Genetic pre-participation screening in selected athletes: a new tool for the prevention of sudden cardiac death?

Sudden cardiac death (SCD) of athletes is a topical issue. “Borderline cardiac abnormalities”, which occur in ~2% of elite male athletes, may result in SCD, which may have a genetic base. Genetic analysis may help identify pathological cardiac abnormalities. We performed phenotype-guided genetic analysis in athletes who, pre-participation, showed ECG and/or echo “borderline” abnormalities, to discriminate subjects at a greater risk of SCD. Methods: We studied 24 elite athletes referred by the National Federation of Olympic sports; and 25 subjects seeking eligibility to practice agonistic sport referred by the Osservatorio Epidemiologico della Medicina dello Sport della Regione Campania. Inclusion criteria: a) ECG repolarization borderline abnormalities; b) benign ventricular arrhythmias; c) left ventricular wall thickness in the grey zone of physiology versus pathology (max wall thickness 12-15 mm in females; 13-16 mm in males). Based on the suspected phenotype, we screened subjects for the LMNA gene, for 8 sarcomeric genes, 5 desmosomal genes, and cardiac calcium, sodium and potassium channel disease genes. Results: Genetic analysis was completed in 37/49 athletes, 22 competitive and 27 non-competitive athletes, showing “borderline” clinical markers suggestive of hypertrophic cardiomyopathy (HCM,n. 24), dilated cardiomyopathy (n. 4), arrhythmogenic right ventricular dysplasia/cathecholaminergic polymorphic ventricular tachycardia (ARVD/CPVT, n. 11), long QT syndrome (LQTS, n. 4), sick sinus syndrome (SSS, n. 5), Brugada syndrome (BrS, n. 1). We identifyed 11 mutations in 9 athletes (an ARVD athlete was compound heterozygote for the PKP2 gene and an HCM athlete was double heterozygote for the MYBPC3 and TNNT2 genes): 3 known mutations related to LQTS, HCM and ARVD, respectively, and 8 novel mutations, located in the SCN5A, RyR2, PKP2, MYBPC3 and ACTC1 genes. The new mutations were absent in ~800 normal chromosomes and were predicted “probably damaging” by in silico analysis. Patch clamp analysis in channelopathies indicated for some mutation abnormal biophysical behavior of the corresponding mutant protein. Conclusion: Genetic analysis may help distinguish between physiology and pathology in athletes with clinically suspected heart disease

Polymeric nanostructured items electrospun on a cylindrical template: A simple procedure for their removal

Tubular structures, obtained by electrospinning on a rotating mandrel, are of interest for use as devices in medical and industrial applications. However, removal of electrospun tubes from the collecting mandrel has been a major problem and various techniques have been proposed, though having severe drawbacks. In our study, a method to safely remove electrospun tubes from a template mandrel (collector) is described. Before electrospinning, a copper wire is rolled up on the mandrel to form a helix, with the purpose of creating a gap between mandrel and electrospun tube once the wire is easily removed from the mandrel. Adopting the described methodology, uniform electrospun polymeric tubes can be easily removed from the mandrel. The procedure for fast rolling up of the wire on the rotating mandrel is also described

Poly(lactic-co-glycolic acid) electrospun fibrous meshes for the controlled release of retinoic acid

Poly(lactic-co-glycolic acid) (PLGA) meshes loaded with retinoic acid (RA) were prepared by applying the electrospinning technique. The purpose of the present work was to combine the biological effects of RA and the advantages of electrospun meshes to enhancing the mass transfer features of controlled release systems and cell interaction with polymeric scaffolds. The processing conditions for the fabrication of three-dimensional meshes were optimized by studying their influence on mesh morphology. Tensile testing showed that RA loading influenced the meshes mechanical properties by increasing their strength and rigidity. Moreover, the drug release and degradation profiles of the electrospun systems were compared to analogous RA-loaded PLGA films prepared by solvent casting. The results of this study highlight that the electrospun meshes preserved their fibrous structure after 4 months under in vitro physiological conditions and showed a sustained controlled release of the loaded agent in comparison to that observed for cast films. The bioactivity of the loaded RA was investigated on murine preosteoblasts cells by evaluating its influence on cell proliferation and morphology

Novel electrospun polyurethane/gelatin composite meshes for vascular grafts

Novel polymeric micro-nanostructure meshes as blood vessels substitute have been developed and investigated as a potential solution to the lack of functional synthetic small diameter vascular prosthesis. A commercial elastomeric polyurethane (Tecoflex(A (R)) EG-80A) and a natural biopolymer (gelatin) were successfully co-electrospun from different spinnerets on a rotating mandrel to obtain composite meshes benefiting from the mechanical characteristics of the polyurethane and the natural biopolymer cytocompatibility. Morphological analysis showed a uniform integration of micrometric (Tecoflex(A (R))) and nanometric (gelatin) fibers. Exposure of the composite meshes to vapors of aqueous glutaraldehyde solution was carried out, to stabilize the gelatin fibers in an aqueous environment. Uniaxial tensile testing in wet conditions demonstrated that the analyzed Tecoflex(A (R))-Gelatin specimens possessed higher extensibility and lower elastic modulus than conventional synthetic grafts, providing a closer matching to native vessels. Biological evaluation highlighted that, as compared with meshes spun from Tecoflex(A (R)) alone, the electrospun composite constructs enhanced endothelial cells adhesion and proliferation, both in terms of cell number and morphology. Results suggest that composite Tecoflex(A (R))-Gelatin meshes could be promising alternatives to conventional vascular grafts, deserving of further studies on both their mechanical behaviour and smooth muscle cell compatibility