Effect of titanium surface roughness on human bone marrow cell proliferation and differentiation: an experimental study

Abstract

To assess the proliferation and differentiation of human bone marrow-derived cells cultured on titanium surfaces with different roughness characteristics. Cells obtained from the iliac crest of an adult human donor were routinely processed and cultured on titanium surfaces of varying roughness, according to their preparation method: polishing only (smooth surface) and polishing followed by etching with HF/HNO3 for 15 and 30 minutes (rough surfaces). Surfaces were assessed using scanning electronic microscopy and profilometry. Titanium disks etched with acid for 15 minutes allowed greater cell proliferation in all culture periods. The level of osteopontin and osteocalcin expression was increased in both acid-etched groups, which indicates an advanced stage of differentiation of cells into osteoblasts. Increased surface roughness accelerates the differentiation of undifferentiated mesenchymal cells into osteogenic lineage cells, but does not necessarily favor cell proliferation. An intermediate surface roughness of 0.5microm (acid etching for 15 minutes) favors both initial and final cell responses.