Biology subjects

Leblanc Latour, M.

Publications and source records attributed to Leblanc Latour, M..

6 recordsLinked to original sources

bioRxiv2025

Poly-L-Ornithine Coated Plant Scaffolds Support Motor Recovery in Rats after Traumatic Spinal Cord Injury

Spinal cord injury (SCI) is a debilitating neurological condition with far-reaching consequences for patients, including loss of motor function and significant limitations to quality of life. Implantable biomaterials have emerged as a therapeutic strategy to modulate the SCI microenvironment and facilitate regeneration of axons. In this study, plant-derived lignocellulosic scaffolds coated with poly-L-ornithine (PLO) are shown to support locomotor recovery and neural tissue repair in a rat model of spinal cord injury. Upon complete transection of the spinal cord, animals were implanted with a plant-derived scaffold coated in poly-L-ornithine, a positively charged amino acid chain that is known to promote neural stem cell differentiation into neurons and enhance myelin regeneration. Recovery of motor function was evaluated by the Basso, Beattie and Bresnahan (BBB) locomotor scale as well as the Karolinska Institutet Swim Assessment Tool (KSAT). Retrograde tracing of ascending sensory tracts revealed enhanced regeneration in animals that received the PLO-coated scaffold. Numerous {beta}-III tubulin and neurofilament 200 positive fibers may indicate axonal sprouting within the lignocellulosic scaffold and LFB staining highlights myelination around the PLO-coated scaffold. These results demonstrate the potential of plant-based biomaterials in a rat model of acute spinal cord injury and highlight their enhancement after PLO functionalization.

bioengineering↗

bioRxiv2021

Biomechanical study of cellulose scaffolds for bone tissue engineering in vivo and in vitro.

Plant-derived cellulose biomaterials have recently been utilized in several tissue engineering applications. These naturally-derived cellulose scaffolds have been shown to be highly biocompatible in vivo, possess structural features of relevance to several tissues, and support mammalian cell invasion and proliferation. Recent work utilizing decellularized apple hypanthium tissue has shown that it possesses a pore size similar to trabecular bone and can successfully host osteogenic differentiation. In the present study, we further examined the potential of apple-derived cellulose scaffolds for bone tissue engineering (BTE) and analyzed their mechanical properties in vitro and in vivo. MC3T3-E1 pre-osteoblasts were seeded in cellulose scaffolds. Following chemically-induced osteogenic differentiation, scaffolds were evaluated for mineralization and for their mechanical properties. Alkaline phosphatase and Alizarin Red staining confirmed the osteogenic potential of the scaffolds. Histological analysis of the constructs revealed cell invasion and mineralization throughout the constructs. Furthermore, scanning electron microscopy demonstrated the presence of mineral aggregates on the scaffolds after culture in differentiation medium, and energy-dispersive spectroscopy confirmed the presence of phosphate and calcium. However, although the Youngs modulus significantly increased after cell differentiation, it remained lower than that of healthy bone tissue. Interestingly, mechanical assessment of acellular scaffolds implanted in rat calvaria defects for 8 weeks revealed that the force required to push out the scaffolds from the surrounding bone was similar to that of native calvarial bone. In addition, cell infiltration and extracellular matrix deposition were visible within the implanted scaffolds. Overall, our results confirm that plant-derived cellulose is a promising candidate for BTE applications. However, the discrepancy in mechanical properties between the mineralized scaffolds and healthy bone tissue may limit their use to low load-bearing applications. Further structural re-engineering and optimization to improve the mechanical properties may be required for load-bearing applications.

bioengineering↗

bioRxiv2021

Mechanosensitive Osteogenesis on Native Cellulose Scaffolds for Bone Tissue Engineering.

In recent years, plant-derived cellulosic biomaterials have become a popular way to create scaffolds for a variety of tissue engineering applications. Moreover, such scaffolds possess similar physical properties (porosity, stiffness) that resemble bone tissues and have been explored as potential biomaterials for tissue engineering applications. Here, plant-derived cellulose scaffolds were seeded with MC3T3-E1 pre-osteoblast cells. Moreover, to assess the potential of these biomaterials, we also applied cyclic hydrostatic pressure (HP) to the cells and scaffolds over time to mimic a bone-like environment more closely. After one week of proliferation, cell-seeded scaffolds were exposed to HP up to 270 KPa at a frequency of 1Hz, once per day, for up to two weeks. Scaffolds were incubated in osteogenic inducing media (OM) or regular culture media (CM). The effect of cyclic HP combined with OM on cell-seeded scaffolds resulted in an increase of differentiated cells. This corresponded to an upregulation of alkaline phosphatase activity and scaffold mineralization. Importantly, the results reveal that well known mechanosensitive pathways cells which regulate osteogenesis appear to remain functional even on novel plant-derived cellulosic biomaterials.

biophysics↗

bioRxiv2020

Homemade Bread: Repurposing an Ancient Technology for Low Cost in vitro Tissue Engineering

Numerous synthetic and naturally-occurring biomaterials have been developed to provide such architectures to support the proliferation of mammalian cells in vitro and in vivo. Our group, and others, have shown that scaffolds derived from plants can be utilized for tissue engineering applications in biomedicine and in the burgeoning cultured meat industry. Such scaffolds are ideally straightforward and inexpensive to prepare, allowing researchers to take advantage of their intrinsic 3D microarchitectures. These efforts inspired us to continue to pursue the development of novel and unconventional biomaterials that are easily produced and high performing in vitro. With this in mind, few plant-derived materials are more ubiquitous than bread. Having observed the porosity of the crumb (i.e. the internal bulk) we sought to investigate whether it might support the proliferation of mammalian cells in vitro. Here, we develop and validate a yeast-free "soda bread" that maintains its mechanical stability over several weeks in culture conditions. Importantly, we also demonstrate that control over the mechanical stability of the scaffold can also be achieved with both chemical and enzymatic means. The scaffolding is a heterogeneous and complex structure of isolated and interconnected pores which allow for the proliferation of multiple cell types. We demonstrate here that mouse fibroblasts, myoblasts and pre-osteoblasts are able to proliferate up to four weeks in culture. Immunohistochemistry demonstrates that the fibroblasts are able to deposit their own fibronectin extracellular matrix and that mouse myoblasts are able to differentiate and fuse into myotubes. Although the pre-osteoblasts proliferated over the course of four weeks their ability to differentiate was inconclusive. Metabolic analyses of proliferation, cytotoxicity and oxidative stress reveal that cells remain highly viable and functional on these novel bread scaffolds. While the results presented in this proof-of-concept study create many new questions and opportunities, the results open up novel possibilities in the development of edible scaffolds that may be utilized in future food applications. Bread derived scaffolds represent a surprising alternative to synthetic or animal-derived scaffolds for addressing a diverse variety of tissue engineering challenges in food science. Future studies will delve deeper into investigating these how possibilities might take advantage of the immense breadth of knowledge about bread making and examine their applicability in the development of lab grown foods and broader applications in cellular agriculture.

bioengineering↗

bioRxiv2020

Engineered Tissue Interfaces for in vitro and in vivo Bioengineering

In regenerative medicine, the healing of the interfacial zone between tissues is a major challenge, yet approaches for studying the complex microenvironment of this interface remain lacking. Here, we study these complex living interfaces by manufacturing modular "blocks" of naturally porous decellularized plant-derived scaffolds with a computer numerical controlled mill. We demonstrate how each scaffold can be seeded with different cell types and easily assembled in a manner akin to LEGO bricks to create an engineered tissue interface (ETI). Cells migrate across the interface formed between an empty scaffold and a scaffold pre-seeded with cells. However, when both scaffolds contain cells, only a shallow cross-over zone of cell infiltration forms at the interface. As a proof-of-concept study, we use ETIs to investigate the interaction between lab grown bone and connective tissues. Consistent with the above, a cross-over zone of the two distinct cell types forms at the interface between scaffolds, otherwise the populations remain distinct. Finally, we demonstrate how ETIs are biocompatible in vivo, becoming vascularized and integrated into surrounding tissue after implantation. This work creates new tissue design avenues for understanding biological processes or the development of synthetic artificial tissues.

biophysics↗

bioRxiv2020

Plant-derived Cellulose Scaffolds for Bone Tissue Engineering.

Plant-derived cellulose biomaterials have recently been utilized in several tissue engineering applications. Naturally-derived cellulose scaffolds have been shown to be highly biocompatible in vivo, possess structural features of relevance to several tissues, as well as support mammalian cell invasion and proliferation. Recent work utilizing decellularized apple hypanthium tissue has shown that it possesses a pore size and properties similar to trabecular bone. In the present study, we examined the potential of apple-derived cellulose scaffolds for bone tissue engineering (BTE). Confocal microscopy revealed that the scaffolds had a suitable pore size for BTE applications. To analyze their in vitro mineralization potential, MC3T3-E1 pre-osteoblasts were seeded in either bare cellulose scaffolds or in composite scaffolds composed of cellulose and collagen I. Following chemically-induced differentiation, scaffolds were mechanically tested and evaluated for mineralization. The Youngs modulus of both types of scaffolds significantly increased after cell differentiation. Alkaline phosphatase and Alizarin Red staining further highlighted the osteogenic potential of the scaffolds. Histological sectioning of the constructs revealed complete invasion by the cells and mineralization throughout the entire constructs. Finally, scanning electron microscopy demonstrated the presence of mineral aggregates deposited on the scaffolds after differentiation, and energy-dispersive spectroscopy confirmed the presence of phosphate and calcium. In summary, our results indicate that plant-derived cellulose is a promising scaffold candidate for bone tissue engineering applications.

bioengineering↗