Electrospun Nanofibers in Biomedical Applications (32)Tissue Engineering and Regenerative Medicine (22)Aortic Disease and Treatment Approaches (10)Advanced Sensor and Energy Harvesting Materials (8)Cardiac Valve Diseases and Treatments (7)
Transcatheter aortic valve replacement (TAVR) has emerged as an effective therapy for inoperable patients with severe aortic stenosis (AS). However, calcification-induced limited durability restricts its application. Fish swim bladders (FSB), which are resistant to calcific degeneration, offer a viable solution to this challenge. In this study, we developed a new TAVR device using FSB as the valve leaflet. Furthermore, the in vitro durability, in vivo performance, and size selection of this TAVR device were assessed by an experimental study and finite element analysis. A self-expandable TAVR device was fabricated by suturing the FSB films into a 23 mm nitinol alloy frame. Further, hemodynamic performance, such as effective orifice area, transvalvular pressure difference and regurgitant fraction, the durability was tested by the pulsatile flow test and accelerated fatigue test, according to the ISO 5840-3. The effect of release size on hydrodynamic performance was also investigated. Finally, the in vivo performance of the TAVR device were examined using a porcine implantation model. The results showed that the strength of the FSB films satisfied the requirements for valve leaflets. The hemodynamic performance of the FSB TAVR device met the requirements of ISO 5840-3 standards. After 400 million cycles, the FSB showed no fiber loss, torn, perforation, or other valve failure phenomena. In porcine models, the devices were well-positioned, functioned well with no stenosis immediately after the operation. Collectively, we successfully developed a TAVR device with FSB as valve leaflets that exhibited good fatigue resistance. STATEMENT OF SIGNIFICANCE: The source of material for the leaflets of commercialized biological heart valves (BHVs) is mainly bovine pericardium, but this material suffers the following problems: large and uneven thickness of the material, the presence of α-Gal and Neu5Gc antigens, and the susceptibility to structural valve degradation (SVD). New material for BHVs leaflets is rarely reported. In this study, we prepared a transcatheter aortic valve (TAV) and performed long-term in vitro and short-term in vivo studies using fish swim bladder (FSB) as the leaflets. The study confirmed that FSB TAV device can complete 400 million fatigue tests and maintain the good morphology of the leaflets, and that it still maintains good functionality after a certain amount of compression, indicating that FSB is a promising material for leaflets.
Conventional methods for analyzing monosaccharides, such as 1-Phenyl-3-methyl-5-pyrazolone (PMP) derivatization coupled with high-performance liquid chromatography (HPLC), struggle to detect ketoses and acidic sugars. This limitation hinders the precise structural analysis of polysaccharides in traditional Chinese medicine (TCM). A methylation-assisted Gas Chromatography-Mass Spectrometry (GC-MS) approach was developed to address this issue in the current study. By optimizing the methylation process and using GC-MS with a BR-17 column and an Electron Ionization (EI) source, simultaneous detection of ten different monosaccharides was achieved within 20 min. GC-MS profiling of monosaccharides generally gives two peaks per analyte, except in the cases of fructose and galacturonic acid. Notably, fructose (Fru) was identified for the first time in the polysaccharides of Polygonatum species: P. sibiricum at 18.55 μg/mg, P. cyrtonema at 16.90 μg/mg, and P. kingianum at 14.35 μg/mg, overcoming the limitations of the inability to detect ketoses in the PMP-HPLC method. Data analysis revealed distinct species-specific markers: P. kingianum polysaccharides (PKP) uniquely contained α-galacturonic acid (α-Gal: 19.95 μg/mg), whereas P. sibiricum polysaccharides (PSP) featured six monosaccharides, including glucose (Glc: 135.45 μg/mg), mannose (Man: 78.95 μg/mg), and ribose (Rib: 26.90 μg/mg), with a total of 299.50 μg/mg. P. cyrtonema polysaccharides (PCP) showed elevated levels of glucuronic acid (GlcA, 38.40 μg/mg). This derivatization-enhanced GC-MS method effectively fingerprints TCM polysaccharides, enabling clear differentiation of Polygonatum species through analysis of monosaccharide composition and total sugar content. This approach establishes clear structural distinctions, overcoming the limitations of conventional chromatographic techniques and enhancing the quality control and authentication of TCM polysaccharides.
Glycosylation modification serves as a pivotal quality attribute in glycoprotein-based therapeutics, emphasizing its role in drug safety and efficacy. Prior studies have underscored the potential immunogenic risks posed by the presence of galactose-α-1,3-galactose (α-Gal) and N-glycolylneuraminic acid (NeuGc) in glycoprotein formulations. This accentuates the imperative for developing robust qualitative and quantitative analytical methods to monitor these immunogenic epitopes, thereby ensuring drug safety. In the present investigation, α-Gal and NeuGc were accurately quantified using UPLC-FLR-MS/MS at the oligosaccharide level. Remarkably, α-Gal could be identified when the ion intensity ratio or the mass-to-charge ratio (m/z) of 528.19 to 366.14 exceeded 1. Concurrently, NeuGc and N-acetylneuraminic acid (NeuAc) could be unambiguously identified through their respective fragment ions at m/z 673.23 and m/z 657.23. Furthermore, relative quantification of α-Gal and NeuGc was achieved using fluorescence signals. This study introduces a sensitive and reliable analytical approach for the qualitative and quantitative assessment of α-Gal and NeuGc in glycoprotein pharmaceuticals. The methodology offers significant potential for application in process control and optimization of glycoprotein production, aimed at minimizing immunogenicity and enhancing product quality.
Obesity has become a common health concern around the world. Maternal obesity could cause poor reproductive outcomes due to chronic ovarian inflammation and decreased oocyte quality. However, the strategies to improve the poor reproductive outcomes of obese females have not been fully studied. In this study, we aimed to explore the effects and underlying mechanisms of nicotinamide mononucleotide (NMN) on oocyte quality and reproductive performance of obese mice. The obese mouse model was established by feeding high-fat diet which was confirmed by body weight record, fasting blood glucose test and oral glucose tolerance test. The expression of ovary development related genes and inflammation related genes, including Lhx8, Bmp4, Adgre1, Ccl2, TNF-α, Gal-3, Clec10a and IL-10 in ovaries and the expression of Bax and Sod1 in oocytes were detected using quantitative reverse transcription PCR (RT-qPCR). The adipose size of abdominal fat tissue was determined with haematoxylin and eosin (H&E) staining. Immunofluorescence staining was performed to measure the ROS level, spindle/chromosome structure, mitochondrial function, actin dynamics and DNA damage of oocytes. The administration of NMN restored ovarian weight and reduced the adipose size of abdominal fat tissue and ovarian inflammation in high fat diet (HFD) mice. Furthermore, NMN treatment improved the oocytes quality partially by restoring the mitochondrial function and actin dynamics, reducing meiotic defects, DNA damage and ROS level and lipid droplet distribution of oocytes in HFD mice. On the long-term effect, NMN restored offspring body weight of HFD mice. NMN could improve the oocyte quality of HFD-induced obese mice.
Scaffolds mimicking the native annulus fibrosus (AF) extracellular matrix (ECM) structure are crucial to guide the seeding cells to regenerate aligned tissue, while fabricating such a scaffold by synthetic material is challengeable. Native acellular scaffolds derived from AF tissue certainly possess the advantages of natural structure and composition. Based on previous studies, we modified decellularization procedure and especially compared two drying methods, including gradient dehydration and freeze-drying. The decellularization process can effectively remove the host cells and antigens such as α-Gal, while maintaining the original ECM including GAG and collagen I. Compared with gradient dehydration, freeze-drying not only rendered the decellularized scaffold in dry state for storage but also gave the scaffold more aligned porous structure and hydrophilicity. And, the acellular porous scaffold manifested better capacity of supporting cell ingrowth when seeded human bone marrow mesenchymal stem cells (hBMSCs) or implanted in vivo. Furthermore, this optimized freeze-dried scaffold showed similar mechanical elastic modulus as native AF and demonstrated rare inflammatory granuloma and immune rejection as observed in HE staining and immunohistochemistry staining (IHC) of CD8 and MAC387 epitopes when implanted subcutaneously in vivo. To sum up, through our decellularization and freeze-drying procedure, an aligned porous three-dimensional scaffold derived from the natural AF ECM was successfully fabricated with good retention of ECM components and benign biocompatibility. It will be a promising scaffold for AF tissue engineering.