RGD多肽化学修饰聚苯乙烯培养板的细胞相容性研究

目的 考察RGD多肽化学修饰聚苯乙烯培养板细胞相容性研究.方法 采用高锰酸钾硫酸溶液对聚苯乙烯表面进行氧化反应,生成羧基位点；水溶性碳二亚胺活化羧基,接枝明胶、胶原和RGD多肽.用红外光谱、X-射线光电子能谱(XPS)、动态接触角等研究了RGD化学修饰聚苯乙烯的变化,并考察了RGD化学修饰聚苯乙烯后细胞相容性的变化.结果 XPS结果证实了聚苯乙烯表面N原子的引入,RGD是共价键合在聚苯乙烯表面的.动态接触角下降显著,证明修饰表面的亲水性能提高.在修饰后的聚苯乙烯培养板种植入表皮细胞,结果显示提高了细胞的黏附和增殖能力.结论 聚苯乙烯表面进行RGD化学修饰,有利于提高细胞在其表面的黏附和增殖能力,有望为免疫磁珠分离得到的高纯度内皮祖细胞提供良好的培养介质.     

表面修饰对羟基磷灰石修复骨缺损的影响

精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp,RGD）多肽是介导种子细胞与支架材料黏附的多肽链．RGD序列可被固有黏附蛋白受体特异性结合．在生物材料表面自发形成一分子层．为与受体介导的种子细胞提供特异性位点而促进细胞的黏附和分化。笔者旨在应用RGD多肽对羟基磷灰石（hydroxyapatite．HA）材料进行表面修饰处理．以促进骨髓基质干细胞（marrow stromal cells．MSC）在其表面的黏附和生长．为骨组织工程提供一种支架材料的表面修饰手段。     

不同多肽修饰方法对纯钛微弧氧化膜层性能的影响CSCD

背景:理论上推测钛基-微弧氧化陶瓷膜-精氨酸-甘氨酸-天冬氨酸(RGD)序列多肽的结合模式应具较好的力学和生物学性能。目的:观察不同修饰方法固定RGD多肽后,钛基体微弧氧化膜层表面的微观结构和细胞增殖。方法:取纯钛与微弧氧化纯钛试件共90枚,分3种方法固定RGD多肽,分别为RGD多肽物理吸附修饰纯钛组、RGD多肽物理吸附修饰微弧氧化组与RGD多肽化学偶联修饰微弧氧化组,每组30枚。应用荧光显微镜观察3组试件表面接枝效果,采用X射线光电子能谱扫描检测试样表面的RGD多肽含量。将3组试件分别与小鼠骨髓基质细胞培养,光镜观察各时间点的细胞黏附及增殖情况。结果与结论:3组试样表面有大小不一、数量不等的绿色荧光亮点,在单位视野中,RGD多肽化学偶联修饰微弧氧化组荧光最强,提示此组试件接枝了更多的多肽。RGD多肽物理吸附修饰纯钛组试样表面仅含少量或微量多肽,RGD多肽物理吸附修饰微弧氧化组含多肽量居中,RGD多肽化学偶联修饰微弧氧化组含肽量最高。3组试件均无明显的细胞毒性,但RGD多肽化学偶联修饰微弧氧化组细胞生长情况最好。表明化学偶联法可以较好地将RGD多肽固定在含微弧氧化膜层的纯钛试样表面,无明显细胞毒性,有利于细胞的生长增殖。     

不同多肽修饰方法对纯钛微弧氧化膜层性能的影响

背景：理论上推测钛基-微弧氧化陶瓷膜-精氨酸-甘氨酸-天冬氨酸(RGD)序列多肽的结合模式应具较好的力学和生物学性能。 目的：观察不同修饰方法固定RGD多肽后,钛基体微弧氧化膜层表面的微观结构和细胞增殖。 方法：取纯钛与微弧氧化纯钛试件共90枚,分3种方法固定RGD多肽,分别为RGD多肽物理吸附修饰纯钛组、RGD多肽物理吸附修饰微弧氧化组与RGD多肽化学偶联修饰微弧氧化组,每组30枚。应用荧光显微镜观察3组试件表面接枝效果,采用X射线光电子能谱扫描检测试样表面的RGD多肽含量。将3组试件分别与小鼠骨髓基质细胞培养,光镜观察各时间点的细胞黏附及增殖情况。 结果与结论：3组试样表面有大小不一、数量不等的绿色荧光亮点,在单位视野中,RGD多肽化学偶联修饰微弧氧化组荧光最强,提示此组试件接枝了更多的多肽。RGD多肽物理吸附修饰纯钛组试样表面仅含少量或微量多肽,RGD多肽物理吸附修饰微弧氧化组含多肽量居中,RGD多肽化学偶联修饰微弧氧化组含肽量最高。3组试件均无明显的细胞毒性,但RGD多肽化学偶联修饰微弧氧化组细胞生长情况最好。表明化学偶联法可以较好地将RGD多肽固定在含微弧氧化膜层的纯钛试样表面,无明显细胞毒性,有利于细胞的生长增殖。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

RGD多肽在骨组织工程中的研究与应用进展

精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp，RGD）多肽是细胞膜整合素受体与细胞外配体相结合的识别位点，利用其对材料进行表面修饰可提高人工骨材料的生物相容性。文章就RGD的生物学效应、影响RGD生物学效应的因素、RGD在骨组织工程中的应用进行综述，并提出存在的问题。     

表面修饰对羟基磷灰石细胞相容性的影响

探讨精氨酸-甘氨酸-天冬氨酸(Arg-Gly-Asp,RGD)多肽表面修饰对羟基磷灰石(hydroxyapatite,HA)细胞相容性的影响。以骨髓基质干细胞(marrow stromal stem cells,MSCs)复合精氨酸-甘氨酸-天冬氨酸多肽表面修饰的羟基磷灰石或单纯材料培养制备组织工程骨,观察骨髓基质干细胞的粘附和生长情况,检测细胞活力和碱性磷酸酶(alkaline phosphatase,ALP)活性,流式细胞仪分析细胞周期。结果表明:骨髓基质干细胞在材料表面和孔隙内均可粘附和生长,粘附于RGD多肽修饰羟基磷灰石的细胞活力和碱性磷酸酶活性明显高于未经RGD多肽修饰组(P<0.01,P<0.05)。各组细胞周期未见明显变化,未见异倍体细胞。说明RGD多肽表面修饰对HA材料的细胞相容性有明显的优化作用。     

表面修饰羟基磷灰石修复骨缺损骨形态发生蛋白-2的表达

目的了解精氨酸-甘氨酸-天冬氨酸多肽表面修饰的羟基磷灰石（hydroxyapatite,HA）修复节段性骨缺损局部骨形态发生蛋白-2（bone morphogenefic protein-2，BMP-）的表达。方法以骨髓基质干细胞（marrow stromal cels，MSCs）复合Arg-Gly-Asp（RGD）多肽表面修饰的HA或单纯材料培养制备组织工程骨，选择60只新西兰白兔。制作15mm长的桡骨节段性骨缺损模型，根据植入不同的材料分为A、B、C、D组。A组：骨缺损区植入MSCs复合RGD多肽表面修饰的HA培养制备的组织工程骨；B组：骨缺损区植入MSCs复合HA培养制备的组织工程骨；C组：骨缺损区植入RGD多肽表面修饰的HA；D组：骨缺损区植入HA。术后4周取材，行修复区局部BMP-2免疫组化分析。结果术后4周各组骨缺损区均有新骨生成，修复区局部BMP-2表达水平依次为：A〉B〉C〉D（P〈0．05）。结论RGD多肽表面修饰对以HA为支架材料组织工程骨的修复作用有明显优化作用。     

多肽修饰可促进心血管植入材料的内皮化

背景:将多肽类生物信息分子应用于心血管植入材料的表面修饰,人工模拟细胞外基质功能蛋白,可以促进材料的内皮化。目的:回顾近年来关于多肽修饰在心血管植入材料内皮化方面的相关研究,为相关研究提供新的实验思路。方法:应用计算机检索1990年1月至2013年12月PubMed数据库中有关多肽修饰促进材料内皮化方面的研究,检索关键词为"peptides,surface modification,endothelialization",根据纳入排除标准选择,最终选择43篇文献进行综述。结果与结论:选择来源于细胞外基质功能蛋白的短肽表面修饰各类材料,既能促进内皮细胞的黏附,也能避免直接引入天然细胞外基质成分的缺陷。非特异性多肽主要包括RGD和YIGSR等,此类多肽均能促进包括内皮细胞在内多种细胞类型的黏附。特异性多肽主要包括REDV、CAG和SVVYGLR等,这些多肽可选择性促进内皮细胞的黏附和扩展。应用此类多肽表面修饰,可特异性促进材料的内皮化。联合应用几种多肽或联合特异性多肽与其他一些生物信息分子也许是未来应用多肽修饰促进心血管植入材料内皮化的理想方案。     

表面修饰对羟基磷灰石异位成骨的影响

目的 了解精氨酸-甘氨酸-天冬氨酸(Arg-Gly-Asp,RGD)多肽表面修饰对羟基磷灰石(hydroxyapatite,HA)异位成骨的影响.方法 以骨髓基质干细胞(marrow stromal cells,MSCs)复合RGD多肽表面修饰的HA或单纯材料培养制备组织工程骨,将材料植入新西兰白兔脊柱旁的肌肉内,根据植入不同材料分为A、B、C和D组.A组植入MSCs复合RGD多肽表面修饰的HA培养制备的组织工程骨;B组植入MSCs复合HA培养制备的组织工程骨;C组植入RGD多肽表面修饰的HA;D组植入HA.术后4、8周取材,行组织学观察和计算机图像分析.结果 术后4、8周,各组异位成骨组织学评估,A＞B(P＜0.05),C和D组无异位成骨.结论 RGD多肽表面修饰对以HA为支架材料组织工程骨的异位成骨有明显优化作用.     

RGD肽表面修饰壳聚糖载基因纳米粒子的体外实验研究

目的将Arg—Gly—Asp（RGD）肽偶联到壳聚糖（CH）材料表面,并制备成包载质粒DNA的纳米粒子,以未偶连RGD的壳聚糖载质粒DNA作为对照,进行体外内皮细胞转染,观察其是否能提高对内皮细胞的转染效率。方法以1-乙基-3-（3-二甲基氨基丙基）碳化二亚胺盐酸盐（EDC）和N-羟基丁二酰亚胺（NHS）为偶联剂,通过酰胺键将RGD肽偶联到壳聚糖表面,对其进行表征,并以未偶连RGD的壳聚糖作为对照,制备载pEGFP-C1质粒DNA纳米粒子,比较2者对Hy926细胞的转染效率。结果壳聚糖-RGD（CH-RGD）载基因纳米粒子转染Hy926细胞的效率明显高于未偶连RGD的壳聚糖载基因纳米粒子（35．7％VS14．3％．P〈0．001）。结论RGD肽表面修饰壳聚糖载基因纳米粒子可用于体外细胞转染,其对细胞的转染效率明显优于未偶连RGD的壳聚糖。     

Protein adhesion and cell response on atmospheric pressure dielectric barrier discharge-modified polymer surfaces

Gaseous plasma discharges are one of the most common means to modify the surface of a polymer without affecting its bulk properties. However, this normally requires the materials to be processed in vacuo to create the active species required to permanently modify the surface chemistry. The ability to invoke such changes under normal ambient conditions in a cost-effective manner has much to offer to enhance the response of medical implants in vivo. It is therefore important to accurately determine the nature and scale of the effects derived from this technology. This paper reports on the modification of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) using atmospheric pressure plasma processing via exposure to a dielectric barrier discharge (DBD). The changes in surface chemistry and topography after DBD treatment were characterised using water contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy. A marked increase in the surface oxygen concentration was observed for both PMMA and PS. An increase in surface roughness was observed for PMMA, but not for PS. These changes were found to result in an increase in surface wettability for both polymers. Adsorption of albumin (Alb) onto these substrates was studied using XPS and quartz crystal microbalance with dissipation (QCM-D). The rate of adsorption of Alb onto pristine PMMA and PS was faster than that on the DBD-treated polymers. XPS indicated that a similar concentration of Alb occurred on both of the treated surfaces. Deconvolution of the C1s XPS spectra showed that Alb is adsorbed differently on pristine (hydrophobic) compared to DBD-treated (hydrophilic) surfaces, with more polar functional groups oriented towards the upper surface in the latter case. The QCM-D data corroborates this finding, in that a more viscoelastic layer of Alb was formed on the DBD-treated surfaces relative to that on the pristine surfaces. It was also found that Alb was more easily replaced by larger proteins from foetal bovine serum on the DBD-treated surfaces. The viability of human lens epithelial cells on both of the DBD-treated polymer surface was significantly (P < 0.05) greater than on the respective pristine surfaces. In addition, cells that adhered to the treated polymers exhibited a polygonal morphology with well spread actin stress fibres compared with the contracted shape displayed on the pristine surfaces. The results presented here clearly indicate that DBD surface modification has the capability to influence key protein and cell responses.     

Enhanced osteogenic promotion around dental implants with synthetic binding motif mimicking bone morphogenetic protein (BMP)-2

Synthetic receptor binding motif mimicking bone morphogenetic protein-2 (BMP-2) was covalently linked to titanium (Ti) surfaces through a chemical conjugation process. The composition and properties of surface-modified Ti were investigated by XPS as well as by measuring surface radioactivity. In vitro tests were conducted with osteoblast-like MC3T3-E1 cells to assess cell attachment, morphology, and expression of osteogenic marker in the cells grown on modified Ti surfaces. In addition, in vivo experiments involved implants in mandibular bone defects of beagles to evaluate the effect of surface modification on bone regeneration. Results of XPS measurements showed a complete and homogeneous peptide overlayer on the Ti surfaces; the content was further measured by gamma counting. Biological evaluations showed that the biochemically modified Ti samples were active in terms of cell attachment behavior. The MC3T3-E1 cell growth rate, marker protein expression, and alkaline phosphatase production of the peptide-modified surfaces were all higher than those of control Ti. Importantly, the implants in the canine mandibles showed significant increase of bone growth when modified with bioactive peptide, thereby confirming that biochemical modifications of Ti surfaces can enhance the rate of bone healing as compared with untreated Ti surfaces.     

Microwave plasma surface modification of silicone elastomer with allylamine for improvement of biocompatibility

The microwave plasma surface modification of silicone elastomer with allylamine was studied to improve the biocompatibility of the material. An effort was made to clarify the relationships among plasma conditions and surface chemical composition, physical surface properties and biocompatibility of material, as well as the stability of plasma deposited layers. ATR-IR, XPS, Ellipsometry measurements, and contact angle measurements were used to investigate the changes of surface. The stability of plasma-treated silicone surfaces were also studied. The results demonstrated that the temperature and pressure had a strong influence on the chemical composition and structure of surface-deposited layer. The layer was nearly completely crosslinking when the modification was carried out at 60 degrees C. The polymerization speed decreased linearly with temperature. The XPS analysis results showed that the nitrogen element content in the surface layer was very high, especially under low pressure. The nitrogen/carbon ratio in the layer even greatly surpassed that of the allylamine monomer. The wettability of the silicone surface was greatly improved after plasma modification, and increased with the quantities of amine groups. The plasma-treated surfaces have good storage stability in air up to 3 months. The wettability of the surfaces decreased incipiently and then it dramatically increased with further time. The human skin fibroblasts were used to evaluate biocompatibility of plasma-treated silicone elastomer. The surface biocompatibility was greatly improved after modification; human skin fibroblasts adhered quickly and grew well on the modified silicone surface.     

Cellular attachment and spatial control of cells using micro-patterned ultra-violet/ozone treatment in serum enriched media

Ultra-violet Ozone (UVO) modified polystyrene (PS) surfaces were analyzed by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle (CA), optical microscopy (OM) and cell culture experiments. UV/Ozone treatment up to 900 s was used to increase the surface oxygen concentration of PS surfaces from 0% to approximately 35% (unwashed) and 0% to approximately 27% (washed). The observed differences in oxygen concentration, between washed and unwashed surfaces, have been previously attributed to the removal of low molecular weight debris produced in this treatment process. Surface roughness (Rq) is known to affect cellular attachment and proliferation. AFM studies of the UV/Ozone treated PS surfaces show the surface roughness is an order of magnitude less than that expected to cause an effect. UV/Ozone treatment of PS showed a marked change in CA which decreased to approximately 60 degrees after 900 s treatment. The increased attachment and proliferation of Chinese hamster ovarian (CHO) and mouse embryo 3T3-L1 (3T3) cells on the treated surfaces compared to untreated PS were found to correlate strongly with the increase in surface oxygen concentration. Surface chemical oxidation patterns on the PS were produced using a simple masking technique and a short UV/Ozone treatment time, typically 20-45 s. The chemical patterns on PS were visualized by water condensation and the spatially selective attachment of CHO and 3T3-L1 cells cultured with 10% (v/v) serum. This paper describes an easily reproducible, one step technique to produce a well-defined, chemically heterogeneous surface with a cellular resolution using UV/Ozone modification. By using a variety of cell types, that require different media conditions, we have been able to expand the potential applications of this procedure.     

Adhesion of corneal epithelial cells to cell adhesion peptide modified pHEMA surfaces

Epithelialization of a corneal implant is a desirable property. In this study we compared surface modification of poly (2-hydroxyethyl methacrylate) (pHEMA) with the cell adhesion peptides RGDS and YIGSR. Various parameters in the tresyl chloride activation and modification reactions were considered in order to maximize surface coverage with the peptide including tresyl chloride reaction solvent. tresyl chloride reaction time, tresyl chloride concentration, peptide concentration, and peptide reaction pH. Surface chemistry and corneal epithelial cell adhesion to the modified surfaces were examined. X-ray photoelectron spectroscopy data suggested that while peptide modification had occurred, surface coverage with the peptide was incomplete. Acetone was found to result in a higher fraction of nitrogen and surface bound carboxyl groups compared to dioxane and ether. Furthermore, corneal epithelial cell adhesion to the surfaces for which acetone was used for the activation reaction was significantly greater. Statistical analysis of the various samples suggests that lower peptide concentrations and higher tresyl chloride reaction times result in better cell adhesion. Furthermore, modification with YIGSR resulted in higher surface concentrations and better cell adhesion than modification with RGDS. Little or no cell adhesion was noted on the unmodified pHEMA controls. Protein adsorption results suggest that the differences in cell adhesion cannot be attributed to differences in serum protein adsorption from the culture medium. We conclude that YIGSR modified surfaces have significant potential for further development in corneal applications.     

Peptide-surface modification of poly(caprolactone) with laminin-derived sequences for adipose-derived stem cell applications

Human adipose tissue has been recognized as a source of adult stem cells for tissue engineering applications such as bone, cartilage, and soft tissue repair. For the success of these tissue-engineering approaches, a cell delivery vehicle such as a hydrogel or scaffold is required to position the stem cells at the site of need. Surface modification techniques have been instrumental in the development of scaffolds that promote cell-surface interactions. In this study, poly(caprolactone) (PCL), surfaces were modified in order to promote the attachment and proliferation of adipose-derived stem cells (ASCs). RGD, YIGSR, and IKVAV peptide sequences derived from the extracellular matrix protein laminin were each covalently attached to an aminated polymer surface using carbodiimide chemistry. The surface was characterized using scanning electron microscopy (SEM), goniometry and X-ray photoelectron spectroscopy (XPS). The attachment and proliferation of ASCs was assessed on the different peptide-treated surfaces. XPS analysis confirmed the presence of the peptide sequences on the surface of the polymer as indicated by the increase in the nitrogen/carbon ratio on the surface of the polymer. Among all peptide sequences tested, IKVAV-treated surfaces had a significantly greater number of ASCs bound 2 and 3 days after cell seeding. SEM confirmed differences in the morphology of the cells attached to the three peptide-treated surfaces. These results indicate that IKVAV is a suitable peptide sequence for use in surface modification techniques aimed at improving the attachment of ASCs to a tissue-engineered scaffold.     

Interactions of corneal epithelial cells and surfaces modified with cell adhesion peptide combinations

In order to facilitate the adhesion of corneal epithelial cells to a poly dimethyl siloxane (PDMS) substrate ultimately for the development of a synthetic keratoprosthesis, PDMS surfaces were modified by covalent attachment of combinations of cell adhesion and synergistic peptides derived from laminin and fibronectin. Peptides studied included YIGSR and its synergistic peptide PDSGR from laminin and the fibronectin derived RGDS and PHSRN. Surfaces were modified with combinations of peptides determined by an experimental design. Peptide surface densities, measured using 125-I labeled tyrosine containing analogs, were on the order of pmol/cm2. Surface density varied as a linear function of peptide concentration in the reaction solution, and was different for the different peptides examined. The lowest surface density at all solution fractions was obtained with GYRGDS, while the highest density was consistently obtained with GYPDSGR. These results provide evidence that the surfaces were modified with multiple peptides. Water contact angles and XPS results provided additional evidence for differences in the chemical composition of the various surfaces. Significant differences in the adhesion of human corneal epithelial cells to the modified surfaces were noted. Statistical analysis of the experimental adhesion results suggested that solution concentration YIGSR, RGDS, and PHSRN as well as the interaction effect of YIGSR and PDSGR had a significant effect on cell interactions. Modification with multiple peptides resulted in greater adhesion than modification with single peptides only. Surface modification with a control peptide PPSRN in place of PHSRN resulted in a decrease in cell adhesion in virtually all cases. These results suggest that surface modification with appropriate combinations of cell adhesion peptides and synergistic peptides may result in improved cell surface interactions.     

Peptide-modified p(AAm-co-EG/AAc) IPNs grafted to bulk titanium modulate osteoblast behavior in vitro

Interpenetrating polymer networks (IPNs) of poly(acrylamide-co-ethylene glycol/acrylic acid) (p(AAm-co-EG/AAc) applied to model surfaces prevent protein adsorption and cell adhesion. Subsequently, IPN surfaces functionalized with the RGD cell-binding domain from rat bone sialoprotein (BSP) modulated bone cell adhesion, proliferation, and matrix mineralization. The objective of this study was to utilize the same biomimetic modification strategy to produce functionally similar p(AAm-co-EG/AAc) IPNs on clinically relevant titanium surfaces. Contact angle goniometry and X-ray photoelectron spectroscopy (XPS) data were consistent with the presence of the intended surface modifications. Cellular response was gauged by challenging the surfaces with primary rat calvarial osteoblast (RCO) surfaces in serum-containing media. IPN modified titanium and negative control (RGE-IPN) surfaces inhibit cell adhesion and proliferation, while RGD-modified IPNs on titanium supported osteoblast attachment and spreading. Furthermore, the latter surfaces supported significant mineralization despite exhibiting lower levels of proliferation than positive control surfaces. These results suggest that with the appropriate optimization, this approach may be practical for surface engineering of osseous implants.     

Poly(dimethyl siloxane) surface modification with biosurfactants isolated from probiotic strains

Depending on the final application envisaged for a given biomaterial, many surfaces must be modified before use. The material performance in a biological environment is mainly mediated by its surface properties that can be improved using suitable modification methods. The aim of this work was to coat poly(dimethyl siloxane) (PDMS) surfaces with biosurfactants (BSs) and to evaluate how these compounds affect the PDMS surface properties. BSs isolated from four probiotic strains (Lactococcus lactis, Lactobacillus paracasei, Streptococcus thermophilus A, and Streptococcus thermophilus B) were used. Bare PDMS and PDMS coated with BSs were characterized by contact angle measurements, infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The influence of the surface modifications on the materials blood compatibility was studied through thrombosis and hemolysis assays. The cytotoxicity of these materials was tested against rat peritoneal macrophages. AFM results demonstrated the successful coating of the surfaces. Also, by contact angle measurements, an increase of the coated surfaces hydrophilicity was seen. Furthermore, XPS analysis indicated a decrease of the silicon content at the surface, and ATR-FTIR results showed the presence of BS characteristic groups as a consequence of the modification. All the studied materials revealed no toxicity and were found to be nonhemolytic. The proposed approach for the modification of PDMS surfaces was found to be effective and opens new possibilities for the application of these surfaces in the biomedical field.     

Characterization of titanium surfaces with calcium and phosphate and osteoblast adhesion

The titanium surfaces containing calcium, phosphate ions and the carbonate apatite were characterized. The effect of surface chemistry on the initial rabbit osteoblast response on these surfaces was investigated. The cell count and alkaline phosphatase (ALP) specific activity assay were used for biochemical analyses. Scanning electron microscopy was used for morphology observation and in particular X-ray photoelectron spectroscopy (XPS) for surface chemistry characterization. The number of cells adhering to the apatite coating surface was the maximum, the number of cells on the surface containing calcium without phosphate ions was higher than that containing phosphate without calcium, and the number on the unmodified titanium surface was the least. The osteoblasts cultured on the apatite surface exhibited the highest ALP specific activity, next were the ones on the surface containing solely calcium, the lowest were on the unmodified titanium surface. On the substrate surfaces removed of adhered cells, the order of nitrogen amounts detected by XPS was consistent with ones of ALP specific activity and cell number, except for the unmodified titanium surface. For the substrate surfaces removed of adhered osteoblasts, XPS analysis showed that calcium and phosphorous amounts decreased during cell adhesion. After cell culture the Ca2p binding energy (BE) values for apatite coating and the surface containing solely calcium were similar to those of the two surfaces adsorbed bovine serum albumin (BSA). The P2p BE values for the surfaces containing phosphate ions, including the apatite coating and the surface containing solely phosphate ions, showed the same change. But after cell culture the decrease of the P2p BE value for the coating surface was larger than the one for the surface containing solely phosphate ions. Considering the bovine serum albumin adsorption on the same samples, these results indicated that calcium ions on titanium surfaces play a more important role than phosphate ions in initial interactions among culture medium, osteoblasts and titanium surfaces. On the apatite coating surface, calcium ions are active sites for osteoblast adhesion, while calcium and phosphate ions co-exist on titanium surfaces, the former promotes the osteoblast adhesion onto the phosphate sites on titanium surfaces. The cell adhesion was a complicated biological and chemical process relating to surface several elements similar to protein adsorption.