Quantitative analysis of autocrine-regulated, matrix-induced, and tumor cell-stimulated endothelial cell migration using a silicon template compartmentalization technique.

Autocrine-regulated, matrix-induced, and tumor cell-stimulated endothelial cell migration was quantitatively analyzed using a two-dimensional, two-compartment coculture system. Silicon templates were used to subdivide 35-mm tissue culture dishes into two separate compartments. Endothelial cells were grown to confluence in the inner compartment and released from growth arrest by removal of the silicon template. The distance of endothelial cell outgrowth from the monolayer was measured in 24-h intervals. Endothelial cells from different vascular beds migrated with different migration rates (large vessel endothelial cells greater than hemangioendothelioma cells greater than microvessel endothelial cells). Prior coating of tissue culture wells with fibronectin, type I collagen, or type IV collagen and increasing serum concentrations strongly enhanced endothelial cell migration. Seeding tumor cells into the outer compartment prior to removal of the silicon template permitted the direct coculture analysis of tumor cell-induced endothelial cell migration. Microvascular endothelial cell migration was stimulated in a tumor cell number-dependent fashion, whereas large vessel endothelial cells could not consistently be stimulated by coculture with tumor cells. It is concluded that silicon templates offer a useful approach for the quantitative study of migration of anchorage-dependent cells, permitting follow-up measurements over several days, the study of matrix effects, and the direct coculture analysis of cell migration.     

Collagen type I together with fibronectin provide a better support for endothelialization

Endothelialization of vascular implants is limited by the inability of cells to retain adhesion when exposed to flow. Extracellular matrix proteins, including fibronectin and collagen, enhance cell adherence on materials. This study investigated the behaviour of Human Umbilical Vein Endothelial Cells (HUVEC) on extracellular matrix coated polystyrene. Collagen and fibronectin were coated as single and double layers to analyse differences in cell proliferation, morphology, and cell-protein interactions. Significantly higher endothelial cell proliferation and migration rates were observed on the collagen and collagen+fibronectin coating compared to the uncoated or fibronectin-coated sample. Immmunofluorescent microscopy showed evidence of extracellular matrix remodelling in the double, collagen+fibronectin coating. These results strongly suggest that a double coating of collagen+fibronectin provides a better support structure for endothelial cell growth and contributes to improve the ability of vascular implants to become and remain endothelialized.     

Quantification of bacterial adherence on different textile fabrics

This research studied the adherent behaviour of gram-negative Escherichia coli on different weft knitted textile fabrics made of cotton, polyester filaments and polyester (staple)-cotton blended yarn. We compared the bacterial adherence of 18-h-old E. coli cells on all the three types of fabrics under the same experimental conditions. The maximum adherence was found in cotton, followed by the polyester blend; the least adherence was in polyester fabrics. Scanning electron micrographs showed that surface morphology of fabrics also plays an important role during adherence. Cotton fabric, with a rough surface, attracted more bacterial cells compared to the smooth polyester surface. Comparing the FTIR spectra of different fabrics and E. coli it was found that both cotton and E. coli have abundant free hydroxyl groups that may interact strongly with each other and with other hydrophilic groups such as carboxyl, phosphate, and amides. This may be one of the reasons for the greater adherence on cotton as compared to hydrophobic polyester fabric. Finally, the effect of bacterial adherence on loss of strength in different fabrics was analysed. It was found that the maximum decrease in strength occurred in cotton fabrics and the least in polyester fabrics. The present study suggests a procedure for quantifying bacterial adherence on different textile fabrics. This technique can be used with different bacterial strains and varieties of fabrics for quantifying the adherent bacterial cells, and would be of great use in developing and comparing different antimicrobial finished products of the textile industry.     

Basic fibroblast growth factor and transforming growth factor beta-1: Synergistic mediators of angiogenesis in vitro

We investigated the relative roles of basic fibroblast growth factor (bFGF) and transforming growth factor beta-1 (TGF-b) on bovine aortic endothelial cell mitogenesis and morphogenesis using two-dimensional Petri dish cultures and a threedimensional hydrated collagen gel. bFGF alone stimulated endothelial cell proliferation with an EC₅₀ of 0.5 ng/ml. At bFGF levels greater than 2.5 ng/ml, morphologic alterations in confluent monolayers predominated; cells changed from a cobblestone morphology to an elongated cell pattern and showed enhanced migration into a denuded area of a Petri dish. In the three-dimensional model, exposure of endothelial cell monolayers to high bFGF levels stimulated minor cell migration directly under the monolayer but no invasion into the gel matrix. In combination with bFGF, heparin potentiated morphogenic changes, but not mitogenesis. bFGF, modification of the antiproliferative effect of TGF-b in confluent cultures was evidenced by induction of endothelial cell sprouting in response to 0.5 ng/ml TGF-b and 10–20 ng/ml bFGF in two-dimensional cultures. On collagen gels, endothelial cells migrated into the deep layers of the gel in a dose-dependent manner: invasion was maximal at 0.3–0.7 ng/ml TGF-b with decreased invasion at higher concentrations. The optimal collagen concentration that supported cell invasion was 0.075% collagen with the number of invading cells decreasing with increasing collagen gel density. By scanning electron microscopy, invading endothelial cells assumed a fibroblast-like appearance with slender cell extensions. We concluded that bFGF and TGF-b had independent effects on endothelial cell morphology and mitogenesis in culture. In combination at specific doses, these agents stimulated sprouting in the two-dimensional model and cell invasion in a collagen gel model. Morphogenic changes may be the primary event in determining angiogenesis. © 1993 Wiley-Liss, Inc.     

Albuminated dacron protheses as improved blood vessel substitutes.

An improved vascular graft was achieved by treating knitted Dacron prostheses with cross-linked albumin. Eight segments, each six centimeters in length, were coated and implanted in the canine thoracic aorta for periods ranging from 24 hours to six months. The results were compared with the eight untreated grafts implanted for similar periods as control experiments. Albumin coating resulted in a faster healing : cells appeared earlier and collagen development was greater. The most beneficial effect of that treatment was the reduction in embolization, as shown by the considerable decrease in kidney damage.     

Composition of culture medium is more important than co-culture with hepatic non-parenchymal cells in albumin production activity of primary rat hepatocytes,and the effect was enhanced by hepatocytes spheroid culture in collagen gel

Co-culture of primary rat hepatocytes with hepatic non-parenchymal cells or sinusoidal endothelial cells for albumin production activity as an index of liver-specific function was studied. The co-cultures were effective for the expression and maintenance of albumin production activity. However, the co-culture effect was not observed when we used a suitable culture medium, which had already been reported to be sufficient for albumin production activity. Albumin production of dispersed cells in collagen gel culture was higher than that of spheroid culture. In addition, albumin production of spheroids in collagen gel culture was higher than that of spheroid culture and dispersed cell collagen gel culture with a suitable culture medium. We found that culture medium composition was more important than co-culture for expression and maintenance of albumin production. Furthermore, we found that cell–cell interaction was effective for the expression of albumin production, but heterotypic cell–cell interaction was not necessary.     

The inhibitory effects of endostatin on endothelial cells are modulated by extracellular matrix

We investigated the ability of extracellular matrix (ECM) proteins to modulate the response of endothelial cells to both promoters and inhibitors of angiogenesis. Using human dermal microvascular endothelial cells (HDMEC), we found that cells demonstrated different adhesive properties and proliferative responses to the growth factor VEGF depending upon which ECM protein with which they were in contact, with fibronectin having the most impact on VEGF-induced HDMEC proliferation and survival. More importantly, we observed that ECM could modulate the ability of the angiogenic inhibitor endostatin to prevent endothelial cell proliferation, survival and migration. We observed that growth on vitronectin or fibronectin impaired the ability of endostatin to inhibit VEGF-induced HDMEC proliferation to the greatest extent as determined by BrdU incorporation. We found that, following growth on collagen I or collagen IV, endostatin only inhibited VEGF-induced HDMEC proliferation at the highest dose tested (2500 ng/ml). In a similar manner, we observed that growth on ECM proteins modulated the ability of endostatin to induce endothelial cell apoptosis, with growth on collagen I, fibronectin and collagen IV impairing endostatin-induced apoptosis. Interestingly, endostatin inhibited VEGF-induced HDMEC migration following culture on collagen I, collagen IV and laminin, while migration was not inhibited by endostatin following HDMEC culture on other matrices including vitronectin, fibronectin and tenascin-C. These results suggest that different matrix proteins may affect different mechanisms of endostatin inhibition of angiogenesis. Taken together, our results suggest that the ECM may have a profound impact on the ability of angiostatic molecules such as endostatin to inhibit angiogenesis and thus may have impact on the clinical efficacy of such inhibitors.     

The Effect of Extracellular Matrix Molecules on the in Vitro Behavior of Bovine Endothelial Cells

Extracellular matrix (ECM) is an important mediator of endothelial functions such as adhesion, spreading, migration, proliferation, and maintenance of differentiated functions. Attachment of cultured cells to tissue culture polystyrene (TCPS) is dependent on vitronectin which adsorbs onto the surface from the serum in the culture medium. Vitronectin (VN) will adsorb efficiently to TCPS even if the latter has been coated with another matrix molecule and blocked with albumin. This means that studies of the interactions of cells with individual coated ECM molecules will be confounded by the presence of adsorbed VN if serum is present in the culture medium. In this study, the adhesion, spreading, growth, and output of endogenous matrix molecules by bovine corneal endothelial (BCE) cells were measured on five different matrix substrates using medium which had been depleted of vitronectin to avoid such confounding effects. The same cell adhesion and spreading maxima were achieved on vitronectin, fibronectin (FN), laminin (LM), and types I and IV collagen (col I, col IV). The coating concentrations required to achieve these maxima, however, differed among the substrates, LM needing considerably higher concentrations than the other substrates for both maximal adhesion and spreading and FN needing higher concentrations for cell spreading. When cells were continuously passaged on each of the five substrates coated at concentrations optimal for cell spreading, no differences in cell proliferation rates or cell morphology were observed. Significant differences, however, were observed in the subcellular output of endogenous matrix molecules (FN, LM, col IV, and thrombospondin) between the different substrates. Col I was a poor substrate for the production of all ECM molecules tested over the 10 passages of the experiment, whereas col IV was a consistently good substrate. LM and FN substrates displayed differential effects on the output of different ECM molecules. VN was unique in that BCE cells at early passage on this substrate produced high levels of endogenous matrix molecules, whereas with continued passage on this substrate, a progressive decline in ECM secretion was observed. These results show that incorporation of individual molecules into the ECM by BCE cells in culture is significantly affected by the nature of the substratum. They further suggest that passage of endothelial cells in media containing serum (which results in coating of VN onto the substrate) may result in a progressive reduction of ECM output.     

Type I collagen synthesis by corneal endothelial cells modulated by polymorphonuclear leukocytes

When primary corneal endothelial cells were grown in polymorphonuclear leukocyte (PMN)-conditioned medium, a minor population of cells acquired fibroblastic morphology. Such modulated endothelial cells supported by PMN-conditioned medium grew much faster than the major nonresponding polygonal endothelial cell. Upon serial passages, the modulated endothelial cells became the dominant cell type and eventually formed a homogeneous fibroblastic culture. At the same time, phenotypic changes of collagen were observed. The primary endothelial cells grown in PMN-conditioned medium, consisting of responding elongated cells and nonresponding polygonal endothelial cells, produced predominantly type IV collagen with type III collagen as a minor component. As cells were subcultured and fibroblastic cells became dominant, type IV collagen synthesis was dramatically decreased and type I collagen synthesis was increased in parallel. When they reached the fully modulated stage, the cultures synthesized types I and III collagen, with type I accounting for 75-85% of the total. Type I collagen synthesized by the fibroblastic endothelial cells shared common characteristics with known type I collagen, such as migration behavior on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, CNBr peptide profiles, and immunologic identity. Thus, PMNs apparently contribute to the modulation of corneal endothelial cells, causing them to acquire characteristics of fibroblasts, cell multilayering, and deposition of interstitial extracellular matrix composed predominantly of interstitial type I collagen.     

Heterogeneity in collagen biosynthesis by sprouting retinal endothelial cells

Bovine retinal microvascular endothelial cells can display two distinct and reversible morphologies in culture: ‘cobblestone’ and ‘sprouting’. The cobblestone morphology resembles the resting cells lining the lumen of mature vessels while the sprouting morphology resembles the angiogenic cells involved in the formation of new vessels. Retinal cells displayed some heterogeneity in the shape of the cells making up the cobblestone monolayer. In contrast, all cell lines displayed an identical sprouting morphology. We have investigated the synthesis of matrix macromolecules by retinal endothelial cells displaying either the cobblestone or the sprouting morphology. Type IV was the only collagen synthesised by eight different lines of early-passage (between one and six) cobblestone endothelial cells. Collagen types I and III were not detected in these cultures. In contrast, heterogeneity was observed in the types of collagen synthesised by four lines of early-passage cells displaying the sprouting morphology. That is, two lines synthesised collagen types I, III and IV, whereas two other lines continued to synthesise only type IV collagen. Both cobblestone and sprouting cells synthesised fibronectin and thrombospondin, although the relative amounts of these macromolecules varied with culture conditions. The pattern of collagen synthesis by cobblestone cells was also affected by in vitro ?ageing”?: 4/5 lines examined above passage eight synthesised collagen types I, III and IV. Our results indicate that there is heterogeneity in the sprouting phenotype displayed by retinal endothelial cells, and that this phenotype is not necessarily associated with the synthesis of type I collagen. We suggest that differences in the spectrum of matrix macromolecules synthesised by sprouting endothelial cells may play a role in the control of angiogenesis. © 1994 wiley-Liss, Inc.     

Retinal capillary endothelial cells prefer different substrates for growth and migration

Recent studies have shown that the extracellular matrix modifies the behaviour of endothelial cells. We have studied the effects of extracellular matrix components on retinal capillary endothelial cell migration and proliferation. Bovine retinal capillary endothelial cells were selectively cultured from collagenase-digested microvessel fragments. In a filter system for the assessment of migration, endothelial cells responded to substrate-bound fibronectin but not to soluble fibronectin. Cell migration on collagen- or gelatin-coated filters was minimal, and these cells failed to adopt a spread morphology, remaining instead as round cells. Cell replication was quantified using a protein dye binding assay for adherent cells in 96 well plates. Serum was essential for growth irrespective of the substrate. Cells harvested from microvessel cultures proliferated more rapidly on collagen- and gelatin-coated plastic than on fibronectin and were unaffected by additions to the medium such as endothelial cell conditioned medium, whereas cells proliferating directly from the microvessels grew at a faster rate on fibronectin and also responded to conditioned medium supplement. When cultured on collagen gels, initial microvessel cells and harvested cells required surface fibronectin in order to adopt a cobblestone morphology. These results show that fibronectin is a requirement for bovine retinal capillary endothelial cell migration, but proliferation of these cells can be supported, with slight differences, by both fibronectin and collagen provided serum growth factors are present. These findings are relevant to the early phase of angiogenesis in which migration and proliferation of endothelial cells occurs.     

Albumin modified by Amadori glucose adducts activates mesangial cell type IV collagen gene transcription

Increased protein glycation has been mechanistically linked to accelerated vascular pathobiology in diabetes. To test the influence of protein modified by Amadori glucose adducts on vascular cell biology, we examined the effect of glycated albumin on replicative capacity and basement membrane collagen production by aortic endothelial cells in culture. Relative to carbohydrate-free albumin, which supported cell proliferation and Type IV collagen synthesis, glycated albumin significantly inhibited³H-thymidine incorporation and Type IV collagen production. The glycated albumin-induced effects were prevented by monoclonal antibodies (A717) that specifically react with Amadori-modified albumin, but not by IgG that was unreactive with glycated albumin. A717 had no effect on thymidine incorporation or collagen synthesis by cells cultured in the presence of nonglycated albumin. The findings indicate that the interaction of glycated albumin with endothelial cells, which have been shown to display dose-responsive, saturable receptors, limits cell replication and triggers maladaptive biosynthetic programs, which may contribute to degenerative macrovascular disease in diabetes.     

Glycated albumin modified by amadori adducts modulates aortic endothelial cell biology

Increased protein glycation has been mechanistically linked to accelerated vascular pathobiology in diabetes. To test the influence of protein modified by Amadori glucose adducts on vascular cell biology, we examined the effect of glycated albumin on replicative capacity and basement membrane collagen production by aortic endothelial cells in culture. Relative to carbohydrate-free albumin, which supported cell proliferation and Type IV collagen synthesis, glycated albumin significantly inhibited³H-thymidine incorporation and Type IV collagen production. The glycated albumin-induced effects were prevented by monoclonal antibodies (A717) that specifically react with Amadori-modified albumin, but not by IgG that was unreactive with glycated albumin. A717 had no effect on thymidine incorporation or collagen synthesis by cells cultured in the presence of nonglycated albumin. The findings indicate that the interaction of glycated albumin with endothelial cells, which have been shown to display dose-responsive, saturable receptors, limits cell replication and triggers maladaptive biosynthetic programs, which may contribute to degenerative macrovascular disease in diabetes.     

Optimization of culture conditions for human corneal endothelial cells

Summary Long-term cultivation of human corneal endothelial cells (HCEC) was optimized with respect to different components of the culture system: 25 different nutrient media, different sera, 6 mitogens and various substrates were tested in their ability to influence clonal growth and morphology of HCEC. F99, a 1∶1 mixture of the two media M199 and Ham’s F12, was the most effective basal medium in promoting clonal growth of HCEC. Among various sera, human serum and fetal bovine serum showed optimal growth promoting activities in combination with F99, whereas newborn bovine serum (NBS) was by far superior for the development of a typically corneal endothelial morphology. Crude fibroblast growth factor (FGF), or alternatively endothelial cell growth supplement, was absolutely essential for clonal growth of HCEC at low serum concentrations, for example 5% NBS. Formation of a monolayer with a morphology similar to corneal endothelium in vivo was observed only on culture dishes coated with basal membrane components such as collagen type IV, laminin, or fibronectin. The most pronounced effect on morphologic appearance was obtained by culturing the cells on the extracellular matrix (ECM) produced by bovine corneal endothelial cells. Moreover, ECM could substitute for crude FGF in clonal growth assays.     

Differential effects of laminin, intact type IV collagen, and specific domains of type IV collagen on endothelial cell adhesion and migration

Laminin and type IV collagen were compared for the ability to promote aortic endothelial cell adhesion and directed migration in vitro. Substratum-adsorbed IV promoted aortic endothelial cell adhesion in a concentration dependent fashion attaining a maximum level 141-fold greater than controls within 30 min. Aortic endothelial cell adhesion to type IV collagen was not inhibited by high levels (10(-3) M) of arginyl-glycyl-aspartyl-serine. In contrast, adhesion of aortic endothelial cells on laminin was slower, attaining only 53% of the adhesion observed on type IV collagen by 90 min. Type IV collagen when added to the lower well of a Boyden chamber stimulated the directional migration of aortic endothelial cells in a concentration dependent manner with a maximal response 6.9-fold over control levels, whereas aortic endothelial cells did not migrate in response to laminin at any concentration (.01-2.0 X 10(-7) M). Triple helix-rich fragments of type IV collagen were nearly as active as intact type IV collagen in stimulating both adhesion and migration whereas the carboxy terminal globular domain was less active at promoting adhesion (36% of the adhesion promoted by intact type IV collagen) or migration. Importantly, aortic endothelial cells also migrate to substratum adsorbed gradients of type IV collagen suggesting that the mechanism of migration is haptotactic in nature. These results demonstrate that the aortic endothelial cell adhesion and migration is preferentially promoted by type IV collagen compared with laminin, and has a complex molecular basis which may be important in angiogenesis and large vessel repair.     

Layer-by-layer assembly to modify poly(l-lactic acid) surface toward improving its cytocompatibility to human endothelial cells

A novel technique to introduce free amino groups onto polyester scaffolds via aminolyzing the ester groups with diamine has been developed recently. Positively charged chitosan was then deposited onto the aminolyzed poly(l-lactic acid) (PLLA) membrane surface in a layer-by-layer assembly manner using poly(styrene sulfonate, sodium salt) (PSS) as a negatively charged polyelectrolyte. The layer-by-layer deposition process of PSS and chitosan was monitored by UV-vis absorbance spectroscopy, energy transfer by fluorescence spectroscopy, and advancing contact angle measurements. The existed chitosan obviously improved the cytocompatibility of PLLA to human endothelial cells. The cell attachment, activity, and proliferation on the PLLA membranes assembled with three or five bilayers of PSS/chitosan with chitosan as the outermost layer were better than those with one bilayer of PSS/chitosan or the control PLLA. The cells also showed morphology of an elongated shape with abundant cytoplasm, and a confluent cell layer was reached after being cultured for 4 days. Measurement of von Willebrand factor secreted by these endothelial cells (ECs) verified the endothelial function. Hence, better ECs compatible PLLA were produced.     

Identification of a synergistic interaction between endothelial cells and retinal pigment epithelium

The retinal pigment epithelium located between the neurosensory retina and the choroidal vasculature is critical for the function and maintenance of both the photoreceptors and underlying capillary endothelium. While the trophic role of retinal pigment epithelium on choroidal endothelial cells is well recognized, the existence of a reciprocal regulatory function of endothelial cells on retinal pigment epithelium cells remained to be fully characterized. Using a physiological long‐term co‐culture system, we determined the effect of retinal pigment epithelium‐endothelial cell heterotypic interactions on cell survival, behaviour and matrix deposition. Human retinal pigment epithelium and endothelial cells were cultured on opposite sides of polyester transwells for up to 4 weeks in low serum conditions. Cell viability was quantified using a trypan blue assay. Cellular morphology was evaluated by H&E staining, S.E.M. and immunohistochemistry. Retinal pigment epithelium phagocytic function was examined using a fluorescent bead assay. Gene expression analysis was performed on both retinal pigment epithelium and endothelial cells by quantitative PCR. Quantification of extracellular matrix deposition was performed on decellularized transwells stained for collagen IV, fibronectin and fibrillin. Our results showed that presence of endothelial cells significantly improves retinal pigment epithelium maturation and function as indicated by the induction of visual cycle‐associated genes, accumulation of a Bruch's membrane‐like matrix and increase in retinal pigment epithelium phagocytic activity. Co‐culture conditions led to increased expression of anti‐angiogenic growth factors and receptors in both retinal pigment epithelium and endothelial cells compared to monoculture. Tube‐formation assays confirmed that co‐culture with retinal pigment epithelium significantly decreased the angiogenic phenotype of endothelial cells. These findings provide evidence of critical interdependent interactions between retinal pigment epithelium and endothelial cell involved in the maintenance of retinal homeostasis.     

Effect of protein-hydroxyethylmethacrylate hydrogels on cultured endothelial cells

The use of protein hydroxy ethylmethacrylate (HEMA) hydrogels to control cell morphology and growth, as well as the synthesis of extracellular matrix components, is described in this communication. HEMA hydrogels prepared with collagen support growth of embryonic lung fibroblasts (IMR-90), as well as bovine aortic and pulmonary artery endothelial cells at a level comparable to the respective cells grown on tissue culture surfaces. On the other hand, HEMA hydrogels prepared with solubilized elastin inhibit the fibroblast growth and prevent both types of endothelial cell cultures from achieving their normal morphology. These morphologically altered endothelial cells resume a normal cobblestone-like appearance when subcultivated from the elastin-HEMA hydrogels to tissue culture plastic. When pulsed with [14C]proline, the procollagens synthesized by the endothelial cells on the different surfaces vary, as shown by immunoprecipitation and polyacrylamide gel electrophoresis. On the standard tissue culture plastic, the confluent cells produce mainly type III procollagen in the medium, whereas those endothelial cells grown on collagen and elastin-HEMA hydrogels synthesize primarily type I procollagen (much like sprouting cells on tissue culture plastic), regardless of their morphology.     

Surface modification of polycaprolactone membrane via aminolysis and biomacromolecule immobilization for promoting cytocompatibility of human endothelial cells

Amino groups were covalently introduced onto a polycaprolactone (PCL) surface by the reaction between 1,6-hexanediamine and the ester groups of PCL. The occurrence of the aminolysis and the introduction of free NH(2) groups were verified qualitatively by fluorescence spectroscopy, where rhodamine B isothiocyanate was employed to label NH(2) groups, and quantitatively by absorbance spectroscopy, where ninhydrin was used to react with NH(2) to generate a blue product. Due to the presence of deep pores on the PCL membrane, the aminolysis reaction could penetrate as deep as 50 microm to yield NH(2) density as high as 2 x 10(-7) mol/cm(2). By use of the NH(2) groups as active sites, biocompatible macromolecules such as gelatin, chitosan, or collagen were further immobilized on the aminolyzed PCL membrane via a cross-linking agent, glutaraldehyde. X-ray photoelectron spectroscopy (XPS) and surface wettability measurements confirmed the coupling of the biomacromolecules. The endothelial cell culture proved that the cytocompatibility of the aminolyzed PCL was improved slightly regardless of the NH(2) amount on the surface. After immobilization of the biomacromolecules, however, the cell attachment and proliferation ratios were obviously improved and the cells showed a similar morphology to those on tissue culture polystyrene. Measurement of the von Willebrand factor (vWF) secreted by these endothelial cells (ECs) verified the endothelial function. Hence, a better EC-compatible PCL was produced.