MNPs-Enriched Biomaterials as Promising Candidates for Nervous Tissue Engineering Applications ^†

Nervous tissue regeneration represents a huge challenge in tissue engineering and therefore, numerous strategies are being investigated for this purpose. Current approaches are focused on the use of magnetic biomaterials to support nerve regeneration, since magnetic field was proven to have a beneficial effect on neuronal differentiation. Our aim was to develop and investigate the cytocompatibility and potential of naturally-based materials enriched with magnetic nanoparticles (MNPs) to support the growth, viability and proliferation of neural stem cells (represented by NE-4C cell line, CRL-2925, ATCC). These composites were developed using an electrospinning technique and were enriched with different concentrations of MNPs (0.5–2%, to be compared to a pure fish gelatin control material), then they were seeded with NE-4C cells and maintained in standard culture conditions for up to seven days. Cell viability and proliferation were tested using the MTT assay, while eventual cytotoxic effects were evaluated based on lactic dehydrogenase (LDH) release in culture medium. The proportion of live and dead cells in contact with MNP-enriched scaffolds was revealed using live/dead assay. Changes in cytoskeleton distribution and focal adhesion assembly were observed by immunolabeling and confocal microscopy. Our results indicated that all tested scaffolds proved to be biocompatible with neural stem cells and did not induce any significant cytotoxic effects for up to one week of in vitro culture. MNP concentration influenced proportionally the rate of cell growth and proliferation, while cytoskeleton immunolabeling revealed an elongated profile of actin microfilaments and emphasized focal adhesion kinase distribution, suggesting beneficial effects of MNP-enriched composites. Thus, biomaterials embedding low concentrations of MNPs display good interaction with neural stem cells and could be used in further studies for nervous tissue regeneration. This work was supported by a PN-III-P1-1.1-TE-2019-1191/MAGNIFICENT grant.