Effect of substrate stiffness on physicochemical properties of normal and fibrotic lung fibroblasts

The presented research aims to verify whether physicochemical properties of lung fibroblasts, modified by substrate stiffness, can be used to discriminate between normal and fibrotic cells from idiopathic pulmonary fibrosis (IPF). The impact of polydimethylsiloxane (PDMS) substrate stiffness on the physicochemical properties of normal (LL24) and IPF-derived lung fibroblasts (LL97A) was examined in detail. The growth and elasticity of cells were assessed using fluorescence microscopy and atomic force microscopy working in force spectroscopy mode, respectively. The number of fibroblasts, as well as their shape and the arrangement, strongly depends on the mechanical properties of the substrate. Moreover, normal fibroblasts remain more rigid as compared to their fibrotic counterparts, which may indicate the impairments of IPF-derived fibroblasts induced by the fibrosis process. The chemical properties of normal and IPF-derived lung fibroblasts inspected using time-of-flight secondary ion mass spectrometry, and analyzed complexly with principal component analysis (PCA), show a significant difference in the distribution of cholesterol and phospholipids. Based on the observed distinctions between healthy and fibrotic cells, the mechanical properties of cells may serve as prospective diagnostic biomarkers enabling fast and reliable identification of idiopathic pulmonary fibrosis (IPF)

Standardized nanomechanical atomic force microscopy procedure (SNAP) for measuring soft and biological samples

We present a procedure that allows a reliable determination of the elastic (Young's) modulus of soft samples, including living cells, by atomic force microscopy (AFM). The standardized nanomechanical AFM procedure (SNAP) ensures the precise adjustment of the AFM optical lever system, a prerequisite for all kinds of force spectroscopy methods, to obtain reliable values independent of the instrument, laboratory and operator. Measurements of soft hydrogel samples with a well-defined elastic modulus using different AFMs revealed that the uncertainties in the determination of the deflection sensitivity and subsequently cantilever's spring constant were the main sources of error. SNAP eliminates those errors by calculating the correct deflection sensitivity based on spring constants determined with a vibrometer. The procedure was validated within a large network of European laboratories by measuring the elastic properties of gels and living cells, showing that its application reduces the variability in elastic moduli of hydrogels down to 1%, and increased the consistency of living cells elasticity measurements by a factor of two. The high reproducibility of elasticity measurements provided by SNAP could improve significantly the applicability of cell mechanics as a quantitative marker to discriminate between cell types and conditions

Effectiveness and safety of PCSK9 inhibitor therapy in patients with familial hypercholesterolemia within a therapeutic program in Poland: Preliminary multicenter data

Background: In Poland, treatment with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has become available free of charge in a therapeutic program. Assessed herein, is the efficacy and safety of alirocumab and evolocumab in patients with heterozygous familial hypercholesterolemia (FH).Methods: Data of 55 adult FH patients who participated in the program were analyzed upon meeting the criteria established by the Ministry of Health (low density lipoprotein cholesterol [LDL-C] above 160 mg/dL on max. tolerated statin dose and ezetimib). The efficacy of PCSK9 inhibitors in reducing LDL-C with drug administration every 2 weeks was assessed after 3 months and 1 year of therapy. A safety profile evaluation was performed at each visit. 48 patients completed the 3-month and 21 for the 1-year observation periods (34 patients treated with alirokumab and 14 with evolocumab).Results: The mean concentration of direct-measured LDL-C decreased from the initial level of 215.1 ± 74.5 mg/dL to 75.3 ± 64.1 mg/dL, i.e., by 65 ± 14% following 3 months of treatment. This effect was stable in 1-year observation (77.7 ± 72.8 mg/dL). Adverse effects were flu-like symptoms (13.0%), injection site reactions (11.1%), fatigue (5.6%) and musculoskeletal symptoms (5.6%). Seven patients failed to complete the 3-month treatment period due to side effects or non-compliance, and 1 patient failed to complete the 1-year treatment due to myalgia.Conclusions: This study confirmed high effectiveness of PCSK9 inhibitors in reducing LDL-C levels in patients with FH. Due to restrictive inclusion criteria with LDL-C threshold level > 160 mg/dL (> 4.1 mmol/L) required for participation in the therapeutic program, a relatively small number of FH patients were eligible for treatment

Biophysical and biochemical characteristics as complementary indicators of melanoma progression

The multi-step character of cancer progression makes it difficult to define a unique biomarker of the disease. Interdisciplinary approaches, combining various complimentary techniques, especially those operating at a nanoscale level, potentially accelerate characterization of cancer cells or tissue properties. Here, we study a relation between the surface and biomechanical properties of melanoma cells, measured by mass spectrometry (ToF SIMS) and atomic force microscopy (AFM). In total, seven cell lines have been studied. Six of them were melanoma cells derived from various stages of tumor progression: (1) WM115 cells derived from a 55 year old female skin melanoma at a vertical growth phase (VGP) in the primary melanoma site, (2) WM793 cells established from the vertical growth phase (VGP) of a primary skin melanoma lesion, (3) WM266-4 cells established from a cutaneous skin metastasis detected in the same patient as WM115 cells, (4) WM239 cells derived from a cutaneous skin metastasis, (5) 1205Lu cells originated from a lung metastasis diagnosed in the same patient as WM793 cells, (6) A375P – cells were derived from a solid malignant tumor located in the lung. As a reference cell line, human epidermal melanocytes from adult skin (primary cell line HE-Ma-LP) was used. Cellular deformability reveals low, medium and large deformability of melanoma cells originating from vertical growth phase (VGP), skin and lung metastasis, respectively. These changes were accompanied by distinct outcome from principal component analysis (PCA). In relation to VGP melanoma cells, cells from skin and lung metastasis reveal similar or significantly different surface properties. The largest deformability difference observed for cells from VGP and lung metastasis was accompanied by the largest separation carried out based on unspecific changes in their surface properties. In this way, we show the evidence that biomechanical and surface biochemical properties of cells change in parallel, indicating a potential of being used as nanobiophysical fingerprints of melanoma progression

Protocol of single cells preparation for time of flight secondary ion mass spectrometry

There are several techniques like time of flight secondary ion mass spectrometry (ToF SIMS) that require a special protocol for preparation of biological samples, in particular, those containing single cells due to high vacuum conditions that must be kept during the experiment. Frequently, preparation methodology involves liquid nitrogen freezing what is not always convenient. In our studies, we propose and validate a protocol for preparation of single cells. It consists of four steps: (i) paraformaldehyde fixation, (ii) salt removal, (iii) dehydrating, and (iv) sample drying under ambient conditions. The protocol was applied to samples with single melanoma cells i.e. WM115 and WM266-4 characterized by similar morphology. The surface and internal structures of cells were monitored using atomic force, scanning electron and fluorescent microscopes, used to follow any potential protocol-induced alterations. To validate the proposed methodology for sample preparation, ToF SIMS experiments were carried out using C60+ cluster ion beam. The applied principal component analysis (PCA) revealed that chemical changes on cell surface of melanoma cells were large enough to differentiate between primary and secondary tumor sites

Effectiveness and safety of PCSK9 inhibitor therapy in patients with familial hypercholesterolemia within a therapeutic program in Poland : Preliminary multicenter data

BACKGROUND: In Poland, treatment with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has become available free of charge in a therapeutic program. Assessed herein, is the efficacy and safety of alirocumab and evolocumab in patients with heterozygous familial hypercholesterolemia (FH). METHODS: Data of 55 adult FH patients who participated in the program were analyzed upon meeting the criteria established by the Ministry of Health (low density lipoprotein cholesterol [LDL-C] above 160 mg/dL on max. tolerated statin dose and ezetimib). The efficacy of PCSK9 inhibitors in reducing LDL-C with drug administration every 2 weeks was assessed after 3 months and 1 year of therapy. A safety profile evaluation was performed at each visit. 48 patients completed the 3-month and 21 for the 1-year observation periods (34 patients treated with alirokumab and 14 with evolocumab). RESULTS: The mean concentration of direct-measured LDL-C decreased from the initial level of 215.1 ± 74.5 mg/dL to 75.3 ± 64.1 mg/dL, i.e., by 65 ± 14% following 3 months of treatment. This effect was stable in 1-year observation (77.7 ± 72.8 mg/dL). Adverse effects were flu-like symptoms (13.0%), injection site reactions (11.1%), fatigue (5.6%) and musculoskeletal symptoms (5.6%). Seven patients failed to complete the 3-month treatment period due to side effects or non-compliance, and 1 patient failed to complete the 1-year treatment due to myalgia. CONCLUSIONS: This study confirmed high effectiveness of PCSK9 inhibitors in reducing LDL-C levels in patients with FH. Due to restrictive inclusion criteria with LDL-C threshold level > 160 mg/dL (> 4.1 mmol/L) required for participation in the therapeutic program, a relatively small number of FH patients were eligible for treatment

Standardized nanomechanical atomic force microscopy procedure (SNAP) for measuring soft and biological samples

We present a procedure that allows a reliable determination of the elastic (Young's) modulus of soft samples, including living cells, by atomic force microscopy (AFM). The standardized nanomechanical AFM procedure (SNAP) ensures the precise adjustment of the AFM optical lever system, a prerequisite for all kinds of force spectroscopy methods, to obtain reliable values independent of the instrument, laboratory and operator. Measurements of soft hydrogel samples with a well-defined elastic modulus using different AFMs revealed that the uncertainties in the determination of the deflection sensitivity and subsequently cantilever's spring constant were the main sources of error. SNAP eliminates those errors by calculating the correct deflection sensitivity based on spring constants determined with a vibrometer. The procedure was validated within a large network of European laboratories by measuring the elastic properties of gels and living cells, showing that its application reduces the variability in elastic moduli of hydrogels down to 1%, and increased the consistency of living cells elasticity measurements by a factor of two. The high reproducibility of elasticity measurements provided by SNAP could improve significantly the applicability of cell mechanics as a quantitative marker to discriminate between cell types and conditions