Paper Title
Effect Of Aligned Wet Spun Plga Microribbons On Neural Stem Cell Behavior

Abstract
Alignment is a very important factor in directing the neural stem cells to differentiate to nerve cells . In order to use the efficacy of effectiveness of alignment, the aligned PLGA microribbons were developed via Wet spinning method. Scanning Electron Microscopy (SEM) revealed the morphology and alignment of the Ribbons. The Fourier Transform Infrared Spectroscopy-Attenuated total reflection (FTIR-ATR) was applied for characterizing the chemical groups on the PLGA scaffolds. The adhesion and proliferation of Neural stem cells, which are extracted from brain of Syrian mice; were evaluated with MTT assay. Introduction: The brain can be damaged by a wide range of degenerative diseases as Parkinson, Alzheimer, Huntington and stroke(1). In these cases of neurodegenerative diseases, the result of damage is loss of neurons which is leading to some dysfunctionalities and neurological symptoms. Now the treatments are just pharmacological therapies which cannot fully restore the lost functions of patients. Today some advanced therapies as stem cell-based therapies, regenerative medicine and tissue engineering have emerged as successful treatments in delivery of the stem cells to the injured brain with the aim of replacing damaged neurons(2-5). Stem cell-based replacing therapies have some problems as poor cell survival, poor control of cellular growth, differentiation and migration to the injured locations. To overcome the disabilities of stem cell therapies, regeneration of the damaged brain with biomaterial scaffold has been approved(2, 6-9). Placing a biomaterial scaffold into the cavity of damaged brain can play the role of substrate for cell infiltration and growth, axon regeneration and neurite formation(10). The scaffold may also provide support for the surrounding brain tissue. In the cases in which stem cells and biomaterial scaffolds are combined, the neural stem cells are isolated from specific locations which are rich of neural stem cells as Subventricular Zone (SVZ) and Subgranular Zone (SGZ) in the brain. The scaffolds should be designed to mimic some of roles of natural ExtraCellular Matrix (ECM) which can control the interaction between the cells and the scaffolds(11, 12). Recently, nano/micro fibrous scaffolds using natural/synthetic polymers have been applied for nerve regeneration due to their capability of providing a microenvironment for proper cell attachment, proliferation and migration. Also, the aligned nano/micro fibers can provide a substrate for conducting directional cell migration, proliferation and neurite growth(13). The Poly lactic-co-glycolic acid (PLGA) aligned fibers are widely used for neural tissue engineering as their ability for promoting differentiation and migration of neural stem cells and guiding neurite outgrowth along the aligned scaffolds(14-17). In the present study, wet spun aligned PLGA microribbons have been fabricated and studied for neural stem cells, isolated from SVZ of mice, attachment and proliferation.