Arteriosclerotic Nanoplaque Formation Research Articles

The role of the proteoglycan receptor in lipoprotein binding

Heparan sulfate proteoglycan can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution representing one receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. A second lipoprotein binding site has been localized to four copies of LDL receptor repeats of core domain II. The binding process was studied by ellipsometric techniques showing that HDL has a high binding affinity to the receptor and a protective effect on interfacial heparan sulfate proteoglycan layers with respect to LDL and Ca2+ complexation. LDL was found to deposit strongly at the proteoheparan sulfate, particularly in the presence of Ca2+, thus creating the complex formation ‘proteoglycan—low density lipoprotein—calcium’. This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. On the other hand, HDL bound to heparan sulfate proteoglycan protected against LDL docking and completely suppressed calcification of the proteoglycan-lipoprotein complex. In addition, HDL was able to both reduce the ternary complex deposition and to disintegrate HS-PG/LDL/Ca2+ aggregates. Therefore, HDL attached to its proteoglycan receptor sites is thought to raise a multidomain barrier, selection and control motif for transmembrane and paracellular lipoprotein uptake into the arterial wall. Although much remains unclear regarding the mechanism of lipoprotein depositions at proteoglycan-coated surfaces, it seems clear that the use of such systems offers possibilities for investigating lipoprotein deposition at a ‘nanoscopic’ level under close to physiological conditions. In particular, Ca2+-promoted LDL deposition and the protective effect of HDL, even at high Ca2+ and LDL concentrations, agree well with previous clinical observations regarding risk and beneficial factors for early stages of atherosclerosis.

The importance of scavenging reactive oxygen species in anti‐aging medicine

AbstractIn a pilot study, we had reported on the beneficial effects of Ginkgo biloba (EGb 761) on arteriosclerotic nanoplaque formation and size in cardiovascular high‐risk patients who had undergone an aortocoronary bypass operation. Briefly, nanoplaque formation and size, the ratio oxLDL/LDL, and the highly atherothrombotic lipoprotein(a) concentration were substantially reduced, while superoxide dismutase activity and the blood concentration of the vasodilating substances cAMP and cGMP were upregulated. Since the arteriosclerosis prophylactic and well‐aging promotive impact of Ginkgo extract has been proven in this pilot study, we wanted to confirm these beneficial effects through a second observational clinical trial. The measurable variables formerly used were additionally supplemented by a wide, novel biomarker spectrum, through which the latest parameters and markers of plaque stability and progression, oxidative stress, and inflammation were available. In eleven patients with metabolic syndrome in the initial stage, the reduction of arteriosclerotic nanoplaque formation amounted to 14.3±2.9% (p<0.0077) and of nanoplaque size to 23.4±3.7% (p<0.0004), respectively, after 2‐months of treatment with Ginkgo biloba extract. Additionally, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were upregulated by 19.6±10.0% (p<0.0785) and 11.6±2.3% (p<0.001), respectively, the quotient oxLDL/LDL lowered by 21.0±4.3% (p<0.002), and lipoprotein(a) concentration decreased by 26.3±4.8% (p<0.001) in the patients' blood. The concentration of cAMP and cGMP was augmented by 43.5±12.0% (p<0.001) and 32.9±10.4% (p<0.001), respectively. Surprisingly, we found a lowering of the serum Ca2+ concentration by 5.4±1.6% (p<0.0076) from 2.37±0.03 to 2.24±0.04 mmol/L (p<0.0069). Apart from an additional vasodilatory effect, the lowered extracellular Ca2+ concentration affects nanoplaque formation restrictively, since this is a Ca2+ driven process. Furthermore, we could show a favourable development of the biomarkers 8‐iso‐PGF2α, oxLDL/LDL, SOD, GPx (oxidative stress), hs‐CRP, MPO, TNFα, TGFβ1 (inflammatory status) and MMP‐9 (plaque stability). The markers selected here are suited to provide a comprehensive risk profile for the prevention of arteriosclerosis. Finally, a multiple regression analysis reveals a basis for a mechanistic explanation of nanoplaque reduction under Ginkgo treatment. The arteriosclerosis inhibiting effect is due to an attenuation of the risk factors oxLDL/LDL, Lp(a), and [Ca2+]o as well as to a significant increase in the vasodilator cAMP and cGMP concentration. Thus, Ginkgo with its pleiotropic effects should be assigned a fixed rank among the anti‐aging medical therapeutics as a prophylactic measure, especially in patients with early‐stage metabolic syndrome.

Reduction of Arteriosclerotic Nanoplaque Formation and Size by n-3 Fatty Acids in Patients after Valvular Defect Operation

Background/Methods: Coating a silica surface with the isolated lipoprotein receptor heparan sulfate proteoglycan (HS-PG) from arterial endothelium and vascular matrices, we could observe the very earliest stages of arteriosclerotic plaque development by ellipsometric techniques in vitro (patent EP 0 946 876). This so-called nanoplaque formation is represented by the ternary aggregational complex of the HS-PG receptor, lipoprotein particles and calcium ions. The model was validated in several clinical studies on statins in cardiovascular high-risk patients applying their native blood lipoprotein fractions. Results: In 7 patients who had undergone a valvular defect operation, the reduction of arteriosclerotic nanoplaque formation in normal Krebs solution amounted to 6.1 ± 2.3% (p < 0.0156) and of nanoplaque size to 37.5 ± 13.2% (p < 0.0312), respectively, after a 3-month therapy with n-3 fatty acids (3 ··3 g daily, Ameu® 500 mg). Additionally, the quotient oxLDL/LDL was lowered by 6.8 ± 2.1% (p < 0.0166), the MDA concentration remained unchanged and the lipoprotein(a) concentration decreased by 15.8 ± 5.6% (p < 0.0469) in the patients’ blood. The concentration of the nanoplaque promoting particles VLDL and total triglycerides was diminished by 34.1 ± 11.6% (p < 0.0469) and 26.7 ± 10.8% (p < 0.0156), respectively. Furthermore, the ratio of the strongly atherogenic small dense to the total LDL cholesterol (LDL5+LDL6)/LDLtot decreased by 9.9 ± 3.0% (p < 0.0174). Conclusions: A combinatorial regression analysis revealed a basis for a mechanistic explanation of nanoplaque reduction under n-3 fatty acid treatment. This effect was possibly due to the beneficial changes in lipid concentrations and an attenuation of the risk factors oxLDL/LDL and (LDL5+LDL6)/LDLtot.

Nanotechnologic biosensor ellipsometry and biomarker pattern analysis in the evaluation of atherosclerotic risk profile

A proteoheparan sulfate coated, hydrophobic silica surface serves as lipoprotein receptor at which the Ca 2+-driven arteriosclerotic nanoplaque formation can be pursued by laser-based ellipsometry. Any lipoprotein from human blood can be very sensitively tested for its atherogenic properties. From the same blood sample, it is possible to determine the concentration and activity of a series of interacting biomarker molecules which, through a pattern analysis, allow to assess the state of health with respect to cardiovascular diseases. These two interlinked and complementary biosensors make a prospective cardio-cerebro-vascular risk stratification feasible, especially the sequelae of an underlying arteriosclerotic disease. Based on these diagnostic tools, an optimized therapy decision for the patient can be taken and the necessary preventive measures for the still healthy person.

Towards biosensing of arteriosclerotic nanoplaque formation using femtosecond spectroscopy

The ultrafast dynamics of proteoheparan sulfate (HS-PG) in Krebs blood substitute solution was measured using femtosecond transient absorption spectroscopy after UV excitation. Interacting with blood lipoproteins and Ca 2+ ions, the proteoglycan HS-PG is the key component of the so-called nanoplaque, the earliest stage in atherogenesis. Since tryptophan (Trp) residues are the main optically active parts of HS-PG, analogous measurements were performed on bare Trp in Krebs solution. The comparison reveals distinct differences to main characteristics of the HS-PG broadband absorption spectra. Analyzing the Trp spectra, we show that the results from transient absorption spectroscopy resemble the time constants of the chromophore ultrafast solvation dynamics that have been found by another group using fluorescence up-conversion techniques. Yet, the broadband transient absorption provides more details about the molecular dynamics, including stimulated emission, excited state absorption and resonant energy transfer. Furthermore, the absorption long time dynamics upon adding Ca 2+ to the HS-PG probe were investigated by transient absorption spectroscopy and by surface force and ellipsometry investigations. Notably, a Ca 2+-induced conformational change responsible for arteriosclerotic nanoplaque formation was detected. Slight differences, which are only visible as broad spectral features in the sub-picosecond time scale, provide a first insight into the molecular formation of nanoplaques in blood vessels, which may yield a better understanding of the genesis of arteriosclerosis.

The effect of Ginkgo biloba (EGb 761) on arteriosclerotic nanoplaque formation and size in a long-term clinical trial

Abstract Utilizing the isolated lipoprotein receptor syndecan (heparan/chondroitin sulfate proteoglycan, HS/CS-PG) from arterial endothelium and smooth muscle cell membranes and coating therewith a silica surface, we were able to observe the very earliest stages of arteriosclerotic plaque development, the so-called nanoplaque build-up, by ellipsometric techniques (patent EP 0 946 876). The arteriosclerotic nanoplaque is represented by the ternary aggregational complex of the HS-PG receptor, lipoprotein particles and calcium ions. The model was validated in several clinical studies [1,2] on cardiovascular high-risk patients applying their blood lipoprotein fractions and, among others, proved the inhibiting effect of Ginkgo biloba on nanoplaque formation. In eight high-risk patients who had undergone an aortocoronary bypass operation, the reduction of arteriosclerotic nanoplaque formation amounted to 11.9 ± 2.5% ( p ≤ 0.0078, non-parametric Wilcoxon-test for paired samples; median 10.6%) and of nanoplaque size to 24.4 ± 8.1% ( p ≤ 0.0234, non-parametric Wilcoxon-test for paired samples; median 20.4%), respectively, in normal blood substitute solution with 2.5 mmol/l [Ca 2+ ] after a 2 month therapy with 2 × 120 mg Ginkgo biloba extract (EGb 761, Rokan® novo). Additionally, we could directly demonstrate and confirm the antioxidative capacity of ginkgo and its oxygen free radical scavenging effect by disclosing an upregulation of superoxide dismutase (SOD) activity of 15.7 ± 7.0% ( p ≤ 0.0391, non-parametric Wilcoxon-test for paired samples; median 16.2%) and a lowering of the quotient oxLDL/LDL by 17.0 ± 5.5% ( p ≤ 0.0234, non-parametric Wilcoxon-test for paired samples; median 16.9%) after the 2 month medication regimen. Furthermore, we measured a significant decrease in lipoprotein(a) concentration falling from 52.4 ± 8.2 to 42.0 ± 9.9 mg/dl ( p ≤ 0.0359, paired Student t-test). Altogether, these beneficial effects of Ginkgo biloba might have partially repaired endothelial dysfunction being responsible for the very earliest stages in arteriosclerosis and could present a basis for a mechanistic explanation of nanoplaque reduction under Ginkgo treatment. This further pleiotropic effect of Ginkgo illuminated for the first time in this biosensor-biomembrane approach has immediate relevance for the formation of arteriosclerotic plaques as well as for its prophylactic and therapeutic potential in patients.

Hemmung der arteriosklerotischen Plaqueentstehung durch Knoblauch

In an in vitro biosensor model (PCT/EP 97/05212), the interplay between different lipoproteins in arteriosclerotic nanoplaque formation, as well as aqueous garlic extract (0.2-5.0 g/l from LI 111 powder) as a possible candidate drug against arterio/atherosclerosis were tested within the frame of a high throughput screening. The processes described below were studied by ellipsometric techniques quantifying the adsorbed amount (nanoplaque formation) and layer thickness (nanoplaque size). A thorough description of the experimental setup has been given previously. Proteoheparan sulfate (HS-PG) adsorption to hydrophobic silica was monoexponential and after approximately 30 min constant. The LDL plasma fraction (100 mg/dl) from a healthy probationer showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. Aqueous garlic extract (GE), preferably in a concentration of 1 g/l, applied acutely in the experiment, markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. In a normal blood Ca2+ concentration of 2.52 mmol/l, the garlic induced reduction of nanoplaque formation and molecular size amounted to 14.8 % and 3.9%, respectively, as compared to the controls. Furthermore, after ternary complex build-up, GE similar to HDL, was able to reduce nanoplaque formation and size. The incubation time for HDL and garlic was only 30 min each in these experiments. Nevertheless, after this short time the deposition of the ternary complex decreased by 6.2% resp. 16.5%, i.e. the complex aggregates were basically resolvable. These experiments clearly proved that garlic extract strongly inhibits Ca2+ binding to HS-PG. In consequence, the formation of the ternary HS-PG/LDL/Ca2+ complex, initially responsible for the 'nanoplaque' composition and ultimately for the arteriosclerotic plaque generation, is decisively blunted.

The effect of garlic on arteriosclerotic nanoplaque formation and size.

In an in vitro biosensor model (PCT/EP 97/05212), the interplay between different lipoproteins in arteriosclerotic nanoplaque formation, as well as aqueous garlic extract (0.2-5.0 g/l from LI 111 powder) as a possible candidate drug against arterio/atherosclerosis were tested within the frame of a high throughput screening. The processes described below were studied by ellipsometric techniques quantifying the adsorbed amount (nanoplaque formation) and layer thickness (nanoplaque size). A thorough description of the experimental setup has been given previously. Proteoheparan sulfate (HS-PG) adsorption to hydrophobic silica was monoexponential and after approximately 30 min constant. The addition of 2.52 mmol/l Ca2+ led to a further increase in HS-PG adsorption because Ca2+ was bound to the polyanionic glycosaminoglycan (GAG) chains thus screening their negative fixed charges and turning the whole molecule more hydrophobic. Incubation with 0.2 g/l aqueous garlic extract (GE) for 30 min did not change the adsorption of HS-PG. However, the following addition of Ca2+ ions reduced the increase in adsorption by 50.8% within 40 min. The adsorption of a second Ca2+ step to 10.08 mmol/l was reduced by even 82.1% within the next 40 min. Having detected this inhibition of receptor calcification, it could be expected that the build-up of the ternary nanoplaque complex is also affected by garlic. The LDL plasma fraction (100 mg/dl) from a healthy probationer showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. GE, preferably in a concentration of 1 g/l, applied acutely in the experiment, markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. In a normal blood Ca2+ concentration of 2.52 mmol/l, the garlic induced reduction of nanoplaque formation and molecular size amounted to 14.8% and 3.9%, respectively, as compared to the controls. Furthermore, after ternary complex build-up, GE similar to HDL, was able to reduce nanoplaque formation and size. The incubation time for HDL and garlic was only 30 min each in these experiments. Nevertheless, after this short time the deposition of the ternary complex decreased by 6.2% resp. 16.5%, i.e. the complex aggregates were basically resolvable. These experiments clearly proved that garlic extract strongly inhibits Ca2+ binding to HS-PG. In consequence, the formation of the ternary HS-PG/LDL/Ca2+ complex, initially responsible for the 'nanoplaque' composition and ultimately for the arteriosclerotic plaque generation, is decisively blunted.

The effect of an HMG-CoA reductase inhibitor on arteriosclerotic nanoplaque formation and size in a biosensor model

Proteoheparan sulfate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution, thereby representing a receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques. Low-density lipoprotein (LDL) was found to deposit strongly at the proteoheparan sulfate-coated surface, particularly in the presence of Ca 2+, apparently through complex formation ‘proteoglycan–LDL–calcium’. This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. HDL bound to heparan sulfate proteoglycan protected against LDL deposition and completely suppressed calcification of the proteoglycan–lipoprotein complex. In addition, HDL was able to decelerate the ternary complex deposition and to disrupt newly formed nanoplaques. Therefore, HDL attached to its proteoglycan receptor sites is thought to raise a multidomain barrier, selection and control motif for transmembrane and paracellular lipoprotein uptake into the arterial wall. The molecular arteriosclerosis model was tested on its reliability in a biosensor application in order to unveil possible acute pleiotropic effects of the lipid lowering drug fluvastatin. The very low-density lipoprotein (VLDL)/intermediate-density lipoprotein (IDL)/LDL and VLDL/IDL/LDL/HDL plasma fractions from a high-risk patient with dyslipoproteinemia and type 2 diabetes mellitus showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca 2+ concentration, with a strong increase at higher Ca 2+ concentrations. Nanoplaque formation and size of the HDL-containing lipid fraction remained well below that of the LDL-containing lipid fraction. Fluvastatin, whether applied acutely to the patient (one single 80 mg slow release matrix tablet) or in a 2-months medication regimen, markedly slowed down this process of ternary aggregational nanoplaque build-up and substantially inhibited nanoplaque size development at all Ca 2+ concentrations used. The acute action resulted without any significant change in lipid concentrations of the patient. Furthermore, after nanoplaque generation, fluvastatin, similar to HDL, was able to reduce nanoplaque formation and size. These immediate effects of fluvastatin have to be taken into consideration while interpreting the clinical outcome of long-term studies.

Biosensing of arteriosclerotic nanoplaque formation and interaction with an HMG-CoA reductase inhibitor.

Proteoheparan sulphate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. As a result of electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution, thereby representing one receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques suggesting that high-density lipoprotein (HDL) has a high binding affinity and a protective effect on interfacial heparan sulphate proteoglycan layers with respect to low-density lipoprotein (LDL) and Ca2+ complexation. Low-density lipoprotein was found to deposit strongly at the proteoheparan sulphate-coated surface, particularly in the presence of Ca2+, apparently through complex formation 'proteoglycan-LDL-calcium'. This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. On the other hand, HDL bound to heparan sulphate proteoglycan protected against LDL deposition and completely suppressed calcification of the proteoglycan-lipoprotein complex. In addition, HDL was able to decelerate the ternary complex deposition. Therefore, HDL attached to its proteoglycan receptor sites is thought to raise a multidomain barrier, selection and control motif for transmembrane and paracellular lipoprotein uptake into the arterial wall. Although much remains unclear regarding the mechanism of lipoprotein depositions at proteoglycan-coated surfaces, it seems clear that the use of such systems offers possibilities for investigating lipoprotein deposition at a 'nanoscopic' level under close to physiological conditions. In particular, Ca2+-promoted LDL deposition and the protective effect of HDL even at high Ca2+ and LDL concentrations agree well with previous clinical observations regarding risk and beneficial factors for early stages of atherosclerosis. Considering this, the system was tested on its reliability in a biosensor application in order to unveil possible acute pleiotropic effects of the lipid lowering drug fluvastatin. The very low-density lipoprotein (VLDL)/intermediate-density lipoprotein (IDL)/LDL plasma fraction from a high risk patient with dyslipoproteinaemia and type 2 diabetes mellitus showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. Fluvastatin, whether applied to the patient (one single 80 mg slow release matrix tablet) or acutely in the experiment (2.2 micromol L-1), markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. This action resulted without any significant change in lipid concentrations of the patient. Furthermore, after ternary complex build-up, fluvastatin, similar to HDL, was able to reduce nanoplaque adsorption and size. These immediate effects of fluvastatin have to be taken into consideration while interpreting the clinical outcome of long-term studies.

The acute effect of fluvastatin on lipoprotein deposition in a model substrate for ellipsometry studies at an endothelial membrane equivalent

Proteoheparan sulfate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution representing one receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques. LDL was found to deposit strongly at the proteoheparan sulfate, particularly in the presence of Ca 2+ thus creating the complex formation proteoglycan — low-density lipoprotein — calcium. This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. Although much remains unclear regarding the mechanism of lipoprotein depositions at proteoglycan-coated surfaces, it seems clear that the use of such systems offers possibilities for investigating lipoprotein deposition at a nanoscopic level under close to physiological conditions. Therefore, we tested the system on its reliability in a biosensor application in order to unveil possible acute pleiotropic effects of the lipid lowering drug fluvastatin. Already with a normal blood Ca 2+ concentration, the VLDL/IDL/LDL plasma fraction from a high-risk patient with dyslipoproteinemia and type 2 diabetes mellitus showed beginning arteriosclerotic nanoplaque formation that massively increased at higher Ca 2+ concentrations. Fluvastatin, whether applied to the patient (one single 80 mg slow release matrix tablet) or acutely in the experiment (2.2 μmol/l), markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca 2+ concentrations used. This action resulted without any change in lipid concentrations of the patient. Furthermore, after ternary complex build-up, fluvastatin was able to reduce nanoplaque adsorption and size. These immediate effects of fluvastatin have to be taken into consideration while interpreting the results of long-term studies. Altogether, the proteoglycan coated hydrophobic silica surface used in these experiments, mimics the endothelial cell membrane in quite a perfect manner with respect to lipoprotein interactions at the blood-endothelium-matrix interface.

A receptor-based biosensor for lipoprotein docking at the endothelial surface and vascular matrix

Proteoheparan sulfate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution, representing a receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques showing that HDL has a high binding affinity to the receptor and a protective effect on interfacial heparan sulfate proteoglycan layers, with respect to LDL and Ca 2+ complexation. LDL was found to deposit strongly at the proteoheparan sulfate, particularly in the presence of Ca 2+, thus creating the complex formation ‘proteoglycan–low density lipoprotein–calcium’. This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. On the other hand, HDL bound to heparan sulfate proteoglycan protected against LDL docking and completely suppressed calcification of the proteoglycan–lipoprotein complex. In addition, HDL and aqueous garlic extract were able to reduce the ternary complex deposition and to disintegrate HS-PG/LDL/Ca 2+ aggregates. Although much remains unclear regarding the mechanism of lipoprotein depositions at proteoglycan-coated surfaces, it seems clear that the use of such systems offers possibilities for investigating lipoprotein deposition at a ‘nanoscopic’ level under close to physiological conditions. In particular, Ca 2+-promoted LDL deposition and the protective effect of HDL, even at high Ca 2+ and LDL concentrations, agree well with previous clinical observations regarding risk and beneficial factors for early stages of atherosclerosis. Therefore, we believe that the system can be of some use in investigations, e.g. of the interplay between different lipoproteins in arteriosclerotic plaque formation, as well as in high throughput screening of candidate drugs to atherosclerosis in a biosensor application.