance amid humans plus nonhuman primates, analysis safety in addition to
usefulness of a spinal nerve conduit is considered as an applicable step before experimentation
on human.
Histology
Histological analysis is required for spinal cord conduit. Histological analysis followed
by neuromorphometry were done. Myelinayed fibres, axons diameter and total nerve fibres,
myelin thickness along with g-ratio need to be recorded. The significance of tissue processing
approaches is required (Carriel et al. 2017). Electrophysiological investigation was used
frequently and measuring different dormancy in addition to generosity of composite muscle
action possibilities (CMAP) or sensory nerve action potentials (SNAP). This would help in
getting a clear analysis of the way the conduit for spinal cord injury would be. The histological
analysis is important as it will provide better analysis for the conduit that are to be designed.

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References
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expression of GAP‐43 and neurofilament during peripheral nerve regeneration through bio‐
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