1,721,114 research outputs found
Prevenzione dei fenomeni di calcificazione mediati dalla glutaraldeide: efficacia del pre-trattamento con sodio-dodecil-solfato (SDS) di radici aortiche porcine
No full textCAKE: Sharing Slices of Confidential Data on Blockchain
No full textCooperative information systems typically involve various entities in a collaborative process within a distributed environment. Blockchain technology offers a mechanism for automating such processes, even when only partial trust exists among participants. The data stored on the blockchain is replicated across all nodes in the network, ensuring accessibility to all participants. While this aspect facilitates traceability, integrity, and persistence, it poses challenges for adopting public blockchains in enterprise settings due to confidentiality issues. In this paper, we present a software tool named Control Access via Key Encryption (CAKE), designed to ensure data confidentiality in scenarios involving public blockchains. After outlining its core components and functionalities, we showcase the application of CAKE in the context of a real-world cyber-security project within the logistics domain
Biocompatibility Evaluation Criteria for Novel Xenograft Materials: Distribution and Quantification of Remnant Nucleic Acid and Alpha-Gal Epitope
Full text linkSelf-seeding heart valve design: self-assembling peptide hydrogel as filler for decellularized pericardium
No full textAlpha-Gal detectors in xenotransplantation research: a word of caution.
No full textXenogeneic tissues are currently employed in clinical practice to create biological substitutes (bioprosthetic heart valves) and in the repair of various damaged tissues (pericardium, gastric-mucosa, nerves, cartilage). Many studies have shown that xenogeneic tissues express superficial epitopes as alpha-Gal, capable of triggering hyperacute and acute vascular rejection phenomena. Currently, no tissue treatment has proven able to completely mask or inactivate such epitopes. In fact, neither glutaraldehyde fixation nor decellularisation procedures ensure a definitive solution because of the persistence of reactive xenoantigen residues. The ability to ascertain alpha-Gal epitope removal from a xenogeneic tissue is closely related to the possibility of its quantitative determination. In the past, detection of the alpha-Gal epitope relied on the use of alpha-Gal reactive isolectin molecules and was limited to isolated cells. Recently, the quantitative evaluation of this antigen has been carried out in whole connective tissue through the use of the monoclonal antibody M86. This article provides an overview of the implications of the alpha-Gal epitope in the current clinical scenario and a definitive comparison between the reliability and specificity of isolectines vs. M86 in alpha-Gal determination
First quantitative assay of alpha-Gal in soft tissues: presence and distribution of the epitope before and after cell removal from xenogeneic heart valves.
No full textDecellularized xenograft heart valves might be the ideal scaffolds for tissue engineered heart valves as the alternative to the currently used biological and mechanical prostheses. However, removal of the alpha-Gal epitope is a prerequisite to avoid hyperacute rejection of untreated xenograft material. The aim of this study was to develop an ELISA soft-tissue assay for alpha-Gal quantification in xenograft heart valves before and after a detergent-based (TriCol) or equivalent cell removal procedure. Leaflets from porcine valves were enzymatically digested to expose the epitope and reacted with the alpha-Gal monoclonal antibody M86 for its recognition. Rabbit erythrocytes were used as a reference for the quantification of alpha-Gal. Native aortic and pulmonary leaflets exhibited different epitope concentration: 4.33×10(11) vs. 7.12×10(11)/10 mg wet tissue (p<0.0001). Sampling of selected zones in native valves revealed a different alpha-Gal distribution within and among different leaflets. The pattern was consistent with immunofluorescence analysis and was unrelated to microvessel density distribution. After TriCol treatment alpha-Gal was no longer detectable in both pulmonary and aortic decellularized valves, confirming the ability of this method to remove both cells and alpha-Gal antigen. These results hold promise for a reliable quantitative evaluation of alpha-Gal in decellularized valves obtained from xenograft material for tissues engineering purposes. Additionally, this method is applicable to further evaluate currently used xenograft bioprostheses
Cells, scaffolds and bioreactors for tissue engineered heart valves: a journey from basic concepts to contemporary developmental innovations
No full textThe development of viable and functional tissue-engineered heart valves (TEHVs) is a challenge that, for almost two decades, the scientific
community has been committed to face to create life-lasting prosthetic devices for treating heart valve diseases. One of the main drawbacks of
tissue-based commercial substitutes, xenografts and homografts, is their lack of viability, and hence failure to grow, repair, and remodel. In
adults, the average bioprostheses life span is around 13 years, followed by structural valve degeneration, such as calcification; in pediatric,
mechanical valves are commonly used instead of biological substitutes, as in young patients, the mobilization of calcium, due to bone remodeling,
accelerates the calcification process. Moreover, neither mechanical nor bioprostheses are able to follow children’s body growth. Cell seeding and
repopulation of acellular heart valve scaffolds, biological and polymeric, appears as a promising way to create a living valve. Biomechanical
stimuli have significant impact on cell behavior including in vitro differentiation, and physiological hemodynamic conditioning has been found to
promote new tissue development. These concepts have led scientists to design bioreactors to mimic the in vivo environment of heart valves. Many
different types of somatic and stem cells have been tested for colonizing both the surface and the core of the valve matrix but controversial
results have been achieved so far
The use of reverse-phase high-performance liquid chromatography and precolumn derivatization with dansyl chloride for quantitation of specific amino acids in collagen and elastin
No full textQUANTITATIVE EVALUATION OF THE ALPHA-GAL XENOANTIGEN IN CURRENTLY HEART VALVE BIOPROSTHESES. COMPARISON WITH THE ALPHA-GAL AMOUNT IN THE ORIGINAL TISSUES UTILIZED FOR THEIR FABRICATION BEFORE AND AFTER DIFFERENT DECELLULARIZATION PROCEDURE
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