Cellular migration to electrospun poly(lactic acid) fibermats.

Nonwoven fabrics prepared via an electrospinning method, so-called electrospun fibermats, are expected to be promising scaffold materials for bone tissue engineering. In the present work, poly(L-lactic acid) (PLLA) fibermats, consisting of fibers with diameters ranging from 1 to 10 μm, were prepared by electrospinning. Mouse osteoblast-like cells (MC3T3-E1) were seeded on the fibermats with various fiber diameters (10, 5 and 2 μm; they are denoted by samples A, B and C, respectively) and cultured in two different directions in order to compare the migration behaviours into the scaffold of the normal condition and the anti-gravity condition. The cells in/on the fibermats were observed by laser confocal microscopy to estimate the cellular migration ability into them. When the MC3T3-E1 cells were cultured in the normal direction, the thickness of their layer increased to approx. 90 μm in the sample A, consisting of 10-μm fibers after 13 days of culture, while that in the sample C, consisting of 2-μm fibers, did not increase. When the MC3T3-E1 cells were cultured in the anti-gravity condition, the thickness of the cell layer in the sample A increased to approx. 60 μm. These results mean that the MC3T3-E1 cells migrated into the inside of sample A in either the normal direction or the anti-gravity one. The cellular proliferation showed no significant difference among the fibermats with three different fiber diameters; MC3T3-E1 cells on the fibermat with 2 μm fiber diameter grew two-dimensionally, while they grew three-dimensionally in the fibermat with 10 μm fiber diameter.