Abstract |
Central nervous system (CNS) injuries, including Spinal Cord Injury (SCI) and Optic Nerve Crush (ONC), are
major health problems worldwide with high morbidity and mortality, affecting thousands of individuals
each year. Spinal cord injury (SCI) may be defined as an injury resulting from an insult inflicted on the
spinal cord that compromises, either completely or incompletely, its major functions (motor, sensory,
autonomic, and reflex). Traumatic optic neuropathy (TON) is a condition, induced when an injury occurs
within the optic pathway and results in vision impairment or permanent vision loss. Despite significant
efforts to unravel the mechanisms that underlie wound healing response after CNS injury, existing
treatments are still deficient. There is an urgent need to understand better the pathophysiology of CNS
injury and develop efficient therapeutic strategies. The study aims to develop novel SCI and/or ONC
therapies that combine 3D biomaterials (porous collagen scaffolds, PCS), small molecule analogs of
neurotrophins (microneurotrophins, MNT) and neural stem cells (NSCs). Initially, evaluate the
characteristics (duration, amount) of MNT delivery via PCS using a drug delivery system comprised of MNT
entrapment in peptide gels inside PCS. Secondly, evaluate MNT neuroprotective and neurogenic effects
in neural cells by quantifying cell phenotypes related to SCI and/or ONC, namely Neural Stem Cell
proliferation, and differentiation. The aim of this project is to characterize and optimize the delivery of
MNTs in vitro and provide promising neuroimplants that can be further evaluated in established SCI/ONC
animal models. MNT delivery was quantified using model drugs. Fluorescein was entrapped inside a
porous collagen-GAG scaffold, and inside a porous collagen-GAG scaffold in a gel formed by self-
assembled peptides for release kinetics assays. The release assay results demonstrate a sustained delivery
of about a 6-hour duration, while the peptide does not seem to delay the release from the PCS further. In
vitro release was studied in neural stem cell culture with brdU delivery. The release was successfully
translated in a cell phenotype alteration and the entire quantity of the molecule was released.
Furthermore, BBN27 effects on NSCs proliferation were studied in a 2D cell culture and differentiation in
a 3D cell culture. BNN27 did not seem to have any effect on NSC proliferation. Finally, regarding
differentiation BNN27 seemed to induce a small increase on NSC differentiation towards neuron lineage
even though no significance was detected by statistical analysis
|