A unique new material developed at the University of Limerick in Ireland is showing great promise for the treatment of spinal cord injuries.
Brand new research conducted at UL’s Bernal Institute – published in a leading international journal. Research on biomaterials – has made exciting advances in the field of spinal cord tissue repair.
According to the researchers, new hybrid biomaterials developed at UL in the form of nanoparticles and building on existing practices in the field of tissue engineering, have been successfully synthesized to promote repair and regeneration after injury of spinal cord.
The UL team led by Professor Maurice N. Collins, an associate professor in the UL School of Engineering, and lead author Aleksandra Serafin, a UL PhD candidate, used a new type of scaffold material and a novel, unique electrically conductive polymer composite to promote the growth and generation of new tissue that could advance the treatment of spinal cord injury.
Spinal cord injury remains one of the most debilitating traumatic injuries a person can sustain in their lifetime, affecting every aspect of their life.
This debilitating disorder results in paralysis below the level of injury, and in the United States alone, annual health care costs for patients with spinal cord injury are $9.7 billion. Since there is currently no treatment available on a large scale, continued research in this area is crucial to find a treatment that can improve the quality of life of patients. The field of research is turning to tissue engineering to find new treatment strategies.
The field of tissue engineering aims to solve the global problem of shortage of donated organs and tissues, in which a new trend has emerged in the form of conductive biomaterials. Cells in the body are affected by electrical stimulation, especially cells of a conductive nature such as heart or nerve cells. »
Professor Maurice N Collins, Associate Professor, UL School of Engineering
The research team describes a growing interest in using electrically conductive scaffolds for tissue engineering, which has emerged due to enhanced cell growth and proliferation when cells are exposed to a conductive scaffold.
“Increasing the conductivity of biomaterials to develop such processing strategies is usually centered on the addition of conductive components such as carbon nanotubes or conductive polymers such as PEDOT:PSS, which is a conductive polymer available in commercially and used to date in the field of tissue engineering,” says lead author Aleksandra Serafin, a PhD candidate on the Bernal team and at UL’s Faculty of Science and Engineering.
“Unfortunately, serious limitations persist when using the PEDOT:PSS polymer in biomedical applications. The polymer relies on the PSS component which allows it to be soluble in water, but when this material is implanted in the body, it exhibits poor biocompatibility.
“This means that when exposed to this polymer, the body has potential toxic or immunological responses, which is not ideal in already damaged tissue that we are trying to regenerate. This severely limits the hydrogel components that can be successfully incorporated to create conductive scaffolds,” she added.
Novel PEDOT nanoparticles (NPs) were developed in the study to overcome this limitation. The synthesis of conductive PEDOT nanoparticles allows the surface of the nanoparticles to be tailored to achieve the desired cellular response and increase the variability of hydrogel components that can be incorporated, without the necessary presence of PSS for solubility in the water.
In this work, hybrid biomaterials composed of gelatin and immunomodulatory hyaluronic acid, a material Professor Collins developed over many years at UL, were combined with the newly developed PEDOT NPs to create biocompatible electrically conductive scaffolds for targeted repair of spinal cord injuries.
A comprehensive study of the structure-property-function relationships of these precision-engineered scaffolds for optimized performance at the injury site was performed, including in-vivo research with spinal injury models. in rats, which was undertaken by Ms. Serafin during a Fulbright research exchange with the Department of Neuroscience at the University of California, San Diego, which was a partner in the project.
“The introduction of PEDOT NPs into the biomaterial increased the conductivity of the samples. Furthermore, the mechanical properties of the implanted materials should mimic the tissue of interest in tissue engineering strategies, with the developed PEDOT NP scaffolds corresponding to the mechanical values of the native spinal cord,” explained the researchers.
The biological response to the developed PEDOT NP scaffolds has been studied with stem cells in-vitro and in animal models of spinal cord injury in-vivo. The researchers observed excellent stem cell attachment and growth on the scaffolds.
The tests showed greater migration of axonal cells to the site of spinal cord injury, in which the NP PEDOT scaffold was implanted, as well as lower levels of scarring and inflammation than in the model. lesion that had no scaffold, according to the study.
Overall, these results show the potential of these materials for spinal cord repair, the research team states.
The impact of a spinal cord injury on a patient’s life is not only physical, but also psychological, as it can seriously affect the patient’s mental health, leading to increased cases of depression, stress or anxiety,” Ms. Serafin explained.
“Treating spinal injuries will therefore not only allow the patient to walk or move again, but also to live their life to the fullest of their ability, which makes projects like this so essential for communities in research and medicine. Additionally, the overall societal impact of providing effective spinal cord injury treatment will result in reduced healthcare costs associated with treating patients.
“These results offer encouraging prospects for patients and further research in this area is planned.
Studies have shown that the motor neuron excitability threshold at the distal end of a spinal cord injury tends to be higher. A future project will further improve the scaffold design and create conductivity gradients in the scaffold, with conductivity increasing towards the distal end of the lesion to further stimulate neuron regeneration,” he said. she adds.
This project was funded by the Irish Research Council in partnership with Johnson & Johnson as well as the Irish Fulbright Association, which enabled a research exchange with the University of California, San Diego. The Faculty of Science and Engineering and the Health Research Institute at UL also provided support.
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Journal reference:
Serafin, A., et al. (2022) Integrated scaffolds of electroconductive PEDOT nanoparticles for spinal cord tissue repair. Research on biomaterials. doi.org/10.1186/s40824-022-00310-5.