Surface topography has marked effects on cell behavior. Generally, cell adhesion is greater on rough surfaces than on smooth surfaces, but the actual rate of adhesion depends on the type of cell. Contact guidance, the phenomenon in which cells align along grooves of the substrate, is one example of surface topography controlling

cell behavior [1] and [2]. Surface roughness alters osteoblast proliferation, differentiation, and matrix production in vitro, and plays a role in determining the phenotypic expression of cells in vivo [3] and [4]. Surface topography is controlled by machining, blasting, acid etching, or laser lithography. Surface physico-chemistry involves the adsorption of proteins, bacteria, and cells on biomaterials. This adsorption reflects the affinity between two substances. Adsorption characteristics http://www.selleckchem.com/screening/epigenetics-compound-library.html are primarily

influenced by hydrophobicity (wettability), which can be determined by measuring the surface energy (hydropathy index), and Pifithrin-�� ic50 electrokinetic potential (zeta potential, isoelectric point), which reflects surface electric charges according to the isoelectric point (x-axis in Fig. 1) and hydropathy index (y-axis in Fig. 1) of the amino acids in the protein ( Fig. 1). A cold plasma-surface modification (Fig. 2) is suitable for change in surface physico-chemistry, which involves dry process including ion implantation, ion plating, ion sputtering, ion beam dynamic mixing, plasma polymerization and plasma treatment with partly ionized gases, which is generated in a high-voltage electric field in a low pressure. This approach is superior in that it is environmentally pollution-free, it yields safe products, and good quality control can be maintained, thus ensuring defect-free films. In this process, substrates and targets are placed in a vacuum chamber, a vacuum is created and the coating materials

are then deposited onto the substrates in a cold plasma atmosphere. Fig. 3 shows the relationship between film thickness and energy of atoms, which is related to adherence of coatings, in various coatings produced by ion beam techniques. It can be seen that the thinner the coatings, the higher the degree of adherence. Surface modification using a cold plasma Farnesyltransferase has advantages; 1) Thin and porosity-free coatings, 2) Control of surface energy and surface electric charge, 3) Introduction of functional groups, 4) Cleaning of surfaces, 5) Graft-polymerization and adhesion, 6) Etching and micro-patterning and 7) Application for drug delivery system. This review will describe the surface modification of titanium implant for bio-functionalization (Fig. 4) [5] related to the surface topography and physico-chemistry of different host tissues. The integration of bone tissue with an implant requires a rough surface topography that maximizes the area in contact with the bone and allows the contact guidance for the development of osteoblasts.