Influence Of Surface Microstructure Of Titanium On The Biological Behaviour Of Rat Osteoblasts And Human Monocytes

Purpose:The purpose of the study was to investigate the effects of surfacetopography of titanium on proliferation of rat osteoblasts and to study the relation of surface topography of titanium and viability, adhesion and cytokine secretion of human monocytes. So provides more information of fundamental research concerning the interaction of titanium implant-bone interface and surface modification of titanium implants. Materials and methods:1. Treat the pure titanium plates with SiC paper-grinding, acid-etching, 50⁶3um Al₂O₃ blasting, sandblasting and large-grits acid-etching, labeled as SiC group, SiC+F group, No.63 group and 63+F group, respectively. Surface topography was observed by SEM and parameter Ra was used to describe the surface roughness.2. Culture primary osteoblasts of rat and seed the 4th osteoblasts on the treated titanium plates in vitro. MTT was given to the cultured cells during one week and the rat osteoblasts' proliferation was estimated.3. Isolate and identify monocytes from human peripheral blood of healthy donors. MTT was used to assess the viability and SEM was given to evaluate the adhesion of human monocytes co-cultured with titanium plates. The TNF- a and IL-1 P content in the supernatants of culture medium at 6h, 24h, 72h and 7d was quantified by ELISA. ANOVA was used to analyze the outcome statistically(/?<0.05).Results:1. The titanium plates demonstrate four different surface topography. The parameter of Ra of SiC group, SiC+F group, No.63 group and 63+F group is 0.1582±0.0221um, 0.2071 ±0.0330um, 0.3448±0.0647um, 0.2424 ±0.0324um, respectively.2. Osteoblasts' proliferation is higher on SiC group, which has regular grooved surface topography and No.63 group, which has the roughest surface.3. Viability and adhesion of human monocytes is different on different surface topography of titanium plates. In general, viability of monocytes on No.63 group is the highest. More monocytes adhere to the surfaces of 63+F group and No.63 group. TNF- a and IL-1 3 content in the co-cultured supernatants changes with surface topography and time.Conclusion:1. Different surface treatments can produce different surface topography. The treatment of SLA can produce symmetrical micro-structure with countless pores.2. Surface topography and surface roughness influence proliferation of rat osteoblasts. Regular grooved surface topography and increased surface roughness enhance osteoblasts' proliferation in the cell model, but not insimple linear relation.3. Surface topography modulates viability and adhesion of human monocytes in vitro. Surface roughness may enhance viability of monocytes. Increased surface roughness and porous micro-structure favor monocytes' adhesion. Surface topography also regulates the secretion of TNF- a and IL-1 P , while surface-dependent cytokine secretion is very complex.