Electrospun nanofibers have been utilized in many biomedical applications as biomimetics of extracellular matrix proteins that promote self-organization of cells into 3D tissue constructs. As progress toward an artificial salivary gland tissue construct, we prepared nanofiber scaffolds using PLGA, which is a biodegradable and biocompatible material. We used electrospinning to prepare nanofiber scaffolds using poly(lactic-co-glycolic acid) (PLGA) with both dimethylformamide (DMF) and hexafluoroisopropanol (HFIP) as solvents. Using a design of experiment approach, the system and process parameters were optimized concurrently, and their effects on the diameter of the resulting fibers were computed into a single model. A transfer function was used to reproducibly produce nanofibers of a defined diameter, which was confirmed by a scanning electron microscope. The salivary gland cell line was seeded on the nanofiber scaffolds, and morphology, cell proliferation, and viability were assayed. Varying two or more parameters simultaneously yielded trends diverging from the linear response predicted by previous studies. Comparison of two solvents revealed that the diameter of PLGA nanofibers generated using HFIP is less sensitive to changes in the system and process parameters than are fibers generated using DMF. Inclusion of NaCl reduced morphological inconsistencies and minimized process variability. The resulting nanofiber scaffolds supported attachment, survival, and cell proliferation of a mouse salivary gland epithelial cell line. In comparison with glass and flat PLGA films, the nanofibers promoted self-organization of the salivary gland cells into 3D cell clusters, or aggregates. These data indicate that nanofiber scaffolds promote salivary gland cell organization, and suggest that a nanofiber scaffold could provide a platform for engineering of an artificial salivary gland tissue construct. This study additionally provides a method for efficient production of nanofiber scaffolds for general application in tissue engineering.
Salivary gland cell aggregates are derived from self-organization of acinar lineage cells
