Study on the influence of scaffold inner organization on the treatment of spinal cord injury

Download
2013
Dursun, Tuğba
Permanent loss of neurologic function occurs when the central nervous system (CNS) is injured. Nerve regeneration is extremely limited because of dense scar tissue formation at the lesion site, especially in the spinal cord. For the treatment of this type of injury, different strategies are needed. The emerging approach to solve these problems is to provide a physical support via tubular bridging devices such as “nerve guides”. They are used to bridge the neural gaps in the treatment of spinal cord injury, and therefore, the design of its inner architecture is very important to provide desired guidance. To test this, the effectiveness of the aligned and random media within tubular nerve guides were compared. Although ultimately a tubular construct is used, planar, composite structures were used for convenient monitoring and analysis. The bottom layer or the main bulk of the nerve guide was a PHBV foam that was prepared by lyophilization. Aligned and randomly oriented PHBV/collagen (2:1) fiber mats, to be placed on this bottom layer were made by electrospinning directly on the PHBV foam. PHBV/collagen (2:1) foam to serve as a 3D disorganized medium was also made by lyophilization. Crosslink ng of the b layer gu des was made by dehydrothermal treatment (DHT) at 150 ̊C for 24 h. Mercury porosimetry showed that porosity of the PHBV foam was 85%, and the pore size was between 5 and 200 μm. Diameter of the fibers were measured by scanning electron microscope and found to be inbetween 200-900 nm. In situ biodegradation test revealed that weight loss of uncrosslinked guides (no DHT) were less than the crosslinked ones (15% after 28 days), and therefore, crosslinking of the scaffolds with DHT was abandoned. Aligned fiber-foam (AF-Fo) and random fiber-foam (RF-Fo) nerve guides were seeded with rat bone marrow stromal cells (rBMSCs) and cultured for 7 days. Cell behavior and differentiation to neural cells on these constructs was examined. Cell attachment and proliferation were found to be better on the RF-Fo construct. The neural differentiation level of the cells were same on both bilayer. No conclusive evidence for the positive contribution of an aligned interior could be observed. It was concluded that the nerve guides prepared had proper porosity, pore size and degradation rate which would allow cell growth at the spinal cord injury site.

Suggestions

Tissue Engineered, Guided Nerve Tube Consisting of Aligned Neural Stem Cells and Astrocytes
Yucel, Deniz; Kose, Gamze Torun; Hasırcı, Vasıf Nejat (2010-12-01)
Injury of the nervous system, particularly in the spinal cord, impairs the quality of life of the patient by resulting in permanent loss of neurologic function. The main limitation in spinal cord regeneration is the lack of extracellular matrix to guide nerves for functional recovery of the transected nerve tissue. In the present study, a tissue engineered nerve tube was prepared by wrapping neural stem cells (NSCs) on aligned fibers using a micropatterned film with astrocytes aligned along the microgrooves...
DEVELOPMENT OF A COMPOSITE GUIDE FOR PERIPHERAL NERVE REGENERATION
Arslantunalı Şahin, Damla; Son, Çağdaş Devrim; Hasırcı, Vasıf Nejat; Department of Biotechnology (2022-2-1)
Any injury in peripheral nerves may result in a loss of neuronal communication along sensory and motor nerves, affecting patients’ daily activities. Today, there are various FDA approved commercial conduit materials; hollow tubes preventing them from used in gaps bigger than 10 mm, because they may lead axonal sprouts to form. The presented study includes pHEMA wrapping structure filled with GelMA-HaMA gel matrix as a nerve guidance channel. Following the structural analysis of the nerve guide, in vitro stu...
Peripheral nerve conduits: Technology update
Hasırcı, Nesrin; Arslantunalı Şahin, Damla; Hasırcı, Vasıf Nejat (2014-12-01)
Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allograf...
Construction of a PLGA based, targeted siRNA delivery system for treatment of osteoporosis
Bilecen, Deniz Sezlev; Carlos Rodriguez-Cabello, Jose; Uludag, Hasan; Hasırcı, Vasıf Nejat (2017-01-01)
Osteoporosis, a systemic skeletal disorder, occurs when bone turnover balance is disrupted. With the identification of the genes involved in the pathogenesis of the disease, studies on development of new treatments has intensified. Shortinterfering RNA (siRNA)is used to knockdown disease related gene expressions. Targeting siRNA in vivo is challenging. The maintenance of therapeutic plasma level is hampered by clearance of siRNA from the body. Targeted systems are useful in increasing the drug concentration...
A novel GeIMA-pHEMA hydrogel nerve guide for the treatment of peripheral nerve damages
DURSUN USAL, TUĞBA; Yucel, Deniz; Hasırcı, Vasıf Nejat (2019-01-01)
Damage to the nervous system due to age, diseases or trauma may inhibit signal transfer along the nervous system. Nerve guides are used to treat these injuries by bridging the proximal and the distal end together. The design of the guide is very important for the reconnection of the severed axons. Methacrylated gelatin-poly(2-hydroxyethylmethacrylate) (GeIMA-pHEMA) hydrogel was produced as the outer part of the nerve guide. pHEMA was added in various amounts into GeIMA and increased the mechanical strength ...
Citation Formats
T. Dursun, “Study on the influence of scaffold inner organization on the treatment of spinal cord injury,” M.S. - Master of Science, Middle East Technical University, 2013.