Preparation and characteristic of nordihydroguaiaretic acid crosslinked porcine decellularized spinal cord scaffold

English Keywords:Decellularized spinal cord  Nordihydroguaiaretic acid  Crosslink  Biomechanics

English Abstract:

  【Abstract】 Objectives: To explore the construct and characteristic of nordihydroguaiaretic acid(NDGA) cross-linked porcine decellularized spinal cord scaffold. Methods: Porcine spinal cord scaffolds were decellularized by chemical extraction and crosslinked with 2.5g/L NDGA in solution. The structure of uncrosslinked and NDGA crosslinked decellularized spinal cord scaffolds were observed by stereoscopic microscope and scanning electron microscopy. Ultimate tensile strength and elastic modulus of nornal porcine thoracic spinal cord, uncrosslinked and NDGA crosslinked decellularized spinal cord scaffolds were determined on instron mechanical testing instrument. The fourth generation of SD rat astrocytes were co-cultured with uncrosslinked and NDGA crosslinked decellularized spinal cord scaffolds, and CCK8 assay for cell growth rate was tested to evaluate the cytotoxicity of scaffolds. The ECM scaffolds were implanted subcutaneously on the dorsal side and were obtained after 1, 2, 4 weeks for degradation rate. And the 4w scaffolds were HE stained for biological compatibility evaluation. Results: The uncrosslinked and the NDGA crosslinked decellularized spinal cord scaffolds possessed a similar three dimensional matrix structure. Tensile strength and elastic modulus of decellularized spinal cord scaffolds were significantly enhanced by NDGA-crosslinkin, difference between the two groups was statistical significance(P<0.05), but the paramenters still lower than those of control group(P<0.05). Astrocytes growed well in both groups, OD value growed as the co-culture time, and the cell proliferation assay by CCK-8 showed there was no statistic signification in the two groups(P>0.05) after co-culturing at 1 day, 3 days and 7 days. NDGA crosslinked decellularized spinal cord scaffolds had lower weight loss at each time point than the uncrosslinked acellular spinal cord scaffolds(P<0.05). The inflammatory cells in experiment group were sgnificantly less than those in control group, and there were a lot of vascular structures without vascular endothelium in experiment groups as well. Conclusions: Porcine decellularized spinal cord scaffolds presents no obvious change in structure after NDGA-crosslinking, but there is significant improvement in the biomechanical properties and ability against in vivo degradation and no marked cytotoxicity. Hence, the NDGA crosslinked scaffolds are promising in tissue engineering for spinal injury.