| Summary: | The long-term success of an implant is governed to a large extent by its surface properties
that will influence cell behaviour reflected in their migration, attachment, morphology, and
proliferation. Also, the integration of the surrounding tissue around the implant is dependent on
the reorganization of the surrounding E C M in a morphogenetic manner. It is of great importance
to understand the interactions of cells with the implant surface, with the E C M , and with other
cells so that failure of implanted devices can be avoided.
This thesis examined the in vitro process of connective tissue reorganization and how it
was affected by the topography of substratum using the following techniques: substrata
micromachining, collagen gels as substrata, Light Microscopy, Polarized Light Microscopy (PSR
stained collagen), Confocal Laser Scanning Microscopy (PI stained nuclei), and Time Lapse
Video Microscopy.
This thesis measured the cell orientation on 6 types of surfaces: T C dish, smooth
titanium, 30IP175S, 3G30P, 30G40P, and 30G175P grooved titanium. The effect of collagen
matrix on cell orientation under three conditions (Control, CellGel, and Gel) was determined.
Also, the effects of cell distribution within a gel on the gel contraction was examined. The
distribution of cells between collagen and titanium surface under the CellGel and Gel conditions
was compared. Gel penetration into grooves was determined.
The following observations and conclusions were made. It appeared that collagen gel did
not penetrate into the grooves of a grooved surface. In the absence of collagen gel, cells formed
patchworks of parallel arrays on TC dish, smooth, and pitted surfaces. Cells aligned with the
grooves on grooved surfaces. The presence of collagen matrix atop a stable culture (CellGel)
disrupted the orientation of cells leading to a lesser alignment. The presence of collagen matrix
around the cells (Gel), resulted in lowest level of alignment. The collagen fibers seemed to
conform with the orientation of cells and also become aligned with the grooves. Orientation of
cells within the three dimensional matrix was not affected by either the surface topography or the
collagen fibers. Cells were found to be essential for the gel contraction. When most cells were
found at the bottom of the gel throughout the experiments (CellGel) a thin sheet of
"orthogonally" arranged fibers was formed after a period of 3-4 weeks. When cells were
distributed throughout a matrix (Gel) a "Ring" of fibers was created. Cells were not only able to
leave titanium surface and make new attachments with the overlaying matrix (CellGel) but also
to leave a collagenous matrix and settle on titanium surface (Gel). The CellGel condition that
leads to a production of a continuous sheet of "tissue" can be used to coat a device prior to
implantation to improve a long term success of such a device.
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