Ke. Healy et al., KINETICS OF BONE CELL ORGANIZATION AND MINERALIZATION ON MATERIALS WITH PATTERNED SURFACE-CHEMISTRY, Biomaterials, 17(2), 1996, pp. 195-208
Materials with spatially resolved chemistries (i.e. patterned surfaces
) have been used to guide and organize the position of mammalian cells
in vitro. A common theme in guiding the spatial distribution of cells
has been the use of patterned alkylsiloxanes, where one region contai
ns an aminosilane and the other an alkylsilane. The regions of the ami
nosilane served as preferential sites for cell attachment and spreadin
g, presumably dependent on the association between cell surface proteo
glycans the positively charged amine. In this study, experiments were
conducted with patterns of N-(2-aminoethyl)-3-aminopropyl-trimethoxysi
lane (EDS) and dimethyldichlorosilane (DMS) to determine the kinetics
of spatial organization of bone-derived cells, and whether initial att
achment and spreading affected the rate of matrix mineralization (i.e.
bone formation) in extended cultures. The bone cells required the pre
sence of serum or preadsorption of serum proteins to the patterned EDS
/DMS surface to organize according to the lithographically defined sur
face chemistry. Time-lapse video microscopy indicated that cells were
randomly distributed over the EDS/DMS surface at the time of plating,
but organized on the EDS regions within 30 min. When cultures were ext
ended for 15 and 25 days, the matrix synthesized by the cells was pref
erentially mineralized on the EDS chemistry. These results demonstrate
the ability of surface chemistry modifications to organize cells and
form mineralized tissue in vitro. The methods employed should have gen
eral value to the engineering of tissues in vitro.