In the tissue regeneration field, stem cell transplantation represents a promising therapeutic strategy. To favor their implantation, proliferation and differentiation need to be controlled. Several studies have demonstrated that stem cell fate can be controlled by applying continuous electric field stimulation. This study aims to characterize the effect of a specific microsecond electric pulse stimulation (bipolar pulses of 100 µs + 100 µs, delivered for 30 min at an intensity of 250 V/cm) to induce an increase in cell proliferation on mesenchymal stem cells (MSCs) and induced neural stem cells (iNSCs). The effect was evaluated in terms of (i) cell counting, (ii) cell cycle, (iii) gene expression, and (iv) apoptosis. The results show that 24 h after the stimulation, cell proliferation, cell cycle, and apoptosis are not affected, but variation in the expression of specific genes involved in these processes is observed. These results led us to investigate cell proliferation until 72 h from the stimulation, observing an increase in the iNSCs number at this time point. The main outcome of this study is that the microsecond electric pulses can modulate stem cell proliferation.

Myelomeningocele (MMC) is a congenital birth defect of the spine and spinal cord, commonly treated clinically through prenatal or postnatal surgery by repairing the unclosed spinal canal. Having previously developed a PLA/PCL polymer smart patch for this condition, we aim to further expand the potential therapeutic options by providing additional cellular and biochemical support in addition to its mechanical properties. Bone morphogenetic proteins (BMPs) are a large class of secreted factors that serve as modulators of development in multiple organ systems, including the CNS. We hypothesize that our smart patch mitigates the astrogenesis induced, at least partly, by increased BMP activity during MMC. To test this hypothesis, neural stem or precursor cells were isolated from rat fetuses and cultured in the presence of Noggin, an endogenous antagonist of BMP action, with recombinant BMPs. We found that the developed PLA/PCL patch not only serves as a biocompatible material for developing neural stem cells but was also able to act as a carrier for BMP–Notch pathway inhibitor Noggin, effectively minimizing the effect of BMP2 or BMP4 on NPCs cultured with the Noggin-loaded patch.

Spinal cord injury disrupts sensorimotor circuits, leading to chronic deficits that require coordinated repair of both spinal and supraspinal circuits. Here, we developed and evaluated a hybrid collagen hydrogel containing chitosan-functionalized iron oxide nanoparticles as a therapeutic scaffold to promote multi-level recovery in a C6 hemisection model in rats. In vitro , both the nanoparticles and the resulting hybrid scaffold show preserved neuronal viability, excitability, and network connectivity. In vivo , scaffold-implanted rats demonstrate significant improvements in gross motor function and postural control, as well as recovery of fine motor skills, forelimb dexterity and grip strength. Sensory evaluations show preserved hindlimb tactile responses accompanied by plasticity within the somatosensory cortex, indicating functional recovery of the different tracts related to sensory and motor functions. At the lesion site, the scaffold enhances neurite outgrowth and modulates the inflammatory milieu, providing a permissive environment for neural repair. These findings indicate that these hybrid collagen scaffolds support relevant integrated structural and functional recovery features after SCI and represent a promising platform for further optimization toward the effective release of therapeutics at the injured spinal cord.

Inflammation plays a pivotal role in a plethora of pathological processes, including spinal cord injury (SCI). However, effective anti‐inflammatory therapies for complex central nervous system pathologies remain an unmet clinical need. Herein, we present polymer‐coated iron oxide nanoparticles (IONPs) as an unprecedented platform combining bioactive coatings, an IL‐4 payload, and superparamagnetic properties validated on relevant in vitro and in vivo models. We demonstrate significant neuroactive and anti‐inflammatory actions driven by IONPs‐IL4 in comparison to soluble IL‐4. Interestingly, both hyaluronic acid‐coated and chitosan‐coated IONPs functionalized with IL‐4 (C12/HA‐IL4 and C12/CHI‐IL4, respectively) preserve maturation features and enhance firing frequency in primary neurons, while decreasing pro‐inflammatory markers in macrophages. In microglia cells, they decrease TNF‐α and increase Arg‐1 and CD206. Importantly, non‐functionalized IONPs also display a beneficial impact on neurons and macrophages. These nanoparticles can be successfully embedded into 3D porous reduced graphene oxide (rGO) scaffolds, retaining effective anti‐inflammatory properties in vitro. When examined in a chronic rat SCI model, rGO carrying C12/HA‐IL4 adequately integrates into the lesion, reduces vimentin at the interfaces, and facilitates total body weight recovery. These promising data encourage further investigation into the therapeutic potential of these nanosystems for SCI, thus paving the way for advanced SCI nanotherapeutics.