ABSTRACT
Objective:
To prepare the
lithium-doped poly-
glycerol sebacate (PGS-Li) scaffold using the specific effects of
lithium ions and the excellent performance of PGS, and to provide the basis for its application prospects in
cementation tissue engineering scaffold.
Methods:
The scaffolds were divided into two groups.The PGS-Li scaffolds prepared by adding
lithium phosphate during the PGS cross-linking process were used as PGS-Li group, and the PGS scaffolds synthesized by the equal-purification of sebacic
acid and
glycerol were used as PGS group.The
molecular weights of the scaffolds in two groups were determined by
gel permeation chromatography.The structures of the scaffolds in two groups were analyzed by
fourier transform infrared spectroscope.The surface morphology and the
porosities and the pore sizes of the scaffolds in two groups were observed by scanning
electron microscope.
X-ray photoelectron (XPS) spectroscope and inductively coupled
plasma optical emission spectrometer were used to determine the Li ion contents in the scaffolds in two groups.Thermogravimetric analyzer was used to analyze the thermal stabilities of the scaffolds in two groups.Contact angle measuring instrument was used to compare the
hydrophilicities of the scaffolds in two groups.
In vitro weight loss test was used to determine the degradation rates of the scaffolds in two groups.The OCCM-30cells were divided into experimental group (added with PGS-Li scaffold extract) , PGS group (added with PGS scaffold extract) and blank
control group (added with DMEM
culture medium) .MTT assay was used to detect the proliferation activities of
cells in various groups at different
time (24, 48and 72h) ;the
cell morphology was observed by calcein-AM
staining.
Results:
The
gel permeation chromatography results showed that the
molecular weight of the PGS-Li scaffold was slightly larger than that of the PGS scaffold.The specific
absorption peak of
phosphate was detected in the fourier infrared spectrum of the PGS-Li scaffold.The scaffolds in two groups had irregular three-dimensional network structures under scanning
electron microscope, and the pore size was 20-160μm, the
porosity of PGS scaffold was (53.92±2.18) %, and the
porosity of PGS-Li scaffold was (53.58±1.73) %, there was no statistical difference between two groups (P>0.05) .The XPS results showed that a peak appeared at 54.9eV in PGS-Li group, which coincided with the Li 1s binding energy, while the inductively coupled
plasma emission spectrometer results showed that the Li ion content in the PGS-Li scaffold was 0.084%.The thermogravimetric
analysis results showed that PGS-Li scaffolds began to degrade at a higher
temperature and ceased at a lower
temperature compared with PGS scaffolds.The contact angle measurement results indicated that both the materials were hydrophilic materials;the contact angle of PGS scaffold meterial was 78.26°±2.00°, and the contact angle of the PGS-Li scaffold material was 69.78°±1.15°;there was statistical difference between two groups (P<0.05) .The
in vitro degradation experiments showed that the degradation rate of PGS-Li scaffolds was faster than that of PGS scaffolds.The proliferation activity of OCCM-30cells in PGS-Li group had no significant difference compared with PGS group and blank
control group (P>0.05) .The calcein-AM
staining results showed the green
fluorescence in the OCCM-30cells in PGS and PGS-Li groups, and there were no significant changes in the morphology of
cementoblasts.
Conclusion:
PGS-Li scaffolds have
similar composition and structure to PGS scaffolds, and have better performance in
hydrophilicity and thermal stability.PGS-Li scaffolds have no effect on the proliferation of
cementoblasts and have broad application prospects in
cementum tissue engineering.