Biomimetic hydrogels direct spinal progenitor cell differentiation and promote functional recovery after spinal cord injury.

OBJECTIVE: Demyelination that results from disease or traumatic injury, such as spinal cord injury (SCI), can have a devastating effect on neural function and recovery. Many researchers are examining treatments to minimize demyelination by improving oligodendrocyte availability in vivo. Transplantation of stem and oligodendrocyte progenitor cells is a promising option, however, trials are plagued by undirected differentiation. Here we introduce a biomaterial that has been optimized to direct the differentiation of neural progenitor cells (NPCs) toward oligodendrocytes as a cell delivery vehicle after SCI. APPROACH: A collagen-based hydrogel was modified to mimic the mechanical properties of the neonatal spinal cord, and components present in the developing extracellular matrix were included to provide appropriate chemical cues to the NPCs to direct their differentiation toward oligodendrocytes. The hydrogel with cells was then transplanted into a unilateral cervical contusion model of SCI to examine the functional recovery with this treatment. Six behavioral tests and histological assessment were performed to examine the in vivo response to this treatment. MAIN RESULTS: Our results demonstrate that we can achieve a significant increase in oligodendrocyte differentiation of NPCs compared to standard culture conditions using a three-component biomaterial composed of collagen, hyaluronic acid, and laminin that has mechanical properties matched to those of neonatal neural tissue. Additionally, SCI rats with hydrogel transplants, with and without NPCs, showed functional recovery. Animals transplanted with hydrogels with NPCs showed significantly increased functional recovery over six weeks compared to the media control group. SIGNIFICANCE: The three-component hydrogel presented here has the potential to provide cues to direct differentiation in vivo to encourage regeneration of the central nervous system.

Electrical Stimulation of Human Mesenchymal Stem Cells on Conductive Nanofibers Enhances their Differentiation toward Osteogenic Outcomes.

Tissue scaffolds allowing the behavior of the cells that reside within them to be controlled are of particular interest for tissue engineering. Herein, the preparation of conductive fiber-based bone tissue scaffolds (nonwoven mats of electrospun polycaprolactone with an interpenetrating network of polypyrrole and polystyrenesulfonate) is described that enable the electrical stimulation of human mesenchymal stem cells to enhance their differentiation toward osteogenic outcomes.

Instructive Conductive 3D Silk Foam-Based Bone Tissue Scaffolds Enable Electrical Stimulation of Stem Cells for Enhanced Osteogenic Differentiation.

Stimuli-responsive materials enabling the behavior of the cells that reside within them to be controlled are vital for the development of instructive tissue scaffolds for tissue engineering. Herein, we describe the preparation of conductive silk foam-based bone tissue scaffolds that enable the electrical stimulation of human mesenchymal stem cells (HMSCs) to enhance their differentiation toward osteogenic outcomes.

Macromol. Rapid Commun. 21/2015.

Back Cover: Tissue scaffolds allowing the behavior of the cells that reside within them to be controlled are of particular interest for tissue engineering. Herein, the preparation of conductive nanofiber-based bone tissue scaffolds are described, made from nonwoven mats of electrospun polycaprolactone with an interpenetrating network of polypyrrole and polystyrenesulfonate. These scaffolds enable the electrical stimulation of human mesenchymal stem cells to enhance their differentiation toward osteogenic outcomes. Further details can be found in the article by J. G. Hardy,* M. K. Villancio-Wolter, R. C. Sukhavasi, D. J. Mouser, D. Aguilar Jr., S. A. Geissler, D. L. Kaplan,* and C. E. Schmidt* on page 1884.