[Osteogenic expression of rat mesenchymal stem cell on collagen and 20α-hydroxycholesterol loaded on the apatite of titanium].

PURPOSE

To investigate the effect of composite layers loaded with 20α-hydroxycholesterol and collagen on the surface of apatite-coated Ti substrates on osteogenesis of rat bone marrow mesenchymal stem cells (BMSCs).

METHODS

BMSCs proliferation was quantitatively assessed by cell counting kit-8 (CCK-8). The early osteogenic expression of BMSCs on composite layers was evaluated by alkaline phosphatase (ALP) activity. The expression of osteocalcin (OC) and collagen TypeⅠ (Col Ⅰ) was evaluated by Western blot. The difference between the different groups was analyzed using SPSS 17.0 software package.

RESULTS

CCK-8 results revealed that simultaneous loading of Col Ⅰ and HC on biomimetic apatite significantly promoted cell proliferation, while HC had no effect on cell proliferation. Dual loading of Col and HC onto apatite stimulated osteogenic differentiation in BMSCs, especially during the early stage. In addition, individual loading of HC seemed to be more efficient than collagen in promoting ALP activity in BMSCs. Dual loading of Col and HC synergistically promoted the expression of OC and ColⅠ, which were the marker of late osteogenic differentiation. HC had no positive effect on the expression of OC and Col Ⅰ.

CONCLUSIONS

Dual loading of collagen and 20α-hydroxycholesterol on apatite-coated titanium substrates had favourable biocompatibility and synergistically promoted osteogenic expression.