Pubblicazioni

Claudio De Lazzari, Igino Genuini, Bernhard Quatem
Interactive simulator for e-Learning environments: a teaching software for health care professionals PDF Stampa E-mail

Claudio De Lazzari1-2*Igino Genuini2-3Domenico M Pisanelli2-4Alessandra D’Ambrosi2-3 and Francesco Fedele2-3

There is an established tradition of cardiovascular simulation tools, but the application of this kind of technology in the e-Learning arena is a novel approach. This paper presents an e-Learning environment aimed at teaching the interaction of cardiovascular and lung systems to health-care professionals. Heart-lung interaction must be analyzed while assisting patients with severe respiratory problems or with heart failure in intensive care unit. Such patients can be assisted by mechanical ventilatory assistance or by thoracic artificial lung.

In silico” cardiovascular simulator was experimented during a training course given to graduate students of the School of Specialization in Cardiology at ‘Sapienza’ University in Rome.

The training course employed CARDIOSIM©: a numerical simulator of the cardiovascular system. Such simulator is able to reproduce pathophysiological conditions of patients affected by cardiovascular and/or lung disease. In order to study the interactions among the cardiovascular system, the natural lung and the thoracic artificial lung (TAL), the numerical model of this device has been implemented. After having reproduced a patient’s pathological condition, TAL model was applied in parallel and hybrid model during the training course.

Results obtained during the training course show that TAL parallel assistance reduces right ventricular end systolic (diastolic) volume, but increases left ventricular end systolic (diastolic) volume. The percentage changes induced by hybrid TAL assistance on haemodynamic variables are lower than those produced by parallel assistance. Only in the case of the mean pulmonary arterial pressure, there is a percentage reduction which, in case of hybrid assistance, is greater (about 40%) than in case of parallel assistance (20-30%).

At the end of the course, a short questionnaire was submitted to students in order to assess the quality of the course. The feedback obtained was positive, showing good results with respect to the degree of students’ learning and the ease of use of the software simulator

Author Affiliations

1 CNR, Institute of Clinical Physiology, UOS of Rome, Via S.M. della Battaglia, 44, 00185 Rome, Italy

2 National Institute for Cardiovascular Research, Bologna, Italy

3 Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, “Sapienza” University of Rome, Rome, Italy

4 CNR, Institute of Cognitive Sciences and Technology (ISTC), Rome, Italy

De Lazzari et al. BioMedical Engineering OnLine 2014, 13:172 http://www.biomedical-engineering-online.com/content/13/1/172

 

 

Interfacing Sca-1pos Mesenchymal Stem Cells with Biocompatible Scaffolds with Different Chemical Composition and Geometry PDF Stampa E-mail

Forte GFranzese OPagliari SPagliari FDi Francesco AMCossa PLaudisi AFiaccavento RMinieri MBonmassar EDi Nardo P.

J Biomed Biotechnol (2009). doi: 10.1155/2009/910610.
Laboratorio di Cardiologia Molecolare e Cellulare, Dipartimento di Medicina Interna, Università di Roma Tor Vergata, 00133 Roma, Italy.

An immortalized murine mesenchymal stem cell line (mTERT-MSC) enriched for Lin(neg)/Sca-1(pos) fraction has been obtained through the transfection of MSC with murine TERT and single-cell isolation. Such cell line maintained the typical MSC self-renewal capacity and continuously expressed MSC phenotype. Moreover, mTERT-MSC retained the functional features of freshly isolated MSC in culture without evidence of senescence or spontaneous differentiation events. Thus, mTERT-MSC have been cultured onto PLA films, 30 and 100 microm PLA microbeads, and onto unpressed and pressed HYAFF-11 scaffolds. While the cells adhered preserving their morphology on PLA films, clusters of mTERT-MSC were detected on PLA beads and unpressed fibrous scaffolds. Finally, mTERT-MSC were not able to colonize the inner layers of pressed HYAFF-11. Nevertheless, such cell line displayed the ability to preserve Sca-1 expression and to retain multilineage potential when appropriately stimulated on all the scaffolds tested.

 

Multiscale 3D Scaffolds for Soft Tissue Engineering via Multimodal Electrospinning PDF Stampa E-mail

Soliman SPagliari SRinaldi AForte GFiaccavento RPagliari FFranzese OMinieri MDi Nardo PLicoccia STraversa E.

Acta Biomater (2010); 6: 1227-1237
NAST Centre and Department of Chemical Science and Technology, University of Rome Tor Vergata, 00133 Rome, Italy.

A novel (scalable) electrospinning process was developed to fabricate bio-inspired multiscale three-dimensional scaffolds endowed with a controlled multimodal distribution of fiber diameters and geared towards soft tissue engineering. The resulting materials finely mingle nano- and microscale fibers together, rather than simply juxtaposing them, as is commonly found in the literature. A detailed proof of concept study was conducted on a simpler bimodal poly(epsilon-caprolactone) (PCL) scaffold with modes of fiber distribution at 600nm and 3.3mum. Three conventional unimodal scaffolds with mean diameters of 300nm and 2.6 and 5.2mum, respectively, were used as controls to evaluate the new materials. Characterization of the microstructure (i.e. porosity, fiber distribution and pore structure) and mechanical properties (i.e. stiffness, strength and failure mode) indicated that the multimodal scaffold had superior mechanical properties (Young’s modulus approximately 40MPa and strength approximately 1MPa) in comparison with the controls, despite the large porosity ( approximately 90% on average). A biological assessment was conducted with bone marrow stromal cell type (mesenchymal stem cells, mTERT-MSCs). While the new material compared favorably with the controls with respect to cell viability (on the outer surface), it outperformed them in terms of cell colonization within the scaffold. The latter result, which could neither be practically achieved in the controls nor expected based on current models of pore size distribution, demonstrated the greater openness of the pore structure of the bimodal material, which remarkably did not come at the expense of its mechanical properties. Furthermore, nanofibers were seen to form a nanoweb bridging across neighboring microfibers, which boosted cell motility and survival. Lastly, standard adipogenic and osteogenic differentiation tests served to demonstrate that the new scaffold did not hinder the multilineage potential of stem cells. Copyright © 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

 

Thick soft tissue reconstruction on highly perfusive biodegradable scaffolds PDF Stampa E-mail

Mandoli CMecheri BForte GPagliari FPagliari SCarotenuto FFiaccavento RRinaldi ADi Nardo PLicoccia STraversa E.

Macromol Biosci. 2010 Feb 11;10(2):127-38
NAST Center & Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, 00133 Roma, Italy.

The lack of a vascular network and poor perfusion is what mostly prevents three-dimensional (3D) scaffolds from being used in organ repair when reconstruction of thick tissues is needed. Highly-porous scaffolds made of poly(L-lactic acid) (PLLA) are prepared by directional thermally induced phase separation (dTIPS) starting from 1,4-dioxane/PLLA solutions. The influence of polymer concentration and temperature gradient, in terms of imposed intensity and direction, on pore size and distribution is studied by comparison with scaffolds prepared by isotropic TIPS. The processing parameters are optimized to achieve an overall porosity for the 3D scaffolds of about 93% with a degree of interconnectivity of 91%. The resulting pore network is characterized by the ordered repetition of closely packed dendrite-like cavities, each one showing stacks of 20 microm large side lamellar branches departing from 70 microm diameter vertical backbones, strongly resembling the vascular patterns. The in vitro biological responses after 1 and 2 weeks are evaluated from mesenchymal (bone marrow stromal) cells (MSC) static culturing. A novel vacuum-based deep-seeding method is set up to improve uniform cell penetration down to scaffold thicknesses of over 1 mm. Biological screenings show significant 3D scaffold colonization even after 18 h, while cellular retention is observed up to 14 d in vitro (DIV). Pore architecture-driven cellular growth is accompanied by cell tendency to preserve their multi-potency towards differentiation. Confluent tissues as thick as 1 mm were reconstructed taking advantage of the large perfusion enhanced by the highly porous microstructure of the engineered scaffolds, which could successfully serve for applications aimed at vascular nets and angiogenesis.

PMID: 20143311 [PubMed – as supplied by publisher]

 

Criticality of the Biological and Physical Stimuli Array Inducing Resident Cardiac Stem Cell Determination. PDF Stampa E-mail

Laboratorio di Cardiologia Molecolare e Cellulare, Dipartimento di Medicina Interna, Università di Roma Tor Vergata, Italy; Istituto Nazionale per le Ricerche Cardiovascolari (INRC), Bologna, Italy.

The replacement of injured cardiac contractile cells with stem cell-derived functionally efficient cardiomyocytes has been envisaged as the resolutive treatment for degenerative heart diseases. Nevertheless, many technical issues concerning the optimal procedures to differentiate and engraft stem cells remain to be answered before heart cell therapy could be routinely used in clinical practice. So far, most studies have been focused on evaluating the differentiative potential of different growth factors without considering that only the synergistic cooperation of biochemical, topographic, chemical and physical factors could induce stem cells to adopt the desired phenotype. The present study demonstrates that the differentiation of cardiac progenitor cells to cardiomyocytes does not occur when cells are challenged with soluble growth factors alone, but requires strictly controlled procedures for the isolation of a progenitor cell population and the artifactual recreation of a microenvironment critically featured by a fine-tuned combination of specific biological and physical factors. Indeed, the scaffold geometry and stiffness are crucial in enhancing growth factor differentiative effects on progenitor cells. The exploitation of this concept could be essential in setting up suitable procedures to fabricate functionally efficient engineered tissues. .

 

Altri articoli…
Difluoromethylornithine stimulates early cardiac commitment of mesenchymal stem cells in a model of mixed culture with cardiomyocytes. PDF Stampa E-mail
J Cell Biochem. 2008;103(4):1046-52.
Muscari C, Bonafé F, Carboni M, Govoni M, Stanic I, Gamberini C, Ricci F, Tazzari PL, Caldarera CM, Guarnieri C.
Department of Biochemistry “G. Moruzzi”, University of Bologna, Bologna, Italy. e-mail claudio.muscari@unibo.it

The efficiency of in vitro mesenchymal stem cell (MSC) differentiation into the myocardial lineage is generally poor. In order to improve cardiac commitment, bone marrow GFP+MSCs obtained from transgenic rats were cultured with adult wild type rat cardiomyocytes for 5 days in the presence of difluoromethylornithine (DFMO), an inhibitor of polyamine synthesis and cell proliferation. The percentage of GFP+MSCs showing cardiac myofibril proteins (cMLC2, cTnI) was about threefold higher after DFMO addition (3%) relative to the untreated control (1%). Another set of experiments was performed with cardiomyocytes incubated for 1 day in the absence of glucose and serum and under hypoxic conditions (pO2 < 1%), in order to simulate severe ischemia. The percentage of cardiac committed GFP+MSCs was about 5% when cultured with the hypoxic/starved cardiomyocytes and further increased to 7% after DFMO addition. The contemporary presence of putrescine in DFMO-treated cells markedly blunted differentiation, while the cytostatic mitomycin C was not able to induce cardiac commitment. The involvement of histone acetylation in DFMO-induced differentiation was evidenced by the strong attenuation of cardiac commitment exerted by anacardic acid, an inhibitor of histone acetylase. Moreover, the percentage of acetylated histone H3 significantly increased in bone marrow MSCs obtained from wild type rats and treated with DFMO. These results suggest that polyamine depletion can represent a useful strategy to improve MSC differentiation into the cardiac lineage, especially in the presence of cardiomyocytes damaged by an ischemic environment.

 

Functional coupling of angiotensin II type 1 receptor with insulin resistance of energy substrate uptakes in immortalized cardiomyocytes (HL-1 cells). PDF Stampa E-mail
Br J Pharmacol. 2008;153(5):907-14.
Functional coupling of angiotensin II type 1 receptor with insulin resistance of energy substrate uptakes in immortalized cardiomyocytes (HL-1 cells).
Alfarano C, Sartiani L, Nediani C, Mannucci E, Mugelli A, Cerbai E, Raimondi L.
Department of Preclinical and Clinical Pharmacology, University of Florence, Florence, Italy.

Background and purpose:Increased angiotensin II levels and insulin resistance coexist at the early stages of cardiomyopathies. To determine whether angiotensin II increases insulin resistance in cardiomyocytes, we studied the effect of angiotensin II on basal and insulin-stimulated transport rate of energy substrates in immortalized cardiomyocytes (HL-1 cells).Experimental approach:Glucose and palmitic acid uptakes were measured using [(3)H]2-deoxy-D-glucose and [(14)C]palmitic acid, respectively, in cells exposed or not exposed to angiotensin II (100 nM), angiotensin II plus irbesartan or PD123319, type 1 and 2 receptor antagonists, or PD98059, an inhibitor of ERK1/2 activation. Cell viability, DNA, protein synthesis and surface area were evaluated by the MTT test, [(3)H]thymydine, [(3)H]leucine and morphometric analysis, respectively. Type 1 receptor levels were measured by western blot analysis.Key results:Basal uptakes of glucose and palmitic acid by HL-1 cells (0.37+/-0.07 and 7.31+/-0.22 pmol per 10(4)cells per min, respectively) were both stimulated by 100 nM insulin (+91 and +64%, respectively). Cells exposed to angiotensin II remained viable and did not show signs of hypertrophy. In these conditions, the basal palmitic acid uptake of the cells increased (11.41+/-0.46 pmol per 10(4) cells per min) and insulin failed to stimulate the uptake of glucose and fatty acids. Changes in the rate of uptake of energy substrates were prevented or significantly reduced by irbesartan or PD98059.Conclusions and implications:Angiotensin II is a candidate for increasing insulin resistance in cardiomyocytes. Our results suggest a further mechanism for the cardiovascular protection offered by the angiotensin II type 1 receptor blockers.

 

The C(242)T polymorphism of the p22phox component of NAD(P)H oxidase and vascular risk. Two case-control studies and a meta-analysis. PDF Stampa E-mail
Thromb Haemost. 2008;99(3):594-601.
The C(242)T polymorphism of the p22phox component of NAD(P)H oxidase and vascular risk. Two case-control studies and a meta-analysis.
Di Castelnuovo A, Soccio M, Iacoviello L, Evangelista V, Consoli A, Vanuzzo D, Diviacco S, Carluccio M, Rignanese L, De Caterina R.
Institute of Cardiology, C/o Ospedale S. Camillo de Lellis, Via Forlanini, 50 – 66100 Chieti, Italy. e-mail: rdecater@unich.it.

NAD(P)H oxidase is a prominent source of reactive oxygen species in the vasculature. Vascular NAD(P)H oxidase is comprised of several subunits, one of which, p22phox, is encoded by a gene exhibiting several allelic variants. Here the C(242)T nucleotide transition has been found to alter superoxide anion production and associated with an altered risk of coronary artery disease (CAD). We assessed the role of this variant in two case-control studies, and performed a meta-analysis of previously reported investigations relating it to vascular risk. Population I was comprised of 492 subjects with type 2 diabetes, with or without macrovascular disease, matched for age, sex, and duration of diabetes. Population II was comprised of 158 subjects with or without either CAD or cerebro-vascular disease, and matched for age, sex, smoking status, weight category and the presence of hypertension, dyslipidemia, and diabetes. Our findings were meta-analyzed together with additional studies retrieved from the literature. The C(242)T polymorphism distribution did not differ between cases and controls in populations I and II both at univariate and multivariate analyses, and this was confirmed in a meta-analysis with 11 previously published populations. The meta-analysis, however, suggested a protective role of the T allele on CAD as an end point in Asian populations. In conclusion, these data suggest a significant heterogeneity for a modulating role of the T allele in the C(242)T polymorphism of p22-phox for the occurrence of CAD across ethnicities, with the absence of a significant effect in Caucasians.

 

 

Human recombinant chromogranin A-derived vasostatin-1 mimics preconditioning via an adenosine/nitric oxide signaling mechanism. PDF Stampa E-mail
Am J Physiol Heart Circ Physiol. 2007;293(1):H719-27.
Human recombinant chromogranin A-derived vasostatin-1 mimics preconditioning via an adenosine/nitric oxide signaling mechanism.
Cappello S, Angelone T, Tota B, Pagliaro P, Penna C, Rastaldo R, Corti A, Losano G, Cerra MC.
Dipartimento di Neuroscienze, Sezione di Fisiologia, Università di Torino, Corso Raffaello 30, 10125 Turin, Italy.

The acidic protein chromogranin A (CgA) is the precursor of several regulatory peptides generated by specific proteolytic processes. Human recombinant CgA NH(2)-terminal fragment STA-CgA(1-78) (hrSTA-CgA(1-78)), containing vasostatin-1 (CgA(1-76)) domain, exerts a negative inotropic effect and counteracts the beta-adrenergic positive inotropic effect on the rat heart. We hypothesized an involvement of nitric oxide (NO)-dependent pathway in both cardiodepression and cardioprotection by hrSTA-CgA(1-78). We also hypothesized an involvement of adenosine A(1) receptor and protein kinase C (PKC) in cardioprotection by hrSTA-CgA(1-78). Therefore, we evaluated whether 1) the cardioinhibition mediated by hrSTA-CgA(1-78) involves the G(i/o) proteins/NO-dependent signal transduction cascade, 2) hrSTA-CgA(1-78) induces ischemic preconditioning-like protective effects on the myocardium, and 3) inhibition of NO synthase (NOS), adenosine A(1) receptor, or PKC affects hrSTA-CgA(1-78) protection. Using the isolated rat heart, we found that the reduction of left ventricular pressure (LVP), rate-pressure product, and maximal values of the first derivative of LVP elicited by hrSTA-CgA(1-78) at 33 nM is abolished by blocking G(i/o) proteins with pertussis toxin, scavenging NO with hemoglobin, and blocking NOS activity with N(G)-monomethyl-l-arginine or N(5)-(iminoethyl)-l-ornithine, soluble guanylate cyclase with 1H-[1,2,4]oxadiazole-[4,4-a]quinoxalin-1-one, and protein kinase (PKG) with KT5823. Data suggest the involvement of the G(i/o) proteins/NO-cGMP-PKG pathway in the hrSTA-CgA(1-78)-dependent cardioinhibition. When given before 30 min of ischemia, hrSTA-CgA(1-78) significantly reduced the size of the infarct from 64 +/- 4 to 32 +/- 3% of the left ventricular mass. This protective effect was abolished by either NOS inhibition or PKC blockade and was attenuated, but not suppressed, by the blockade of A(1) receptors. These results suggest that hrSTA-CgA(1-78) activity triggers two different pathways: one of these pathways is mediated by A(1) receptors, and the other is mediated by NO release. As with repeated brief preconditioning ischemia, hrSTA-CgA(1-78) may be considered a stimulus strong enough to trigger both pathways, which may converge on PKC.