INTRODUCTION TO PROCESSING OF BIOMATERIALS - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 256

Figure 8.7. Tissue biomaterial interactions: events occurring at the tissue biomaterial inter-
face at varying time and length scales.
can take as long as few days [10]. The fast initial response is generally governed
by the surface chemistry of the implanted biomaterial/device. Surface chemistry
modulates adhesion and signaling of cells which in turn controls phenotype and
cell function while degree of adhesion modulates proliferation and differentia-
tion [9]. Therefore, alterations on the surface of a biomaterial can modulate cell
behavior/function, which in turn governs the tissue response to the implant/
device. Hence, it is important to understand cell-biomaterial surface interaction
to enable better integration of the implant/device.
Cell behavior/function such as adhesion, cell morphology, migration, orienta-
tion, and differentiation are infl uenced by biomaterial surface topography and
surface chemistry [71]. This has been evidenced in the native environment wherein
fi brous proteins present in the ECM of tissue have diameters in the micrometer
range, while mineral particles present in the ECM of bone tissue have diameters
in the nanometer range and both of these scales (fi ber - micrometer and mineral
particle-nanometer) have a different effect on cell behavior, though the exact
mechanism is still not well understood. Therefore, surface chemistry and surface
topography [72, 73] are important design considerations during the development
of a biomaterial-based implant to improve integration and compatibility.
8.4.1.2 Types of Surface Modifi cation [1, 7, 10, 74]
8.4.1.2.1 SURFACE CHEMISTRY. To date several ways of modifying surface
chemistry have been explored [1, 7, 9, 15]. Changes in surface chemistry can pro-