CARDIAC STEM CELLS AND BIOMATERIALS: INDUCTION OF MYOGENIC DIFFERENTIATION AND IMPLANTION OF BIOSYNTHETIC AND NATURAL MATRICES IN THE ADULT HEART

Principal purpose of regenerative medicine for the cardiac tissue is to find the best way to inoculate stem cells in a specific myocardial area damage, improving their homing, integration and survival. To achieve this goal, the field of biomaterials is important to bypass this obstacles, modulating the environment for implanted cells and enhance CSC function in the heart. Biomaterials can mimic or include naturally occurring extracellular matrix and instruct stem cell function in different ways: promoting angiogenesis, enhancing stem cell engraftment and differentiation, and accelerating electromechanical integration of transplanted cells. The aim of this thesis was to assess whether the properties of three-dimensional polymer matrices in synthetic biomaterial such as polylactic acid and in natural origin as silk fibroin, if and how influence differentiative process of stem cells cardiac c-kit +. Another point considered was been the evaluation of expression of cardiac markers and sarcomeric proteins of cells isolated, inoculated in different types of scaffold and maintained in colture for 21gg in vitro and analyzed in RT-PCR and Real-time quantitative RT–PCR analysis. Also it was analyzed the immunogenicity of the scaffold when implanted in the dorsal subcutaneous region of nude mice, nude rats and SCID mice in order a possible use in vivo in the cardiac regeneration. These experiments showed a myocardial-like differentiation, in which the CSCs acquired a muscle-like shape, with the formation of initial intercalated disks, and a striated-like myofilament organization. In results shown below highlights evidence of an higher degree of differentiation using 3D scaffold for CSCs c-Kit+ that can be induced to differentiate definitely into cardiomyocytes thanks to three-dimensional culture of the scaffold, where is possible an environment similar to a cardiac niche in vivo

Do fat supplements increase physical performance?

Fish oil and conjugated linoleic acid (CLA) belong to a popular class of food supplements known as "fat supplements", which are claimed to reduce muscle glycogen breakdown, reduce body mass, as well as reduce muscle damage and inflammatory responses. Sport athletes consume fish oil and CLA mainly to increase lean body mass and reduce body fat. Recent evidence indicates that this kind of supplementation may have other side-effects and a new role has been identified in steroidogenensis. Preliminary findings demonstrate that fish oil and CLA may induce a physiological increase in testosterone synthesis. The aim of this review is to describe the effects of fish oil and CLA on physical performance (endurance and resistance exercise), and highlight the new results on the effects on testosterone biosynthesis. In view of these new data, we can hypothesize that fat supplements may improve the anabolic effect of exercise

Silk fibroin scaffolds enhance cell commitment of adult rat cardiac progenitor cells.

The use of three-dimensional (3D) cultures may induce cardiac progenitor cells to synthesize their own extracellular matrix (ECM) and sarcomeric proteins to initiate cardiac differentiation. 3D cultures grown on synthetic scaffolds may favour the implantation and survival of stem cells for cell therapy when pharmacological therapies are not efficient in curing cardiovascular diseases and when organ transplantation remains the only treatment able to rescue the patient’s life. Silk fibroin-based scaffolds may be used to increase cell affinity to biomaterials and may be chemically modified to improve cell adhesion. In the present study, porous, partially orientated and electrospun nanometric nets were used. Cardiac progenitor cells isolated from adult rats were seeded by capillarity in the 3D structures and cultured inside inserts for 21 days. Under this condition, the cells expressed a high level of sarcomeric and cardiac proteins and synthesized a great quantity of ECM. In particular, partially orientated scaffolds induced the synthesis of titin, which is a fundamental protein in sarcomere assembly

Effects of antioxidants on CSE-induced cell death in human asthmatic primary bronchial epithelial cells

The link between cigarette smoke (CS) and lung inflammation is quite strong, however relatively little is still known on the effects of CS on human bronchial epithelial cells survival during asthma. In this study we focused our attention on the apoptotic effects of CS on healthy (HC) and asthmatic (AS) primary bronchial epithelial cells (PBEC) and on the role of antioxidants to protect epithelial cells from CSE-induced apoptosis. Twenty subjects (10 HC and 10 AS) were recruited for this study and PBEC were obtained by bronchoscopy. PBEC were treated with oxidants (H2O), anti-oxidants (GSH and AA) and cigarette smoke extracts (CSE). Early apoptosis (EA) and necrosis were measured by flow cytometry using Annexin-V and propidium iodide. After treatment with CSE 20%, AS showed an increased susceptibility to the CSE treatment compared to HC (24.34+/-9.61 vs 48.45+/-11.91, p=0.003). Similarly, when EA was taken into consideration, there was a significant increase of EA cells in the AS group treated with CSE compared to HC (33.12+/-10.38 vs 16.73+/-6.92, p<0.05). AA failed to protect both HS and AS PBEC from CSE-induced cell death. GSH instead was able to protect significantly both HS and AS from CSE-induced cell death. In particular, the association between GSH and CSE 20% determined a significant (p=0.005 in HC and p=0.003 in AS) increase of viability when compared to CSE alone and at the same time EA levels dropped considerably (p<0.05 in HC and p=0.003 in AS) down in the presence of this antioxidant Moreover, GSH treatment determined a significantly bigger (p=0.002) overall increase in viability in the AS group when compared to the HC group. In view of this data it could be possible to hypothesise that the typical imbalance in oxidants-antioxidants levels of asthmatic bronchial epithelial cells might be responsible for their increased susceptibility to oxidative stress

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity &gt; 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI