Leblanc-Latour, M. | Search bioRxiv

bioRxiv2020

Plant Scaffolds Support Motor Recovery and Regeneration in Rat Spinal Cord Injury

As of yet, no standard of care incorporates biomaterials to treat traumatic spinal cord injury (SCI). However, intense development of biomaterials for treating SCI has focused on fabricating microscale channels to support the regrowth of axons while minimizing scar formation. We previously demonstrated that plant tissues could be decellularized and processed to form sterile, biocompatible and implantable biomaterials that support cell infiltration and vascularization in vivo. Vascularized plant tissues contain continuous microscale channels with geometries relevant for supporting neural regeneration. We hypothesized that decellularized vascular bundles would support neural regeneration and motor recovery in SCI. Sprague Dawley rats received a complete T8-T9 spinal cord transection and were implanted with acellular plant-derived scaffolds and allowed to recover over 28 weeks. Animals that received the scaffolds alone, with no other therapeutic compounds, demonstrated a significant and stable partial improvement in motor function compared to control animals as early as week 4 post-injury. Hind-limb motor function did not deteriorate over the remaining 28 weeks. Histological analysis revealed minimal astrocyte scarring at the spinal cord - scaffold interface, aligned axonal projection through the scaffolds, populations of serotonergic neurons and Schwann cells, laminin and collagen deposition and the presence of blood vessels. Axonal reconnection via the scaffold was also confirmed by Fluro-gold retrograde tracing. Taken together, our work defines a novel route for building upon naturally occurring plant microarchitectures to support the repair of the spinal cord post-injury. Notably, these results were achieved without the use of growth factors, stem/progenitor cells, or any other interventions.

bioengineering↗

bioRxiv2017

Spontaneous Phase Separation of Cocultured Cell Mixtures In vitro

During Embryogenesis, cells undergo constant organizational remodelling. Biochemical and biophysical guidance cues act in tandem to guide migration and morphogenesis into distinct cellular patterns. It has been shown that various cell types will express different configurations of cellular adhesion molecules known as cadherins and integrins. Cocultured in vitro experiments have focused on revealing the extensive genetic expression profiles that modulate embryogenesis whilst overlooking the physical cell-cell and cell-substrate interactions that influence organization. We demonstrate that NIH3T3 and MDCK cells undergo a spontaneous phase separation when cocultured in vitro and that this phenomenon occurs through purely physical binding energies. A Monte Carlo simulation model of a mixture of cells with different cell-cell and cell-substrate binding energies reveals that the spontaneous phase separation occurs due to the minimization of interfacial free energy within the system. Cell-cell and cell-substrate binding plays a critical role in cell organization and is capable of phase separating different populations of cells in vitro.

biophysics↗