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The surface properties of drug containers should reduce the adsorption of the drug and avoid packaging surface/drug interactions, especially in the case of biologically-derived products. Here, we developed a multi-technique approach that combined Differential Scanning Calorimetry (DSC), Atomic Force Microscopy (AFM), Contact Angle (CA), Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), and X-ray Photoemission Spectroscopy (XPS) to investigate the interactions of rhNGF on different pharma grade polymeric materials. Polypropylene (PP)/polyethylene (PE) copolymers and PP homopolymers, both as spin-coated films and injected molded samples, were evaluated for their degree of crystallinity and adsorption of protein. Our analyses showed that copolymers are characterized by a lower degree of crystallinity and lower roughness compared to PP homopolymers. In line with this, PP/PE copolymers also show higher contact angle values, indicating a lower surface wettability for the rhNGF solution on copolymers than PP homopolymers. Thus, we demonstrated that the chemical composition of the polymeric material and, in turn, its surface roughness determine the interaction with the protein and identified that copolymers may offer an advantage in terms of protein interaction/adsorption. The combined QCM-D and XPS data indicated that protein adsorption is a self-limiting process that passivates the surface after the deposition of roughly one molecular layer, preventing any further protein adsorption in the long term.

The aim of this mini-review is to draw together the main concepts and findings that have emerged from recent studies of the cardiac channel protein Nav1.5. This complex protein is encoded by the SCN5A gene that, in its mutated form, is implicated in various diseases, particularly channelopathies, specifically at cardiac tissue level. Here we describe the structural, and functional aspects of Nav1.5 including post-translational modifications in normal conditions, and the main human channelopathies in which this protein may be the cause or trigger. Lastly, we also briefly discuss interacting proteins that are relevant for these channel functions in normal and disease conditions.

Congenital long QT syndrome (LQTS) is associated with high genetic and allelic heterogeneity. In some cases, more than one genetic variant is identified in the same (compound heterozygosity) or different (digenic heterozygosity) genes, and subjects with multiple pathogenic mutations may have a more severe disease. Standard-of-care clinical genetic testing for this and other arrhythmia susceptibility syndromes improves the identification of complex genotypes. Therefore, it is important to distinguish between pathogenic mutations and benign rare variants. We identified four genetic variants (KCNQ1-p.R583H, KCNH2-p.C108Y, KCNH2-p.K897T, and KCNE1-p.G38S) in an LQTS family. On the basis of in silico analysis, clinical data from our family, and the evidence from previous studies, we analyzed two mutated channels, KCNQ1-p.R583H and KCNH2-p.C108Y, using the whole-cell patch clamp technique. We found that KCNQ1-p.R583H was not associated with a severe functional impairment, whereas KCNH2-p.C108Y, a novel variant, encoded a non-functional channel that exerts dominant-negative effects on the wild-type. Notably, the common variants KCNH2-p.K897T and KCNE1-p.G38S were previously reported to produce more severe phenotypes when combined with disease-causing alleles. Our results indicate that the novel KCNH2-C108Y variant can be a pathogenic LQTS mutation, whereas KCNQ1-p.R583H, KCNH2-p.K897T, and KCNE1-p.G38S could be LQTS modifiers.

Fibrous meshes based on three different poly(vinyl alcohol) (PVA) polymers, with 12% vinyl acetate monomeric units and molar weights of 37,000, 67,000, and 130,000 were developed as potential scaffolds for regenerative medical applications. The meshes were electrospun and characterized by molecular weight, concentration, applied voltage, and needle—collector distance. The influence of feed rate and the electrodes configuration (needle-to-tip and screen-to-screen system) was determined. Highly porous, 3D structures composed of randomly oriented ultrafine fibers, with an average fiber diameter of a few hundred nanometers were developed. Solutions of PVA and human serum albumin were successfully electrospun and the fibrous mesh was stabilized with glutaraldehyde. The influence of these operations on the mechanical properties was evaluated by uniaxial tensile testing.

Melt electrospinning is one aspect of electrospinning with relatively little published literature, although the technique avoids solvent accumulation and/or toxicity which is favoured in certain applications. In the study reported, we melt-electrospun blends of poly(ε-caprolactone) (PCL) and an amphiphilic diblock copolymer consisting of poly(ethylene glycol) and PCL segments (PEG-block-PCL). A custom-made electrospinning apparatus was built and various combinations of instrument parameters such as voltage and polymer feeding rate were investigated. Pure PEG-block-PCL copolymer melt electrospinning did not result in consistent and uniform fibres due to the low molecular weight, while blends of PCL and PEG-block-PCL, for some parameter combinations and certain weight ratios of the two components, were able to produce continuous fibres significantly thinner (average diameter of ca 2 µm) compared to pure PCL. The PCL fibres obtained had average diameters ranging from 6 to 33 µm and meshes were uniform for the lowest voltage employed while mesh uniformity decreased when the voltage was increased. This approach shows that PCL and blends of PEG-block-PCL and PCL can be readily processed by melt electrospinning to obtain fibrous meshes with varied average diameters and morphologies that are of interest for tissue engineering purposes. Copyright © 2010 Society of Chemical Industry

a CEINGE‐Biotecnologie Avanzate s.c.ar.l., Naples, Italy b Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita di Napoli Federico II, Naples, Italy c Unita Operativa Clinica di Cardiologia, Ospedale dei Colli, Seconda Universita di Napoli, Naples, Italy d Medicina dello Sport, Dipartimento di Scienze Biomediche Avanzate, University of Naples Federico II, Naples, Italy e IRCCS-Fondazione SDN, Naples, Italy

Disturbances in cardiac sodium channel function are associated with inherited arrhythmia susceptibility. Mutations in SCN5A, which encodes the cardiac sodium channel (NaV1.5), cause congenital long QT syndrome type 3 (LQT3), Brugada syndrome (BrS) and a variety of cardiac conduction disorders (CCD) [1,2]. These disorders have can have complex genotype-phenotype relationships [3,4]. Here we report the clinical features of an LQTS family segregating a novel amino acid deletion mutation (N1472del) in SCN5A that produces a unique pattern of biophysical disturbances consistent with the clinical phenotype.

An electrospinning procedure allowing the spinning of a straight jet of polymer solution was developed. By using proper collector devices, it enables to collect winded and aligned fibers and to prepare polymeric constructs developing along the Z axis. The reported results are expected to provide basic understandings on which parameters are controlling the stability/instability of the process and implement new applications of electrospinning with specific reference to the preparation of well defined three-dimensional structures.

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. Copyright © 2011 Society of Chemical Industry

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 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) 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-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 alone, the electrospun composite constructs enhanced endothelial cells adhesion and proliferation, both in terms of cell number and morphology. Results suggest that composite Tecoflex-Gelatin meshes could be promising alternatives to conventional vascular grafts, deserving of further studies on both their mechanical behaviour and smooth muscle cell compatibility.

Hypertrophic cardiomyopathy (HCM) is the most frequent genetic cardiovascular disorder worldwide. It is the leading cause of sudden cardiac-related death in young people and a major cause of cardiac failure and death in elderly people. However, HCM frequently goes undiagnosed until the appearance of overt signs and symptoms, thereby delaying prophylactic and therapeutic measures. We screened patients for sarcomeric genes associated with HCM to obtain information that could be useful for an early diagnosis and so limit the severe consequences of silent HCM. We recruited 39 families with HCM from southern Italy and found mutations in 41% of families (12 with familial HCM and 4 with sporadic HCM). The remaining 23 families (59%) were negative for myofilament gene mutations. Of the 12 mutations identified, 8 were novel. Screening of the other family members available revealed that 27 had mutations; 11 of these individuals had no signs or symptoms suggestive of HCM. This study, besides characterizing the spectrum of mutations in another childhood population, and revealing an even greater genetic heterogeneity than formerly recognized, may increase genotype-phenotype correlations, and thus may help to identify asymptomatic candidates for early preventive or therapeutic measures. © 2009 John Wiley & Sons A/S.

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.

Isolated familial pseudohyperkalemia is a dominant red cell trait characterized by cold-induced ‘passive leak’ of red cell potassium ions into plasma. The causative gene of this condition is ABCB6, which encodes an erythrocyte membrane ABC transporter protein bearing the Langereis blood group antigen system. In this study analyzing three new families, we report the first functional characterization of ABCB6 mutants, including the homozygous mutation V454A, heterozygous mutation R276W, and compound heterozygous mutations R276W and R723Q (in trans). All these mutations are annotated in public databases, suggesting that familial pseudohyperkalemia could be common in the general population. Indeed, we identified variant R276W in one of 327 random blood donors (0.3%). Four weeks’ storage of heterozygous R276W blood cells resulted in massive loss of potassium compared to that from healthy control red blood cells. Moreover, measurement of cation flux demonstrated greater loss of potassium or rubidium ions from HEK-293 cells expressing ABCB6 mutants than from cells expressing wild-type ABCB6. The R276W/R723Q mutations elicited greater cellular potassium ion efflux than did the other mutants tested. In conclusion, ABCB6 missense mutations in red blood cells from subjects with familial pseudohyperkalemia show elevated potassium ion efflux. The prevalence of such individuals in the blood donor population is moderate. The fact that storage of blood from these subjects leads to significantly increased levels of potassium in the plasma could have serious clinical implications for neonates and infants receiving large-volume transfusions of whole blood. Genetic tests for familial pseudohyperkalemia could be added to blood donor pre-screening. Further study of ABCB6 function and trafficking could be informative for the study of other pathologies of red blood cell hydration.