Silicon Enhances Neurogenesis in Neurons Via Elevated Growth Associated Protein

Objectives: Silicon based biomaterials has been found to promote angiogenesis and osteogenesis in bone healing. Yet, peripheral neurogenesis is an aspect that has been under studied. Elucidating the effect of ionic silicon on neurogenesis could facilitate improved bone healing with these biomaterials. Growth-associated protein (Gap 43) marker has been shown to be associated with peripheral nerve regeneration. Thus, we hypothesize that ionic silicon enhances peripheral nerve regeneration via enhancement of Gap43 marker expression.
Methods: Mouse neuroblastoma x rat glioma hybrid (NG108) cell line was cultured for up to 6 days in DMEM supplemented with 10% fetal bovine serum, 1X HAT, 2mM L-glutamine, 1% penicillin/ streptomycin, and 10mM HEPES. We studied the effect of 0.1, 0.5, and1.0 mM ionic silicon concentration for 1,3, and 6 days on the differentiation and growth of these nerve cells. Using polymerase chain reaction (PCR), we assayed for GAP43 gene expression using ribosomal protein 19, RPL19, as the internal reference gene. The PCR results were then reported using analysis of variance with p<0.05 used to indicate statistical significance.
Results: All three experimental groups, 0.1, 0.5, and 1.0 mM ionic silicon concentration, show higher expression of Gap43 than the control group. There was more than a two-fold increase in the expression of Gap43 at 0.5 mM compared to the control group after 7 days of culture.
Conclusions: Elevated levels of Gap43 show that ionic silicon enhances nerve cell growth, which could be applied in improving the healing of bone after traumatic injury.