成纤维细胞在PHB可降解材料上的粘附与生长研究

聚羟基丁酸酯（PHB）多孔材料可作为组织工程用的支架,然而细胞在此材料表面不易粘附生长,这与粘附蛋白在聚合物材料表面的吸附有关。基于材料表面的粘附与细胞生长、增殖、分化和组织发育密切相关,粘附强度可影响工程组织的最终结构与功能,本文通过对PHB材料进行多聚赖氨酸衣被,有效地实现了在PHB可降解支架上种植细胞来构建工程组织。用离心法制备厚度为20um的透明PHB薄膜,用多聚赖氨酸衣被,对照组为不衣被的PHB薄膜和玻璃片。接种成纤维细胞系NIH3T3,相差显微镜观察细胞的粘附生长过程。细胞在多聚赖氨酸衣被表面迅速粘…     

骨组织工程支架材料表面修饰的试验研究

观察骨髓基质细胞 (BMSC)在吸附了多聚赖氨酸 (Poly -L -Lysine,PLL)的羟基磷灰石 (HA)上的生长情况。探讨改进材料表面活性 ,促进种子细胞黏附和生长的方法。利用组织工程学的方法 ,将体外培养的BMSC种植于吸附了多聚赖氨酸的HA上 ,立体培养一周 ,用环境扫描电镜和倒置相差显微镜观察细胞的生长情况。结果表明 ,细胞在体外可以立体培养成活 ,吸附了多聚赖氨酸的HA上细胞较多。多聚赖氨酸可以改善HA的表面活性 ,促进细胞的黏附和生长。     

可降解聚氨酯构建组织工程前交叉韧带支架材料的可行性

背景：前交叉韧带是膝关节常见损伤部位,组织工程前交叉韧带研究在过去的10年内取得了长足的进展,但人们尚未找到理想的支架材料。 目的：探讨使用可降解聚氨酯材料构建组织工程交叉韧带支架的可行性。 方法：将可降解聚氨酯纤维丝编织的聚氨酯材料于含胎牛血清的DMEM培养基制备浸提液,分别以体积分数100%,50%,25%,12.5%的浸提液培养NIH3T3细胞,CCK-8实验检测聚氨酯材料浸提液的细胞毒性;然后将体外分离培养的兔前交叉韧带细胞和NIH3T3细胞分别种植在支架材料上进行立体培养,观察细胞在支架材料上的生长情况;使用电子拉力机测试支架材料的力学性能并分析。 结果与结论：构建组织工程交叉韧带支架的可降解聚氨酯材料没有细胞毒性;前交叉韧带和NIH3T3细胞贴附于该材料生长,生长状态良好;支架材料的杨氏模量,极限抗张强度和断裂伸长率分别为(41.2±2.1) MPa,(51.0±1.5) MPa和(600±60)%。提示聚氨酯支架材料具有良好的生物相容性和生物安全性。     

多聚赖氨酸对脂肪来源干细胞三维立体条件下生物学特性的影响

背景：多聚赖氨酸可促进软骨细胞、表皮细胞的黏附、生长及增殖。 目的：观察多聚赖氨酸对脂肪来源干细胞三维立体培养下生物学活性的影响。 方法：采用流式细胞仪检测昆明小鼠脂肪来源干细胞表面CD29、CD34、CD44、CD45的表达,将脂肪来源干细胞分别与经多聚赖氨酸表面修饰的珊瑚羟基磷灰石或空白珊瑚羟基磷灰石体外复合培养。 结果与结论：与空白珊瑚羟基磷灰石组比较,经多聚赖氨酸修饰的珊瑚羟基磷灰石上黏附的脂肪来源干细胞较空白珊瑚羟基磷灰石组多,并分泌较多细胞基质,复合培养2,4,8 d的A值较明显增高(P < 0.05);但经多聚赖氨酸修饰的珊瑚羟基磷灰石上黏附的脂肪来源干细胞碱性磷酸酶活性值升高不明显(P > 0.05)。说明多聚赖氨酸能促进脂肪来源干细胞在珊瑚羟基磷灰石表面的黏附、生长和增殖,不影响脂肪来源干细胞向成骨细胞转化。     

多聚赖氨酸修饰钛氧膜并固定纤连蛋白对内皮细胞生长的影响

为了进一步提高钛氧膜与内皮细胞的亲和性,研究了一种表面生物化学方法对钛氧膜表面内皮细胞生长的影响.先利用盐酸和双氧水活化钛氧膜表面,使其产生羟基基团,再涂覆多聚赖氨酸作为中间过渡层,最后在表面上固定纤连蛋白.采用傅立叶红外光谱仪、X射线光电子能谱仪及接触角测量的方法对每步处理后的材料表面进行分析与测试.通过体外人脐静脉原代内皮细胞培养实验评价内皮细胞在样品表面的黏附和生长.研究结果显示,通过表面活化后涂覆多聚赖氨酸并固定纤连蛋白的方法能促进内皮细胞在钛氧膜表面的黏附和生长.     

聚乳酸表面的氨等离子处理及成骨细胞相容性研究

聚乳酸材料是一种应用广泛的可降解的组织工程支架材料，但是由于其表面亲水性差，影响了细胞的黏附和生长。为了提高聚乳酸材料表面的细胞相容性，首先利用溶液浇铸法制备聚L-乳酸（PLLA）膜材料，然后采用氨等离子技术进行表面处理，采用光电子能谱（XPS）和原子力显微镜（AFM）研究了处理条件对材料表面的化学结构和形貌的影响，结果表明处理后的PLLA膜的亲水性基团和表面平均粗糙度明显增加。最后研究了成骨细胞在材料表面的黏附，增殖和细胞周期的变化，结果表明成骨细胞在处理后的材料表面的黏附和生长较改性前有了很大提高，细胞能够更快地进入细胞分裂周期。     

不同预处理脱细胞牛骨基质复合成骨化骨髓间充质干细胞生物相容性研究

目的将经成骨化诱导后大鼠骨髓间充质干细胞(MSC)与脱细胞牛骨基质(ABECM)复合,构建组织工程骨。实验着重观察不同预处理方法对构建的组织工程骨的过程——细胞与ABECM复合和生长的影响,为有效快速构建组织工程化骨奠定理论基础。方法用Wistar大鼠2只,从股骨取MSC在体外扩增、纯化、诱导成骨化,做苏木精-伊红染色鉴定。实验组用胎牛血清(FBS)、多聚赖氨酸(PLL),对照组用磷酸盐缓冲溶液预处理的ABECM复合构建组织工程骨,体外培养。用流式细胞仪计数并计算细胞黏附率、测定碱性磷酸酶活性,倒置光学显微镜、扫描电子显微镜观察细胞生长、增殖情况。结果接种后6、12h实验组细胞黏附率高于对照组(P0.05)。扫描电子显微镜观察:复合培养第3天,实验组细胞在材料表面已完全伸展,附着在材料表面;对照组细胞大多呈不规则形,未完全伸展。碱性磷酸酶活性测定:复合培养第3、6天,实验组的碱性磷酸酶活性均明显高于对照组(P0.05)。结论用FBS和PLL分别预处理,可以改善ABECM材料表面特性,利于提高细胞接种效率,从而能更有效、更快速地构建组织工程骨。     

医用可降解锌合金材料抗菌性能及细胞相容性的体外实验研究

目的研究医用可降解锌合金材料的体外抗菌性能及细胞相容性。 方法大肠杆菌与金黄色葡萄球菌菌株分别与LB培养基混合,采用细菌比浊仪将浓度调节至1.0×10⁸CFU/mL,在二氧化碳恒温箱内37℃下培养24 h,作为细菌原液;各取相同尺寸锌合金与钛合金棒,打磨、除去表面氧化层,在100%乙醇、蒸馏水中超声波震荡洗涤,后用环氧乙烷消毒,备用。(1)大肠杆菌/金黄色葡萄球菌分别与可降解锌合金、钛合金于LB培养基中共培养,培养0、2、4、6、8、12、24、48、72 h后分别用酶标仪测定其在600 nm波长下的吸光度值。(2)将可降解锌合金、钛合金置于含金黄色葡萄球菌的固体培养平板上,培养24、48 h后观察抑菌圈大小。(3)不同浓度锌合金浸提液培养L929细胞,培养1、5 d后观察细胞形态,并用CCK8法检测细胞增殖情况,计算细胞相对增值率(RGR)。(4)将小鼠胚胎成骨细胞前体细胞(MC3T3－E1细胞)接种于可降解锌合金、钛合金表面,培养2 d后观察细胞在不同材料表面的黏附生长情况。组间数据比较采用单因素方差分析(ANOVA)及t检验。 结果不同时相点,大肠杆菌加锌合金共培养组的吸光度值明显低于单纯大肠杆菌培养组、大肠杆菌加钛合金共培养组,差异均有统计学意义(P值均小于0.05);不同时相点,金黄色葡萄球菌加锌合金共培养组吸光度值明显低于单纯金黄色葡萄球菌培养组、金黄色葡萄球菌加钛合金共培养组,差异有统计学意义(P值均小于0.05)。可降解锌合金周围出现抑菌圈,培养24 h后,锌合金圆柱体周围(4.38±0.40)mm范围内无菌落出现,培养48 h后锌合金圆柱体周围(4.75±0.44)mm范围内无菌落出现,培养24 、48 h的抑菌圈大小比较差异无统计学意义(t＝－1.10,P＝0.31),而钛合金周围未出现抑菌圈。不同浓度锌合金浸提液培养组与阴性对照组,L929细胞细胞生长状况良好,CCK8检测提示不同时相点各浸提液组细胞RGR均大于75%,细胞毒性为0～1级,细胞毒性安全性合格。MC3T3－E1细胞能黏附生长于锌合金与钛合金材料表面,细胞形态与钛合金组相比未见异常。 结论锌合金材料具有良好的抗菌性能,对大肠杆菌及金黄色葡萄球菌均有抑菌效果;具有良好的细胞相容性,细胞毒性安全性合格,细胞能在其表面黏附生长。     

PC-1基因表达诱导NIH3T3细胞恶性转化

目的 通过建立稳定表达外源PC-1基因的小鼠成纤维细胞株,初步探讨PC-1基因表达对肿瘤发生、发展的影响。方法 通过脂质体介导的方法,将真核表达载体pcDNA3、1(-)／myc-his-pc-1稳定转染NIH3T3细胞,之后利用PCR、逆转录PCR(RT-PCR)技术,确定外源PC-1基因在靶细胞染色体上的整合及在转录水平的表达。通过细胞形态学分析、MTT实验、细胞周期分析、软琼脂集落形成和裸鼠成瘤实验,观察PC-1基因表达对NIH3T3生物学特性的影响。结果建立了稳定转染PC-1基因的NIH3T3细胞株。PC-1基因表达的小鼠成纤维细胞NIH3T3生长速度加快,在软琼脂上生长并形成集落,接种裸鼠后可成瘤(6／6)。结论 PC-1基因在NIH3T3细胞中稳定表达具有诱导正常NIH3T3细胞发生恶性转化的重要生物功能。     

表面改性聚合物左旋聚乳酸-多聚赖氨酸可促进骨髓基质细胞的初始黏附

背景：通过增加表面活性基团对生物支架材料进行表面改性,可提高材料对细胞的亲和力,有效提高材料的细胞相容性。 目的：合成表面改性聚合膜左旋聚乳酸-多聚赖氨酸(PLLA-PLL),并观察其对骨髓基质细胞黏附、增殖的影响。 方法：通过开环聚合反应合成不同组分高分子聚合膜PLLA139-PLL131,PLLA77-PLL72,PLLA45-PLL246,将人骨髓基质细胞接种至不同组分聚合膜PLLA-PLL表面、左旋聚乳酸及商品化的细胞培养板,寻找最佳PLLA-PLL组分。 结果与结论：与左旋聚乳酸比较,不同组分PLLA-PLL聚合膜细胞黏附量均升高,以PLLA77-PLL72聚合膜组增高显著(P < 0.05),所以最佳组分为PLLA77-PLL72,连续培养结果显示PLLA77-PLL72聚合膜表面骨髓基质细胞骨架蛋白表达丰富,清晰有序,增殖实验也证实了PLLA77-PLL72聚合膜可促进骨髓基质细胞增殖。     

Cell adhesion to a series of hydrophilic-hydrophobic copolymers studied with a spinning disc apparatus

Adhesion of cells to substrates strongly influences many of their functions and therefore plays an important role in a variety of processes, including growth, phagocytosis, hemostasis, and the response of tissue to implanted materials. In previous studies, the influence of substrate hydrophilicity on cell adhesion has not been separated from effects due to major differences in other properties of the substrate, such as charge, rigidity, and the specific chemical composition of the materials. In addition, very few careful studies of the force required for cell detachment from various substrates have been performed. In this study, 3T3 cell detachment from a chemically homologous series of copolymers based on hydroxyethylmethacrylate (HEMA) and ethylmethacrylate (EMA) was measured with a spinning-disc apparatus. The spinning-disc technique allowed measurements of cell detachment over a wide range of applied shear stress on each sample. Cell detachment did not occur until a critical value of shear stress was exceeded. The critical shear stress of detachment decreased linearly with increasing HEMA content, from 18 dynes/cm2 on poly-EMA to 0 on the polymers containing 83% or more HEMA. "Plating efficiency," calculated as the fraction of cells initially applied which remained after dip rinsing the surfaces, did not vary significantly among most of the copolymers. Dip rinsing, however, exposes the cells to only one, relatively low shear stress (estimated to be somewhat less than 3 dynes/cm2). The existence of a critical shear stress for 3T3 cell detachment suggests that cell adhesion to surfaces cannot be fully understood with single shear stress methods because cells may attach with a wide range of strengths which are either all above or all below the applied shear stress. The influence of surface hydrophilicity on cell adhesion and the variety of forces which may contribute to this phenomenon are discussed.     

ICAM-1 and VCAM-1 expression by endothelial cells grown on fibronectin-coated TCPS and PS

Small-diameter vascular grafts rapidly fail as a result of blood coagulation and platelet deposition. Endothelial cells lining the inner side of blood vessels can provide the graft lumen with an antithrombogenic surface. One of the remaining problems is cell detachment after restoration of blood flow, because of infiltration of leukocytes that respond to an inflammatory-like activation of the endothelial cells. This endothelial activation is possibly caused by the surface characteristics of the underlying polymer. To get more insight into the effects of the polymer surface on endothelial cell activation, we seeded human umbilical vein endothelial cells (HUVECs) in various densities and subsequently grew them on tissue culture polystyrene (TCPS; hydrophilic) and polystyrene (PS; hydrophobic) surfaces. To improve cell adhesion, surfaces were coated with purified fibronectin prior to cell seeding. During proliferation, the expressions of the leukocyte adhesion molecules ICAM-1 and VCAM-1 were determined. Results indicate that ICAM-1 expression is not influenced by the character of the polymer surface, and that VCAM-1 expression is slightly higher on the TCPS surface. Expressions of both adhesion molecules are influenced by the seeding density and time of proliferation. At low seeding densities (< or = 10,000 cells/cm(2)), a relatively low percentage of nonexogenously activated cells expressed ICAM-1 during the first 3 days of proliferation compared to higher seeding densities. Although less pronounced, this was also observed for the percentage of cells expressing VCAM-1. During proliferation, the amount of ICAM-1 per endothelial cell increased, whereas the expression of VCAM-1 remained low. The absence of large differences in leukocyte adhesion molecule expression by endothelial cells grown on TCPS or PS is possibly caused by coating of the surfaces with fibronectin. It is known that surface hydrophilicity influences protein adsorption. Although this had no or little effect on leukocyte adhesion molecule expression, endothelial cell growth was affected, because proliferation was slower on the hydrophobic PS.     

Different growth behaviour of human umbilical vein endothelial cells and an endothelial cell line seeded on various polymer surfaces

Major obstacles for successful application of endothelial cell seeding in synthetic vascular grafts include the source of autologous endothelial cells, the efficiency of cell seeding and detachment of adherent endothelial cells from the graft surface after restoration of circulation. Human umbilical vein endothelial cells (HUVECs) are frequently used to investigate the in vitro adhesion and proliferation of endothelial cells on polymer surfaces. In order to minimize the biological variation of HUVECs isolated from different umbilical veins, it would be advantageous to use an endothelial cell line in in vitro proliferation experiments. Aim of the present study was to compare the proliferation of primary HUVECs and the endothelial cell line EC-RF24 on several polymer surfaces coated with various concentrations of the adhesive protein fibronectin. EC-RF24 cells grow to a higher density than primary HUVECs. Moreover, the EC-RF24 cell line is able to proliferate on surfaces with sub-optimal adhesive properties. Therefore, it is concluded that the EC-RF24 cell line is less suitable for evaluation of the in vitro proliferation of endothelial cells on polymer surfaces.     

A stable matrix for generation of tissue-engineered nonthrombogenic vascular grafts

The potential of freeze-dried fibrin glue (FG) in combination with growth factor (GF) and gelatin (GEL) is evaluated for use as a matrix for endothelialization of artificial vascular grafts made of polytetrafluoroethylene (PTFE, Teflon) and polyethyleneterephthalate (Dacron). Improved adhesion and proliferation of human umbilical vein endothelial cells are demonstrated on different substrates coated with the FG-GF/FG-GF-GEL mixture, compared with the respective bare surfaces. The strength of adhesion of endothelial cells on the coated matrices was found to be adequate to resist shear stress when monolayers were exposed to forces of flow in an in vitro parallel plate flow chamber. The monolayers maintained physiological nonthrombogenic character as evidenced by in vitro platelet adhesion and response to agonist measurements. Nitric oxide synthesis by cells grown on the study matrices was also found to be normal. Thus, the matrix composition and the coating technique, as presented here, can be easily applied to generate tissue-engineered biomaterials with a nonthrombogenic endothelial cell monolayer for cardiovascular implants. The freeze-drying of the coated matrix ensures prolonged stability and thus the materials can be stored in a ready-to-use state for endothelial cell sodding or seeding.     

Quantitative comparison of clumping factor- and coagulase-mediated Staphylococcus aureus adhesion to surface-bound fibrinogen under flow.

The contributions of clumping factor and coagulase in mediating Staphylococcus aureus adhesion to surface-adsorbed fibrinogen have been quantified by using a new methodology and analysis. The attachment or detachment kinetics of bacteria were directly observed in a radial flow chamber with a well-defined laminar flow field and a spatially varying shear rate and were quantified by recursively scanning the chamber surface and counting cells via automated video microscopy and image analysis with a motorized stage and focus control. Intrinsic rate constants for attachment or detachment were estimated as functions of shear rate for the wild-type Newman strain of S. aureus and for mutants lacking clumping factor, coagulase, or both proteins on surfaces coated with plasma, fibrinogen, or albumin. Clumping factor, but not coagulase, increased the probability of attachment and decreased the probability of detachment of S. aureus on plasma-coated surfaces; however, both clumping factor and, to a lesser extent, coagulase increased the probability of attachment on the purified-fibrinogen-coated surface. All mutants were resistant to detachment on the purified-fibrinogen-coated surface, suggesting the possibility of an additional adhesion mechanism which was independent of coagulase or clumping factor and effective only for fully attached cells. Together, these results suggest that the presence of clumping factor plays the primary role in enhancing adhesion to surfaces with adsorbed fibrinogen, not only by enhancing the probability of cell attachment but also by increasing the strength of the resulting adhesion.     

Evaluation of an in vitro endothelialized vascular graft under pulsatile shear stress with a novel radiolabeling procedure

OBJECTIVE: To improve the hemocompatibility of vascular grafts, endothelial cell (EC) seeding of biomaterials prior to implantation is critical. The current in vitro study was designed to investigate such a feasibility on a collagen-coated heparin-bonded graft and to evaluate cell detachment upon pulsatile shear stress. MATERIALS AND METHODS: Endothelial cells (EA-hy-926) were seeded onto grafts. The endothelialization of the grafts was evaluated by the [3H]-thymidine incorporation, scanning electron microscopy (SEM) and histological examinations. After in situ EC radiolabeling with a novel 99mTc technique, the prostheses were exposed to pulsatile shear stress (0.27 N/m2), mimicking the shear rate occurring in a superficial femoral artery, for 3 h in a flow circuit and EC loss quantified by gamma camera detection. RESULTS: Complete EC coverage was achieved after 5 days. Three hours of artificial perfusion resulted in a low EC loss (12.9+/-0.8%, n = 7). SEM shows EC withstanding shear stress in valleys of prosthesis circumvolutions. CONCLUSIONS: These satisfactory results could be explained by the high affinity of EC for heparinized surfaces in addition to cell surface receptors involved in adhesion to collagen.     

Cell adhesion and detachment on gold surfaces modified with a thiol-functionalized RGD peptide

The dynamic nature of cell adhesion and detachment is critically important to a variety of physiological and pathophysiological phenomena. Much, however, still remains uncertain and controversial about the mechanochemical players and processes involved in cellular adhesion and detachment. This leads to the need for quantitative characterization of the adhesion and detachment of anchorage-dependent cells. Here, cell adhesion and detachment up to subcellular level are examined using gold surfaces modified with a thiol-functionalized arginine-glycine-aspartic acid (RGD) peptide. A thiol self-assembled monolayer (SAM) on top of the gold surfaces is reductively desorbed with activation potential to spatiotemporally manipulate both cell adhesion and detachment. This method maintains cells of interest living and intact during experiments, making it possible to quantify cell adhesion and detachment as close as possible to in?vivo conditions. Experimental characterizations for NIH 3T3 fibroblasts are carried out with a focus on the following issues: the effect of the size and geometric shape of gold surfaces on cell adhesion; the effect of cell confluency, cell shape, and activation potential magnitude on cell detachment; changes in the material properties of cells during cell detachment. The findings of this study should lead to better understanding of cellular dynamics in anchorage-dependent cells.     

Effect of adsorbed fibronectin concentration on cell adhesion and deformation under shear on hydrophobic surfaces.

To facilitate tissue integration with biomaterials proteins and peptides frequently are immobilized on the biomaterial surface. In particular, extracellular matrix proteins--which interact specifically with integrin adhesion receptors on the cell surface--can stimulate initial cell attachment by serving both as a ligand for receptor-mediated attachment and as a stimulant of focal adhesion formation and cytoskeletal reorganization. Consequently, the strength of cell adhesion should depend both on the strength of cell/surface contacts and cytoskeleton-dependent properties of the cell (i.e., morphology, compliance). To examine this dual role of extracellular matrix proteins, murine fibroblasts were seeded onto self-assembled monolayers (SAMs) of dodecanethiolate coated with 0 to 0.45 microg/cm(2) of fibronectin (Fn) and then detached by hydrodynamic shear using a radial-flow chamber (RFC). Cell adhesion was characterized in terms of the critical wall shear stress for detachment (tau(wc)), and the compliance was evaluated from measurements of cell displacement and elongation as a function of the fibronectin concentration. Critical wall shear stress and cell displacement were found to be insensitive to Fn at concentrations below 0.23 microg/cm(2) while above this threshold tau(wc) increased and displacement decreased with increasing Fn concentration. Elongation of the cells in the direction of flow was independent of Fn concentration, but correlated linearly with tau(wc) for Fn densities below 0.23 microg/cm(2). These studies show that Fn concentration affects both tau(wc) and cell displacement under shear, and that tau(wc) is sensitive to cell compliance. In addition, they suggest that the dominant mechanism of cell detachment from hydrophobic substrates involves cell displacement.     

Influence of substratum wettability on the strength of adhesion of human fibroblasts.

To determine the strength of adhesion and the detachment mechanisms of fibroblasts from substrata with different wettability, the behaviour of adhered cells was studied in a parallel-plate flow chamber during exposure to shear. Adhered cells were observed in situ, i.e. in the flow chamber, by phase-contrast microscope and images were analysed semiautomatically. Detachment was found to be dependent both on shear stress and time, although a critical shear stress can be found below which no detachment occurs. On all substrata, cells round up before detachment and are approximately spherical immediately before detachment. The strength of adhesion calculated ranged from 0.6-3.5 x 10(-10) N per cell on FEP-Teflon (the least wettable material included) to 9.4 x 10(-9) N per cell for glass (the most wettable). Ease of detachment seemed to decrease with increasing wettability. However, cells reacted more strongly with tissue culture polystyrene (TCPS) than expected on the basis of its wettability, probably due to surface chemistry.     

A centrifugation cell adhesion assay for high-throughput screening of biomaterial surfaces

A quantitative analysis of cell adhesion is essential in understanding physiological phenomena and designing biomaterials, implant surfaces, and tissue-engineering scaffolds. The most common cell adhesion assays used to evaluate biomaterial surfaces lack sensitivity and reproducibility and/or require specialized equipment and skill-intensive operation. We describe a modified centrifugation cell adhesion assay that uses simple and convenient techniques with standard laboratory equipment and provides reliable, quantitative measurements of cell adhesion. This centrifugation assay applies controlled and uniform detachment forces to a large population of adherent cells, providing robust statistics for quantifying cell adhesion. The applicability of this system to the design and characterization of biomaterial surfaces is shown by evaluating cell adhesion on substrates using different coating proteins, cell types, seeding times, and relative centrifugal forces (RCF). Results verify that this centrifugation cell adhesion assay represents a simple, convenient, and standard method for high-throughput characterization of a variety of biomaterial surfaces and conditions.