Fibrochondrocyte Behavior on Titanium Dioxide Nanofilms

The temporomandibular joint (TMJ) disc is an integral joint component promoting smoothness of movement and absorbing shock and stresses accompanying joint function. Disc derangements of the TMJ are a rising health concern. Bioengineering tissue scaffolds with enhanced cell supportive surfaces may offer a promising alterative to current treatment modalities. OBJECTIVE: Growth and functionality of bovine TMJ discal fibrochondrocytes (FCs) cultured on titanium dioxide (TiO2) nanoparticle substrates was examined as a potential system for engineering a biomaterial for discal repair. METHODS: Nanoparticle thinfilms were produced using layer-by-layer (LBL) nanoassembly with TiO2 acting as the terminating layer on each substrate. Fibrochondrocytes were cultured on 5, 10, 15 and 20-layered TiO2 nanosubstrates and treated with TGFb (10 ng/ml) over a 14 day experimental period. Control cultures were grown as monolayers on glass and received no treatment. Growth and functionality of FCs on different layered substrates, in the presence or absence of TGFb, was assessed using cell proliferation assays, protein assays, and immunocytochemical techniques for extracellular matrix (ECM) expression (collagen types I and II, aggrecan and decorin). RESULTS: The addition of TGFb stimulated FC proliferation to some degree but enhanced synthesis of types I and II collagen and aggrecan in all cultures. Thicker nanofilms, with an increased surface roughness, promoted increased FC proliferation and ECM synthesis. Immunocytochemical assays and protein assays showed an increased production of aggrecan and collagen types I and II on treated nanofilms with an earlier onset as compared with FCs grown on glass and on untreated nanofilms. CONCLUSION: TiO2 nanothin films promoted enhanced cell adhesion, proliferation and ECM synthesis. TGFb, in conjunction with thicker thinfilms, had a pronounced stimulatory effect on FC ECM synthesis. TiO2 thinfilms, used as a surface modification technique with a bioengineered scaffold, may hold promise as method for treating TMJ disc disorder.