羟基磷灰石/聚DL-乳酸复合内固定材料对成骨细胞活性影响的体外研究

目的 :与单纯聚DL 乳酸 (PDLLA)材料比较研究羟基磷灰石 /聚DL 乳酸 (HA/PDLLA)复合内固定材料的降解产物对成骨细胞增殖和分化的影响。方法 :检测HA/PDLLA材料和PDLLA材料体外降解过程中降解液 pH值、钙离子、无机磷浓度的变化 ;通过四甲基偶氮唑盐 (MTT)酶反应比色法检测成骨细胞在材料降解产物作用下的增殖情况 ,通过检测碱性磷酸酶 (ALP)活性了解其分化情况 ,扫描电镜 (SEM)观察成骨细胞在材料直接作用下的形态学表现。结果 :体外自然降解时 ,HA/PDLLA材料降解液 pH值下降较PDLLA材料慢 ,HA/PDLLA材料降解时有钙磷成分溶出。与对照组比较 ,HA/PDLLA材料所设全部七个浓度的浸提液及PDLLA材料从 1∶2 5 6到 1∶16这四个浓度的浸提液对成骨细胞增殖均无抑制 (P >0 .0 5 ) ,PDLLA材料 1∶4及 1∶1两个浓度的浸提液抑制了成骨细胞增殖 (P <0 .0 5及P <0 .0 1)。作用 1d和 4d后的成骨细胞ALP活性在HA/PDLLA材料组与同期对照组相比均无显著性差异(P >0 .0 5 ) ,在PDLLA材料组与同期对照组及HA/PDLLA材料组相比均有显著性升高 (P <0 .0 1)。HA/PDLLA材料表面的成骨细胞呈纺锤形及延展为多角状 ;PDLLA材料表面的成骨细胞呈球形及延展不充分 ,且数量较少 ;HA/PDL LA材料表面可见HA颗粒。结论 :HA/PDLLA材料降     

新工艺制备纳米钛酸钙涂层及生物相容性评价

目的 :研究新型纳米钛酸钙(CaTiO_3)涂层钛合金材料的生物相容性。方法 :将钛板、羟基磷灰石涂层钛板和纳米CaTiO_3涂层钛板分为钛板组、涂层组、纳米组(各60例)。通过扫描电镜、X射线衍射对3组材料进行分析。将各组材料与成骨细胞(MC3T3-E1)共培养,通过免疫荧光染色、MTT法、碱性磷酸酶(ALP)含量测定评估材料表面细胞的存活、增殖及分化情况;通过电镜检测材料表面成骨细胞的钙化。结果 :涂层组、纳米组比钛板组有更高的活细胞数量、MTT值、ALP含量,有更好的细胞结构形态和钙化,而涂层组、纳米组无差异。结论 :该新型纳米CaTiO_3涂层材料有良好的生物相容性,为其将来临床植入体内提供了一定的实验依据。     

成骨细胞与镁合金表面硅酸盐-磷酸盐复合涂层的体外相容性

目的 评价成骨细胞在镁合金表面硅酸盐磷酸盐复合涂层上的生长状况,探讨镁合金表面硅酸盐磷酸盐复合涂层与成骨细胞的生物相容性。 方法 用胶原酶消化法分离培养大鼠成骨细胞,并用免疫荧光和茜素红染色法进行鉴定;然后将第4代大鼠的成骨细胞接种于材料表面,用扫描电镜观察成骨细胞在不同表面上黏附形态的变化,同时制备材料浸提液,用浸提液法培养细胞,并通过四甲基偶氮唑盐（MTT）法和碱性磷酸酶（ALP）活性法检测成骨细胞的增殖和分化情况。 结果 将成骨细胞与材料进行复合培养后,扫描电镜下可见,涂层组的成骨细胞生长活力旺盛、形态饱满、分布均匀,而单纯镁合金组未见细胞生长;MTT和ALP活性分析结果显示,硅含量为1%~5%涂层对大鼠成骨细胞的体外生长、增殖和分化的促进作用最佳。 结论 镁合金表面硅酸盐磷酸盐涂层与成骨细胞具有良好的相容性,在体外培养的环境下,有利于细胞的生长、黏附、增殖和分化。     

表面粗糙度对种植体钛片表面成骨细胞的影响

目的探讨种植体表面粗糙度对成骨细胞增殖、分化、功能及基因表达的影响。方法种植体钛片分为3组,表面粗糙度(Ra)分别为0.175μm(1组)、1.00μm(2组)及1.689μm(3组)。将人成骨肉瘤细胞系MG63细胞接种于3组材料表面,利用激光共聚焦显微镜观察细胞在各组钛材料表面黏附铺展形态,采用MTY法、碱性磷酸酶(ALP)、骨钙素活性检测评价成骨细胞在钛片表面黏附、增殖和分化水平,通过RT- PCR检测细胞内Cbfa1mRNA表达。结果Mg63在各组材料表面均生长良好,4h时各组细胞均附着,第2组细胞可见突起,24h时各组细胞均伸展,形态不规则。各组细胞在1、5、10d,第2组ALP及骨钙素(OC)活性均逐渐增高,在15d有所下降,在5、10d,ALP及OC活性显著高于其他两组(P<0.05)。第2组的Cbfal mRNA表达高于其他两组(P<0.01)。结论种植体表面适度粗化能够促进成骨细胞的功能,1.00μm是比较适宜的表面粗糙度。     

成人成骨细胞与多孔钛联合培养观察

目的观察成人成骨细胞在多孔钛表面的生长情况，评价多孔钛的生物相容性。方法将成人骨髓来源的成骨细胞与多孔钛联合培养，以多孔羟基磷灰石（hydroxyapatite，HA）为对照，倒置显微镜、扫描电镜观察细胞生长情况，MTT法检测细胞活性。结果成骨细胞在钛微孔表面生长良好，MTT法检测细胞活性，两组吸光度值无显著性差异（P〉0．05）。结论多孔钛具有良好的生物相容性，是比较理想的成骨细胞载体。     

聚醚醚酮-羟基磷灰石-碳纤维复合材料的生物相容性研究

目的对聚醚醚酮(PEEK)-羟基磷灰石(HA)-碳纤维(CF)复合材料的生物相容性进行评价。方法应用注塑法制备不同质量分数的PEEK-HA-CF复合材料,选择70PEEK-20HA-10CF复合材料(PEEK、HA、CF质量分数分别为70%、20%、10%)为实验组,75PEEK-05HA-20CF复合材料(PEEK、HA、CF质量分数分别为75%、5%、20%)为阳性对照组,70PEEK-30CF(PEEK、CF质量分数分别为70%、30%)为阴性对照组。从新生SD大鼠颅盖骨提取原代成骨细胞,培养至第2代,用于实验。测定不同质量分数的PEEK-HA-CF复合材料的黏附性、增殖能力、细胞形态及相关碱性磷酸酶(ALP)、Ⅰ型胶原(COL-Ⅰ)、骨钙素(OCN)mRNA含量,评价复合材料的生物相容性。结果荧光显微镜下CF和HA均匀分布在PEEK中。与对照组相比,各组细胞黏附性差异无统计学意义(P 0.05);实验组第5天、第7天光密度(OD)分别为1.88±0.08、2.83±0.15,阳性对照组第5天、第7天OD值为1.55±0.09、2.56±0.12,阴性对照组第3天、第5天OD值分别为1.47±0.03、2.46±0.06;实验组增殖力明显高于对照组(P 0.05)。ALP mRNA、COL-ⅠmRNA含量在第14天时达到高峰;在第5、7天时,实验组高于对照组(P 0.05),而两对照组间差异无统计学意义(P 0.05);第14天时,实验组ALP mRNA、COL-ⅠmRNA含量高于对照组(P 0.05),且阳性对照组高于阴性对照组(P 0.05),而3组间OCN mRNA表达差异无统计学意义(P 0.05)。扫描电子显微镜观察发现,细胞在复合材料上生长良好,并随着时间的延长,细胞在材料表面达到融合,形成矿化颗粒。结论 PEEK-HA-CF复合材料具有良好的生物相容性和生物活性。     

TiO_2纳米管对DPT在成骨细胞中表达的影响及机制研究

目的研究不同管径TiO_2纳米管修饰的钛材料与成骨细胞在体外复合培养,观察其对成骨细胞的粘附、增殖和分化的影响,并探讨可能的机制,为纳米材料的临床应用提供理论依据。方法将骨植入材料金属物质分成四组,其中三组经处理后分别内置有50 nm、100 nm、CDW图案的纳米管,以未经任何处理的钛片作为对照组,将MG-63成骨细胞分别接种于内置有50 nm、100 nm、CDW图案的纳米管与对照组钛片的6孔板中,采用MTT实验对四组材料复合培养MG-63的细胞活力进行评估;应用碱性磷酸酶(alkline phosphatase,ALP)试剂盒检测四组细胞碱性磷酸酶活性的改变;荧光共聚焦检测皮肤桥蛋白(DPT)的表达情况;通过Western blot实验检测DPT、黏着斑激酶,粘着斑激酶(Focal Adhesion Kinase,FAK)、骨桥蛋白(osteopontin,OPN)蛋白的表达变化。结果MTT检测显示,三种纳米管复合培养MG-63活性比对照组钛片复合培养的MG-63活性增强,培养的第3d,5d,7d MG-63细胞活性增强显著,呈时间依赖性。与钛片复合培养组相比,50 nm、100 nm、CDW图案的纳米管复合培养组ALP、DPT、FAK及OPN表达水平增加。结论50 nm、100 nm、CDW图案的纳米管复合培养更能促进成骨细胞的生长与铺展,具有良好的生物相容性,其机制可能与增加ALP的表达水平和激活DPT/FAK信号通路相关。     

新型钛基溶胶凝胶涂层的细胞相容性研究

目的 通过对涂层的表面结构及其细胞相容性的研究,对新型的钛基溶胶凝胶HA涂层技术进行评价.方法 在纯钛材料表面制备新型的溶胶凝胶HA涂层,采用SEM对涂层表面特征进行测试.体外成骨细胞(MC-3T3)培养测试涂层的细胞相容性,并将钛基HA溶胶凝胶涂层的细胞相容性与传统的钛基等离子喷涂HA涂层做比较.结果 经过水热处理的钛基涂层表面为均一的晶体颗粒表面,细胞学实验发现与等离子HA涂层相比较,水热处理溶胶凝胶表面增强了细胞粘附作用,具有较好的成骨细胞粘附(P＜0.05).结论 本实验结果提示这种新型的水热处理钛基HA溶胶凝胶表面具有良好的成骨细胞粘附特性,因而有待于作进一步研究.     

低强度脉冲超声波作用下羟基磷灰石/磷酸三钙三维支架上成骨细胞的生物学行为的研究

目的评价低强度脉冲超声波对羟基磷灰石(HA)/磷酸三钙(TCP)三维多孔支架材料上的MC3T3-E1成骨细胞的生物学行为的影响。方法将鼠MC3T3-E1成骨细胞与HA/TCP支架材料复合培养4 d和7 d。超声组每天接受20 min的低强度脉冲(1 MHz)超声波辐照,对照组为不开功率源的假辐照。通过观察成骨细胞在支架材料上的附着和细胞活力,检测细胞长入支架深度、DNA含量等指标评价低强度脉冲超声波对成骨细胞生物学行为的影响。结果 14 d和7 d时超声组HA/TCP支架材料上成骨细胞生长密度高于对照组。24 d和7 d时超声组HA/TCP支架材料上成骨细胞长入深度较对照组分别增加了34.45%和23.45%,4 d时二者差异无统计学意义(P=0.057),而7 d差异有统计学意义(P=0.032)。34 d和7 d时超声组较对照组DNA含量分别增加了27.54%(P=0.000)和24.39%(P=0.000),差异均有显著统计学意义。结论加载低强度脉冲超声波有利于成骨细胞在HA/TCP支架材料上的生长与增殖。     

盐酸小檗碱通过PI3K/Akt信号通路促进小鼠前成骨细胞MC3T3-E1的分化

目的:研究盐酸小檗碱对小鼠前成骨细胞系MC3T3-E1分化与矿化的调控作用及其机制。方法:MC3T3-E1细胞给予不同浓度(0、1、5、10和20 mg/L)的盐酸小檗碱刺激3 d,CCK-8法检测细胞活性。不同浓度的盐酸小檗碱分别干预3 d和7 d,检测细胞碱性磷酸酶(ALP)活性。进一步将实验随机分为4组:对照组、盐酸小檗碱组、盐酸小檗碱+LY249002(PI3K/Akt通路抑制剂)组及LY249002组。干预2 d后,采用real-time PCR检测成骨细胞分化相关因子ALP、骨钙素(OCN)、骨桥蛋白(OPN)及Runt相关转录因子2(Runx2)的mRNA表达情况,采用Western blot检测PI3K/Akt信号通路相关蛋白p-Akt的表达水平。将MC3TC-E1细胞用矿化培养基诱导21 d,茜素红染色检测其矿化情况。结果:与对照组相比,不同浓度的盐酸小檗碱对细胞活性的影响没有明显差异;不同浓度的盐酸小檗碱处理MC3T3-E1细胞后ALP活性有不同程度升高。Real-time PCR结果表明,盐酸小檗碱(5 mg/L)促进ALP、OCN、OPN及Runx2的mRNA表达(P 0. 01),而LY294002能抑制这些分化相关因子的表达。Western blot检测结果表明,盐酸小檗碱(5 mg/L)促进p-Akt蛋白的表达(P 0. 01),其作用被LY249002抑制。茜素红染色发现盐酸小檗碱组矿化明显,但LY294002能抑制盐酸小檗碱的促进作用。结论:盐酸小檗碱可以促进小鼠前成骨细胞的分化与矿化,其机制可能与其激活PI3K/Akt信号通路有关。     

聚醚醚酮-羟基磷灰石-碳纤维复合材料的体外细胞相容性研究

将大鼠成骨细胞与聚醚醚酮-羟基磷灰石-碳纤维(PEEK-HA-CF)复合材料间接和直接培养,通过CCK-8对复合材料的细胞毒性进行评价;流式细胞仪测定材料对细胞增殖指数的影响;测定复合培养后成骨细胞的碱性磷酸酶活性变化;应用扫描电镜(SEM)观察成骨细胞形态学变化。结果表明PEEK-HA-CF复合材料无细胞毒性,复合材料组胞增殖指数与空白对照组比无差异,3d时高于钛合金组。第7d时,PEEK-HA-CF组的碱性磷酸酶活性升高。SEM下,细胞在复合材料上生长良好。PEEK-HA-CF复合材料具有良好的细胞相容性,有希望成为一种新的骨科植入材料。     

胶原-纳米羟基磷灰石复合支架的细胞相容性

背景：观察成骨细胞在生物材料上的形态、增殖和分化等项目,可评估生物支架材料的生物相容性。 目的：观察复合支架材料纳米羟基磷灰石/胶原对成骨细胞增殖、分化的影响。 方法：取新生24 h内Wistar大鼠的颅盖骨,采用改良胶原酶消化法进行成骨细胞原代培养,取第3代细胞与纳米羟基磷灰石/胶原支架或普通羟基磷灰石材料体外复合培养。培养3,6,9 d后,观察材料周边的细胞形态及支架材料对细胞分化、增殖的影响。 结果与结论：纳米羟基磷灰石/胶原材料较普通的羟基磷灰石材料更有利于成骨细胞的黏附、生长、分化、增殖,证实其生物相容性更好,有望成为一种新型的骨组织工程支架材料。     

Modulation of osteoblast function using poly(D,L-lactic acid) surfaces modified with alkylation derivative of chitosan

Poly(D,L-lactic acid) (PDLLA) was modified with alkylated chitosan (N-butyl chitosan and N-cetyl chitosan), and the effects of modified films on the functions of rat osteoblasts were investigated. The characteristics of surfaces (both modified and control) were examined by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). Cell morphologies on these surfaces were taken using scanning electron microscopy (SEM). Cell attachment and proliferation were used to assess cell behavior on modified surface and control. MTT assay was used to determined cell viability, and alkaline phosphatase (ALP) activity was taken to evaluate differentiated cell function. Compared with the untreated films, no significant difference in cell attachment of osteoblasts was found on the modified films at a period of 8 h (p > 0.05). However, cell proliferation of N-butyl chitosan rather than N-cetyl chitosan modified PDLLA films was significantly higher than that found on control one (p < 0.05) at the end of the 4th and 7th days. The cell viability of osteoblasts on N-butyl chitosan modified PDLLA films were found higher than that on control (p < 0.05). These results suggested that N-butyl chitosan contributed greater than N-cetyl chitosan when used to modify PDLLA films for improving its biocompatibility.     

Biocompatibility of bioresorbable poly(L-lactic acid) composite scaffolds obtained by supercritical gas foaming with human fetal bone cells

The aim of this investigation was to test the biocompatibility of three-dimensional bioresorbable foams made of poly(L-lactic acid) (PLA), alone or filled with hydroxyapatite (HA) or beta-tricalcium phosphate (beta-TCP), with human primary osteoblasts, using a direct contact method. Porous constructs were processed by supercritical gas foaming, after a melt-extrusion of ceramic/polymer mixture. Three neat polymer foams, with pore sizes of 170, 310, and 600 microm, and two composite foams, PLA/5 wt% HA and PLA/5 wt% beta-TCP, were examined over a 4-week culture period. The targeted application is the bone tissue-engineering field. For this purpose, human fetal and adult bone cells were chosen because of their highly osteogenic potential. The association of fetal bone cells and composite scaffold should lead to in vitro bone formation. The polymer and composite foams supported adhesion and intense proliferation of seeded cells, as revealed by scanning electron microscopy. Cell differentiation toward osteoblasts was demonstrated by alkaline phosphatase (ALP) enzymatic activity, gamma-carboxylated Gla-osteocalcin production, and the onset of mineralization. The addition of HA or beta-TCP resulted in higher ALP enzymatic activity for fetal bone cells and a stronger production of Gla-osteocalcin for adult bone cells.     

Modulation of osteoblast function using poly(D,L-lactic acid) surfaces modified with alkylation derivative of chitosan

Poly(D,L-lactic acid) (PDLLA) was modified with alkylated chitosan (N-butyl chitosan and N-cetyl chitosan), and the effects of modified films on the functions of rat osteoblasts were investigated. The characteristics of surfaces(both modified and control) were examined by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). Cell morphologies on these surfaces were taken using scanning electron microscopy (SEM). Cell attachment and proliferation were used to assess cell behavior on modified surface and control. MTT assay was used to determined cell viability, and alkaline phosphatase (ALP) activity was taken to evaluate differentiated cell function. Compared with the untreated films, no significant difference in cell attachment of osteoblasts was found on the modified films at a period of 8 h (p > 0.05). However, cell proliferation of N-butyl chitosan rather than N-cetyl chitosan modified PDLLA films was significantly higher than that found on control one (p < 0.05) at the end of the 4th and 7th days. The cell viability of osteoblasts on N-butyl chitosan modified PDLLA films were found higher than that on control (p < 0.05). These results suggested that N-butyl chitosan contributed greater than N-cetyl chitosan when used to modify PDLLA films for improving its biocompatibility.     

The influence of titania/hydroxyapatite composite coatings on in vitro osteoblasts behaviour

The biocompatibility of titania/hydroxyapatite (TiO2 /HA) composite coatings, at different ratio obtained by sol-gel process, were investigated studying the behaviour of human MG63 osteoblast-like cells. The biocompatibility was evaluated by means of cytotoxicity and cytocompatibility tests. Cytotoxicity tests, i.e., neutral red (NR), MTT and kenacid blue (KB) assays, were performed to assess the influence of the material extracts on lysosomes, mitochondria and cell proliferation, respectively. Cell proliferation, some preliminary indications of cell morphology, alkaline phosphatase activity, collagen and osteocalcin production of MG63 cells, cultured directly onto TiO2/HA substrates, were evaluated. The results showed that these materials have no toxic effects. Cell growth and morphology were similar on all the materials tested: on the contrary, alkaline-phosphatase-specific activity and collagen production of osteoblasts cultured on TiO2/HA coatings were significantly higher than uncoated titanium and polystyrene of culture plate and were influenced by chemical composition of the coatings. In particular, TiO2/HA coating at 1:1 ratio (w/w) seems to stimulate more than others the expression of some differentiation markers of osteoblastic phenotype. TiO2/HA coatings resulted to be bioactive owing to the presence of hydroxyl groups detected on their surface that promote the calcium and phosphate precipitation and improve the interactions with osteoblastic cells.     

Rat osteoblast functions on the o-carboxymethyl chitosan-modified poly(D,L-lactic acid) surface

In this study, the functions of rat osteoblasts on o-carboxymethyl chitosan-modified poly(D,L-lactic acid) (PDLLA) films were investigated in vitro. The surface characterization was measured by contact angle and electron spectroscopy for chemical analysis (ESCA). Cell adhesion and proliferation were used to assess cell behavior on the modified surface and control. The MTT assay was used to determined cell viability and alkaline phosphatase (ALP) activity was performed to evaluate differentiated cell function. Compared to the control films, cell adhesion of osteoblasts on o-carboxymethyl chitosan-modified PDLLA films was significantly higher (p < 0.05) after 6 and 8 h culture, and osteoblast proliferation was also significantly higher (p < 0.01) between 4 and 7 days. The MTT assay suggested cell viability of osteoblasts cultured on o-carboxymethyl chitosan modified PDLLA films was significantly greater (p < 0.05) than that seeded on control one, and the ALP activity of cells cultured on modified PDLLA films was significantly higher (p < 0.01) than that found on control. These results give the first evidence that o-carboxymethyl chitosan could be used to modify PDLLA surface for improving biocompatibility.     

Phenotypic expression of bone-related genes in osteoblasts grown on calcium phosphate ceramics with different phase compositions

Calcium phosphate ceramics with different hydroxyapatite (HA) and tricalcium phosphate (TCP) ratios have different chemical properties. Does the difference in phase composition affect osteoblast behavior? In this study, osteoblasts were cultured on 4 kinds of calcium phosphate ceramics, i.e. pure (HA), HT1 (HA/TCP, 70/30), HT2 (HA/TCP, 35/65), and pure TCP. Cell proliferation of SaOS-2 cells together with bone-related genes' mRNA expression and protein production in osteoblasts cultured on different calcium phosphate ceramics were detected at different time points. Data suggested that cell proliferation rate on TCP ceramics was lower than that on the other substrates tested. Generally, mRNA expressions for osteonectin and osteocalcin were similar among the four kinds of ceramics in most circumstances, whereas at six days, alkaline phosphatase mRNA expression was higher on HA and HT1 surfaces than on the other two materials. Collagen I mRNA expression was also affected by the phase composition of substrates. Osteocalcin and bone sialoprotein production in SaOS-2 cells was very similar no matter which ceramic surface the cells were grown upon. This study revealed that calcium phosphate ceramics substrate could support osteoblast growth and bone-related gene expression and its gene expression pattern explained the basis of the biocompatibility and bioactivity for calcium phosphate ceramics.     

In vitro reactions of human osteoblasts in culture with zirconia and alumina ceramics.

The biocompatibility of two implantable materials, zirconia and alumina ceramics, was investigated in vitro using human osteoblast cell cultures. The viability of osteoblast cells with the materials was evaluated by the methylthiazole sulfate test that revealed an absence of any cytostatic or cytotoxic effect. Cell proliferation kinetic and total protein synthesis in osteoblasts with zirconia or alumina were similar to that observed in control cells cultured on glass coverslips. Light and scanning electron microscopic examinations showed an intimate contact between osteoblasts and the substrates; well-spread cells were observed on the surfaces of both materials. Adhesion ability and morphological characteristics were preserved in osteoblast cultures with these substrates. Moreover, immunohistochemical staining in osteoblasts with zirconia and alumina showed the capacity of these cells to elaborate the extracellular matrix composed of types I and V collagen, osteocalcin, osteonectin, bone sialoprotein, and cellular fibronectin. Finally, DNA image cytometry and interphase silver-nucleolar organizer regions quantification were applied as complementary biocompatibility tests to detect any changes in DNA synthesis and cell proliferation, respectively. The results showed that neither material altered cell ploidy or cell growth rate in accordance with the absence of any inducing effect on DNA synthesis or proliferation.     

Effect of surface roughness of hydroxyapatite on human bone marrow cell adhesion, proliferation, differentiation and detachment strength

Initial attachment of osteoblast cells and mineralization phenomena are generally enhanced on rough, sandblasted substrata. In the present work the effect of surface roughness of hydroxyapatite (HA) on human bone marrow cell response was investigated. Human bone marrow cells were plated onto HA disc-shaped pellets, prepared from synthetic HA powder. The pellets were sintered and polished with SiC paper 180-, 600- and 1200-grit, resulting in three surface roughness grades. Cell adhesion, proliferation and differentiation (evaluated with the expression of ALP activity) were determined following various incubation periods. Cell detachment strength was determined as the shear stress required to detach a given quantity of the adherent cells from the different substrata, using a rotating disc device that applied a linear range of shear stresses to the cells. The cells attached and grew faster on culture plastic in comparison with HA. No statistically significant differences were observed in the expression of ALP activity on all three HA surfaces and culture plastic. Cell adhesion, proliferation and detachment strength were surface roughness sensitive and increased as the roughness of HA increased. The percentage of the adherent cells decreased in a sigmoidal mode as a function of the applied shear stress. In conclusion, surface roughness of HA generally improved the short- and longer-term response of bone marrow cells in vitro. This behavior could be explained by the selective adsorption of serum proteins.