MG-63 osteoblast-like cell proliferation on auxetic PLGA scaffold with mechanical stimulation for bone tissue regeneration

Background: Auxetic scaffolds (experimental) was fabricated by using poly(D, L-lactic-co-glycolic acid), 50:50, (PLGA) for effective bone cell proliferation with mechanical stimulation. Methods: Negative Poisson's ratio in scaffold, 3-directional volumetric compression was applied during the scaffold fabrication at adequate temperature ($60^{\circ}C$). The pore size of scaffold ranged between 355 and $400{\mu}m$. Results: The porous morphology of the prepared auxetic scaffolds had shown partially concave and dent shapes in SEM image as expected. The lowest Poisson's ratios of experimental group was -0.07 at $60^{\circ}C/10min$. Compressive strength of experimental group was shown about 3.12 times higher than control group (conventional scaffold) in dry state at $25^{\circ}C$. The compressive strengths of both groups were tended to be decreased dramatically in wet state compared to in dry state. However, compressive strengths of experimental group were higher 3.08 times and 1.88 times in EtOH/PBS ($25^{\circ}C$) and EtOH/PBS/DMEM ($37^{\circ}C$) than control group in wet state, respectively. Degradation rate of the scaffolds showed about 16 % weight loss in 5 weeks. In cell attachment test, experimental group showed 1.46 times higher cell proliferation than control group at 1-day with compressive stimulation. In 3-day culture, the experimental group showed 1.32 times higher than control group. However, there was no significant difference in cell proliferation in 5-day cultivation. Conclusion: Overall, negative Poisson's ratio scaffolds with static mechanical stimulation could affect the cell proliferation at initial cultivation time.