Engineering muscle networks in 3D gelatin methacryloyl hydrogels: influence of mechanical stiffness and geometrical confinement

In this work, the influence of mechanical stiffness and geometrical confinement on the 3D culture of myoblast-laden gelatin methacryloyl (GelMA) photo-crosslinkable hydrogels was evaluated in terms of in vitro myogenesis. We formulated a set of cell-laden GelMA hydrogels with a compressive modulus in the range 1÷17 kPa, obtained by varying GelMA concentration and degree of cross-linking. C2C12 myoblasts were chosen as the cell model, to investigate the supportiveness of different GelMA hydrogels on myotube formation up to 2 weeks. Results showed that the hydrogels with a stiffness in the range 1÷3 kPa provided enhanced support to C2C12 differentiation in terms of myotube number, rate of formation and space distribution. Finally, we studied the influence of geometrical confinement on myotube orientation by confining cells within thin hydrogel slabs having different cross-sections: i) 2000×2000 m, ii) 1000×1000 m and iii) 500×500 m. The obtained results showed that by reducing the cross-section—i.e., by increasing the level of confinement—myotubes were more likely restrained and formed aligned myostructures that better mimicked the native morphology of skeletal muscle

High-density ZnO nanowires for cellular biointerfaces: a new role as myogenic differentiation switch

The design of artificial platforms for expanding undifferentiated stem cells is of tremendous importance for regenerative medicine [1]. We have recently demonstrated that a ZnO nanowires (NWs) decorated glass support permits to obtain a differentiation switch during proliferation for mesoangioblasts (MABs)– i.e. multipotent progenitor cells which are remarkable candidates for the therapy of muscle diseases [2]. We have optimized the ZnO NWs synthesis on glass surfaces by numerical simulations and experimental systematic investigations, considering zinc speciation and supersaturation [3]. In particular, we demonstrated by numerical simulations that the ligand ethylenediamine, at the isoelectric point of the ZnO NWs tips, can effectively control – at 1:1 stoichiometric ratio with zinc – both speciation and supersaturation of zinc in the nutrient solution. In this regard, we employed ethanolamine (a safer precursor) for in-situ producing ethylenediamine by means of a zinc-catalysed amination reaction of ethanolamine by ammonia. The obtained highquality ZnONWs-cells biointerface allows cells to maintain viability and a spherical viable undifferentiated state during the 8 days observation time. Simulations of the interface by theoretical models [4] and our experimental investigations by SEM and confocal microscopy demonstrate that NWs do not induce any damage on the cellular membrane, whilst blocking their differentiation. More specifically, the myosin heavy chain, typically expressed in differentiated myogenic progenitors, is completely absent. Interestingly, the differentiation capabilities are completely restored upon cell removal from the NW-functionalized substrate and regrowing onto a standard culture glass dish. These results open the way towards unprecedented applications of ZnO NWs for cell-based therapy and tissue engineering [5]. References [1] G. Cossu, P. Bianco, Curr. Opin. Genet. Dev. 2003, 13, 537-542. [2] V. Errico, G. Arrabito, E. Fornetti, C. Fuoco, S. Testa, G. Saggio, S. Rufini, S. M. Cannata, A. Desideri, C. Falconi, C. Gargioli, ACS Appl. Mater. Interfaces, 2018, 10, 14097- 14107. [3] G. Arrabito, V. Errico, Z. Zhang, W. Han, C. Falconi, Nano Energy, 2018, 46, 54-62. [4] N. Buch-Månson, S. Bonde, J. Bolinsson, T. Berthing, J. Nygård, K.L. Martinez, Adv. Funct. Mater. 2015, 25, 3246-3255. [5] Y. Su, I. Cockerill, Y. Wang, Y.-X. Qin, L. Chang, Y. Zheng, and D. Zhu, Trends in Biotechnology, 2019, 37, 428-441

TRAIT (TRAnscript Integrated Table): a knowledgebase of human skeletal muscle transcripts.

Abstract Summary: TRAIT is a knowledgebase integrating information on transcripts with related data from genome, proteins, ortholog genes and diseases. It was initially built as a system to manage an EST-based gene discovery project on human skeletal muscle, which yielded over 4500 independent sequence clusters. Transcripts are annotated using automatic as well as manual procedures, linking known transcripts to public databases and unknown transcripts to tables of predicted features. Data are stored in a MySQL database. Complex queries are automatically built by means of a user-friendly web interface that allows the concurrent selection of many fields such as ontology, expression level, map position and protein domains. The results are parsed by the system and returned in a ranked order, in respect to the number of satisfied criteria. Availability: http://muscle.cribi.unipd.it and http://muscle.cribi.unipd.it/features/querystrait.html Contact: [email protected]; [email protected] * To whom correspondence should be addressed

Predicting LVOT Obstruction in Transcatheter Mitral Valve Replacement for Failed Surgical Annuloplasty

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Parametric analysis of transcatheter aortic valve replacement in transcatheter aortic valve replacement: evaluation of coronary flow obstruction

Transcatheter aortic valve replacement (TAVR) is increasingly being considered for use in younger patients having longer life expectancy than those who were initially treated. The TAVR-in-TAVR procedure represents an appealing strategy to treat failed transcatheter heart valves (THV) likely occurring in young patients. However, the permanent displacement of first THV can potentially compromise the coronary access and ultimately inhibit the blood flow circulation. The objective of this study was to use finite-element analysis (FEA) to quantify coronary flow in a patient who underwent TAVR-in-TAVR. A parametric investigation was carried out to determine the impact of both the implantation depth and device size on coronary flow for several deployment configurations. The FEAs consisted of first delivering the SAPIEN 3 Ultra THV and then positioning the Evolut PRO device. Findings indicates that high implantation depth and device undersize of the second THV could significantly reduce coronary flow to 20% of its estimated level before TAVR. Additionally, a positive correlation was observed between coronary flow and the valve-to-coronary distance (R = 0.86 and p = 0.032 for the left coronary artery, and R = 0.93 and p = 0.014 for the right coronary artery). This study demonstrated that computational modeling can provide valuable insights to improve the pre-procedural planning of TAVR-in-TAVR

Percutaneous Edge-to-Edge Mitral Valve Repair with the Mitraclip System in Barlow's Disease

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In-hospital and thirty-day outcomes of the SAPIEN 3 Ultra balloon-expandable transcatheter aortic valve : the S3U registry

Aims: The aim of this study was to evaluate 30-day safety and efficacy outcomes of transcatheter aortic valve implantation (TAVI) performed with the SAPIEN 3 Ultra system. Methods and results: The S3U registry is a physician-led, post-approval, multicentre, observational registry of transfemoral TAVI with the SAPIEN 3 Ultra. New features include an improved sealing skirt, a 14 Fr expandable sheath and a new delivery catheter. Overall, 139 consecutive patients at nine participating centres were enrolled. Mean age was 81.4 +/- 8.3 years, average STS score 3.8 +/- 2.4%. The vast majority (97.2%) underwent TAVI with local anaesthesia (28.8%) or conscious sedation (68.3%). Balloon predilatation was performed in 30 patients (21.6%), post-dilatation in three (2.2%). In-hospital, there were no cases of death, stroke, or conversion to open heart surgery. Major vascular complications occurred in three patients (2.2%), as well as major or life-threatening bleedings in three patients (2.2%). There were two moderate (1.4%) and no moderate/severe paravalvular leaks. Median length of stay after TAVI was three days (IQR 3-5 days). At 30 days, there were no deaths, MI, or strokes, and the incidence of new permanent pacemaker implantation was 4.4%. Conclusions: This first multicentre international experience of transfemoral TAVI with the SAPIEN 3 Ultra transcatheter heart valve shows good in-hospital and 30-day clinical outcomes.Peer reviewe

The Effects of Granulocyte Colony-Stimulating Factor in Patients with a Large Anterior Wall Acute Myocardial Infarction to Prevent Left Ventricular Remodeling. A 10-Year Follow-Up of the RIGENERA Study

Background: the RIGENERA trial assessed the efficacy of granulocyte-colony stimulating factor (G-CSF) in the improvement of clinical outcomes in patients with severe acute myocardial infarction. However, there is no evidence available regarding the long-term safety and efficacy of this treatment. Methods: in order to evaluate the long-term effects on the incidence of major adverse events, on the symptom burden, on the quality of life and the mean life expectancy and on the left ventricular (LV) function, we performed a clinical and echocardiographic evaluation together with an assessment using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the Seattle Heart Failure Model (SHFM) at 10-years follow-up, in the patients cohorts enrolled in the RIGENERA trial. Results: thirty-two patients were eligible for the prospective clinical and echocardiography analyses. A significant reduction in adverse LV remodeling was observed in G-CSF group compared to controls, 9% vs. 48% (p = 0.030). The New York Heart Association (NYHA) functional class was lower in G-CSF group vs. controls (p = 0.040), with lower burden of symptoms and higher quality of life (p = 0.049). The mean life expectancy was significantly higher in G-CSF group compared to controls (15 +/- 4 years vs. 12 +/- 4 years, p = 0.046. No difference was found in the incidence of major adverse events. Conclusions: this longest available follow-up on G-CSF treatment in patients with severe acute myocardial infarction (AMI) showed that this treatment was safe and associated with a reduction of adverse LV remodeling and higher quality of life, in comparison with standard-of-care treatment

Intermittent fasting applied in combination with rotenone treatment exacerbates dopamine neurons degeneration in mice

Intermittent fasting (IF) was suggested to be a powerful nutritional strategy to prevent the onset of age-related neurodegenerative diseases associated with compromised brain bioenergetics. Whether the application of IF in combination with a mitochondrial insult could buffer the neurodegenerative process has never been explored yet. Herein, we defined the effects of IF in C57BL/6J mice treated once per 24 h with rotenone (Rot) for 28 days. Rot is a neurotoxin that inhibits the mitochondrial complex I and causes dopamine neurons degeneration, thus reproducing the neurodegenerative process observed in Parkinson\u2019s disease (PD). IF (24 h alternate-day fasting) was applied alone or in concomitance with Rot treatment (Rot/IF). IF and Rot/IF groups showed the same degree of weight loss when compared to control and Rot groups. An accelerating rotarod test revealed that only Rot/IF mice have a decreased ability to sustain the test at the higher speeds. Rot/IF group showed a more marked decrease of dopaminergic neurons and increase in alpha-synuclein (a-syn) accumulation with respect to Rot group in the substantia nigra (SN). Through lipidomics and metabolomics analyses, we found that in the SN of Rot/IF mice a significant elevation of excitatory amino acids, inflammatory lysophospholipids and sphingolipids occurred. Collectively, our data suggest that, when applied in combination with neurotoxin exposure, IF does not exert neuroprotective effects but rather exacerbate neuronal death by increasing the levels of excitatory amino acids and inflammatory lipids in association with altered brain membrane composition