Enhance Of Proliferation And Differentiation Of Mesenchymal Stem Cells By Basic Fibrous Groth Factor Controlled Release Nanoparticles

Battle wound and various kinds of chronicdiseases such as rheumatic heart disease caused heartvalve defects influence patient's outward appearance and their function. It is significant to repair it to improve patient's quality of life. Therefore, autologous, allogeneic heart valves and some artificial materials have been used in clinical. However, the disadvantages such as supply limited, hard to match and tend to calciy had restricted the development. Tissue engineering uses the principles and methods of engineering and life sciences to repair and reconstruction of tissue defects. Seed cells, the material of scaffolds and microenvironment are key factors in the tissue engineering.In order to investigate the effect of basic fibrous growth factor (bFGF) controlled release hydrogel nanoparticles on the proliferation and differentiation of mesenchymal stem cells. The Dex-GMA-bFGF-NPs were prepared by improved emulsion polymerization method. Their morphology, size and encapsulated ratio were assessed by routine procedure. Dynamic dialysis method was used to determine the release characteristics of dex-GMA-bFGF- NPs in vitro. The secondary culture MSCs were divided into four groups according the different ingredients being added into the DMEM culture medium: free bFGF group (A), blank dex-GMA nanoparticles group (B), dex-GMA- bFGF nanoparticles group (C), nothing group (D).The proliferation of cultured MSCs was measured by using cell counting method, MTT method and flow cytometry. ALP kit was used to evaluate the ALP activity of the MSCs to show the differentiation of the cells by adding the dex-GMA-bFGF-NPs to the DMEM culture medium (C group) or bFGF only (A group). B and D group were taken as the controls. The results were analyzed by statistical analysis software (SPSS11.0). All results show that the shape of Dex-GMA-bFGF-NPs was spherical. The encapsulated ratio was 80.9% and the encapsulated bFGF can be released during 25 days. The in vitro cellular study showed the control release of bFGF from nanoparticles couled promote the profliferation of MSCs.After 14 days,the cell number in groups A,B and C was (21.97±0.25),(12.43±0.13),(27.45±0.78) and (12.03±0.43)×104 cells/ml, with the difference being significant among them (P<0.05) The flow cytometry revealed that the G2/M+S percentage in group C were the highest 4-8 days after plate culture(P<0.05). During the first 3 days, the proliferation and differentiation of BMSCs between group A and B had no significance (P>0.05), but much faster than group C and D. After 5 days, Dex-GMA-bFGF-NPs could enhance BMSCs proliferation and differentiation continually, but bFGF had no enhancement any more, the difference between group A and B become more significant (P<0.05). So we made the conclusion that the bFGF loading dex-GMA hydrogel nanoparticles can release bFGF more than 25 days and promote the proliferation and differentiation of the MSCs through a long period of controlled release of bFGF. Dex-GMA-bFGF-NPs may be an ideal controlled release carrier for bioactive growth factors.