hMSC proliferation on PCL/gelatin (the ratio: 100/0, 75/25, and 50/50) composite electrospun scaffolds with and without craterlike structures after 4 hours, 1 day, and 7 days of cell seeding measured by an MTS assay (*p < 0.05 vs. 100/0 PCL/gelatin WO at 1 day, **p < 0.01 vs. 100/0 PCL/gelatin WO at 1 day, #p < 0.05 vs. 100/0 PCL/ gelatin WC at 1 day, ###p < 0.001 vs. 100/0 PCL/gelatin WC at 1 day, +p < 0.05 vs. 100/0 PCL/gelatin WO at 7 day, ++p < 0.01 vs. 100/0 PCL/ gelatin WO at 7 day, ×××p < 0.001 vs. 100/0 PCL/gelatin WC at 7 day).