Clinical Hemorheology and Microcirculation

To investigate three-year outcomes of patients presenting with nonSTelevation acute coronary syndrome (NSTE-ACS) treated with bioresorbable everolimus-eluting vascular scaffolds (BRS).

The study included a total of 488 consecutive patients, enrolled between May 2012 and December 2013 (median age 65 [56–74], 392 men. 269 patients presented with either NSTEMI or unstable angina at the time of enrolling, 219 patients with stable or silent angina. The primary device-oriented endpoint (Target Lesion Failure, TLF) was defined as a combination of cardiovascular death, target vessel myocardial infarction or clinically driven target lesion revascularization.

Among the cardiac risk factors, NSTE-ACS patients were more frequently smokers (P = 0.028), had less frequently dyslipidemia (P = 0.003) and a history of prior PCI (P < 0.01).

The median follow-up was 1070[763–1197] days. The three-years incidence of TLF was slightly higher but did not differ significantly between groups (NSTE-ACS: 16.3% vs. 15.9%, p = 0.163). Accordingly, there was no difference in any of the other endpoints.

Treatment of NSTE-ACS with BRS appears to be safe and effective. In this group, risk factors for events during follow up did not differ as compared to the general population.

Cutaneous microcirculation (cMC) is influenced by many factors. In cardiac surgery, most operations are performed with a cardiopulmonary bypass (CPB) and cardiac arrest induced by cardioplegic solutions.

Aim of this study was to examine a correlation between cMC and hemodynamic parameters in patients undergoing heart surgery with two different cardioplegic solutions.

20 patients were included and divided into Histidine-Tryptophane-α-Ketoglutarate solution- (HTK, n = 10) and blood cardioplegia- (BCP, n = 10) groups. With initiation of CPB, cMC was continuously monitored with Laser-Doppler-Perfusion (LDP) until termination of CPB. Additionally, we measured hemoglobin-concentration (HbC) with a Blood-Parameter-Monitoring-System.

LDP pulsation was almost equal before and after CPB and decreased during aortic cross clamping. The following factors influenced LDP: central venous pressure (CVP), mean arterial pressure (MAP), total peripheral resistance (TPR) and flow of the heart-lung machine. We measured relative LDP and HbC (RLDP; RHbC). Five and 25 min after administration of cardioplegia, RLDP (1.22±0.8; 1.17±0.94) and RHbC (0.92±0.06; 0.96±0.09) in the HTK-group were lower than in the BCP-group: RLDP (1.58±1.11; 1.58±2.2) and RHbC (1.00±0.05; 0.99±0.13). HTK-patients with a body surface area (BSA) <2 m² showed a lower RLDP (0.75±0.50), than patients over 2 m² (RLDP = 1.64±0.97).

The cMC is influenced by CPB. Cutaneous LDP monitoring is a non-invasive method, for estimating hemodynamics intraoperatively.

Diabetes mellitus is frequently associated with vascular pathologies and hemorheological disorders.

105 patients with diabetic retinopathy (DRP) (mean age 64.64±9.01 years, 56 males, 49 females), 35 age-matched non-diabetic (mean age 61.65±7.6 years, 14 males and 21 females) and 42 young healthy volunteers (mean age 25.52±3.32 years, 22 males, 20 females) were recruited. Lower extremity artery disease (LEAD) and microcirculatory alterations were screened by hand-held Doppler, transcutaneous partial tissue oxygen tension (tcpO₂), tuning fork test, 6-minute walk test, erythrocyte aggregation and deformability.

High prevalence of LEAD was detected in diabetic population: 55.3% fulfilled the criteria of LEAD based on ankle-brachial index; severely impaired tcpO₂ was measured in 18.6%. The results of non-invasive measurements of the diabetic patients were significantly worse than those of the control groups (p < 0.05). Hemorheological disturbances could be characterized by the significantly higher erythrocyte aggregation (p < 0.05) and lower erythrocyte deformability (p < 0.05) in the diabetic population.

Macro- and microcirculatory lower limb disorders could be revealed at high prevalence in diabetic patients with retinopathy. Measurement of tcpO₂ and hemorheological variables could be useful to discover patients at higher risk for diabetic foot complications.

Perioperatively, patients’ hemodynamics are modulated predominantly by intravenous fluid administration and vasoactive pharmacological support. Vasopressor agents are suspected to be detrimental on free flap survival by the cause of vasoconstriction of the pedicle with consecutive reduced overall flap perfusion and by aggravation of flap dissection.

A novel, standardized fluid restrictive perioperative hemodynamic management was assessed for its feasibility in clinical practice in free flap patients undergoing breast reconstruction.

Patients were randomized to two perioperative regimens with different fluid and vasopressor limits. The primary endpoint regarded flap survival. Secondary endpoints included surgery times, time of patient ambulation and length of hospital stay.

There was one total flap failure with liberal fluid administration (LFA). No total or partial flap failure was noted in the fluid restrictive regimen with norepinephrine administration up to 0.04μg/kg/min (FRV). No delay regarding operation time (p = 0.217), patient mobilization (p = 0.550) or hospital discharge (p = 0.662) was registered in the FRV study subpopulation compared to LFA.

The results of this prospective interventional trial could not detect any negative impact of vasopressors, neither for the primary endpoint of flap survival nor for the overall patient outcome. The fear of vasopressor associated flap complications has led to a traditional liberal fluid administration, which failed to demonstrate any benefits when compared to a fluid restrictive vasopressor strategy.

Retrospective analysis of 197 patients (136 female; 61 male; 3–86 years) with 135 venous (VM), 39 arterio-venous (AVM), 8 lymphatic and 15 veno-lymphatic peripheral vascular malformations before and after the first percutaneous treatment.

CEUS was performed after i.v. injection of 1-2.4 ml of sulfur hexafluoride microbubbles (SonoVue^®) using a 6-9 MHz linear probe. Digitally stored cine loops (starting in the early arterial phase for 60 sec) were read by independent readers in consensus. Regions of interest (ROI) were defined in the center and at the margins of the malformation, as well as in the healthy surrounding tissue. TIC analyses with Time to Peak (TTP) and Area under the Curve (AUC) were calculated using integrated perfusion software.

After the treatment there was a significant decrease for median AUC in VM in the center from 297.8 (14.5–2167.6) rU down to 243.3 (0.1–1678.8) rU (p = 0.043) and in the surrounding tissue down to 107.7 (20.2–660.2) rU (p = 0.018). For the other malformations AUC decreased in the center and the margins as well. TTP rose, however these changes did not reach the level of significance.

Analyzing the capillary microcirculation TICs offer a possibility of monitoring therapy-induced capillary changes of vascular malformations.

 With the rising number of percutaneous ablation therapies in malignant liver lesions there is a need of reliable diagnostics after the intervention to differentiate between reactive changes and tumor.

To assess the success of percutaneous ablation therapies for malignant liver lesions using CEUS with perfusion analysis.

Retrospective analysis of perfusion analysis for 67 patients with 94 malignant liver lesions, treated with ablation therapies. The lesions were 70 hepatocellular carcinomas (HCC), 18 metastases, 4 cholangiocellular carcinomas (CCC), 2 lesions remained unclear. CEUS was performed after bolus injection of 1.6–2.4 ml of sulfur-hexafluoride microbubbles. The perfusion analysis was calculated using Peak, TTP, mTT and AUC with integrated software during the late arterial to early portal-venous phase for approximately 9 sec (5–15 sec). For the evaluation of the success after percutaneous treatment the perfusion results were compared to the follow-up control after 6 months with CT and MRI and CEUS.

Perfusion analyses after percutaneous treatment of malignant liver lesions showed highly significant perfusion differences when comparing the center to the surrounding tissue and the margins (p<0.0001) for Peak and also for AUC. 62 lesions were successfully treated, meaning there was no local recurrence after 6 months. In cases of residual tumor CEUS showed a nodular marginal enhancement, the corresponding perfusion analyses showed nodular red and yellow pseudo-color shades.

Using CEUS and perfusion analysis, a critical analysis of post-ablation defects in malignant liver lesions is possible. With the help of pseudo-colors, remaining tumor-vascularization can be detected.

Renal transplant patients have a higher risk for malignancies of the renal transplant. In most cases suspected renal malignancies will be detected during the regular ultrasound follow-up and will require cross-sectional imaging to rule out a malignant aetiology. But it is well known that contrast agents for computed tomography or magnetic resonance imaging are critical in patients with limited renal function.

This study aims to compare the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and gold standard imaging modalities in characterizing suspected renal transplant malignancies in renal transplant patients.

A total of 22 renal transplant patients who underwent one or more CEUS examinations and at least one standard imaging modality (CT or MRI) between 2005 and 2017 were included. Patient ages ranged from 28.2 years to 74.6 (mean age 55.7 years; SD±13.0 years). CEUS of 22 patients was correlated with a standard imaging modality, CT (15 out of 22) or MRI (7 out of 22), serving as gold standard.

CEUS showed a sensitivity of 100%, a specificity of 94.4%, a positive predictive value (PPV) of 80%, and a negative predictive value (NPV) of 100%.

CEUS is an eligible method to help characterizing suspected renal malignancies in renal transplant patients compared to the well-established imaging modalities CT and MRI. As an imaging modality with no nephrotoxic effects CEUS can be used repeatedly even in patients with limited renal function.

Despite of the more potent immunosuppressive medication, vascular rejection is still a major issue after renal transplantation. Renal biopsy is the gold standard diagnostic to evaluate acute and chronic allograft rejection. As it is an invasive diagnostic there is the risk of complications like haematoma, arteriovenous fistulas, active bleeding or infection. Contrast-enhanced ultrasound is a non-invasive imaging modality that allows visualising renal transplant perfusion.

To analyse the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) compared to biopsy as gold standard in diagnosing vascular rejection in renal transplant patients.

A total of 57 renal transplant recipients with poor renal allograft function with initial diagnostic imaging between 2006 and 2017 were included in the study. Clinical data and imaging studies were analysed retrospectively. The diagnostic accuracy of CEUS in diagnosing vascular rejection of the renal transplant was compared to renal biopsy as gold standard. Out of 57 patients 7 patients showed signs of vascular rejection in biopsy. In 6 out of these 7 patients CEUS described irregularities in renal perfusion suspicious of vascular rejection.

CEUS showed a sensitivity of 85.7%, a specificity of 100%, a positive predictive value (PPV) of 100%, and a negative predictive value (NPV) of 98.0%.

CEUS is a safe, non-nephrotoxic imaging modality for the initial imaging of renal transplant recipients with elevated kidney function parameters suspicious of vascular rejection. Compared to renal biopsy as gold standard CEUS shows a high specificity and PPV in detecting signs of vascular rejection. Since sub-types of vascular rejection with cellular and humoral components with greater risk for allograft loss have been described renal biopsy is inevitable in these cases.

Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique to conventional ultrasound in order to clarify gallbladder findings, CEUS is easy and fast to perform, overcomes the limitations of gray-scale ultrasonography and is a safe tool.

The aim of this retrospective mono-center analysis study is to evaluate the diagnostic performance of CEUS in the assessment of gallbladder disease by comparing its results with additional CT findings.

A total of 24 patients between 2009 and 2017 with unclear gallbladder appearance were retrospectively analysed. The contrast agent administered was a second-generation blood pool agent (SonoVue^®, Bracco, Milan, Italy). Examinations were performed and interpreted by a single experienced radiologist with more than fifteen years’ experience.

24 patients were successfully examined without any adverse reaction. CEUS presented a sensitivity of 75%, a specificity of 100.0%, a positive predictive value of 100.0% and a negative predictive value of 95%.

In conclusion, the excellent results in this study acknowledged that CEUS is a feasible alternative tool to differentiate gallbladder pathologic alterations.

Reduced acceptance of radical prostatectomy in patients with low risk or intermediate risk prostate cancer has significantly changed treatment strategies in prostate cancer (PCa) during the last years. Focal therapy of the prostate with high intensity focused ultrasound (HIFU) is an organ-preserving treatment for prostate cancer with less impairment of health-related quality of life. Follow-up after HIFU therapy by imaging modalities remains a major problem as eg. MRI performs poorly. Contrast enhanced ultrasound (CEUS) allows to monitor the vascular architecture of organs non-invasively. However, only limited data are available using CEUS to define successful and complete HIFU treatment of the prostate. In this study, we aimed to evaluate short-term image findings using CEUS and image fusion before and after HIFU treatment.

Prospective single arm study in patients with uni- or bilateral, low or intermediate risk prostate cancer or recurrent cancer after radiotherapy treated with HIFU at our institution between October 2016 and November 2017. HIFU hemiablation or whole gland treatment was performed using the Focal One^® device. PCa was diagnosed either by multiparametric magnetic resonance imaging (mpMRI) followed by MRI fusion based targeted biopsy combined with 12 core transrectal ultrasound (TRUS) guided biopsy or 12 core random biopsy only. Monitoring of the target region before, immediately and 24 hours after the ablation was done by CEUS in combination with image fusion using an axial T2-weighted MRI sequence.

6 consecutive patients with Gleason score (GS) 6, 5 patients with GS 7a prostate cancer and one patient with biochemical recurrence after radiotherapy were included in the study. Three patients underwent whole gland treatment due to histological proven bilateral PCa or recurrent PCa after radiotherapy. Hemiablation was performed in 9 patients with unilateral tumor and no PIRADS 4 or 5 lesion in the contralateral lobe. Median patient age was 69.8 years and median PSA (prostate-specific antigen) level was 8.4 ng/ml. CEUS showed markedly reduced microbubbles in the ablated area, the prostate capsule still showed signs of perfusion. The study is limited by the short follow up and small number of patients.

CEUS examination showed a reduction of microcirculation in the treated area immediately after the treatment and 24 hours later. The combination of CEUS and image fusion seems to be helpful for detecting the PCa target lesion and monitor the success of HIFU ablation treatment. Evidence for image findings after HIFU-therapy are rare. Further studies on this topic are needed.

Recent studies have shown increased RBC aggregation and no difference in plasma viscosity in the presence of markedly lower hematocrit in women at term compared to non-pregnant women. Little is known about the outcome of blood rheological parameters and red blood cell (RBC) deformability particularly in the course of normal pregnancy.

During a 36 months interval 1.913 blood samples were randomly collected from a total of 945 pregnant women in the course of their pregnancy (n = 1.259) and during puerperium (upto 1 week; n = 654). Next to the blood count, hemorheological parameters including red blood cell (RBC) -aggregation (stasis E0; low shear E1), -deformability (low, moderate and high shear conditions) and plasma viscosity (pv) were assessed. Plasma viscosity (pv) was examined using KSPV 1 Fresenius, RBC aggregation (stasis: E0 and low shear: E1) using MA1-Aggregometer; Myrenne and RBC deformability (def) was determined by Rheodyn SSD Diffractometer, Myrenne, Roetgen, Germany were tested. In some of these women laboratory results prior to pregnancy (n = 145) were available which were compared with those during pregnancy.

Mean maternal pv remained unchanged within each trimester and compared to the values before pregnancy and during early puerperium (Range of means: 1.18–1.20 mPa S). In contrast, RBC agg (E0 and E1) was markedly higher in the 2nd (21.8 ± 7.0 and 28.9 ± 9.4; p < 0.001) and 3rd trimester (18.74 ± 8.4 and 28.2 ± 9.4; p < 0.01) compared to the values before pregnancy (16.4 ± 6.4 and 20 ± 7.5) and during 1st trimester (17.49 ± 6.5 and 22.4 ± 7.4). There was a stat. significant temporary reduction in RBC def. under all shear rate conditions during 2nd trimester compared to the values before pregnancy which remained significantly lower during 3rd trimester only under high shear rates.

An increase RBC agg was stat. significantly inversely correlated with reduced RBC def being most pronounced under low shear rate conditions. While RBC rigidity was stat. significantly correlated with higher hematocrit values there was only a weak correlation between RBC agg and haematocrit (E0: r = –0.084; p = 0.03; E1: r = –0.06; p = 0.1). Pv was not correlated with haematocrit or RBC def but stat. significantly correlated with RBC agg.

Blood rheological changes manifest during 1st trimester, and fairly remain unchanged during 2nd trimester until term. Physiologic hemodilution and increasing hypercoagulability is accompanied by high RBC -aggregation and – rigidity during 2nd trimester while plasma viscosity remains nearly unaffected throughout normal pregnancy.

The Microcirculatory Shock Occurrence in Acutely Ill Patients (micro-SOAP) study investigated associations of microcirculation and mortality. Risk stratification in critically ill patients is of utmost interest. Established score such as APACHE2 (Acute Physiology And Chronic Health Evaluation 2) are relatively complex and might therefore be of limited use. Blood urea nitrogen (BUN) was described to be associated with mortality in various diseases. We therefore aimed (i) to evaluate BUN for prediction of mortality in a cohort of critically ill patients and (ii) to investigate associations of BUN with microcirculation.

412 patients were included in our post-hoc analysis of the prospective multicenter microSOAP study. Assesment of the sublingual microcirculation (Sidestream Dark Field (SDF) imaging) and collection of laboratory values were performed on the same day in this point prevalence study. Evaluation of associations with mortality was done by logistic regression analysis. An optimal BUN cut-off was calculated by means of the Youden Index.

Median BUN was 9.0 mmol/L. BUN was associated with in-hospital-mortality in a logistic regression analysis (HR 1.03; 95% CI 1.01–1.05; p < 0.001). Per quartile (BUN 0–5.4 mmol/L, 5.4–9.0 mmol/L, 9.0–15.9 mmol/L and above 15.9 mmol/L) in-hospital mortality increased by as much as 51% (HR 1.51; 95% CI 1.23–1.85; p < 0.001). ROC analysis was done (AUC 0.63 95% CI 0.58–0.67) and the statistically optimal cut-off calculated by means of the Youden Index: 9.7 mmol/L. This cut-off was associated with a significant 3-fold increase in mortality (HR 2.97 95% CI 1.88–4.70; p < 0.001) and remained robustly associated with adverse outcome after correction for APACHE2 (HR 2.71 95% CI 1.61–4.59; p < 0.001), renal function as expressed by creatinine (HR 2.63 95% CI 1.59–4.33; p = 0.001), as well in an integrative model (MAP<60 mmHg, tachycardia (heart rate >90/min), lactate above 1.5 mmol/L, age above 80 years; HR 2.43 95% CI 1.50–3.92; p < 0.001). Parameters of microvascular perfusion were associated neither with BUN nor mortality.

BUN is associated with hospital mortality and a combination of BUN and clinical signs might constitute a powerful but easy-to-use tool for risk stratification in critically ill patients and help improve their outcome. BUN was not associated with parameters of microcirculation which were not associated with mortality.

Multiple symmetric lipomatosis is a rare disease characterized by the excessive growth of uncapsulated masses of adipose tissue. Although the etiology has yet to be elucidated, a connection to brown adipose tissue has been proposed recently. The mTOR pathway which is found to be regulated in lipomatous tissue as well as associated with brown adipose tissue can be inhibited by a compound called rapamycin.

We isolated adipose tissue derived stem cells from both affected and unaffected tissue and treated these cells with different concentrations of rapamycin.

The differences in both proliferation and differentiation between adipose tissue derived stem cells (ASCs) from lipomatous and normal tissue decreased after mTOR pathway inhibition. In some patients regulation of mTOR genes was opposed in the ASCs from the two different tissues.

Treatment with rapamycin might be a novel therapeutical approach for patients suffering from multiple symmetric lipomatosis.

Non-infectious uveitis is an inflammatory disease of the eye commonly treated by corticosteroids, though important side effects may result. A main mediator of inflammation are oxygen free radicals generated in iron-dependent pathways. As such, we investigated the efficacy of a novel iron chelator, DIBI, as an anti-inflammatory agent in local and systemic models of endotoxin induced uveitis (EIU).

Firstly, the effects of DIBI in systemic EIU in Lewis rats were established. 2 hours post intravenous LPS or LPS/DIBI injections, leukocyte activation and functional capillary density (FCD) were examined using intravital microscopy (IVM) of the iridial microcirculation. Secondly, the toxicity of DIBI was evaluated in BALB/C mice for both acute and chronic dosages through gross ocular examination, intraocular pressure measurements and hematoxylin-eosin staining of ocular tissue. Lastly, three groups of BALB/C mice, control, LPS or DIBI + LPS, were studied to evaluate the effectiveness of DIBI in treating local EIU. Five hours post-local intravitreal (i.v) injection, leukocyte activation and capillary density were examined via IVM.

Treatment of systemic EIU with DIBI resulted in a reduction of leukocyte activation and FCD improvement within the iridial microcirculation. Toxicity studies suggested that acute and chronic DIBI administration had no adverse effects in the eye. In the local EIU model, DIBI was shown to reduce leukocyte activation and restored the FCD/DCD ratio, providing evidence for its anti-inflammatory properties.

Our study has provided evidence that DIBI has anti-inflammatory effects in experimental uveitis. Additionally, no local ocular toxicity was observed.

Gold nanoparticles (GNPs) are key diagnostic and therapeutic agents in biomedical sciences. Several studies have been carried out in different therapeutic areas such as in cancer treatment, antibacterial topical agents, imaging agents etc. There is a necessity to evaluate the gold nanoparticles cytotoxicity at all fronts. Since blood is the first point of contact in any therapy, it is required to have a thorough in vitro investigation of gold nanoparticles to avoid any adverse effects.

The objective of the current study is to evaluate the effect of gold nanoparticles capped with lipase on blood clotting factors, platelets, coagulation time and blood clotting strength.

Whole blood samples were drawn from healthy volunteers. Plasma and plasma with platelets were isolated from the blood and all the samples were treated with lipase capped gold nanoparticles, except control. Plasma fibrinogen formed in the blood coagulation process after contacting with nanoparticles was quantitatively evaluated. In addition, platelet aggregation, blood clotting kinetics, strength of the blood clot and time were evaluated post nanoparticle treatment.

The work primarily explores the effect of GNPs on blood with changing concentrations of lipase capping. Plasma fibrinogen levels of plasma samples were found to be moderately elevated, however, there is no significant effect on blood clotting kinetics, strength, and platelet aggregation. Also, the study showed that lipase capped GNPs did not result in aggregation upon interaction with plasma components and remained stable for 1 hour after incubation.

Our study revealed that lipase capped GNPs synthesized using NaBH₄ approach were stable and hemocompatible. There is an increase in fibrinogen levels after the exposure to nanoparticles, an observation which is consistent with other studies. However, the functional consequences of such increase are unknown. The results of no significant platelet aggregation, change in blood clotting time, kinetics, and clot strength revealed the non-toxic effect of lipase capped GNPs towards blood components, which is essential for any in vivo applications.

To assess the relationships of clinical and laboratory parameters, with erythrocyte oxygen concentration.

The study group consisted of 47 healthy adults out of which 16 showed slightly higher blood pressure and were classified as individuals with prehypertension. For each individual, data were obtained on: systolic and diastolic blood pressure (SBP, DBP), blood morphology, lipids profile, fibrinogen, hs-CRP. The erythrocyte oxygen concentration was assessed with the Raman spectroscopy technique. Arithmetic means for all laboratory parameters were estimated by oxygen concentration tertiles and tested for statistical significance of linear trends across tertiles.

The multivariate regression analysis showed statistically significant negative relationship of triglycerides level with oxygen concentration.

A hypothesis has been formulated that triglycerides level is an indicator of the erythrocyte ability to transport oxygen to the tissues.

Physical and chemical characteristics of implant materials determine the fate of long-term cardiovascular devices. However, there is still a lack of fundamental understanding of the molecular mechanisms occurring in the material-tissue interphase. In a previous study, soft covalently crosslinked poly(n-butyl acrylate) networks (cPnBA) were introduced as sterilizable, non-toxic and immuno-compatible biomaterials with mechanical properties adjustable to blood vessels. Here we study the influence of different surface treatments in particular oxygen plasma modification and fibrinogen deposition as well as a combinatorial approach on the adhesion and viability of fibroblasts.

Two types of cPnBA networks with Young’s moduli of 0.19±0.01 MPa (cPnBA04) and 1.02±0.01 MPa (cPnBA73) were synthesized and post-modified using oxygen plasma treatment (OPT) or fibrinogen coating (FIB) or a combination of both (OPT+FIB). The water contact angles of the differently post-treated cPnBAs were studied to monitor changes in the wettability of the polymer surfaces. Because of the key role of vascular fibroblasts in regeneration processes around implant materials, here we selected L929 fibroblasts as model cell type to explore morphology, viability, metabolic activity, cell membrane integrity as well as characteristics of the focal adhesions and cell cytoskeleton on the cPnBA surfaces.

Compared to non-treated cPnBAs the advancing water-contact angles were found to be reduced after all surface modifications (p < 0.05, each), while lowest values were observed after the combined surface treatment (OPT+FIB). The latter differed significantly from the single OPT and FIB. The number of adherent fibroblasts and their adherence behavior differed on both pristine cPnBA networks. The fibroblast density on cPnBA04 was 743±434 cells·mm^-2, was about 6.5 times higher than on cPnBA73 with 115±73 cells·mm^-2. On cPnBA04 about 20% of the cells were visible as very small, round and buckled cells while all other cells were in a migrating status. On cPnBA73, nearly 50% of fibroblasts were visible as very small, round and buckled cells. The surface functionalization either using oxygen plasma treatment or fibrinogen coating led to a significant increase of adherent fibroblasts, particularly the combination of both techniques, for both cPnBA networks. It is noteworthy to mention that the fibrinogen coating overruled the characteristics of the pristine surfaces; here, the fibroblast densities after seeding were identical for both cPnBA networks. Thus, the binding rather depended on the fibrinogen coating than on the substrate characteristics anymore. While the integrity of the fibroblasts membrane was comparable for both polymers, the MTS tests showed a decreased metabolic activity of the fibroblasts on cPnBA.

The applied surface treatments of cPnBA successfully improved the adhesion of viable fibroblasts. Under resting conditions as well as after shearing the highest fibroblast densities were found on surfaces with combined post-treatment.

Drug-induced liver injury (DILI) is the most common reason for withdrawal of anticancer drugs from the market. To prevent adverse side effects of drugs, it is important to investigate potential toxicity in vitro. However, outcome of cytotoxicity screenings can differ remarkably depending on the method used.

We aimed to compare XTT, ATP-based CellTiter-Glo^®2.0 and trypan blue exclusion (TBE) assays regarding their sensitivity in detecting acute cytotoxicity on HepG2 cells after incubation with the classical anticancer drugs Taxol and Imatinib or with the proteasome inhibitor MG-132.

HepG2 cells were treated for 48 h and cell viability was analysed by XTT, CellTiter-Glo^®2.0 or TBE assay.

All tested compounds showed a reduction of viability of HepG2 cells. However, assay results differed significantly: Both ATP-based and TBE assay showed concentration-dependent cytotoxic effects, but outcomes were less pronounced with TBE. In contrast, the widely used XTT assay did not detect any acute cytotoxicity of Taxol and Imatinib.

Acute cytotoxic effects of tested compounds could be revealed. However, results were significantly different from each other with ATP assay being the most sensitive one under the conditions tested. Thus, acute cytotoxicity can be dramatically underestimated if only standard XTT test is used.