Extracellular Matrix Molecules Improve Periodontal Ligament Cell Adhesion to Anorganic Bone Matrix

Abstract

Bone replacement graft (BRG) materials are used in periodontal therapy to encourage new bone formation. Extracellular matrix proteins may improve periodontal ligament fibroblast (PDLF) attachment to these materials. We demonstrate that PDLFs adhere well to the extracellular matrix (ECM) proteins fibronectin, vitronectin, laminin, and collagen types I and IV. PDLFs express numerous ECM-receptor integrin subunit transcripts (α1, a2, a3, a4, a5, α11, (31, β5, and (38) at high levels, while others (a6, a9, aV, β3, (36, and β7) are expressed at reduced levels. Despite the fact that PDLFs adhere well to fibronectin and collagen type IV bound to plastic, and express integrins that recognize these ECM proteins, they do not attach well to anorganic bovine bone matrix (ABM) coated with these same proteins. However, the addition of vitronectin, laminin, or collagen type I to these same ABMs substantially increased PDL cell attachment. Thus, selective use of ECM proteins may be clinically useful in promoting cell attachment to ABM and bone regrowth. Abbreviations: extracellular matrix (ECM), periodontal ligament (PDL), bone replacement graft (BRG), anorganic bovine bone matrix (ABM), reverse transcriptase polymerase chain-reaction (RT-PCR).