Objective       To determine the effect of the direction of poly(ε-caprolactone) (PCL)/collagen (COL) nanofiber orientation on the morphology

proliferation

and differentiation in mouse preosteoblast cells

(MC3T3-E1).       Methods       The morphologies of the random (bad-oriented) and aligned (well-oriented) PCL/COL nanofiber scaffolds were observed by scanning electron microscopy (SEM). MC3T3-E1 cells were cultured on the 2 kinds of nanofiber scaffolds to study the effects of fiber orientation on cell morphology through SEM and laser confocal microscopy (LSCM). The cell proliferation and numbers of viable cells were observed by cell counting kit-8 (CCK-8). Real-time RT-PCR was used to testify the mRNA expression of osteogenic markers

such as collagen type Ⅰ (COL Ⅰ)

alkaline phosphatase (ALP) and osteocalcin (OCN) to study the sense and response of MC3T3-E1 cells to different oriented scaffolds.       Results       The random PCL/COL nanofibers showed isotropic fiber alignments

the aligned nanofibers exhibited anisotropic fiber alignments. The difference of the fibers diameter was not statistically significant between the 2 scaffolds (586±239 vs 625±155 nm

P

0.05). SEM and LSCM showed that MC3T3-E1 cells exhibited a star-like shape and irregular cytoskeletons on the random nanofibers

while these cells on the aligned nanofibers had a prolate shape and elongated cytoskeletons along the aligned fibers. CCK-8 results showed that there was no significant difference in the proliferation rates of the cells on the random and aligned nanofiber scaffolds at 1

3

5 and 7 d (

P

0.05). Real-time PCR demonstrated the differences in expression profiles of osteogenic markers in MC3T3-E1 cells cultured on 2 scaffolds. The expression levels of COL Ⅰon random and aligned scaffolds were not significantly different (

P

0.05)

while ALP and OCN expression levels were significantly elevated on the random scaffold compared with the aligned scaffolds (

P

0.05).       Conclusion       The random and aligned PCL/COL nanofiber scaffolds provides a good microenvironment for cell growth and proliferation

compared with the aligned PCL/COL nanofibers scaffolds. The random PCL/COL nanofiber scaffolds is more benefici

al for the osteogenic differentiation of MC3T3-E1 cells which may have potential applications in bone tissue engineering.