2022, Vol. 26 ›› Issue (25): 3974-3979

Chitosan/poly(lactic-co-glycolic acid)/polylactic acid scaffold with sustained release of nerve growth factor promotes the differentiation of bone marrow mesenchymal stem cells into neurons

Ji Hangyu1, 2, Gu Jun2, Xie Linghan1, Bao Junping1, Peng Xin1, Wu Xiaotao1, 3   

Abstract: BACKGROUND: More and more evidences demonstrate that nerve growth factor plays important roles in promoting neuronal survival and differentiation. However, nerve growth factor has a short half-life and poor stability, which limits its wide clinical application.  
OBJECTIVE: To investigate the feasibility of rat bone marrow mesenchymal stem cells to differentiate into neuronal cells on chitosan/poly(lactic-co-glycolic acid)/polylactic acid scaffolds that can continuously release nerve growth factors.
METHODS: Chitosan/poly(lactic-co-glycolic acid)/polylactic acid scaffolds that sustainably released nerve growth factor and chitosan/poly(lactic-co-glycolic acid)/polylactic acid scaffolds that did not contain nerve growth factor were constructed, and rat bone marrow mesenchymal stem cells were inoculated on the surface of two kinds of scaffolds. The induction program of basic fibroblast growth factor, brain-derived neurotrophic factor and N2 and B27 nerve cell growth additives added to the low-glucose DMEM complete medium was used to induce neurogenesis and differentiation. After 18 days of induction, immunofluorescence staining was used to detect the expression of neuronal markers (microtubule-associated protein 2 and nestin), and western blot assay was utilized to determine the expression of p-TrkA and p-ERK proteins.  
RESULTS AND CONCLUSION: (1) After 18 consecutive days of induction, immunofluorescence detection displayed that the microtubule-associated protein 2-positive cells were approximately 30% in the blank scaffold group, and approximately 70% in the sustained release nerve growth factor group. Nestin-positive cells were 40% in the blank scaffold group, and approximately 60% in the sustained release nerve growth factor group. The difference between the two groups was significant. (2) Western blot assay exhibited that the expression levels of p-TrkA and p-ERK in the sustained release nerve growth factor group were significantly higher than those of the blank scaffold group. (3) The results have confirmed that on the surface of the chitosan/poly(lactic-co-glycolic acid)/polylactic acid scaffold that continuously releases nerve growth factor, bone marrow mesenchymal stem cells can achieve better differentiation of neuronal cells through the TrkA/ERK pathway.
Key words: stem cells, bone marrow mesenchymal stem cells, nerve growth factor, chitosan poly(lactic-co-glycolic acid), polylactic acid, scaffold, neuron