Lithium chloride prevents glucocorticoid-induced osteonecrosis of femoral heads and strengthens mesenchymal stem cell activity in rats / 中华医学杂志(英文版)

BACKGROUND@#Accumulating evidence suggests that lithium influences mesenchymal stem cell (MSC) proliferation and osteogenic differentiation. As decreased bone formation in femoral heads is induced by glucocorticoids (GCs), we hypothesized that lithium has a protective effect on GC-induced osteonecrosis of femoral heads (ONFH).@*METHODS@#A rat ONFH model was induced by methylprednisolone (MP) and the effect of lithium chloride on the models was evaluated. Micro-computed tomography (CT)-based angiography and bone scanning were performed to analyze the vessels and bone structure in the femoral heads. Hematoxylin and eosin and immunohistochemical staining were performed to evaluate the trabecular structure and osteocalcin (OCN) expression, respectively. Bone marrow-derived MSCs were isolated from the models, and their proliferative and osteogenic ability was evaluated. Western blotting and quantitative real-time polymerase chain reaction were performed to detect osteogenic-related proteins including Runx2, alkaline phosphatase, and Collagen I.@*RESULTS@#Micro-CT analysis showed a high degree of osteonecrotic changes in the rats that received only MP injection. Treatment with lithium reduced this significantly in rats that received lithium (MP + Li group); while 18/20 of the femoral heads in the MP showed severe osteonecrosis, only 5/20 in the MP + Li showed mild osteonecrotic changes. The MP + Li group also displayed a higher vessel volume than the MP group (0.2193 mm3vs. 0.0811 mm3, P < 0.05), shown by micro-CT-based angiography. Furthermore, histological analysis showed better trabecular structures and more OCN expression in the femoral heads of the MP + Li group compared with the MP group. The ex vivo investigation indicated higher proliferative and osteogenic ability and upregulated osteogenic-related proteins in MSCs extracted from rats in the MP + Li group than that in the MP group.@*CONCLUSIONS@#We concluded that lithium chloride has a significant protective effect on GC-induced ONFH in rats and that lithium also enhances MSC proliferation and osteogenic differentiation in rats after GC administration.

Preparation and characterization of a novel injectable strontium-containing calcium phosphate cement with collagen / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>To develop a novel injectable strontium-containing calcium phosphate cement with collagen.</p><p><b>METHODS</b>A novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated.</p><p><b>RESULTS</b>The results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained (48.0 MPa ± 2.3 MPa); histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth.</p><p><b>CONCLUSION</b>A novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.</p>

Isolation, culture and purification of olfactory ensheathing cells from human fetal olfactory mucosa / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the method for obtaining olfactory ensheathing cells from human fetal olfactory mucosa by cell culture for selective adhesion in the presence of neurotrophin-3 (NT3) and low-concentration serum.</p><p><b>METHODS</b>The olfactory ensheathing cells were cultured alternatively in DMEM/F12 culture medium containing 10% fetal bovine serum (FBS) and the medium containing NT3 and 2.5% FBS every 72 h. The cells were observed for morphological changes and identified using immunocytochemistry with P75NTR and GFAP, and the cell purity was estimated.</p><p><b>RESULTS</b>The olfactory ensheathing cells from human fetal olfactory mucosa were positive for P75(NTR) and GFAP, and in in vitro culture, the cells exhibited dipolar or tripolar appearance with long thin neurites. On the 9th day of cell culture, the purity of the olfactory ensheathing cells reached about 83%.</p><p><b>CONCLUSION</b>The olfactory ensheathing cells can be obtained by in vitro culture for selective adhesion in the presence of NT3 and low-concentration serum.</p>