Perpustakaan Digital ITB

The topography of electrospun fi ber sca ff olds modi fi es astrocytes toward in vivo -like morphologies and behaviors. However, little is known about how electrospun fi ber diameter in fl uences astrocyte behavior. In this work, aligned fi bers with two distinct nanoscale fi ber diameters (808 and 386 nm) were prepared, and the astrocyte response was measured over time. Astrocytes on the large diameter fi bers showed signi fi cantly increased elongation as early as 2 h after seeding and remained signi fi cantly more elongated for up to 4 days compared to those on small diameter fi bers. Astrocytes extending along larger diameter fi bers were better equipped to support long neurite outgrowth from dorsal root ganglia neurons, and neurite outgrowth along these astrocytes was less branched than outgrowth along astrocytes cultured on small diameter fi bers. The di ff erences in astrocyte shape observed on the small or large diameter fi bers did not translate into di ff erences in GLT-1, GFAP, or GLAST protein expression. Thus, di ff erent fi ber diameters were unable to in fl uence astrocyte protein expression uniquely. Nevertheless, astrocytes cultured in either small or large fi bers signi fi cantly increased their expression of GLT-1 compared to astrocytes cultured on non fi ber ( fi lm) controls. Fibrous-induced increases in astrocyte GLT-1 expression protected astrocyte/neuron cocultures from toxicity generated by high extracellular glutamate. Alternatively, astrocytes/neurons cultured on fi lms were less able to protect these cells from culture conditions consisting of high glutamate levels. Biomaterials, such as the fi brous materials presented here, may help stimulate astrocytes to increase GLT-1 expression and uptake more glutamate, since astrocytes are less likely to uptake glutamate in neurodegenerative pathologies or following central nervous system injury.