Chitosan supports the initial attachment and spreading of osteoblasts preferentially over fibroblasts

The aim of this study was to determine chitosan's effect on osteoblast and fibroblast cell attachment. Mouse MC3T3-E1 osteoblasts and 3T3 fibroblasts were grown in the presence of serum on two commercially available chitosans, Chitosan-H (CH) and Protasan CL212 (PR). Cell attachment and immunofluorescent analysis at various time points were done to analyze initial phenotypic profiles. At 1h, significantly (P<0.05) fewer fibroblasts attached to CH or PR than serum-coated substrates. Osteoblast attachment to the same biopolymers at 1h was significantly greater than those seen with fibroblasts. At 24 h, levels of cell attachment for fibroblasts to both CH and PR significantly increased and were similar to levels seen in osteoblast cultures at both 1 and 24 h. Morphologically, immunofluorescent analysis showed that osteoblasts plated on the biopolymers were attached and beginning to spread at 1h, whereas fibroblasts appeared more rounded. At 24 h, fibroblasts plated on CH or PR revealed a heterogeneous population of round and semi-spread cells. In comparison, osteoblasts displayed phenotypes that were well spread with a developed cytoskeleton. These results suggest that CH and PR support the initial attachment and spreading of osteoblasts preferentially over fibroblasts, and that manipulation of the biopolymer can alter the level of attachment and spreading.