Optimal Neuropeptide Concentration for Cell
Proliferation
and Matrix Expression.
Doctor Ray Vanderby has been my mentor
for two years. His main interests (and mine) lie in
the fields of orthopedic research in biomedical engineering
and surgery. This project interests me especially
because my specialty will be orthopedic surgery and
recovery and biofactors such as these that we are
researching may prove to help with post surgery recovery,
which is invaluable to patient and surgeon.
With an increasing number of joint
replacement and spinal surgeries come accompanying
ailments such as articular cartilage and intervertebral
disk degeneration. It has been shown that connective
tissues without peripeheral innervation, such as cartilage,
heal poorly. In a preliminary study by Nyung, Vanderby
and Anderson, nucleus pulposus and articular cartilage
from bovine calf spines and femoral condyles were
exposed to different neuropeptides including calcitonin
gene -related peptide, neuropeptide Y substance P
and vasointestinal peptide. At various points in growth
(days 1,5 and 8) they were harvested and were subjected
to various calorimetric and luminescent assays to
quantify the effect of each neuropeptide on proliferation.
Most neuropeptides tested were found to have a positive
effect on bovine articular proliferation and bovine
nucleus pulposus cell proliferation. However, the
effect of different dosages has not been tested.
In order to quantify and optimize cell proliferation
and matrix synthesis, I will be testing different
concentrations of the same periperal neuropeptides
on rabbit intervertebral disc cells. Nucleus pulposus
is dissected from each spinal disc and incubated.
The cells are then harvested, plated and incubated
overnight. The following day neuropeptides are added
at different starting concentrations. These concentrations
will be varied up and down by a factor of 19 until
optimal cell proliferation and matrix protein expression
is found. Proliferation assays and GAG assays will
be performed in culture for one week to quantify results.
Statistical analysis will be used to establish significance
of differences between test groups and the control
group.
