Objective: To study the effect of substrate stiffness on proliferation, migration of fibroblast and integrin β(1) expression in fibroblast.
Methods: Fibroblasts were inoculated on silicon substrate with stiffness of (16.2 ± 0.5), (19.8 ± 1.1), and (200.1 ± 2.6) kPa. After being cultured for 5 days or 6 days, cells were counted and cell proliferative activities (recorded as absorbance value) were assessed with methyl thiazolyl blue (MTT). After being cultured for 3 days, cell cycle was detected and proliferation index (PI) was calculated. The cell scratch test was used for determination of cell migration rate on post scratch day (PSD) 0 (the day of scratch), 1, 2, and 3. After being cultured for 2 days, the expression of integrin β(1) was determined by flow cytometry with fluorescence. Data were processed with one-way analysis of variance.
Results: (1) The proliferative speed and proliferative activity of fibroblasts were all increased along with the increase in substrate stiffness. PI of fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5), (19.8 ± 1.1), and (200.1 ± 2.6) kPa was respectively 24.8%, 27.4%, 32.4%. On PSD 2, migration rate of fibroblasts inoculated on silicon substrate with stiffness of (19.8 ± 1.1) and (200.1 ± 2.6) kPa was respectively (91.4 ± 5.1)%, (100.0 ± 1.3)%, which were higher than that of fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5) kPa [(55.8 ± 6.8)%, with F value respectively 3.5, 4.0, P values all below 0.01]. (3) The expression rate of integrin β(1) in fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5) kPa was the lowest (43.22%), and that in fibroblast inoculated on silicon substrate with stiffness of (200.1 ± 2.6) kPa was the highest (81.26%).
Conclusions: Substrate stiffness may have a great effect on proliferation and migration of fibroblast during the process of wound healing and scar formation, which can be related to regulation of integrin β(1) expression.