MG-63 cells proliferation following various types of mechanical stimulation on cells by auxetic hybrid scaffolds.
BACKGROUND
Mechanical properties and cyto-compatibility of a composite scaffold which possessed negative (-) Poisson's ratio (NPR) was investigated for effective load transfer from auxetic scaffold to cell.


METHODS
Organic/inorganic composite scaffolds were prepared by mixing hydroxyapatite (HA) to poly(lactide-co-glycolide) (PLGA). To induce NPR in composite scaffold, 3-directional volumetric compression was applied during the scaffold fabrication at adequate temperature(60°C). The pore size of scaffold ranged between 355-400 μm.


RESULTS
Poisson's ratios of NPR scaffolds and control scaffolds were -0.07 and 0.16 at 10 % strain. For stable physical stimulating to loaded cells, ceramic/polymer composite scaffold was prepared by incorporating HA in PLGA to increase mechanical strength. Compressive strength of the HA/PLGA composite scaffold (15 wt. % HA to PLGA) was about 21.7 % higher than that of PLGA-only scaffold. The recovery rates of the NPR composite scaffold after applying compression in the dry and wet states were 90 % and 60 %, respectively. Also the composite scaffold was shown to have better hydrophilicity (61.9°) compared to the PLGA-only scaffolds (65.3°). Cell proliferation of osteoblast-like cell line (MG-63) in the composite scaffold was 20 % higher than in PLGA-only scaffold at static compressive stimulation. For dynamic compressive stimulation (15 min cyclic interval), cell proliferation in the composite scaffold was 2 times higher than that of in PLGA-only scaffold. In conclusion, NPR composite (HA/PLGA) scaffold was effective in isotropic compressive load delivery for osteogenic cell proliferation.


CONCLUSIONS
This composite scaffold with stimulation can be used as tissue engineered scaffold and dynamic cell culture system for bone tissue regeneration.
Department of Biomedical Engineering, Inje University, Obang-Dong, Gimhae, Gyeongnam 621-749 South Korea.
Hong Jin
HJ
Choi
Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37212 USA.
Jun Jae
JJ
Lee
Department of Biomedical Engineering, Inje University, Obang-Dong, Gimhae, Gyeongnam 621-749 South Korea.
Jung Bok
JB
Lee
Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37212 USA.
Hak-Joon
HJ
Sung
Department of Biomedical Engineering, Inje University, Obang-Dong, Gimhae, Gyeongnam 621-749 South Korea.
Jung-Woog
JW
Shin
Department of Biomedical Engineering, Inje University, Obang-Dong, Gimhae, Gyeongnam 621-749 South Korea.
Ji Won
JW
Shin
Department of Biomedical Engineering, Inje University, Obang-Dong, Gimhae, Gyeongnam 621-749 South Korea.
Yanru
Y
Wu
Department of Biomedical Engineering, Inje University, Obang-Dong, Gimhae, Gyeongnam 621-749 South Korea.
Jeong Koo
JK
Kim
Dynamic compression stimulation; Hydroxyapatite; Negative Poisson’s ratio; Osteoblast; PLGA