Politécnica de Madrid

New advanced biomaterial to repair damaged nervous tissue

Researchers from Universidad Politécnica de Madrid have has achieved the functional recovery from a stroke after implanting silk fibroin hydrogels-encapsulated stem cells in stroke mice.

A team of researchers from the Centre for Biomedical Technology (CTB) at Universidad Politécnica de Madrid (UPM) in collaboration with the Universidad Complutense de Madrid (UCM), the Instituto Cajal and the Hospital Clínico San Carlos have developed an innovative treatment to repair damaged brain tissues. Thanks to the implantation of encapsulated stem cells in an innocuous biomaterial and fully biocompatible (silk fibroin), researchers have achieved the functional recovery of mice after suffering an induced brain stroke.

This encapsulation can increase the survival rate of stem cells implanted in the brain and, in addition to positively influencing the repair of damaged nerve tissue, it can prevent the extent of the damage.

A wide range of neurological disorders can cause permanent physical and cognitive disabilities. Our nervous system has a limited capacity to recover after an injury, for instance after a stroke or brain trauma but also in neurodegenerative diseases such as Alzheimer's or Parkinson's in which there is a progressive deterioration of our brain.

Stem cell therapies are a step forward the treatment of these diseases given its therapeutic potential to protect and repair the damaged brain. However, the stem cell transplant has its difficulties, among others, its reduced survival rate in the brain after transplant. This a barrier to achieve the most suitable therapy.

Fluorescence microscopy images showing stem cells (green) implanted in a brain tissue (blue). The four figures at the right show the survival of non-encapsulated stem cells, and the figures at the right show the silk fibroin hydrogels-encapsulated stem cells. Credit: Front Cell Neurosci. 2018 Sep 6;12:296. doi: 10.3389/fncel.2018.00296

In order to overcome this barrier, a team led by researchers from the Centre for Biomedical Technology, in collaboration with UCM, the Instituto Cajal and the Hospital Clínico San Carlos, has developed an innovative bioengineering strategy to repair the damaged brain tissue. To do this, researchers implanted mesenchymal stem cells in mice with infarct brain encapsulated in an innocuous biomaterial and fully biocompatible: silk fibroin.

After the treatment, the mice experienced a significant improvement in their sensory and motor skills which had been profoundly altered after the stroke. Besides, by using electrophysiological techniques, researchers have shown the improvement of brain reorganization in adjacent areas to the damaged zone. Another relevant aspect of this research was that silk fibroin considerably increased the survival of stem cells implanted in the brain, preventing an extent of the damage after de induced stroke in animals.

According to Daniel González Nieto, a CTB-UPM researcher: “these results are a step forward in new treatments of neurologic disorders when using silk fibroin as a drug delivery vehicle, achieving a higher therapy performance and the functional improvement of patients”.

This study has been funded by the Community of Madrid through the NeuroCentro project (B2017/BMD-3760), an initiative to create a new a technological center in the region of Madrid for the integrated treatment of neurologic disorders. The study has been also funded by the Ministry of Economy and Competitiveness (MAT2016-79832-R, MAT2016-79832-R y MAT2015-66666-C3-3-R projects).

Besides, SILKBIOMED C. was involved in this project, SILKBIOMED is a UPM spin-off company which is a pioneer in the development of a great variety of advanced medical products made of silk fibroin for the treatment of diverse of neurologic disorders.

Fernández-García L, Pérez-Rigueiro J, Martinez-Murillo R, Panetsos F, Ramos M, Guinea GV, González-Nieto D. Cortical Reshaping and Functional Recovery Induced by Silk Fibroin Hydrogels-Encapsulated Stem Cells Implanted in Stroke Animals. Front Cell Neurosci. 2018 Sep 6;12:296. doi: 10.3389/fncel.2018.00296.

Fernández-García L, Marí-Buyé N, Barios JA, Madurga R, Elices M, Pérez-Rigueiro J, Ramos M, Guinea GV, González-Nieto D. Safety and tolerability of silk fibroin hydrogels implanted into the mouse brain. Acta Biomater. 2016 Nov;45:262-275.

Daniel González-Nieto, Laura Fernández-García, José Pérez-Rigueiro, Gustavo V. Guinea and Fivos Panetsos. Hydrogels-Assisted Cell Engraftment for Repairing the Stroke-Damaged Brain: Chimera or Reality. Polymers. 2018. 10:184