Fabrication of a biomimetic spinal cord tissue construct with heterogenous mechanical properties using intrascaffold cell assembly

2020 ◽  
Vol 117 (10) ◽  
pp. 3094-3107
Author(s):  
Kevin F. Firouzian ◽  
Yu Song ◽  
Feng Lin ◽  
Ting Zhang
2004 ◽  
Vol 51 (4) ◽  
pp. 59-64
Author(s):  
M. Spaic ◽  
Dusan Mikicic ◽  
S. Ilic ◽  
I. Milosavljevic ◽  
S. Ivanovic ◽  
...  

Mechanical properties of the spinal cord tissue - biological basis for the development of the modality of the DREZ surgery lesioning technique Successful treatment of the chronic neurogenic pain of spinal cord and cauda equina injury origin remains a significant management problem. The mechanism of this pa-in phenomenon has been shown to be related to neurochemical changes that lead to the state of hypereactivity of the second order dorsal horn neurons. The DREZ surgery (Dorsal Root Entry Zone lesion), designed to destroy anatomy structures involved in pain generating thus interrupting the neurogenic pain mechanism, as a causative procedure in treating this chronic pain, has been performed by using different technical modalities: Radiofrequency (RF) coagulation technique, Laser, Ultrasound and Microsurgical DREZotomy technic. The purpose of the study was to assess the possibility for the establishment of the lesioning technique based on the natural difference in the mechanical properties between the white and gray cord substance. We experimentally determinate mechanical properties of the human cadaveric cord white versus gray tissue for the purpose of testing possibility of selective suction of the dorsal horn gray substance as a DREZ lesioning procedure. Based on the fact of the difference in tissue elasticity between white and gray cord substance we established a new and simple DREZ surgical lesioning technique that was tested on cadaver cord. For the purpose of testing and comparing the size and shape of the DREZ lesion achieved the DREZ surgery has been performed on cadaver cord by employing selective dorsal horn suction as a lesioning method. After the procedure cadaver cord underwent histological fixation and analysis of the DREZ lesions achieved. Our result revealed that the white cord substance with longitudinal fiber structure had four time higher dynamical viscosity than gray substance of local neuronal network structure (150 PaS versus 37,5 PaS) that provided possibility for the safe and selective suction of the gray substance of the dorsal horn. Technique includes incision of the dorsolateral sulcus according to Sindous Microsurgical DREZotomy technique than suction under visual control of the dorsal horn gray matter using sucker adopted from the lumbar puncture nidle. Operative experimental testing and hystological analysis confirmed expected size and shape of the DREZ lesion performed by dorsal horn suction as DREZ lesioning technique. The utility, selectivity and safety of this technique has been provided by the natural mechanical properties of the cord tissue itself. Application of the Dorsal horn suction as a DREZ lesioning in humans confirmed this technique as a safe and reliable DREZ lesioning method.


2017 ◽  
Author(s):  
Raimund Schlüßler ◽  
Stephanie Möllmert ◽  
Shada Abuhattum ◽  
Gheorghe Cojoc ◽  
Paul Müller ◽  
...  

AbstractThe mechanical properties of biological tissues are increasingly recognized as important factors in developmental and pathological processes. Most existing mechanical measurement techniques either necessitate destruction of the tissue for access or provide insufficient spatial resolution. Here, we show for the first time a systematic application of confocal Brillouin microscopy to quantitatively map the mechanical properties of spinal cord tissues during biologically relevant processes in a contact-free and non-destructive manner. Living zebrafish larvae were mechanically imaged in all anatomical planes, during development and after spinal cord injury. These experiments revealed that Brillouin microscopy is capable of detecting the mechanical properties of distinct anatomical structures without interfering with the animal’s natural development. The Brillouin shift within the spinal cord increased during development and transiently decreased during the repair processes following spinal cord transection. By taking into account the refractive index distribution, we explicitly determined the apparent longitudinal modulus and viscosity of different larval zebrafish tissues. Importantly, mechanical properties differed between tissues in situ and in excised slices. The presented work constitutes the first step towards an in vivo assessment of spinal cord tissue mechanics during regeneration, provides a methodical basis to identify key determinants of mechanical tissue properties and allows to test their relative importance in combination with biochemical and genetic factors during developmental and regenerative processes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paige Smith ◽  
Natalia Ogrodnik ◽  
Janani Satkunarajah ◽  
Meaghan A. O’Reilly

AbstractExtensive studies on focused ultrasound (FUS)-mediated drug delivery through the blood–brain barrier have been published, yet little work has been published on FUS-mediated drug delivery through the blood-spinal cord barrier (BSCB). This work aims to quantify the delivery of the monoclonal antibody trastuzumab to rat spinal cord tissue and characterize its distribution within a model of leptomeningeal metastases. 10 healthy Sprague–Dawley rats were treated with FUS + trastuzumab and sacrificed at 2-h or 24-h post-FUS. A human IgG ELISA (Abcam) was used to measure trastuzumab concentration and a 12 ± fivefold increase was seen in treated tissue over control tissue at 2 h versus no increase at 24 h. Three athymic nude rats were inoculated with MDA-MB-231-H2N HER2 + breast cancer cells between the meninges in the thoracic region of the spinal cord and treated with FUS + trastuzumab. Immunohistochemistry was performed to visualize trastuzumab delivery, and semi-quantitative analysis revealed similar or more intense staining in tumor tissue compared to healthy tissue suggesting a comparable or greater concentration of trastuzumab was achieved. FUS can increase the permeability of the BSCB, improving drug delivery to specifically targeted regions of healthy and pathologic tissue in the spinal cord. The achieved concentrations within the healthy tissue are comparable to those reported in the brain.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1872
Author(s):  
Shaowei Guo ◽  
Idan Redenski ◽  
Shulamit Levenberg

Spinal cord injury (SCI) is a debilitating condition, often leading to severe motor, sensory, or autonomic nervous dysfunction. As the holy grail of regenerative medicine, promoting spinal cord tissue regeneration and functional recovery are the fundamental goals. Yet, effective regeneration of injured spinal cord tissues and promotion of functional recovery remain unmet clinical challenges, largely due to the complex pathophysiology of the condition. The transplantation of various cells, either alone or in combination with three-dimensional matrices, has been intensively investigated in preclinical SCI models and clinical trials, holding translational promise. More recently, a new paradigm shift has emerged from cell therapy towards extracellular vesicles as an exciting “cell-free” therapeutic modality. The current review recapitulates recent advances, challenges, and future perspectives of cell-based spinal cord tissue engineering and regeneration strategies.


2017 ◽  
Vol 23 (3) ◽  
pp. 105-115 ◽  
Author(s):  
Ping Sui ◽  
Hiroyuki Watanabe ◽  
Konstantin Artemenko ◽  
Wei Sun ◽  
Georgy Bakalkin ◽  
...  

Spinal cord as a connection between brain and peripheral nervous system is an essential material for studying neural transmission, especially in pain-related research. This study was the first to investigate pain-related neuropeptide distribution in rat spinal cord using a matrix-assisted laser desorption ionization-time of flight imaging mass spectrometry (MALDI TOF MS) approach. The imaging workflow was evaluated and showed that MALDI TOF MS provides efficient resolution and robustness for neuropeptide imaging in rat spinal cord tissue. The imaging result showed that in naive rat spinal cord the molecular distribution of haeme, phosphatidylcholine, substance P and thymosin beta 4 were well in line with histological features. Three groups of pain-related neuropeptides, which are cleaved from prodynorphin, proenkephalin and protachykinin-1 proteins were detected. All these neuropeptides were found predominantly localized in the dorsal spinal cord and each group had unique distribution pattern. This study set the stage for future MALDI TOF MS application to elucidate signalling mechanism of pain-related diseases in small animal models.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Shaohui Zong ◽  
Gaofeng Zeng ◽  
Ye Fang ◽  
Jinzhen Peng ◽  
Yong Tao ◽  
...  

Study Design.In this study, we investigated the role of IL-17 via activation of STAT3 in the pathophysiology of SCI.Objective.The purpose of the experiments is to study the expression of IL-17 and related cytokines via STAT3 signaling pathways, which is caused by the acute inflammatory response following SCI in different periods via establishing an acute SCI model in rat.Methods.Basso, Beattie, and Bresnahan hind limb locomotor rating scale was used to assess the rat hind limb motor function. Immunohistochemistry was used to determine the expression levels of IL-17 and p-STAT3 in spinal cord tissues. Western blotting analysis was used to determine the protein expression of p-STAT3 in spinal cord tissue. RT-PCR was used to analyze the mRNA expression of IL-17 and IL-23p19 in the spleen tissue. ELISA was used to determine the peripheral blood serum levels of IL-6, IL-21, and IL-23.Results.Compared to the sham-operated group, the expression levels of IL-17, p-STAT3, IL-6, IL-21, and IL-23 were significantly increased and peaked at 24 h after SCI. The increased levels of cytokines were correlated with the SCI disease stages.Conclusion.IL-17 may play an important role in promoting spinal cord neuroinflammation after SCI via activation of STAT3.


2012 ◽  
Vol 46 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Joanna H.L. Diong ◽  
Robert D. Herbert ◽  
Lisa A. Harvey ◽  
Li Khim Kwah ◽  
Jillian L. Clarke ◽  
...  

Author(s):  
Andrew C. Smith ◽  
Denise R. O’Dell ◽  
Wesley A. Thornton ◽  
David Dungan ◽  
Eli Robinson ◽  
...  

Background: Using magnetic resonance imaging (MRI), widths of ventral tissue bridges demonstrated significant predictive relationships with future pinprick sensory scores, and widths of dorsal tissue bridges demonstrated significant predictive relationships with future light touch sensory scores, following spinal cord injury (SCI). These studies involved smaller participant numbers, and external validation of their findings is warranted. Objectives: The purpose of this study was to validate these previous findings using a larger independent data set. Methods: Widths of ventral and dorsal tissue bridges were quantified using MRI in persons post cervical level SCI (average 3.7 weeks post injury), and pinprick and light touch sensory scores were acquired at discharge from inpatient rehabilitation (average 14.3 weeks post injury). Pearson product-moments were calculated and linear regression models were created from these data. Results: Wider ventral tissue bridges were significantly correlated with pinprick scores (r = 0.31, p < 0.001, N = 136) and wider dorsal tissue bridges were significantly correlated with light touch scores (r = 0.31, p < 0.001, N = 136) at discharge from inpatient rehabilitation. Conclusion: This retrospective study’s results provide external validation of previous findings, using a larger sample size. Following SCI, ventral tissue bridges hold significant predictive relationships with future pinprick sensory scores and dorsal tissue bridges hold significant predictive relationships with future light touch sensory scores.


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