Effect of Platelet-rich Plasma on the Proliferation and Osteogenic Differentiation of Human Mesenchymal Stem Cells on Distinct Calcium Phosphate Scaffolds: The Specific Surface Area Makes a Difference

The in vitro effect of platelet-rich plasma (PRP) on cell loading, proliferation, and osteogenic differentiation of human mesenchymal stem cells (MSC) is assessed on distinct resorbable and synthetic calcium *Author to whom correspondence should be addressed. E-mail: [email protected] Figures 1–4 and 6 appear in color online: http://jba.sagepub.com JOURNAL OF BIOMATERIALS APPLICATIONS Volume 23 — September 2008 169 0885-3282/08/02 0169–20 $10.00/0 DOI: 10.1177/0885328207088269 SAGE Publications 2008 Los Angeles, London, New Delhi and Singapore phosphate scaffolds. A high specific surface area scaffold composed of calciumdeficient hydroxyapatite (CDHA; 48m/g) is compared with one made out of b-tricalcium phosphate (b-TCP; surface area50.5m/g). Fivefold concentrated fresh PRP is applied to scaffolds loaded with 2 10 MSC (n1⁄4 5). These constructs are kept in a medium with osteogenic supplements for 3 weeks. The addition of PRP leads to a higher cell loading efficiency of MSC on CDHA ( p1⁄4 0.0001), that reaches the values of b-TCP. Proliferation over 21 days is improved by PRP both on CDHA ( p1⁄4 0.0001) and b-TCP ( p1⁄4 0.014) compared to MSC/calcium phosphate composites. Without the addition of PRP, CDHA has a lower cell loading efficiency ( p1⁄4 0.0001) and proliferation ( p1⁄4 0.001) than b-TCP. The ALP activity is higher in the MSC/ceramics groups than in the monolayer controls ( p50.05). The addition of PRP does not significantly affect ALP activity. However, ALP activity varies considerably within the cell donors and different PRP-pools ( p1⁄4 0.001), while the cell numbers do not vary within these two parameters. PRP generates a positive effect on the loading efficiency of MSC on the high specific surface scaffold CDHA that thereby reaches the loading efficiency of b-TCP. PRP improved proliferation, but its osteogenic properties on both calcium phosphate scaffolds are weak.