Osteoblast response and calcium deposition on phospholipid modified surfaces

In this study, the effect of calcium phosphate complexed phospholipid (Ca-PL-PO4) coatings on solid surfaces on the in vitro calcium (Ca) deposition and on the osteoblast responses was evaluated. Commercially available phospholipids were converted to their Ca-PL-PO4, and were coated on glass Petri dishes. The coated dishes were immersed in the simulated body fluid for up to 14 days under sterilized conditions at 37 degrees C, and the amount of calcium (Ca) deposited was quantified. Similarly, by measuring the alkaline phosphatase specific activity, the differentiation of osteoblast precursor cells were evaluated after seeding the cells on Ca-PL-PO4 coated cell culture plastics. It was observed that all Ca-PL-PO4 enhanced Ca deposition on coated surfaces. The, polar head group of phospholipids in coated surfaces was observed to have an influence on the Ca deposition as well as the osteoblast differentiation. Among the phospholipids evaluated, phosphatidylserine (Ca-PS-PO4) exhibited the strongest calcium deposition and more enhanced alkaline phosphatase specific activity. It was therefore concluded from this study that Ca-PS-PO4 surface modification may be an alternative method for enhancing bone-implant interactions.