Multidomain Peptide Hydrogels for Transected Nerve Regeneration

Date
2022-10-20
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract

Transected peripheral nerve injury (PNI) is caused by traumatic accidents or medical interventions, leading to the loss of motor and sensory functions in patients. While autografts and FDA-approved nerve guidance conduits (NGCs) are partially effective in treating transected PNI, they suffer from multiple constraints that confine their use to human nerve defects < 3 cm. Hence, further research is conducted to create bioengineered NGCs that strive for accelerated axonal growth, which correlates to better surgical outcome. Recent tissue engineering strategies consist of neurotrophic factors delivery, stem cell encapsulation, and inner structural support. Multidomain peptide (MDP) hydrogels are of interest due to their extracellular matrix-like architecture and bioactive nature that recapitulate native nerve tissues. In this thesis, the neuroregenerative capability of MDP hydrogels and NGCs was vigorously investigated by bridging 10 mm in vivo rat nerve defects and performing functional characterizations at sacrificial timepoints. In chapter 1, the background information of self-assembling peptide hydrogels was reviewed, followed by the previous and current developments of NGCs. In chapter 2, an electrospun poly(ϵ-caprolactone) (PCL) nerve conduit was successfully developed to hold MDP hydrogels and nerve segments in place. In chapter 3, preliminary in vitro and in vivo studies were conducted to optimize the experimental design and to perform initial evaluation on MDPs. Chapter 4 focuses on assessing the efficacy of cationic and anionic MDP hydrogels in restoring motor and electrical functions after rat sciatic nerve transections. Anionic MDP outperforms its cationic counterpart 16 weeks post operation. In chapter 5, the acrylamidation and nucleobase-conjugation on MDPs were examined with potential application in promoting peripheral nerve regeneration. Despite its poor biocompatibility, photo-responsive peptide material can be created by incorporating acrylamides in cationic MDPs. The research on nucleobase modification remains in progress. Fundamentally, the objective of this research is to determine whether MDP hydrogels, when placed within PCL nerve conduits, can accelerate nerve regeneration after sciatic nerve injury and to explore the additional functionalities of MDPs with two modifications.

Description
Degree
Doctor of Philosophy
Type
Thesis
Keywords
Self-assembling peptide, Hydrogels, Peripheral nerve regeneration, Nerve guidance conduits, Electromyography, Nerve transection
Citation

Lai, Cheuk Sun Edwin. "Multidomain Peptide Hydrogels for Transected Nerve Regeneration." (2022) Diss., Rice University. https://hdl.handle.net/1911/113750.

Has part(s)
Forms part of
Published Version
Rights
Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.
Link to license
Citable link to this page