Facile engineering of interactive double network hydrogels for heart valve regeneration.

Regenerative heart valve prostheses are essential for treating valvular heart disease, which requested interactive materials that can adapt to the tissue remodeling process. Such materials typically involves intricate designs with multiple active components, limiting their translational potential. This study introduces a facile method to engineer interactive materials for heart valve regeneration using 1,1'-thiocarbonyldiimidazole (TCDI) chemistry. TCDI crosslinking forms cleavable thiourea and thiocarbamate linkages which could gradually release H2S during degradation, therefore regulates the immune microenvironment and accelerates tissue remodeling. By employing this approach, a double network hydrogel was formed on decellularized heart valves (DHVs), showcasing robust anti-calcification and anti-thrombosis properties post fatigue testing. Post-implantation, the DHVs could adaptively degrade during recellularization, releasing H2S to further support tissue regeneration. Therefore, the comprehensive endothelial cell coverage and notable extracellular matrix remodeling could be clearly observed. This accessible and integrated strategy effectively overcomes various limitations of bioprosthetic valves, showing promise as an attractive approach for immune modulation of biomaterials.

Shear stress activates the Piezo1 channel to facilitate valvular endothelium-oriented differentiation and maturation of human induced pluripotent stem cells.

Valvular endothelial cells (VECs) derived from human induced pluripotent stem cells (hiPSCs) provide an unlimited cell source for tissue engineering heart valves (TEHVs); however, they are limited by their low differentiation efficiency and immature function. In our study, we applied unidirectional shear stress to promote hiPSCs differentiation into valvular endothelial-like cells (VELs). Compared to the static group, shear stress efficiently promoted the differentiation and functional maturation of hiPSC-VELs, as demonstrated by the efficiency of endothelial differentiation reaching 98.3% in the high shear stress group (45 dyn/cm2). Furthermore, we found that Piezo1 served as a crucial mechanosensor for the differentiation and maturation of VELs. Mechanistically, the activation of Piezo1 by shear stress resulted in the influx of calcium ions, which in turn initiated the Akt signaling pathway and promoted the differentiation of hiPSCs into mature VELs. Moreover, VELs cultured on decellularized heart valves (DHVs) exhibited a notable propensity for proliferation, robust adhesion properties, and antithrombotic characteristics, which were dependent on the activation of the Piezo1 channel. Overall, our study demonstrated that proper shear stress activated the Piezo1 channel to facilitate the differentiation and maturation of hiPSC-VELs via the Akt pathway, providing a potential cell source for regenerative medicine, drug screening, pathogenesis, and disease modeling. STATEMENT OF SIGNIFICANCE: This is the first research that systematically analyzes the effect of shear stress on valvular endothelial-like cells (VELs) derived from human induced pluripotent stem cells (hiPSCs). Mechanistically, unidirectional shear stress activates Piezo1, resulting in an elevation of calcium levels, which triggers the Akt signaling pathway and then facilitates the differentiation of functional maturation VELs. After exposure to shear stress, the VELs exhibited enhanced proliferation, robust adhesion capabilities, and antithrombotic characteristics while being cultured on decellularized heart valves. Thus, it is of interest to develop hiPSCs-VELs using shear stress and the Piezo1 channel provides insights into the functional maturation of valvular endothelial cells, thereby serving as a catalyst for potential applications in the development of therapeutic and tissue-engineered heart valves in the future.

On-chip lateral Si:Te PIN photodiodes for room-temperature detection in the telecom optical wavelength bands.

Photonic integrated circuits require photodetectors that operate at room temperature with sensitivity at telecom wavelengths and are suitable for integration with planar complementary-metal-oxide-semiconductor (CMOS) technology. Silicon hyperdoped with deep-level impurities is a promising material for silicon infrared detectors because of its strong room-temperature photoresponse in the short-wavelength infrared region caused by the creation of an impurity band within the silicon band gap. In this work, we present the first experimental demonstration of lateral Te-hyperdoped Si PIN photodetectors operating at room temperature in the optical telecom bands. We provide a detailed description of the fabrication process, working principle, and performance of the photodiodes, including their key figure of merits. Our results are promising for the integration of active and passive photonic elements on a single Si chip, leveraging the advantages of planar CMOS technology.

Early plasma proteomic biomarkers and prediction model of acute respiratory distress syndrome after cardiopulmonary bypass: a prospective nested cohort study.

BACKGROUND: Early recognition of the risk of acute respiratory distress syndrome (ARDS) after cardiopulmonary bypass (CPB) may improve clinical outcomes. The main objective of this study was to identify proteomic biomarkers and develop an early prediction model for CPB-ARDS. METHODS: The authors conducted three prospective nested cohort studies of all consecutive patients undergoing cardiac surgery with CPB at Union Hospital of Tongji Medical College Hospital. Plasma proteomic profiling was performed in ARDS patients and matched controls (Cohort 1, April 2021-July 2021) at multiple timepoints: before CPB (T1), at the end of CPB (T2), and 24 h after CPB (T3). Then, for Cohort 2 (August 2021-July 2022), biomarker expression was measured and verified in the plasma. Furthermore, lung ischemia/reperfusion injury (LIRI) models and sham-operation were established in 50 rats to explore the tissue-level expression of biomarkers identified in the aforementioned clinical cohort. Subsequently, a machine learning-based prediction model incorporating protein and clinical predictors from Cohort 2 for CPB-ARDS was developed and internally validated. Model performance was externally validated on Cohort 3 (January 2023-March 2023). RESULTS: A total of 709 proteins were identified, with 9, 29, and 35 altered proteins between ARDS cases and controls at T1, T2, and T3, respectively, in Cohort 1. Following quantitative verification of several predictive proteins in Cohort 2, higher levels of thioredoxin domain containing 5 (TXNDC5), cathepsin L (CTSL), and NPC intracellular cholesterol transporter 2 (NPC2) at T2 were observed in CPB-ARDS patients. A dynamic online predictive nomogram was developed based on three proteins (TXNDC5, CTSL, and NPC2) and two clinical risk factors (CPB time and massive blood transfusion), with excellent performance (precision: 83.33%, sensitivity: 93.33%, specificity: 61.16%, and F1 score: 85.05%). The mean area under the receiver operating characteristics curve (AUC) of the model after 10-fold cross-validation was 0.839 (95% CI: 0.824-0.855). Model discrimination and calibration were maintained during external validation dataset testing, with an AUC of 0.820 (95% CI: 0.685-0.955) and a Brier Score of 0.177 (95% CI: 0.147-0.206). Moreover, the considerably overexpressed TXNDC5 and CTSL proteins identified in the plasma of patients with CPB-ARDS, exhibited a significant upregulation in the lung tissue of LIRI rats. CONCLUSIONS: This study identified several novel predictive biomarkers, developed and validated a practical prediction tool using biomarker and clinical factor combinations for individual prediction of CPB-ARDS risk. Assessing the plasma TXNDC5, CTSL, and NPC2 levels might identify patients who warrant closer follow-up and intensified therapy for ARDS prevention following major surgery.

CircRNA/lncRNA-miRNA-mRNA network and gene landscape in calcific aortic valve disease.

BACKGROUND: Calcific aortic valve disease (CAVD) is a common valve disease with an increasing incidence, but no effective drugs as of yet. With the development of sequencing technology, non-coding RNAs have been found to play roles in many diseases as well as CAVD, but no circRNA/lncRNA-miRNA-mRNA interaction axis has been established. Moreover, valve interstitial cells (VICs) and valvular endothelial cells (VECs) play important roles in CAVD, and CAVD differed between leaflet phenotypes and genders. This work aims to explore the mechanism of circRNA/lncRNA-miRNA-mRNA network in CAVD, and perform subgroup analysis on the important characteristics of CAVD, such as key cells, leaflet phenotypes and genders. RESULTS: We identified 158 differentially expressed circRNAs (DEcircRNAs), 397 DElncRNAs, 45 DEmiRNAs and 167 DEmRNAs, and constructed a hsa-circ-0073813/hsa-circ-0027587-hsa-miR-525-5p-SPP1/HMOX1/CD28 network in CAVD after qRT-PCR verification. Additionally, 17 differentially expressed genes (DEGs) in VICs, 9 DEGs in VECs, 7 DEGs between different leaflet phenotypes and 24 DEGs between different genders were identified. Enrichment analysis suggested the potentially important pathways in inflammation and fibro-calcification during the pathogenesis of CAVD, and immune cell patterns in CAVD suggest that M0 macrophages and memory B cells memory were significantly increased, and many genes in immune cells were also differently expressed. CONCLUSIONS: The circRNA/lncRNA-miRNA-mRNA interaction axis constructed in this work and the DEGs identified between different characteristics of CAVD provide a direction for a deeper understanding of CAVD and provide possible diagnostic markers and treatment targets for CAVD in the future.

Safe Handling of Patient Gowns During the COVID-19 Pandemic: An Intelligent System for Patients With Cancer Undergoing Daily Radiotherapy.

BACKGROUND/AIM: Nosocomial infection is a substantial clinical, societal and economic burden, especially during the COVID-19 pandemic. Patients with cancer are required to change into patient gowns before receiving radiotherapy. To improve efficiency and infection control, we designed novel intelligent devices for both gown distribution and recycling. We conducted a pilot study to provide evidence for the device in healthcare quality improvement. MATERIALS AND METHODS: We designed and set up intelligent machines with an infrared sensor for patient gown distribution and recycling. The performance of these machines was assessed by questionnaire survey of patients' perceptions and handling by laundry personnel. RESULTS: We composed a questionnaire to measure patient/personnel satisfaction upon gown handling based on the existing data of our hospital. Two generations of patient gown distribution machines were introduced. One was the novel automated device for both gown distribution and recycling. The other one was the conventional wooden cabinets and/or hamper stands with foot pedals. Survey results showed that approximately 90% satisfaction was achieved with the automated machines. Overall satisfaction with the new soiled gown recycling machines was significantly higher than that with the conventional receptacles (p<0.01). CONCLUSION: The automated patient gown distribution machines safely and efficiently provide patients with suitable gowns. The automated patient gown recycling machine reduces contamination of the gown recycling area. Using these machines improves infection control in the hospital environment and effectively reduces the risk of nosocomial infection.

Enhanced light emission of germanium light-emitting-diode on 150 mm germanium-on-insulator (GOI).

Germanium-on-insulator (GOI) has emerged as a novel platform for Ge-based electronic and photonic applications. Discrete photonic devices, such as waveguides, photodetectors, modulators, and optical pumping lasers, have been successfully demonstrated on this platform. However, there is almost no report on the electrically injected Ge light source on the GOI platform. In this study, we present the first fabrication of vertical Ge p-i-n light-emitting diodes (LEDs) on a 150 mm GOI substrate. The high-quality Ge LED on a 150-mm diameter GOI substrate was fabricated via direct wafer bonding followed by ion implantations. As a tensile strain of 0.19% has been introduced during the GOI fabrication process resulting from the thermal mismatch, the LED devices exhibit a dominant direct bandgap transition peak near 0.785 eV (∼1580 nm) at room temperature. In sharp contrast to conventional III-V LEDs, we found that the electroluminescence (EL)/photoluminescence (PL) spectra show enhanced intensities as the temperature is raised from 300 to 450 K as a consequence of the higher occupation of the direct bandgap. The maximum enhancement in EL intensity is a factor of 140% near 1635 nm due to the improved optical confinement offered by the bottom insulator layer. This work potentially broadens the GOI's functional variety for applications in near-infrared sensing, electronics, and photonics.

Infant heart transplantation with extremely oversized donor heart: is the donor-recipient size matching too conservative?

Heart transplantation (HTx) remains the gold standard treatment for end-stage heart failure in children but is restricted due to the limitation of donors. The donor-recipient weight ratio (DRWR) of 0.8-2.5 was the main selection criterion, and reports were particularly scarce in cases of DRWR > 3.0. We present an infant HTx case with DRWR of 6.5. The recipient was a 66-day-old female infant, weighing 3 kg, diagnosed with complex congenital heart disease and refractory severe heart failure, whereas the donor was a 4-year-old girl weighing 19.5 kg. The phased delayed sternal closure was performed and accomplished on the 23rd day after operation without wound infection. After treating complications with extracorporeal membrane oxygenation, peritoneal dialysis, and mechanical ventilation, the patient was successfully discharged. After 1 year of follow-up, the patient was still in optimal condition. Extending DRWR range may help enlarge the donor pool and shorten recipients' waiting time.

Atorvastatin Attenuates Radiotherapy-Induced Intestinal Damage through Activation of Autophagy and Antioxidant Effects.

Abdominal or pelvic radiotherapy (RT) often results in small intestinal injury, such as apoptosis of epithelial cells and shortening of the villi. Atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has many biological effects including cholesterol reduction, protection from cell damage, and autophagy activation. To reduce the extent of radiotherapy- (RT-) induced enteritis, we investigated the protective effects of atorvastatin against RT-induced damage of the intestinal tract. In this study, C57BL/6 mice were randomly distributed into the following groups (n = 8 per group): (1) control group: mice were fed water only, (2) atorvastatin group (Ator): mice were administered atorvastatin, (3) irradiation group (IR): mice received abdominal RT, (4) Ator+IR group: mice received abdominal RT following atorvastatin administration, and (5) Ator+IR+3-MA group: abdominal RT following atorvastatin and 3-methyladenine (an autophagy inhibitor) administration. Based on the assessment of modified Chiu's injury score and villus/crypt ratio, we found that atorvastatin administration significantly reduced intestinal mucosal damage induced by RT. Atorvastatin treatment reduced apoptosis (cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase), DNA damage (γH2AX and 53BP1), oxidative stress (OS, 4-hydroxynonenal), inflammatory molecules (phospho-NF-κB p65 and TGF-ß), fibrosis (collagen I and collagen III), barrier leakage (claudin-2 and fluorescein isothiocyanate-dextran), disintegrity (fatty acid-binding protein 2), and dysfunction (lipopolysaccharide) caused by RT in small intestinal tissue. In addition, atorvastatin upregulated the expression of autophagy-active molecules (LC3B), antioxidants (heme oxygenase 1 and thioredoxin 1), and tight junction proteins (occludin and zonula occludens 1). However, the biological functions of atorvastatin in decreasing RT-induced enteritis were reversed after the administration of 3-MA; the function of antioxidant molecules and activity of thioredoxin reductase were independent of autophagy activation. Our results indicate that atorvastatin can effectively relieve RT-induced enteritis through autophagy activation and associated biological functions, including maintaining integrity and function and decreasing apoptosis, DNA damage, inflammation, OS, and fibrosis. It also acts via its antioxidative capabilities.

Mechanisms and Drug Therapies of Bioprosthetic Heart Valve Calcification.

Valve replacement is the main therapy for valvular heart disease, in which a diseased valve is replaced by mechanical heart valve (MHV) or bioprosthetic heart valve (BHV). Since the 2000s, BHV surpassed MHV as the leading option of prosthetic valve substitute because of its excellent hemocompatible and hemodynamic properties. However, BHV is apt to structural valve degeneration (SVD), resulting in limited durability. Calcification is the most frequent presentation and the core pathophysiological process of SVD. Understanding the basic mechanisms of BHV calcification is an essential prerequisite to address the limited-durability issues. In this narrative review, we provide a comprehensive summary about the mechanisms of BHV calcification on 1) composition and site of calcifications; 2) material-associated mechanisms; 3) host-associated mechanisms, including immune response and foreign body reaction, oxidative stress, metabolic disorder, and thrombosis. Strategies that target these mechanisms may be explored for novel drug therapy to prevent or delay BHV calcification.

Activation of the G Protein-Coupled Estrogen Receptor Prevented the Development of Acute Colitis by Protecting the Crypt Cell.

G protein-coupled estrogen receptor (GPER) might be involved in ulcerative colitis (UC), but the direct effect of GPER on UC is still unclear. We used male C57BL/6 mice to establish the acute colitis model with administration of dextran sulfate sodium and explored the effect of GPER on acute colitis and its possible mechanism. The selective GPER agonist G-1 inhibited weight loss and colon shortening and decreased the disease activity index for colitis and histologic damage in mice with colitis. All of these effects were prevented by a selective GPER blocker. G-1 administration prevented the dysfunction of tight junction protein expression and goblet cells in colitis model and thus inhibited the increase of mucosal permeability in colitis-suffering mice significantly. GPER activation reduced expression of glucose-regulating peptide-78 and anti-CCAAT/enhancer-binding protein homologous protein and attenuated the three arms of the unfolded protein response in colitis. G-1 therapy inhibited the increase of cleavage caspase-3- and TUNEL-positive cells in colonic crypts in the colitis model, increased the number of Ki67- and bromodeoxyuridine-positive cells in crypts, and reversed the decrease of cyclin D1 and cyclin B1 expression in colitis, indicating its protective effect on crypt cells. In cultured CCD841 cells, G-1 treatment fought against cell injury induced by endoplasmic reticulum stress. These findings demonstrate that GPER activation prevents colitis by protecting the colonic crypt cells, which are associated with inhibition of endoplasmic reticulum stress. SIGNIFICANCE STATEMENT: We demonstrate that G protein-coupled estrogen receptor (GPER) activation prevents dextran sulfate sodium-induced acute colitis by protecting the crypt cells, showing that it inhibited the crypt cell apoptosis and protected proliferation of crypt cells, which resulted in protection of the intestinal mucosal barrier. This protective effect was achieved (at least in part) by inhibiting endoplasmic reticulum stress. Mucosal healing is regarded as a key therapeutic target for colitis, and GPER is expected to become a new therapeutic target for colitis.

Development and trend in the field of valvular heart disease in China: an analysis based on the National Natural Science Foundation of China.

BACKGROUND: National Natural Science Foundation of China (NSFC) plays a vital role promoting advancement of science in China. The incidence and mortality rate of valvular heart disease (VHD) increase with aging population. Therefore, it is of significance to discuss the development and trend in the field of VHD and provide references for scholars to carry out further Foundations. METHODS: Internet-based Science Information System and other websites were used to search for projects supported by NSFC related to VHD in 2008-2019 and related information of applicants. Publications, citations and impact factors were queried by Google Scholar and InCites Journal Citation Reports 2.0 and analyzed by SPSS for Windows version 24.0. Key words extracted from these project titles were imported into Citespace for analysis. RESULTS: A total of 117 projects and related information were acquired. Although the annual amount of projects and funding has fluctuated in recent years, they still maintained an upward trend. Institutes were mainly distributed over Hubei Province, Shanghai and Jiangsu Province. Applicants characterized as senior title, male, cardiac surgeon have accounted for a larger proportion of projects, with a greater amount of funding. Through the analysis of keywords and subject distribution, molecular-biology-based mechanism study combined with tissue engineering has become the principal research hot spot and trend in recent years. Annual changes in output in scientific research were consistent with changes in the amount of funding. CONCLUSIONS: This paper collated funding situation supported by NSFC in VHD, analyzed distribution of keywords and summarized the research trend, so as to supply guidance to researchers for advanced researches.

Volumetric modulated arc therapy for nasopharyngeal carcinoma: a dosimetric comparison with TomoTherapy and step-and-shoot IMRT.

PURPOSE: Volumetric modulated arc therapy (VMAT), a novel technique, employs a linear accelerator to conduct dynamic modulation rotation radiotherapy. The goal of this study was to compare VMAT with helical tomotherapy (HT) and step-and-shoot intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) patients with regard to the sparing effect on organs at risk (OARs), dosimetric quality, and efficiency of delivery. MATERIALS AND METHODS: Twenty patients with NPC treated by HT were re-planned by VMAT (two arcs) and IMRT (7-9 fields) for dosimetric comparison. The target area received three dose levels (70, 60, and 54 Gy) in 33 fractions using simultaneous integrated boosts technique. The Philips Pinnacle Planning System 9.0 was adopted to design VMAT, using SmartArc as the planning algorithm. For a fair comparison, the planning target volume (PTV) coverage of the 3 plans was normalized to the same level. Dosimetric comparisons between VMAT, HT, and IMRT plans were analyzed to evaluate (1) coverage, homogeneity, and conformity of PTV, (2) sparing of OARs, (3) delivery time, and (4) monitor units (MUs). RESULTS: The VMAT, HT, and IMRT plans had similar PTV coverage with an average of 96%. There was no significant difference between VMAT and HT in homogeneity, while the homogeneity indices of VMAT (1.06) and HT (1.06) were better than IMRT plans (1.07, p<0.05). HT plans provided a better conformity index (1.17) than VMAT (1.28, p=0.01) and IMRT (1.36, p=0.02). When compared with IMRT, VMAT and HT had a better sparing effect on brain stem and spinal cord (p<0.05). The effect of parotid sparing was similar between VMAT (mean=26.3 Gy) and HT (mean=27.5 Gy), but better than IMRT (mean=31.3 Gy, p<0.01). The delivery time per fraction for VMAT (5.7 min) were much lower than for HT (9.5 min, p<0.01) and IMRT (9.2 min, p<0.01). CONCLUSIONS: Our results indicate that VMAT provides better sparing of normal tissue, homogeneity, and conformity than IMRT, and shorter delivery time than HT.