# Trans-septal delivery of hydrogel-encapsulated human umbilical cord MSC-derived neurospheres for acute neuroprotection in traumatic brain injury

## TL;DR

This study shows that hydrogel-encapsulated human umbilical cord stem cell-derived neurospheres can protect the brain and improve recovery after traumatic brain injury in rodents.

## Contribution

The novel approach of using hydrogel-encapsulated hUC-MSC-derived neurospheres for acute neuroprotection in TBI is demonstrated for the first time.

## Key findings

- Trans-septal delivery of hydrogel-encapsulated neurospheres reduced neuronal damage and improved neurological outcomes in a TBI model.
- Encapsulation in hydrogel enhanced cell survival and neuroprotective effects in co-cultured HT22 cells and in vivo.
- Neurospheres preserved dendritic integrity and reduced neurodegenerative markers in hippocampal regions after TBI.

## Abstract

This study explores the therapeutic potential of hydrogel-encapsulated neurospheres derived from human umbilical cord mesenchymal stem cells (hUC-MSCs) in mitigating traumatic brain injury (TBI) and enhancing functional recovery in a rodent model. Trans-septal (intranasal) transplantation of these neurospheres demonstrated significant neurological improvement, reduced neuronal damage, and preserved neuronal structures and functions. The hUC-MSCs cultured in a customized bioreactor retained essential MSC characteristics, including marker expression and multi-lineage differentiation potential, ensuring their therapeutic efficacy. Following neural induction, hUC-MSCs formed neurospheres that promoted cell aggregation, differentiation, and neuroprotective effects. Encapsulation within a hydrogel provided a stable environment, significantly reducing TBI-induced cell death in co-cultured HT22 cells and improving in vivo outcomes. Therapeutic benefits were evidenced by decreased modified neurological severity scores (mNSS), improved ΔmNSS, and restoration of neurotrophic factors, such as brain-derived neurotrophic factor in the hippocampal CA1 region, which supports cognitive and memory functions. Immunohistochemical and immunofluorescence analyses confirmed the neurospheres' ability to mitigate TBI-induced neurodegeneration, oxidative stress, and dendritic damage. Reduced neurodegenerative markers and preserved dendritic integrity, particularly microtubule-associated protein 2 expression in the CA1 and dentate gyrus (DG) regions, underscore the potential of hUC-MSC–derived neurospheres in maintaining neural connectivity and function after TBI.