Keele Research Repository

Achieving neural regeneration after spinal cord injury (SCI) represents a significant challenge. Neural stem cell (NSC) therapy offers replacement of damaged cells and delivery of pro-regenerative factors, but >95% of cells die when transplanted to sites of neural injury. Biomaterial scaffolds provide cellular protective encapsulation to improve cell survival. However, current available scaffolds are overwhelmingly not approved for human use, presenting a major barrier to clinical translation. Surgical biomaterials offer the unique benefit of being FDA-approved for human implantation. Specifically, a neurosurgical grade material, DuraGenTM, used predominantly for human duraplasty has many attractive features of an ideal biomaterial scaffold. Here, we have investigated the use of DuraGenTM as a three-dimensional (3D) cell encapsulation device for potential use in combinatorial, regenerative therapies. To show the feasibility of enhancing the therapeutic potential of this construct, we genetically engineered the NSCs prior to DuraGenTM encapsulation, which could offer the opportunity to increase expression of therapeutic biomolecules at the site of injury. A combination of magnetofection and minicircle technologies were used for genetic engineering of the NSCs.
I show that DuraGenTM can support the survival (ca 95% viability at 12 days) and 3D growth of NSCs. Key parameters including maintenance of NSC phenotype, proliferative capacity and differentiation into astroglial lineage cells, neurons and oligodendrocytes were unaffected by DuraGenTM. Furthermore, proof of concept of the capacity of DuraGenTM to maintain a viable genetically engineered NSC transplant population is demonstrated using reporter protein expression which could be detected for up to eight days (latest time point examined) within the construct. The findings support the concept that a ‘combinatorial therapy’, consisting of NSCs engineered to produce therapeutic biomolecules and protected within the DuraGenTM construct, is a promising clinically translatable neuro-regenerative therapy.