Attachment, spreading, and adhesion strength of human bone marrow cells on chitosan

The successful integration of an orthopedic implant into bone depends on the mechanisms at the tissue-implant interface and mostly on the osteoblast attachment phenomenon. Chitosan has emerged as an attractive biomacromolecule favoring osseointegration. In this study highly deacetylated chitosan coatings, with roughness of about 1 nm, were bonded to glass surfaces via silane-glutaraldehyde molecules. Human osteoblasts were used to study the development of attachment during the first 60 min. Chitosan favored the number of the attached cells compared to the uncoated surfaces for 30 min seeding time (t (s)). For t (s) up to 60 min the attached cell area was almost 210% significantly higher on the chitosan surfaces, indicating an enhanced spreading process. To determine the cell attachment strength, a micropipette aspiration method was used, where the value of the term I = ∫Fdt is representative of the single cell attachment-adhesion procedure and quantitatively reflects the strength evolution during attachment: F equals the detaching force applied on the cell. The results showed higher strength values on the chitosan surfaces. The findings reinforce the favorable environment of the biomacromolecule for the osteoblast and the new approach regarding the quantitatively evaluation of adhesion provides important contribution for the study of cell-material interaction, especially during the crucial first phase of cell attachment.